Merge back earlier ACPI PM material for v4.3.

drivers/acpi/Makefile

···
 # Power management related files
 acpi-y				+= wakeup.o
 acpi-$(CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT) += sleep.o
-acpi-y				+= device_pm.o
+acpi-y				+= device_sysfs.o device_pm.o
 acpi-$(CONFIG_ACPI_SLEEP)	+= proc.o
 
 

drivers/acpi/bus.c

···
 	acpi_evaluate_ost(handle, type, ost_code, NULL);
 }
 
+static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_device *device = data;
+
+	device->driver->ops.notify(device, event);
+}
+
+static void acpi_device_notify_fixed(void *data)
+{
+	struct acpi_device *device = data;
+
+	/* Fixed hardware devices have no handles */
+	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
+}
+
+static u32 acpi_device_fixed_event(void *data)
+{
+	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
+	return ACPI_INTERRUPT_HANDLED;
+}
+
+static int acpi_device_install_notify_handler(struct acpi_device *device)
+{
+	acpi_status status;
+
+	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
+		status =
+		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
+						     acpi_device_fixed_event,
+						     device);
+	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
+		status =
+		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
+						     acpi_device_fixed_event,
+						     device);
+	else
+		status = acpi_install_notify_handler(device->handle,
+						     ACPI_DEVICE_NOTIFY,
+						     acpi_device_notify,
+						     device);
+
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return 0;
+}
+
+static void acpi_device_remove_notify_handler(struct acpi_device *device)
+{
+	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
+		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
+						acpi_device_fixed_event);
+	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
+		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
+						acpi_device_fixed_event);
+	else
+		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+					   acpi_device_notify);
+}
+
+/* --------------------------------------------------------------------------
+                             Device Matching
+   -------------------------------------------------------------------------- */
+
+/**
+ * acpi_device_is_first_physical_node - Is given dev first physical node
+ * @adev: ACPI companion device
+ * @dev: Physical device to check
+ *
+ * Function checks if given @dev is the first physical devices attached to
+ * the ACPI companion device. This distinction is needed in some cases
+ * where the same companion device is shared between many physical devices.
+ *
+ * Note that the caller have to provide valid @adev pointer.
+ */
+bool acpi_device_is_first_physical_node(struct acpi_device *adev,
+					const struct device *dev)
+{
+	bool ret = false;
+
+	mutex_lock(&adev->physical_node_lock);
+	if (!list_empty(&adev->physical_node_list)) {
+		const struct acpi_device_physical_node *node;
+
+		node = list_first_entry(&adev->physical_node_list,
+					struct acpi_device_physical_node, node);
+		ret = node->dev == dev;
+	}
+	mutex_unlock(&adev->physical_node_lock);
+
+	return ret;
+}
+
+/*
+ * acpi_companion_match() - Can we match via ACPI companion device
+ * @dev: Device in question
+ *
+ * Check if the given device has an ACPI companion and if that companion has
+ * a valid list of PNP IDs, and if the device is the first (primary) physical
+ * device associated with it.  Return the companion pointer if that's the case
+ * or NULL otherwise.
+ *
+ * If multiple physical devices are attached to a single ACPI companion, we need
+ * to be careful.  The usage scenario for this kind of relationship is that all
+ * of the physical devices in question use resources provided by the ACPI
+ * companion.  A typical case is an MFD device where all the sub-devices share
+ * the parent's ACPI companion.  In such cases we can only allow the primary
+ * (first) physical device to be matched with the help of the companion's PNP
+ * IDs.
+ *
+ * Additional physical devices sharing the ACPI companion can still use
+ * resources available from it but they will be matched normally using functions
+ * provided by their bus types (and analogously for their modalias).
+ */
+struct acpi_device *acpi_companion_match(const struct device *dev)
+{
+	struct acpi_device *adev;
+	struct mutex *physical_node_lock;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return NULL;
+
+	if (list_empty(&adev->pnp.ids))
+		return NULL;
+
+	physical_node_lock = &adev->physical_node_lock;
+	mutex_lock(physical_node_lock);
+	if (list_empty(&adev->physical_node_list)) {
+		adev = NULL;
+	} else {
+		const struct acpi_device_physical_node *node;
+
+		node = list_first_entry(&adev->physical_node_list,
+					struct acpi_device_physical_node, node);
+		if (node->dev != dev)
+			adev = NULL;
+	}
+	mutex_unlock(physical_node_lock);
+
+	return adev;
+}
+
+/**
+ * acpi_of_match_device - Match device object using the "compatible" property.
+ * @adev: ACPI device object to match.
+ * @of_match_table: List of device IDs to match against.
+ *
+ * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
+ * identifiers and a _DSD object with the "compatible" property, use that
+ * property to match against the given list of identifiers.
+ */
+static bool acpi_of_match_device(struct acpi_device *adev,
+				 const struct of_device_id *of_match_table)
+{
+	const union acpi_object *of_compatible, *obj;
+	int i, nval;
+
+	if (!adev)
+		return false;
+
+	of_compatible = adev->data.of_compatible;
+	if (!of_match_table || !of_compatible)
+		return false;
+
+	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
+		nval = of_compatible->package.count;
+		obj = of_compatible->package.elements;
+	} else { /* Must be ACPI_TYPE_STRING. */
+		nval = 1;
+		obj = of_compatible;
+	}
+	/* Now we can look for the driver DT compatible strings */
+	for (i = 0; i < nval; i++, obj++) {
+		const struct of_device_id *id;
+
+		for (id = of_match_table; id->compatible[0]; id++)
+			if (!strcasecmp(obj->string.pointer, id->compatible))
+				return true;
+	}
+
+	return false;
+}
+
+static bool __acpi_match_device_cls(const struct acpi_device_id *id,
+				    struct acpi_hardware_id *hwid)
+{
+	int i, msk, byte_shift;
+	char buf[3];
+
+	if (!id->cls)
+		return false;
+
+	/* Apply class-code bitmask, before checking each class-code byte */
+	for (i = 1; i <= 3; i++) {
+		byte_shift = 8 * (3 - i);
+		msk = (id->cls_msk >> byte_shift) & 0xFF;
+		if (!msk)
+			continue;
+
+		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
+		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
+			return false;
+	}
+	return true;
+}
+
+static const struct acpi_device_id *__acpi_match_device(
+	struct acpi_device *device,
+	const struct acpi_device_id *ids,
+	const struct of_device_id *of_ids)
+{
+	const struct acpi_device_id *id;
+	struct acpi_hardware_id *hwid;
+
+	/*
+	 * If the device is not present, it is unnecessary to load device
+	 * driver for it.
+	 */
+	if (!device || !device->status.present)
+		return NULL;
+
+	list_for_each_entry(hwid, &device->pnp.ids, list) {
+		/* First, check the ACPI/PNP IDs provided by the caller. */
+		for (id = ids; id->id[0] || id->cls; id++) {
+			if (id->id[0] && !strcmp((char *) id->id, hwid->id))
+				return id;
+			else if (id->cls && __acpi_match_device_cls(id, hwid))
+				return id;
+		}
+
+		/*
+		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
+		 * "compatible" property if found.
+		 *
+		 * The id returned by the below is not valid, but the only
+		 * caller passing non-NULL of_ids here is only interested in
+		 * whether or not the return value is NULL.
+		 */
+		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
+		    && acpi_of_match_device(device, of_ids))
+			return id;
+	}
+	return NULL;
+}
+
+/**
+ * acpi_match_device - Match a struct device against a given list of ACPI IDs
+ * @ids: Array of struct acpi_device_id object to match against.
+ * @dev: The device structure to match.
+ *
+ * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
+ * object for that handle and use that object to match against a given list of
+ * device IDs.
+ *
+ * Return a pointer to the first matching ID on success or %NULL on failure.
+ */
+const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
+					       const struct device *dev)
+{
+	return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
+}
+EXPORT_SYMBOL_GPL(acpi_match_device);
+
+int acpi_match_device_ids(struct acpi_device *device,
+			  const struct acpi_device_id *ids)
+{
+	return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
+}
+EXPORT_SYMBOL(acpi_match_device_ids);
+
+bool acpi_driver_match_device(struct device *dev,
+			      const struct device_driver *drv)
+{
+	if (!drv->acpi_match_table)
+		return acpi_of_match_device(ACPI_COMPANION(dev),
+					    drv->of_match_table);
+
+	return !!__acpi_match_device(acpi_companion_match(dev),
+				     drv->acpi_match_table, drv->of_match_table);
+}
+EXPORT_SYMBOL_GPL(acpi_driver_match_device);
+
+/* --------------------------------------------------------------------------
+                              ACPI Driver Management
+   -------------------------------------------------------------------------- */
+
+/**
+ * acpi_bus_register_driver - register a driver with the ACPI bus
+ * @driver: driver being registered
+ *
+ * Registers a driver with the ACPI bus.  Searches the namespace for all
+ * devices that match the driver's criteria and binds.  Returns zero for
+ * success or a negative error status for failure.
+ */
+int acpi_bus_register_driver(struct acpi_driver *driver)
+{
+	int ret;
+
+	if (acpi_disabled)
+		return -ENODEV;
+	driver->drv.name = driver->name;
+	driver->drv.bus = &acpi_bus_type;
+	driver->drv.owner = driver->owner;
+
+	ret = driver_register(&driver->drv);
+	return ret;
+}
+
+EXPORT_SYMBOL(acpi_bus_register_driver);
+
+/**
+ * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
+ * @driver: driver to unregister
+ *
+ * Unregisters a driver with the ACPI bus.  Searches the namespace for all
+ * devices that match the driver's criteria and unbinds.
+ */
+void acpi_bus_unregister_driver(struct acpi_driver *driver)
+{
+	driver_unregister(&driver->drv);
+}
+
+EXPORT_SYMBOL(acpi_bus_unregister_driver);
+
+/* --------------------------------------------------------------------------
+                              ACPI Bus operations
+   -------------------------------------------------------------------------- */
+
+static int acpi_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
+
+	return acpi_dev->flags.match_driver
+		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
+}
+
+static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
+}
+
+static int acpi_device_probe(struct device *dev)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
+	int ret;
+
+	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
+		return -EINVAL;
+
+	if (!acpi_drv->ops.add)
+		return -ENOSYS;
+
+	ret = acpi_drv->ops.add(acpi_dev);
+	if (ret)
+		return ret;
+
+	acpi_dev->driver = acpi_drv;
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			  "Driver [%s] successfully bound to device [%s]\n",
+			  acpi_drv->name, acpi_dev->pnp.bus_id));
+
+	if (acpi_drv->ops.notify) {
+		ret = acpi_device_install_notify_handler(acpi_dev);
+		if (ret) {
+			if (acpi_drv->ops.remove)
+				acpi_drv->ops.remove(acpi_dev);
+
+			acpi_dev->driver = NULL;
+			acpi_dev->driver_data = NULL;
+			return ret;
+		}
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
+			  acpi_drv->name, acpi_dev->pnp.bus_id));
+	get_device(dev);
+	return 0;
+}
+
+static int acpi_device_remove(struct device * dev)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	struct acpi_driver *acpi_drv = acpi_dev->driver;
+
+	if (acpi_drv) {
+		if (acpi_drv->ops.notify)
+			acpi_device_remove_notify_handler(acpi_dev);
+		if (acpi_drv->ops.remove)
+			acpi_drv->ops.remove(acpi_dev);
+	}
+	acpi_dev->driver = NULL;
+	acpi_dev->driver_data = NULL;
+
+	put_device(dev);
+	return 0;
+}
+
+struct bus_type acpi_bus_type = {
+	.name		= "acpi",
+	.match		= acpi_bus_match,
+	.probe		= acpi_device_probe,
+	.remove		= acpi_device_remove,
+	.uevent		= acpi_device_uevent,
+};
+
 /* --------------------------------------------------------------------------
                              Initialization/Cleanup
    -------------------------------------------------------------------------- */
···
 	 */
 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
 
-	return 0;
+	result = bus_register(&acpi_bus_type);
+	if (!result)
+		return 0;
 
 	/* Mimic structured exception handling */
       error1:

drivers/acpi/device_pm.c

···
 	if (dev->pm_domain)
 		return -EEXIST;
 
+	/*
+	 * Only attach the power domain to the first device if the
+	 * companion is shared by multiple. This is to prevent doing power
+	 * management twice.
+	 */
+	if (!acpi_device_is_first_physical_node(adev, dev))
+		return -EBUSY;
+
 	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
 	dev->pm_domain = &acpi_general_pm_domain;
 	if (power_on) {

drivers/acpi/device_sysfs.c

···
+/*
+ * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
+ *
+ * Copyright (C) 2015, Intel Corp.
+ * Author: Mika Westerberg <[e-mail]>
+ * Author: Rafael J. Wysocki <[e-mail]>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/nls.h>
+
+#include "internal.h"
+
+/**
+ * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
+ * Creates hid/cid(s) string needed for modalias and uevent
+ * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
+ * char *modalias: "acpi:IBM0001:ACPI0001"
+ * Return: 0: no _HID and no _CID
+ *         -EINVAL: output error
+ *         -ENOMEM: output is truncated
+*/
+static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
+			       int size)
+{
+	int len;
+	int count;
+	struct acpi_hardware_id *id;
+
+	/*
+	 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
+	 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
+	 * device's list.
+	 */
+	count = 0;
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
+		if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
+			count++;
+
+	if (!count)
+		return 0;
+
+	len = snprintf(modalias, size, "acpi:");
+	if (len <= 0)
+		return len;
+
+	size -= len;
+
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
+		if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
+			continue;
+
+		count = snprintf(&modalias[len], size, "%s:", id->id);
+		if (count < 0)
+			return -EINVAL;
+
+		if (count >= size)
+			return -ENOMEM;
+
+		len += count;
+		size -= count;
+	}
+	modalias[len] = '\0';
+	return len;
+}
+
+/**
+ * create_of_modalias - Creates DT compatible string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
+ * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
+ * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
+ * ACPI/PNP IDs.
+ */
+static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
+			      int size)
+{
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+	const union acpi_object *of_compatible, *obj;
+	int len, count;
+	int i, nval;
+	char *c;
+
+	acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
+	/* DT strings are all in lower case */
+	for (c = buf.pointer; *c != '\0'; c++)
+		*c = tolower(*c);
+
+	len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
+	ACPI_FREE(buf.pointer);
+
+	if (len <= 0)
+		return len;
+
+	of_compatible = acpi_dev->data.of_compatible;
+	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
+		nval = of_compatible->package.count;
+		obj = of_compatible->package.elements;
+	} else { /* Must be ACPI_TYPE_STRING. */
+		nval = 1;
+		obj = of_compatible;
+	}
+	for (i = 0; i < nval; i++, obj++) {
+		count = snprintf(&modalias[len], size, "C%s",
+				 obj->string.pointer);
+		if (count < 0)
+			return -EINVAL;
+
+		if (count >= size)
+			return -ENOMEM;
+
+		len += count;
+		size -= count;
+	}
+	modalias[len] = '\0';
+	return len;
+}
+
+int __acpi_device_uevent_modalias(struct acpi_device *adev,
+				  struct kobj_uevent_env *env)
+{
+	int len;
+
+	if (!adev)
+		return -ENODEV;
+
+	if (list_empty(&adev->pnp.ids))
+		return 0;
+
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
+				  sizeof(env->buf) - env->buflen);
+	if (len < 0)
+		return len;
+
+	env->buflen += len;
+	if (!adev->data.of_compatible)
+		return 0;
+
+	if (len > 0 && add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	len = create_of_modalias(adev, &env->buf[env->buflen - 1],
+				 sizeof(env->buf) - env->buflen);
+	if (len < 0)
+		return len;
+
+	env->buflen += len;
+
+	return 0;
+}
+
+/**
+ * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
+ *
+ * Create the uevent modalias field for ACPI-enumerated devices.
+ *
+ * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
+ * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
+ */
+int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
+{
+	return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
+}
+EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
+
+static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
+{
+	int len, count;
+
+	if (!adev)
+		return -ENODEV;
+
+	if (list_empty(&adev->pnp.ids))
+		return 0;
+
+	len = create_pnp_modalias(adev, buf, size - 1);
+	if (len < 0) {
+		return len;
+	} else if (len > 0) {
+		buf[len++] = '\n';
+		size -= len;
+	}
+	if (!adev->data.of_compatible)
+		return len;
+
+	count = create_of_modalias(adev, buf + len, size - 1);
+	if (count < 0) {
+		return count;
+	} else if (count > 0) {
+		len += count;
+		buf[len++] = '\n';
+	}
+
+	return len;
+}
+
+/**
+ * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
+ *
+ * Create the modalias sysfs attribute for ACPI-enumerated devices.
+ *
+ * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
+ * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
+ */
+int acpi_device_modalias(struct device *dev, char *buf, int size)
+{
+	return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
+}
+EXPORT_SYMBOL_GPL(acpi_device_modalias);
+
+static ssize_t
+acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
+}
+static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
+
+static ssize_t real_power_state_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+	int state;
+	int ret;
+
+	ret = acpi_device_get_power(adev, &state);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%s\n", acpi_power_state_string(state));
+}
+
+static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
+
+static ssize_t power_state_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
+}
+
+static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
+
+static ssize_t
+acpi_eject_store(struct device *d, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct acpi_device *acpi_device = to_acpi_device(d);
+	acpi_object_type not_used;
+	acpi_status status;
+
+	if (!count || buf[0] != '1')
+		return -EINVAL;
+
+	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
+	    && !acpi_device->driver)
+		return -ENODEV;
+
+	status = acpi_get_type(acpi_device->handle, &not_used);
+	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
+		return -ENODEV;
+
+	get_device(&acpi_device->dev);
+	status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
+	if (ACPI_SUCCESS(status))
+		return count;
+
+	put_device(&acpi_device->dev);
+	acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
+			  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
+	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
+}
+
+static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
+
+static ssize_t
+acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
+}
+static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
+
+static ssize_t acpi_device_uid_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
+}
+static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
+
+static ssize_t acpi_device_adr_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "0x%08x\n",
+		       (unsigned int)(acpi_dev->pnp.bus_address));
+}
+static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
+
+static ssize_t
+acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
+	int result;
+
+	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
+	if (result)
+		goto end;
+
+	result = sprintf(buf, "%s\n", (char*)path.pointer);
+	kfree(path.pointer);
+end:
+	return result;
+}
+static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+
+/* sysfs file that shows description text from the ACPI _STR method */
+static ssize_t description_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	int result;
+
+	if (acpi_dev->pnp.str_obj == NULL)
+		return 0;
+
+	/*
+	 * The _STR object contains a Unicode identifier for a device.
+	 * We need to convert to utf-8 so it can be displayed.
+	 */
+	result = utf16s_to_utf8s(
+		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
+		acpi_dev->pnp.str_obj->buffer.length,
+		UTF16_LITTLE_ENDIAN, buf,
+		PAGE_SIZE);
+
+	buf[result++] = '\n';
+
+	return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
+static ssize_t
+acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
+		     char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	acpi_status status;
+	unsigned long long sun;
+
+	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return sprintf(buf, "%llu\n", sun);
+}
+static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
+
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+				char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	acpi_status status;
+	unsigned long long sta;
+
+	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return sprintf(buf, "%llu\n", sta);
+}
+static DEVICE_ATTR_RO(status);
+
+/**
+ * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
+ * @dev: ACPI device object.
+ */
+int acpi_device_setup_files(struct acpi_device *dev)
+{
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_status status;
+	int result = 0;
+
+	/*
+	 * Devices gotten from FADT don't have a "path" attribute
+	 */
+	if (dev->handle) {
+		result = device_create_file(&dev->dev, &dev_attr_path);
+		if (result)
+			goto end;
+	}
+
+	if (!list_empty(&dev->pnp.ids)) {
+		result = device_create_file(&dev->dev, &dev_attr_hid);
+		if (result)
+			goto end;
+
+		result = device_create_file(&dev->dev, &dev_attr_modalias);
+		if (result)
+			goto end;
+	}
+
+	/*
+	 * If device has _STR, 'description' file is created
+	 */
+	if (acpi_has_method(dev->handle, "_STR")) {
+		status = acpi_evaluate_object(dev->handle, "_STR",
+					NULL, &buffer);
+		if (ACPI_FAILURE(status))
+			buffer.pointer = NULL;
+		dev->pnp.str_obj = buffer.pointer;
+		result = device_create_file(&dev->dev, &dev_attr_description);
+		if (result)
+			goto end;
+	}
+
+	if (dev->pnp.type.bus_address)
+		result = device_create_file(&dev->dev, &dev_attr_adr);
+	if (dev->pnp.unique_id)
+		result = device_create_file(&dev->dev, &dev_attr_uid);
+
+	if (acpi_has_method(dev->handle, "_SUN")) {
+		result = device_create_file(&dev->dev, &dev_attr_sun);
+		if (result)
+			goto end;
+	}
+
+	if (acpi_has_method(dev->handle, "_STA")) {
+		result = device_create_file(&dev->dev, &dev_attr_status);
+		if (result)
+			goto end;
+	}
+
+        /*
+         * If device has _EJ0, 'eject' file is created that is used to trigger
+         * hot-removal function from userland.
+         */
+	if (acpi_has_method(dev->handle, "_EJ0")) {
+		result = device_create_file(&dev->dev, &dev_attr_eject);
+		if (result)
+			return result;
+	}
+
+	if (dev->flags.power_manageable) {
+		result = device_create_file(&dev->dev, &dev_attr_power_state);
+		if (result)
+			return result;
+
+		if (dev->power.flags.power_resources)
+			result = device_create_file(&dev->dev,
+						    &dev_attr_real_power_state);
+	}
+
+end:
+	return result;
+}
+
+/**
+ * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
+ * @dev: ACPI device object.
+ */
+void acpi_device_remove_files(struct acpi_device *dev)
+{
+	if (dev->flags.power_manageable) {
+		device_remove_file(&dev->dev, &dev_attr_power_state);
+		if (dev->power.flags.power_resources)
+			device_remove_file(&dev->dev,
+					   &dev_attr_real_power_state);
+	}
+
+	/*
+	 * If device has _STR, remove 'description' file
+	 */
+	if (acpi_has_method(dev->handle, "_STR")) {
+		kfree(dev->pnp.str_obj);
+		device_remove_file(&dev->dev, &dev_attr_description);
+	}
+	/*
+	 * If device has _EJ0, remove 'eject' file.
+	 */
+	if (acpi_has_method(dev->handle, "_EJ0"))
+		device_remove_file(&dev->dev, &dev_attr_eject);
+
+	if (acpi_has_method(dev->handle, "_SUN"))
+		device_remove_file(&dev->dev, &dev_attr_sun);
+
+	if (dev->pnp.unique_id)
+		device_remove_file(&dev->dev, &dev_attr_uid);
+	if (dev->pnp.type.bus_address)
+		device_remove_file(&dev->dev, &dev_attr_adr);
+	device_remove_file(&dev->dev, &dev_attr_modalias);
+	device_remove_file(&dev->dev, &dev_attr_hid);
+	if (acpi_has_method(dev->handle, "_STA"))
+		device_remove_file(&dev->dev, &dev_attr_status);
+	if (dev->handle)
+		device_remove_file(&dev->dev, &dev_attr_path);
+}

drivers/acpi/internal.h

···
 		    void (*release)(struct device *));
 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
 			     int type, unsigned long long sta);
+int acpi_device_setup_files(struct acpi_device *dev);
+void acpi_device_remove_files(struct acpi_device *dev);
 void acpi_device_add_finalize(struct acpi_device *device);
 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
 bool acpi_device_is_present(struct acpi_device *adev);
 bool acpi_device_is_battery(struct acpi_device *adev);
+bool acpi_device_is_first_physical_node(struct acpi_device *adev,
+					const struct device *dev);
+
+/* --------------------------------------------------------------------------
+                     Device Matching and Notification
+   -------------------------------------------------------------------------- */
+struct acpi_device *acpi_companion_match(const struct device *dev);
+int __acpi_device_uevent_modalias(struct acpi_device *adev,
+				  struct kobj_uevent_env *env);
 
 /* --------------------------------------------------------------------------
                                   Power Resource

drivers/acpi/power.c

···
 /*
- *  acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
+ * drivers/acpi/power.c - ACPI Power Resources management.
  *
- *  Copyright (C) 2001, 2002 Andy Grover <[e-mail]>
- *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[e-mail]>
+ * Copyright (C) 2001 - 2015 Intel Corp.
+ * Author: Andy Grover <[e-mail]>
+ * Author: Paul Diefenbaugh <[e-mail]>
+ * Author: Rafael J. Wysocki <[e-mail]>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
···
  * ACPI power-managed devices may be controlled in two ways:
  * 1. via "Device Specific (D-State) Control"
  * 2. via "Power Resource Control".
- * This module is used to manage devices relying on Power Resource Control.
+ * The code below deals with ACPI Power Resources control.
  * 
- * An ACPI "power resource object" describes a software controllable power
- * plane, clock plane, or other resource used by a power managed device.
+ * An ACPI "power resource object" represents a software controllable power
+ * plane, clock plane, or other resource depended on by a device.
+ *
  * A device may rely on multiple power resources, and a power resource
  * may be shared by multiple devices.
  */

drivers/acpi/scan.c

···
 	return 0;
 }
 
-/**
- * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
- * @acpi_dev: ACPI device object.
- * @modalias: Buffer to print into.
- * @size: Size of the buffer.
- *
- * Creates hid/cid(s) string needed for modalias and uevent
- * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
- * char *modalias: "acpi:IBM0001:ACPI0001"
- * Return: 0: no _HID and no _CID
- *         -EINVAL: output error
- *         -ENOMEM: output is truncated
-*/
-static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
-			       int size)
-{
-	int len;
-	int count;
-	struct acpi_hardware_id *id;
-
-	/*
-	 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
-	 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
-	 * device's list.
-	 */
-	count = 0;
-	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
-		if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
-			count++;
-
-	if (!count)
-		return 0;
-
-	len = snprintf(modalias, size, "acpi:");
-	if (len <= 0)
-		return len;
-
-	size -= len;
-
-	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
-		if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
-			continue;
-
-		count = snprintf(&modalias[len], size, "%s:", id->id);
-		if (count < 0)
-			return -EINVAL;
-
-		if (count >= size)
-			return -ENOMEM;
-
-		len += count;
-		size -= count;
-	}
-	modalias[len] = '\0';
-	return len;
-}
-
-/**
- * create_of_modalias - Creates DT compatible string for modalias and uevent
- * @acpi_dev: ACPI device object.
- * @modalias: Buffer to print into.
- * @size: Size of the buffer.
- *
- * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
- * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
- * ACPI/PNP IDs.
- */
-static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
-			      int size)
-{
-	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
-	const union acpi_object *of_compatible, *obj;
-	int len, count;
-	int i, nval;
-	char *c;
-
-	acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
-	/* DT strings are all in lower case */
-	for (c = buf.pointer; *c != '\0'; c++)
-		*c = tolower(*c);
-
-	len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
-	ACPI_FREE(buf.pointer);
-
-	if (len <= 0)
-		return len;
-
-	of_compatible = acpi_dev->data.of_compatible;
-	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
-		nval = of_compatible->package.count;
-		obj = of_compatible->package.elements;
-	} else { /* Must be ACPI_TYPE_STRING. */
-		nval = 1;
-		obj = of_compatible;
-	}
-	for (i = 0; i < nval; i++, obj++) {
-		count = snprintf(&modalias[len], size, "C%s",
-				 obj->string.pointer);
-		if (count < 0)
-			return -EINVAL;
-
-		if (count >= size)
-			return -ENOMEM;
-
-		len += count;
-		size -= count;
-	}
-	modalias[len] = '\0';
-	return len;
-}
-
-/*
- * acpi_companion_match() - Can we match via ACPI companion device
- * @dev: Device in question
- *
- * Check if the given device has an ACPI companion and if that companion has
- * a valid list of PNP IDs, and if the device is the first (primary) physical
- * device associated with it.  Return the companion pointer if that's the case
- * or NULL otherwise.
- *
- * If multiple physical devices are attached to a single ACPI companion, we need
- * to be careful.  The usage scenario for this kind of relationship is that all
- * of the physical devices in question use resources provided by the ACPI
- * companion.  A typical case is an MFD device where all the sub-devices share
- * the parent's ACPI companion.  In such cases we can only allow the primary
- * (first) physical device to be matched with the help of the companion's PNP
- * IDs.
- *
- * Additional physical devices sharing the ACPI companion can still use
- * resources available from it but they will be matched normally using functions
- * provided by their bus types (and analogously for their modalias).
- */
-static struct acpi_device *acpi_companion_match(const struct device *dev)
-{
-	struct acpi_device *adev;
-	struct mutex *physical_node_lock;
-
-	adev = ACPI_COMPANION(dev);
-	if (!adev)
-		return NULL;
-
-	if (list_empty(&adev->pnp.ids))
-		return NULL;
-
-	physical_node_lock = &adev->physical_node_lock;
-	mutex_lock(physical_node_lock);
-	if (list_empty(&adev->physical_node_list)) {
-		adev = NULL;
-	} else {
-		const struct acpi_device_physical_node *node;
-
-		node = list_first_entry(&adev->physical_node_list,
-					struct acpi_device_physical_node, node);
-		if (node->dev != dev)
-			adev = NULL;
-	}
-	mutex_unlock(physical_node_lock);
-
-	return adev;
-}
-
-static int __acpi_device_uevent_modalias(struct acpi_device *adev,
-					 struct kobj_uevent_env *env)
-{
-	int len;
-
-	if (!adev)
-		return -ENODEV;
-
-	if (list_empty(&adev->pnp.ids))
-		return 0;
-
-	if (add_uevent_var(env, "MODALIAS="))
-		return -ENOMEM;
-
-	len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
-				  sizeof(env->buf) - env->buflen);
-	if (len < 0)
-		return len;
-
-	env->buflen += len;
-	if (!adev->data.of_compatible)
-		return 0;
-
-	if (len > 0 && add_uevent_var(env, "MODALIAS="))
-		return -ENOMEM;
-
-	len = create_of_modalias(adev, &env->buf[env->buflen - 1],
-				 sizeof(env->buf) - env->buflen);
-	if (len < 0)
-		return len;
-
-	env->buflen += len;
-
-	return 0;
-}
-
-/*
- * Creates uevent modalias field for ACPI enumerated devices.
- * Because the other buses does not support ACPI HIDs & CIDs.
- * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
- * "acpi:IBM0001:ACPI0001"
- */
-int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
-{
-	return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
-}
-EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
-
-static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
-{
-	int len, count;
-
-	if (!adev)
-		return -ENODEV;
-
-	if (list_empty(&adev->pnp.ids))
-		return 0;
-
-	len = create_pnp_modalias(adev, buf, size - 1);
-	if (len < 0) {
-		return len;
-	} else if (len > 0) {
-		buf[len++] = '\n';
-		size -= len;
-	}
-	if (!adev->data.of_compatible)
-		return len;
-
-	count = create_of_modalias(adev, buf + len, size - 1);
-	if (count < 0) {
-		return count;
-	} else if (count > 0) {
-		len += count;
-		buf[len++] = '\n';
-	}
-
-	return len;
-}
-
-/*
- * Creates modalias sysfs attribute for ACPI enumerated devices.
- * Because the other buses does not support ACPI HIDs & CIDs.
- * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
- * "acpi:IBM0001:ACPI0001"
- */
-int acpi_device_modalias(struct device *dev, char *buf, int size)
-{
-	return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
-}
-EXPORT_SYMBOL_GPL(acpi_device_modalias);
-
-static ssize_t
-acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
-	return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
-}
-static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
-
 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 {
 	struct acpi_device_physical_node *pn;
···
 	unlock_device_hotplug();
 }
 
-static ssize_t real_power_state_show(struct device *dev,
-				     struct device_attribute *attr, char *buf)
-{
-	struct acpi_device *adev = to_acpi_device(dev);
-	int state;
-	int ret;
-
-	ret = acpi_device_get_power(adev, &state);
-	if (ret)
-		return ret;
-
-	return sprintf(buf, "%s\n", acpi_power_state_string(state));
-}
-
-static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
-
-static ssize_t power_state_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct acpi_device *adev = to_acpi_device(dev);
-
-	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
-}
-
-static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
-
-static ssize_t
-acpi_eject_store(struct device *d, struct device_attribute *attr,
-		const char *buf, size_t count)
-{
-	struct acpi_device *acpi_device = to_acpi_device(d);
-	acpi_object_type not_used;
-	acpi_status status;
-
-	if (!count || buf[0] != '1')
-		return -EINVAL;
-
-	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
-	    && !acpi_device->driver)
-		return -ENODEV;
-
-	status = acpi_get_type(acpi_device->handle, &not_used);
-	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
-		return -ENODEV;
-
-	get_device(&acpi_device->dev);
-	status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
-	if (ACPI_SUCCESS(status))
-		return count;
-
-	put_device(&acpi_device->dev);
-	acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
-			  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
-	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
-}
-
-static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
-
-static ssize_t
-acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-
-	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
-}
-static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
-
-static ssize_t acpi_device_uid_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
-{
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-
-	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
-}
-static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
-
-static ssize_t acpi_device_adr_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
-{
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-
-	return sprintf(buf, "0x%08x\n",
-		       (unsigned int)(acpi_dev->pnp.bus_address));
-}
-static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
-
-static ssize_t
-acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
-	int result;
-
-	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
-	if (result)
-		goto end;
-
-	result = sprintf(buf, "%s\n", (char*)path.pointer);
-	kfree(path.pointer);
-end:
-	return result;
-}
-static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
-
-/* sysfs file that shows description text from the ACPI _STR method */
-static ssize_t description_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf) {
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	int result;
-
-	if (acpi_dev->pnp.str_obj == NULL)
-		return 0;
-
-	/*
-	 * The _STR object contains a Unicode identifier for a device.
-	 * We need to convert to utf-8 so it can be displayed.
-	 */
-	result = utf16s_to_utf8s(
-		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
-		acpi_dev->pnp.str_obj->buffer.length,
-		UTF16_LITTLE_ENDIAN, buf,
-		PAGE_SIZE);
-
-	buf[result++] = '\n';
-
-	return result;
-}
-static DEVICE_ATTR(description, 0444, description_show, NULL);
-
-static ssize_t
-acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
-		     char *buf) {
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	acpi_status status;
-	unsigned long long sun;
-
-	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
-
-	return sprintf(buf, "%llu\n", sun);
-}
-static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
-
-static ssize_t status_show(struct device *dev, struct device_attribute *attr,
-				char *buf) {
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	acpi_status status;
-	unsigned long long sta;
-
-	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
-
-	return sprintf(buf, "%llu\n", sta);
-}
-static DEVICE_ATTR_RO(status);
-
-static int acpi_device_setup_files(struct acpi_device *dev)
-{
-	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
-	acpi_status status;
-	int result = 0;
-
-	/*
-	 * Devices gotten from FADT don't have a "path" attribute
-	 */
-	if (dev->handle) {
-		result = device_create_file(&dev->dev, &dev_attr_path);
-		if (result)
-			goto end;
-	}
-
-	if (!list_empty(&dev->pnp.ids)) {
-		result = device_create_file(&dev->dev, &dev_attr_hid);
-		if (result)
-			goto end;
-
-		result = device_create_file(&dev->dev, &dev_attr_modalias);
-		if (result)
-			goto end;
-	}
-
-	/*
-	 * If device has _STR, 'description' file is created
-	 */
-	if (acpi_has_method(dev->handle, "_STR")) {
-		status = acpi_evaluate_object(dev->handle, "_STR",
-					NULL, &buffer);
-		if (ACPI_FAILURE(status))
-			buffer.pointer = NULL;
-		dev->pnp.str_obj = buffer.pointer;
-		result = device_create_file(&dev->dev, &dev_attr_description);
-		if (result)
-			goto end;
-	}
-
-	if (dev->pnp.type.bus_address)
-		result = device_create_file(&dev->dev, &dev_attr_adr);
-	if (dev->pnp.unique_id)
-		result = device_create_file(&dev->dev, &dev_attr_uid);
-
-	if (acpi_has_method(dev->handle, "_SUN")) {
-		result = device_create_file(&dev->dev, &dev_attr_sun);
-		if (result)
-			goto end;
-	}
-
-	if (acpi_has_method(dev->handle, "_STA")) {
-		result = device_create_file(&dev->dev, &dev_attr_status);
-		if (result)
-			goto end;
-	}
-
-        /*
-         * If device has _EJ0, 'eject' file is created that is used to trigger
-         * hot-removal function from userland.
-         */
-	if (acpi_has_method(dev->handle, "_EJ0")) {
-		result = device_create_file(&dev->dev, &dev_attr_eject);
-		if (result)
-			return result;
-	}
-
-	if (dev->flags.power_manageable) {
-		result = device_create_file(&dev->dev, &dev_attr_power_state);
-		if (result)
-			return result;
-
-		if (dev->power.flags.power_resources)
-			result = device_create_file(&dev->dev,
-						    &dev_attr_real_power_state);
-	}
-
-end:
-	return result;
-}
-
-static void acpi_device_remove_files(struct acpi_device *dev)
-{
-	if (dev->flags.power_manageable) {
-		device_remove_file(&dev->dev, &dev_attr_power_state);
-		if (dev->power.flags.power_resources)
-			device_remove_file(&dev->dev,
-					   &dev_attr_real_power_state);
-	}
-
-	/*
-	 * If device has _STR, remove 'description' file
-	 */
-	if (acpi_has_method(dev->handle, "_STR")) {
-		kfree(dev->pnp.str_obj);
-		device_remove_file(&dev->dev, &dev_attr_description);
-	}
-	/*
-	 * If device has _EJ0, remove 'eject' file.
-	 */
-	if (acpi_has_method(dev->handle, "_EJ0"))
-		device_remove_file(&dev->dev, &dev_attr_eject);
-
-	if (acpi_has_method(dev->handle, "_SUN"))
-		device_remove_file(&dev->dev, &dev_attr_sun);
-
-	if (dev->pnp.unique_id)
-		device_remove_file(&dev->dev, &dev_attr_uid);
-	if (dev->pnp.type.bus_address)
-		device_remove_file(&dev->dev, &dev_attr_adr);
-	device_remove_file(&dev->dev, &dev_attr_modalias);
-	device_remove_file(&dev->dev, &dev_attr_hid);
-	if (acpi_has_method(dev->handle, "_STA"))
-		device_remove_file(&dev->dev, &dev_attr_status);
-	if (dev->handle)
-		device_remove_file(&dev->dev, &dev_attr_path);
-}
-/* --------------------------------------------------------------------------
-			ACPI Bus operations
-   -------------------------------------------------------------------------- */
-
-/**
- * acpi_of_match_device - Match device object using the "compatible" property.
- * @adev: ACPI device object to match.
- * @of_match_table: List of device IDs to match against.
- *
- * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
- * identifiers and a _DSD object with the "compatible" property, use that
- * property to match against the given list of identifiers.
- */
-static bool acpi_of_match_device(struct acpi_device *adev,
-				 const struct of_device_id *of_match_table)
-{
-	const union acpi_object *of_compatible, *obj;
-	int i, nval;
-
-	if (!adev)
-		return false;
-
-	of_compatible = adev->data.of_compatible;
-	if (!of_match_table || !of_compatible)
-		return false;
-
-	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
-		nval = of_compatible->package.count;
-		obj = of_compatible->package.elements;
-	} else { /* Must be ACPI_TYPE_STRING. */
-		nval = 1;
-		obj = of_compatible;
-	}
-	/* Now we can look for the driver DT compatible strings */
-	for (i = 0; i < nval; i++, obj++) {
-		const struct of_device_id *id;
-
-		for (id = of_match_table; id->compatible[0]; id++)
-			if (!strcasecmp(obj->string.pointer, id->compatible))
-				return true;
-	}
-
-	return false;
-}
-
-static bool __acpi_match_device_cls(const struct acpi_device_id *id,
-				    struct acpi_hardware_id *hwid)
-{
-	int i, msk, byte_shift;
-	char buf[3];
-
-	if (!id->cls)
-		return false;
-
-	/* Apply class-code bitmask, before checking each class-code byte */
-	for (i = 1; i <= 3; i++) {
-		byte_shift = 8 * (3 - i);
-		msk = (id->cls_msk >> byte_shift) & 0xFF;
-		if (!msk)
-			continue;
-
-		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
-		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
-			return false;
-	}
-	return true;
-}
-
-static const struct acpi_device_id *__acpi_match_device(
-	struct acpi_device *device,
-	const struct acpi_device_id *ids,
-	const struct of_device_id *of_ids)
-{
-	const struct acpi_device_id *id;
-	struct acpi_hardware_id *hwid;
-
-	/*
-	 * If the device is not present, it is unnecessary to load device
-	 * driver for it.
-	 */
-	if (!device || !device->status.present)
-		return NULL;
-
-	list_for_each_entry(hwid, &device->pnp.ids, list) {
-		/* First, check the ACPI/PNP IDs provided by the caller. */
-		for (id = ids; id->id[0] || id->cls; id++) {
-			if (id->id[0] && !strcmp((char *) id->id, hwid->id))
-				return id;
-			else if (id->cls && __acpi_match_device_cls(id, hwid))
-				return id;
-		}
-
-		/*
-		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
-		 * "compatible" property if found.
-		 *
-		 * The id returned by the below is not valid, but the only
-		 * caller passing non-NULL of_ids here is only interested in
-		 * whether or not the return value is NULL.
-		 */
-		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
-		    && acpi_of_match_device(device, of_ids))
-			return id;
-	}
-	return NULL;
-}
-
-/**
- * acpi_match_device - Match a struct device against a given list of ACPI IDs
- * @ids: Array of struct acpi_device_id object to match against.
- * @dev: The device structure to match.
- *
- * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
- * object for that handle and use that object to match against a given list of
- * device IDs.
- *
- * Return a pointer to the first matching ID on success or %NULL on failure.
- */
-const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
-					       const struct device *dev)
-{
-	return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
-}
-EXPORT_SYMBOL_GPL(acpi_match_device);
-
-int acpi_match_device_ids(struct acpi_device *device,
-			  const struct acpi_device_id *ids)
-{
-	return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
-}
-EXPORT_SYMBOL(acpi_match_device_ids);
-
-bool acpi_driver_match_device(struct device *dev,
-			      const struct device_driver *drv)
-{
-	if (!drv->acpi_match_table)
-		return acpi_of_match_device(ACPI_COMPANION(dev),
-					    drv->of_match_table);
-
-	return !!__acpi_match_device(acpi_companion_match(dev),
-				     drv->acpi_match_table, drv->of_match_table);
-}
-EXPORT_SYMBOL_GPL(acpi_driver_match_device);
-
 static void acpi_free_power_resources_lists(struct acpi_device *device)
 {
 	int i;
···
 	acpi_free_power_resources_lists(acpi_dev);
 	kfree(acpi_dev);
 }
-
-static int acpi_bus_match(struct device *dev, struct device_driver *drv)
-{
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
-
-	return acpi_dev->flags.match_driver
-		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
-}
-
-static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
-{
-	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
-}
-
-static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
-{
-	struct acpi_device *device = data;
-
-	device->driver->ops.notify(device, event);
-}
-
-static void acpi_device_notify_fixed(void *data)
-{
-	struct acpi_device *device = data;
-
-	/* Fixed hardware devices have no handles */
-	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
-}
-
-static u32 acpi_device_fixed_event(void *data)
-{
-	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
-	return ACPI_INTERRUPT_HANDLED;
-}
-
-static int acpi_device_install_notify_handler(struct acpi_device *device)
-{
-	acpi_status status;
-
-	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
-		status =
-		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
-						     acpi_device_fixed_event,
-						     device);
-	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
-		status =
-		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
-						     acpi_device_fixed_event,
-						     device);
-	else
-		status = acpi_install_notify_handler(device->handle,
-						     ACPI_DEVICE_NOTIFY,
-						     acpi_device_notify,
-						     device);
-
-	if (ACPI_FAILURE(status))
-		return -EINVAL;
-	return 0;
-}
-
-static void acpi_device_remove_notify_handler(struct acpi_device *device)
-{
-	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
-		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
-						acpi_device_fixed_event);
-	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
-		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
-						acpi_device_fixed_event);
-	else
-		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
-					   acpi_device_notify);
-}
-
-static int acpi_device_probe(struct device *dev)
-{
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
-	int ret;
-
-	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
-		return -EINVAL;
-
-	if (!acpi_drv->ops.add)
-		return -ENOSYS;
-
-	ret = acpi_drv->ops.add(acpi_dev);
-	if (ret)
-		return ret;
-
-	acpi_dev->driver = acpi_drv;
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-			  "Driver [%s] successfully bound to device [%s]\n",
-			  acpi_drv->name, acpi_dev->pnp.bus_id));
-
-	if (acpi_drv->ops.notify) {
-		ret = acpi_device_install_notify_handler(acpi_dev);
-		if (ret) {
-			if (acpi_drv->ops.remove)
-				acpi_drv->ops.remove(acpi_dev);
-
-			acpi_dev->driver = NULL;
-			acpi_dev->driver_data = NULL;
-			return ret;
-		}
-	}
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
-			  acpi_drv->name, acpi_dev->pnp.bus_id));
-	get_device(dev);
-	return 0;
-}
-
-static int acpi_device_remove(struct device * dev)
-{
-	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_driver *acpi_drv = acpi_dev->driver;
-
-	if (acpi_drv) {
-		if (acpi_drv->ops.notify)
-			acpi_device_remove_notify_handler(acpi_dev);
-		if (acpi_drv->ops.remove)
-			acpi_drv->ops.remove(acpi_dev);
-	}
-	acpi_dev->driver = NULL;
-	acpi_dev->driver_data = NULL;
-
-	put_device(dev);
-	return 0;
-}
-
-struct bus_type acpi_bus_type = {
-	.name		= "acpi",
-	.match		= acpi_bus_match,
-	.probe		= acpi_device_probe,
-	.remove		= acpi_device_remove,
-	.uevent		= acpi_device_uevent,
-};
 
 static void acpi_device_del(struct acpi_device *device)
 {
···
 	next = child->node.next;
 	return next == head ? NULL : list_entry(next, struct acpi_device, node);
 }
-
-/* --------------------------------------------------------------------------
-                                 Driver Management
-   -------------------------------------------------------------------------- */
-/**
- * acpi_bus_register_driver - register a driver with the ACPI bus
- * @driver: driver being registered
- *
- * Registers a driver with the ACPI bus.  Searches the namespace for all
- * devices that match the driver's criteria and binds.  Returns zero for
- * success or a negative error status for failure.
- */
-int acpi_bus_register_driver(struct acpi_driver *driver)
-{
-	int ret;
-
-	if (acpi_disabled)
-		return -ENODEV;
-	driver->drv.name = driver->name;
-	driver->drv.bus = &acpi_bus_type;
-	driver->drv.owner = driver->owner;
-
-	ret = driver_register(&driver->drv);
-	return ret;
-}
-
-EXPORT_SYMBOL(acpi_bus_register_driver);
-
-/**
- * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
- * @driver: driver to unregister
- *
- * Unregisters a driver with the ACPI bus.  Searches the namespace for all
- * devices that match the driver's criteria and unbinds.
- */
-void acpi_bus_unregister_driver(struct acpi_driver *driver)
-{
-	driver_unregister(&driver->drv);
-}
-
-EXPORT_SYMBOL(acpi_bus_unregister_driver);
 
 /* --------------------------------------------------------------------------
                                  Device Enumeration
···
 int __init acpi_scan_init(void)
 {
 	int result;
-
-	result = bus_register(&acpi_bus_type);
-	if (result) {
-		/* We don't want to quit even if we failed to add suspend/resume */
-		printk(KERN_ERR PREFIX "Could not register bus type\n");
-	}
 
 	acpi_pci_root_init();
 	acpi_pci_link_init();

drivers/base/core.c

···
 }
 EXPORT_SYMBOL_GPL(device_unregister);
 
+static struct device *prev_device(struct klist_iter *i)
+{
+	struct klist_node *n = klist_prev(i);
+	struct device *dev = NULL;
+	struct device_private *p;
+
+	if (n) {
+		p = to_device_private_parent(n);
+		dev = p->device;
+	}
+	return dev;
+}
+
 static struct device *next_device(struct klist_iter *i)
 {
 	struct klist_node *n = klist_next(i);
···
 	return error;
 }
 EXPORT_SYMBOL_GPL(device_for_each_child);
+
+/**
+ * device_for_each_child_reverse - device child iterator in reversed order.
+ * @parent: parent struct device.
+ * @fn: function to be called for each device.
+ * @data: data for the callback.
+ *
+ * Iterate over @parent's child devices, and call @fn for each,
+ * passing it @data.
+ *
+ * We check the return of @fn each time. If it returns anything
+ * other than 0, we break out and return that value.
+ */
+int device_for_each_child_reverse(struct device *parent, void *data,
+				  int (*fn)(struct device *dev, void *data))
+{
+	struct klist_iter i;
+	struct device *child;
+	int error = 0;
+
+	if (!parent->p)
+		return 0;
+
+	klist_iter_init(&parent->p->klist_children, &i);
+	while ((child = prev_device(&i)) && !error)
+		error = fn(child, data);
+	klist_iter_exit(&i);
+	return error;
+}
+EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
 
 /**
  * device_find_child - device iterator for locating a particular device.

drivers/base/dd.c

···
  *
  * This function must be called with @dev lock held.  When called for a
  * USB interface, @dev->parent lock must be held as well.
+ *
+ * If the device has a parent, runtime-resume the parent before driver probing.
  */
 int driver_probe_device(struct device_driver *drv, struct device *dev)
 {
···
 	pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
 		 drv->bus->name, __func__, dev_name(dev), drv->name);
 
+	if (dev->parent)
+		pm_runtime_get_sync(dev->parent);
+
 	pm_runtime_barrier(dev);
 	ret = really_probe(dev, drv);
 	pm_request_idle(dev);
+
+	if (dev->parent)
+		pm_runtime_put(dev->parent);
 
 	return ret;
 }
···
 
 	device_lock(dev);
 
+	if (dev->parent)
+		pm_runtime_get_sync(dev->parent);
+
 	bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
 	dev_dbg(dev, "async probe completed\n");
 
 	pm_request_idle(dev);
+
+	if (dev->parent)
+		pm_runtime_put(dev->parent);
 
 	device_unlock(dev);
 
···
 			.want_async = false,
 		};
 
+		if (dev->parent)
+			pm_runtime_get_sync(dev->parent);
+
 		ret = bus_for_each_drv(dev->bus, NULL, &data,
 					__device_attach_driver);
 		if (!ret && allow_async && data.have_async) {
···
 		} else {
 			pm_request_idle(dev);
 		}
+
+		if (dev->parent)
+			pm_runtime_put(dev->parent);
 	}
 out_unlock:
 	device_unlock(dev);

drivers/base/power/power.h

···
 extern void pm_qos_sysfs_remove_resume_latency(struct device *dev);
 extern int pm_qos_sysfs_add_flags(struct device *dev);
 extern void pm_qos_sysfs_remove_flags(struct device *dev);
+extern int pm_qos_sysfs_add_latency_tolerance(struct device *dev);
+extern void pm_qos_sysfs_remove_latency_tolerance(struct device *dev);
 
 #else /* CONFIG_PM */
 

drivers/base/power/qos.c

···
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
+
+/**
+ * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace
+ * @dev: Device whose latency tolerance to expose
+ */
+int dev_pm_qos_expose_latency_tolerance(struct device *dev)
+{
+	int ret;
+
+	if (!dev->power.set_latency_tolerance)
+		return -EINVAL;
+
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+	ret = pm_qos_sysfs_add_latency_tolerance(dev);
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance);
+
+/**
+ * dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace
+ * @dev: Device whose latency tolerance to hide
+ */
+void dev_pm_qos_hide_latency_tolerance(struct device *dev)
+{
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+	pm_qos_sysfs_remove_latency_tolerance(dev);
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
+
+	/* Remove the request from user space now */
+	pm_runtime_get_sync(dev);
+	dev_pm_qos_update_user_latency_tolerance(dev,
+		PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT);
+	pm_runtime_put(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance);

drivers/base/power/sysfs.c

···
 	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
+int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
+{
+	return sysfs_merge_group(&dev->kobj,
+				 &pm_qos_latency_tolerance_attr_group);
+}
+
+void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
+{
+	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
+}
+
 void rpm_sysfs_remove(struct device *dev)
 {
 	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);

drivers/dma/Kconfig

···
 	help
 	  Enable support for the Intel(R) IOP Series RAID engines.
 
+config IDMA64
+	tristate "Intel integrated DMA 64-bit support"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable DMA support for Intel Low Power Subsystem such as found on
+	  Intel Skylake PCH.
+
 source "drivers/dma/dw/Kconfig"
 
 config AT_HDMAC

drivers/dma/Makefile

···
 obj-$(CONFIG_MPC512X_DMA) += mpc512x_dma.o
 obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/
 obj-$(CONFIG_MV_XOR) += mv_xor.o
+obj-$(CONFIG_IDMA64) += idma64.o
 obj-$(CONFIG_DW_DMAC_CORE) += dw/
 obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_AT_XDMAC) += at_xdmac.o

drivers/dma/idma64.c

···
+/*
+ * Core driver for the Intel integrated DMA 64-bit
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Author: Andy Shevchenko <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "idma64.h"
+
+/* Platform driver name */
+#define DRV_NAME		"idma64"
+
+/* For now we support only two channels */
+#define IDMA64_NR_CHAN		2
+
+/* ---------------------------------------------------------------------- */
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+	return &chan->dev->device;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void idma64_off(struct idma64 *idma64)
+{
+	unsigned short count = 100;
+
+	dma_writel(idma64, CFG, 0);
+
+	channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask);
+	channel_clear_bit(idma64, MASK(BLOCK), idma64->all_chan_mask);
+	channel_clear_bit(idma64, MASK(SRC_TRAN), idma64->all_chan_mask);
+	channel_clear_bit(idma64, MASK(DST_TRAN), idma64->all_chan_mask);
+	channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
+
+	do {
+		cpu_relax();
+	} while (dma_readl(idma64, CFG) & IDMA64_CFG_DMA_EN && --count);
+}
+
+static void idma64_on(struct idma64 *idma64)
+{
+	dma_writel(idma64, CFG, IDMA64_CFG_DMA_EN);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void idma64_chan_init(struct idma64 *idma64, struct idma64_chan *idma64c)
+{
+	u32 cfghi = IDMA64C_CFGH_SRC_PER(1) | IDMA64C_CFGH_DST_PER(0);
+	u32 cfglo = 0;
+
+	/* Enforce FIFO drain when channel is suspended */
+	cfglo |= IDMA64C_CFGL_CH_DRAIN;
+
+	/* Set default burst alignment */
+	cfglo |= IDMA64C_CFGL_DST_BURST_ALIGN | IDMA64C_CFGL_SRC_BURST_ALIGN;
+
+	channel_writel(idma64c, CFG_LO, cfglo);
+	channel_writel(idma64c, CFG_HI, cfghi);
+
+	/* Enable interrupts */
+	channel_set_bit(idma64, MASK(XFER), idma64c->mask);
+	channel_set_bit(idma64, MASK(ERROR), idma64c->mask);
+
+	/*
+	 * Enforce the controller to be turned on.
+	 *
+	 * The iDMA is turned off in ->probe() and looses context during system
+	 * suspend / resume cycle. That's why we have to enable it each time we
+	 * use it.
+	 */
+	idma64_on(idma64);
+}
+
+static void idma64_chan_stop(struct idma64 *idma64, struct idma64_chan *idma64c)
+{
+	channel_clear_bit(idma64, CH_EN, idma64c->mask);
+}
+
+static void idma64_chan_start(struct idma64 *idma64, struct idma64_chan *idma64c)
+{
+	struct idma64_desc *desc = idma64c->desc;
+	struct idma64_hw_desc *hw = &desc->hw[0];
+
+	channel_writeq(idma64c, SAR, 0);
+	channel_writeq(idma64c, DAR, 0);
+
+	channel_writel(idma64c, CTL_HI, IDMA64C_CTLH_BLOCK_TS(~0UL));
+	channel_writel(idma64c, CTL_LO, IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN);
+
+	channel_writeq(idma64c, LLP, hw->llp);
+
+	channel_set_bit(idma64, CH_EN, idma64c->mask);
+}
+
+static void idma64_stop_transfer(struct idma64_chan *idma64c)
+{
+	struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
+
+	idma64_chan_stop(idma64, idma64c);
+}
+
+static void idma64_start_transfer(struct idma64_chan *idma64c)
+{
+	struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
+	struct virt_dma_desc *vdesc;
+
+	/* Get the next descriptor */
+	vdesc = vchan_next_desc(&idma64c->vchan);
+	if (!vdesc) {
+		idma64c->desc = NULL;
+		return;
+	}
+
+	list_del(&vdesc->node);
+	idma64c->desc = to_idma64_desc(vdesc);
+
+	/* Configure the channel */
+	idma64_chan_init(idma64, idma64c);
+
+	/* Start the channel with a new descriptor */
+	idma64_chan_start(idma64, idma64c);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void idma64_chan_irq(struct idma64 *idma64, unsigned short c,
+		u32 status_err, u32 status_xfer)
+{
+	struct idma64_chan *idma64c = &idma64->chan[c];
+	struct idma64_desc *desc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	desc = idma64c->desc;
+	if (desc) {
+		if (status_err & (1 << c)) {
+			dma_writel(idma64, CLEAR(ERROR), idma64c->mask);
+			desc->status = DMA_ERROR;
+		} else if (status_xfer & (1 << c)) {
+			dma_writel(idma64, CLEAR(XFER), idma64c->mask);
+			desc->status = DMA_COMPLETE;
+			vchan_cookie_complete(&desc->vdesc);
+			idma64_start_transfer(idma64c);
+		}
+
+		/* idma64_start_transfer() updates idma64c->desc */
+		if (idma64c->desc == NULL || desc->status == DMA_ERROR)
+			idma64_stop_transfer(idma64c);
+	}
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+}
+
+static irqreturn_t idma64_irq(int irq, void *dev)
+{
+	struct idma64 *idma64 = dev;
+	u32 status = dma_readl(idma64, STATUS_INT);
+	u32 status_xfer;
+	u32 status_err;
+	unsigned short i;
+
+	dev_vdbg(idma64->dma.dev, "%s: status=%#x\n", __func__, status);
+
+	/* Check if we have any interrupt from the DMA controller */
+	if (!status)
+		return IRQ_NONE;
+
+	/* Disable interrupts */
+	channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask);
+	channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
+
+	status_xfer = dma_readl(idma64, RAW(XFER));
+	status_err = dma_readl(idma64, RAW(ERROR));
+
+	for (i = 0; i < idma64->dma.chancnt; i++)
+		idma64_chan_irq(idma64, i, status_err, status_xfer);
+
+	/* Re-enable interrupts */
+	channel_set_bit(idma64, MASK(XFER), idma64->all_chan_mask);
+	channel_set_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
+
+	return IRQ_HANDLED;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static struct idma64_desc *idma64_alloc_desc(unsigned int ndesc)
+{
+	struct idma64_desc *desc;
+
+	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+	if (!desc)
+		return NULL;
+
+	desc->hw = kcalloc(ndesc, sizeof(*desc->hw), GFP_NOWAIT);
+	if (!desc->hw) {
+		kfree(desc);
+		return NULL;
+	}
+
+	return desc;
+}
+
+static void idma64_desc_free(struct idma64_chan *idma64c,
+		struct idma64_desc *desc)
+{
+	struct idma64_hw_desc *hw;
+
+	if (desc->ndesc) {
+		unsigned int i = desc->ndesc;
+
+		do {
+			hw = &desc->hw[--i];
+			dma_pool_free(idma64c->pool, hw->lli, hw->llp);
+		} while (i);
+	}
+
+	kfree(desc->hw);
+	kfree(desc);
+}
+
+static void idma64_vdesc_free(struct virt_dma_desc *vdesc)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(vdesc->tx.chan);
+
+	idma64_desc_free(idma64c, to_idma64_desc(vdesc));
+}
+
+static u64 idma64_hw_desc_fill(struct idma64_hw_desc *hw,
+		struct dma_slave_config *config,
+		enum dma_transfer_direction direction, u64 llp)
+{
+	struct idma64_lli *lli = hw->lli;
+	u64 sar, dar;
+	u32 ctlhi = IDMA64C_CTLH_BLOCK_TS(hw->len);
+	u32 ctllo = IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN;
+	u32 src_width, dst_width;
+
+	if (direction == DMA_MEM_TO_DEV) {
+		sar = hw->phys;
+		dar = config->dst_addr;
+		ctllo |= IDMA64C_CTLL_DST_FIX | IDMA64C_CTLL_SRC_INC |
+			 IDMA64C_CTLL_FC_M2P;
+		src_width = min_t(u32, 2, __fls(sar | hw->len));
+		dst_width = __fls(config->dst_addr_width);
+	} else {	/* DMA_DEV_TO_MEM */
+		sar = config->src_addr;
+		dar = hw->phys;
+		ctllo |= IDMA64C_CTLL_DST_INC | IDMA64C_CTLL_SRC_FIX |
+			 IDMA64C_CTLL_FC_P2M;
+		src_width = __fls(config->src_addr_width);
+		dst_width = min_t(u32, 2, __fls(dar | hw->len));
+	}
+
+	lli->sar = sar;
+	lli->dar = dar;
+
+	lli->ctlhi = ctlhi;
+	lli->ctllo = ctllo |
+		     IDMA64C_CTLL_SRC_MSIZE(config->src_maxburst) |
+		     IDMA64C_CTLL_DST_MSIZE(config->dst_maxburst) |
+		     IDMA64C_CTLL_DST_WIDTH(dst_width) |
+		     IDMA64C_CTLL_SRC_WIDTH(src_width);
+
+	lli->llp = llp;
+	return hw->llp;
+}
+
+static void idma64_desc_fill(struct idma64_chan *idma64c,
+		struct idma64_desc *desc)
+{
+	struct dma_slave_config *config = &idma64c->config;
+	struct idma64_hw_desc *hw = &desc->hw[desc->ndesc - 1];
+	struct idma64_lli *lli = hw->lli;
+	u64 llp = 0;
+	unsigned int i = desc->ndesc;
+
+	/* Fill the hardware descriptors and link them to a list */
+	do {
+		hw = &desc->hw[--i];
+		llp = idma64_hw_desc_fill(hw, config, desc->direction, llp);
+		desc->length += hw->len;
+	} while (i);
+
+	/* Trigger interrupt after last block */
+	lli->ctllo |= IDMA64C_CTLL_INT_EN;
+}
+
+static struct dma_async_tx_descriptor *idma64_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	struct idma64_desc *desc;
+	struct scatterlist *sg;
+	unsigned int i;
+
+	desc = idma64_alloc_desc(sg_len);
+	if (!desc)
+		return NULL;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		struct idma64_hw_desc *hw = &desc->hw[i];
+
+		/* Allocate DMA capable memory for hardware descriptor */
+		hw->lli = dma_pool_alloc(idma64c->pool, GFP_NOWAIT, &hw->llp);
+		if (!hw->lli) {
+			desc->ndesc = i;
+			idma64_desc_free(idma64c, desc);
+			return NULL;
+		}
+
+		hw->phys = sg_dma_address(sg);
+		hw->len = sg_dma_len(sg);
+	}
+
+	desc->ndesc = sg_len;
+	desc->direction = direction;
+	desc->status = DMA_IN_PROGRESS;
+
+	idma64_desc_fill(idma64c, desc);
+	return vchan_tx_prep(&idma64c->vchan, &desc->vdesc, flags);
+}
+
+static void idma64_issue_pending(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	if (vchan_issue_pending(&idma64c->vchan) && !idma64c->desc)
+		idma64_start_transfer(idma64c);
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+}
+
+static size_t idma64_active_desc_size(struct idma64_chan *idma64c)
+{
+	struct idma64_desc *desc = idma64c->desc;
+	struct idma64_hw_desc *hw;
+	size_t bytes = desc->length;
+	u64 llp;
+	u32 ctlhi;
+	unsigned int i = 0;
+
+	llp = channel_readq(idma64c, LLP);
+	do {
+		hw = &desc->hw[i];
+	} while ((hw->llp != llp) && (++i < desc->ndesc));
+
+	if (!i)
+		return bytes;
+
+	do {
+		bytes -= desc->hw[--i].len;
+	} while (i);
+
+	ctlhi = channel_readl(idma64c, CTL_HI);
+	return bytes - IDMA64C_CTLH_BLOCK_TS(ctlhi);
+}
+
+static enum dma_status idma64_tx_status(struct dma_chan *chan,
+		dma_cookie_t cookie, struct dma_tx_state *state)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	struct virt_dma_desc *vdesc;
+	enum dma_status status;
+	size_t bytes;
+	unsigned long flags;
+
+	status = dma_cookie_status(chan, cookie, state);
+	if (status == DMA_COMPLETE)
+		return status;
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	vdesc = vchan_find_desc(&idma64c->vchan, cookie);
+	if (idma64c->desc && cookie == idma64c->desc->vdesc.tx.cookie) {
+		bytes = idma64_active_desc_size(idma64c);
+		dma_set_residue(state, bytes);
+		status = idma64c->desc->status;
+	} else if (vdesc) {
+		bytes = to_idma64_desc(vdesc)->length;
+		dma_set_residue(state, bytes);
+	}
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+
+	return status;
+}
+
+static void convert_burst(u32 *maxburst)
+{
+	if (*maxburst)
+		*maxburst = __fls(*maxburst);
+	else
+		*maxburst = 0;
+}
+
+static int idma64_slave_config(struct dma_chan *chan,
+		struct dma_slave_config *config)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+
+	/* Check if chan will be configured for slave transfers */
+	if (!is_slave_direction(config->direction))
+		return -EINVAL;
+
+	memcpy(&idma64c->config, config, sizeof(idma64c->config));
+
+	convert_burst(&idma64c->config.src_maxburst);
+	convert_burst(&idma64c->config.dst_maxburst);
+
+	return 0;
+}
+
+static void idma64_chan_deactivate(struct idma64_chan *idma64c)
+{
+	unsigned short count = 100;
+	u32 cfglo;
+
+	cfglo = channel_readl(idma64c, CFG_LO);
+	channel_writel(idma64c, CFG_LO, cfglo | IDMA64C_CFGL_CH_SUSP);
+	do {
+		udelay(1);
+		cfglo = channel_readl(idma64c, CFG_LO);
+	} while (!(cfglo & IDMA64C_CFGL_FIFO_EMPTY) && --count);
+}
+
+static void idma64_chan_activate(struct idma64_chan *idma64c)
+{
+	u32 cfglo;
+
+	cfglo = channel_readl(idma64c, CFG_LO);
+	channel_writel(idma64c, CFG_LO, cfglo & ~IDMA64C_CFGL_CH_SUSP);
+}
+
+static int idma64_pause(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	if (idma64c->desc && idma64c->desc->status == DMA_IN_PROGRESS) {
+		idma64_chan_deactivate(idma64c);
+		idma64c->desc->status = DMA_PAUSED;
+	}
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+
+	return 0;
+}
+
+static int idma64_resume(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	if (idma64c->desc && idma64c->desc->status == DMA_PAUSED) {
+		idma64c->desc->status = DMA_IN_PROGRESS;
+		idma64_chan_activate(idma64c);
+	}
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+
+	return 0;
+}
+
+static int idma64_terminate_all(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&idma64c->vchan.lock, flags);
+	idma64_chan_deactivate(idma64c);
+	idma64_stop_transfer(idma64c);
+	if (idma64c->desc) {
+		idma64_vdesc_free(&idma64c->desc->vdesc);
+		idma64c->desc = NULL;
+	}
+	vchan_get_all_descriptors(&idma64c->vchan, &head);
+	spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
+
+	vchan_dma_desc_free_list(&idma64c->vchan, &head);
+	return 0;
+}
+
+static int idma64_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+
+	/* Create a pool of consistent memory blocks for hardware descriptors */
+	idma64c->pool = dma_pool_create(dev_name(chan2dev(chan)),
+					chan->device->dev,
+					sizeof(struct idma64_lli), 8, 0);
+	if (!idma64c->pool) {
+		dev_err(chan2dev(chan), "No memory for descriptors\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void idma64_free_chan_resources(struct dma_chan *chan)
+{
+	struct idma64_chan *idma64c = to_idma64_chan(chan);
+
+	vchan_free_chan_resources(to_virt_chan(chan));
+	dma_pool_destroy(idma64c->pool);
+	idma64c->pool = NULL;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#define IDMA64_BUSWIDTHS				\
+	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)		|	\
+	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES)		|	\
+	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
+
+static int idma64_probe(struct idma64_chip *chip)
+{
+	struct idma64 *idma64;
+	unsigned short nr_chan = IDMA64_NR_CHAN;
+	unsigned short i;
+	int ret;
+
+	idma64 = devm_kzalloc(chip->dev, sizeof(*idma64), GFP_KERNEL);
+	if (!idma64)
+		return -ENOMEM;
+
+	idma64->regs = chip->regs;
+	chip->idma64 = idma64;
+
+	idma64->chan = devm_kcalloc(chip->dev, nr_chan, sizeof(*idma64->chan),
+				    GFP_KERNEL);
+	if (!idma64->chan)
+		return -ENOMEM;
+
+	idma64->all_chan_mask = (1 << nr_chan) - 1;
+
+	/* Turn off iDMA controller */
+	idma64_off(idma64);
+
+	ret = devm_request_irq(chip->dev, chip->irq, idma64_irq, IRQF_SHARED,
+			       dev_name(chip->dev), idma64);
+	if (ret)
+		return ret;
+
+	INIT_LIST_HEAD(&idma64->dma.channels);
+	for (i = 0; i < nr_chan; i++) {
+		struct idma64_chan *idma64c = &idma64->chan[i];
+
+		idma64c->vchan.desc_free = idma64_vdesc_free;
+		vchan_init(&idma64c->vchan, &idma64->dma);
+
+		idma64c->regs = idma64->regs + i * IDMA64_CH_LENGTH;
+		idma64c->mask = BIT(i);
+	}
+
+	dma_cap_set(DMA_SLAVE, idma64->dma.cap_mask);
+	dma_cap_set(DMA_PRIVATE, idma64->dma.cap_mask);
+
+	idma64->dma.device_alloc_chan_resources = idma64_alloc_chan_resources;
+	idma64->dma.device_free_chan_resources = idma64_free_chan_resources;
+
+	idma64->dma.device_prep_slave_sg = idma64_prep_slave_sg;
+
+	idma64->dma.device_issue_pending = idma64_issue_pending;
+	idma64->dma.device_tx_status = idma64_tx_status;
+
+	idma64->dma.device_config = idma64_slave_config;
+	idma64->dma.device_pause = idma64_pause;
+	idma64->dma.device_resume = idma64_resume;
+	idma64->dma.device_terminate_all = idma64_terminate_all;
+
+	idma64->dma.src_addr_widths = IDMA64_BUSWIDTHS;
+	idma64->dma.dst_addr_widths = IDMA64_BUSWIDTHS;
+	idma64->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	idma64->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+	idma64->dma.dev = chip->dev;
+
+	ret = dma_async_device_register(&idma64->dma);
+	if (ret)
+		return ret;
+
+	dev_info(chip->dev, "Found Intel integrated DMA 64-bit\n");
+	return 0;
+}
+
+static int idma64_remove(struct idma64_chip *chip)
+{
+	struct idma64 *idma64 = chip->idma64;
+	unsigned short i;
+
+	dma_async_device_unregister(&idma64->dma);
+
+	/*
+	 * Explicitly call devm_request_irq() to avoid the side effects with
+	 * the scheduled tasklets.
+	 */
+	devm_free_irq(chip->dev, chip->irq, idma64);
+
+	for (i = 0; i < idma64->dma.chancnt; i++) {
+		struct idma64_chan *idma64c = &idma64->chan[i];
+
+		tasklet_kill(&idma64c->vchan.task);
+	}
+
+	return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int idma64_platform_probe(struct platform_device *pdev)
+{
+	struct idma64_chip *chip;
+	struct device *dev = &pdev->dev;
+	struct resource *mem;
+	int ret;
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->irq = platform_get_irq(pdev, 0);
+	if (chip->irq < 0)
+		return chip->irq;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	chip->regs = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(chip->regs))
+		return PTR_ERR(chip->regs);
+
+	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret)
+		return ret;
+
+	chip->dev = dev;
+
+	ret = idma64_probe(chip);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, chip);
+	return 0;
+}
+
+static int idma64_platform_remove(struct platform_device *pdev)
+{
+	struct idma64_chip *chip = platform_get_drvdata(pdev);
+
+	return idma64_remove(chip);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int idma64_pm_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct idma64_chip *chip = platform_get_drvdata(pdev);
+
+	idma64_off(chip->idma64);
+	return 0;
+}
+
+static int idma64_pm_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct idma64_chip *chip = platform_get_drvdata(pdev);
+
+	idma64_on(chip->idma64);
+	return 0;
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops idma64_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(idma64_pm_suspend, idma64_pm_resume)
+};
+
+static struct platform_driver idma64_platform_driver = {
+	.probe		= idma64_platform_probe,
+	.remove		= idma64_platform_remove,
+	.driver = {
+		.name	= DRV_NAME,
+		.pm	= &idma64_dev_pm_ops,
+	},
+};
+
+module_platform_driver(idma64_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("iDMA64 core driver");
+MODULE_AUTHOR("Andy Shevchenko <[e-mail]>");
+MODULE_ALIAS("platform:" DRV_NAME);

drivers/dma/idma64.h

···
+/*
+ * Driver for the Intel integrated DMA 64-bit
+ *
+ * Copyright (C) 2015 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __DMA_IDMA64_H__
+#define __DMA_IDMA64_H__
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "virt-dma.h"
+
+/* Channel registers */
+
+#define IDMA64_CH_SAR		0x00	/* Source Address Register */
+#define IDMA64_CH_DAR		0x08	/* Destination Address Register */
+#define IDMA64_CH_LLP		0x10	/* Linked List Pointer */
+#define IDMA64_CH_CTL_LO	0x18	/* Control Register Low */
+#define IDMA64_CH_CTL_HI	0x1c	/* Control Register High */
+#define IDMA64_CH_SSTAT		0x20
+#define IDMA64_CH_DSTAT		0x28
+#define IDMA64_CH_SSTATAR	0x30
+#define IDMA64_CH_DSTATAR	0x38
+#define IDMA64_CH_CFG_LO	0x40	/* Configuration Register Low */
+#define IDMA64_CH_CFG_HI	0x44	/* Configuration Register High */
+#define IDMA64_CH_SGR		0x48
+#define IDMA64_CH_DSR		0x50
+
+#define IDMA64_CH_LENGTH	0x58
+
+/* Bitfields in CTL_LO */
+#define IDMA64C_CTLL_INT_EN		(1 << 0)	/* irqs enabled? */
+#define IDMA64C_CTLL_DST_WIDTH(x)	((x) << 1)	/* bytes per element */
+#define IDMA64C_CTLL_SRC_WIDTH(x)	((x) << 4)
+#define IDMA64C_CTLL_DST_INC		(0 << 8)	/* DAR update/not */
+#define IDMA64C_CTLL_DST_FIX		(1 << 8)
+#define IDMA64C_CTLL_SRC_INC		(0 << 10)	/* SAR update/not */
+#define IDMA64C_CTLL_SRC_FIX		(1 << 10)
+#define IDMA64C_CTLL_DST_MSIZE(x)	((x) << 11)	/* burst, #elements */
+#define IDMA64C_CTLL_SRC_MSIZE(x)	((x) << 14)
+#define IDMA64C_CTLL_FC_M2P		(1 << 20)	/* mem-to-periph */
+#define IDMA64C_CTLL_FC_P2M		(2 << 20)	/* periph-to-mem */
+#define IDMA64C_CTLL_LLP_D_EN		(1 << 27)	/* dest block chain */
+#define IDMA64C_CTLL_LLP_S_EN		(1 << 28)	/* src block chain */
+
+/* Bitfields in CTL_HI */
+#define IDMA64C_CTLH_BLOCK_TS(x)	((x) & ((1 << 17) - 1))
+#define IDMA64C_CTLH_DONE		(1 << 17)
+
+/* Bitfields in CFG_LO */
+#define IDMA64C_CFGL_DST_BURST_ALIGN	(1 << 0)	/* dst burst align */
+#define IDMA64C_CFGL_SRC_BURST_ALIGN	(1 << 1)	/* src burst align */
+#define IDMA64C_CFGL_CH_SUSP		(1 << 8)
+#define IDMA64C_CFGL_FIFO_EMPTY		(1 << 9)
+#define IDMA64C_CFGL_CH_DRAIN		(1 << 10)	/* drain FIFO */
+#define IDMA64C_CFGL_DST_OPT_BL		(1 << 20)	/* optimize dst burst length */
+#define IDMA64C_CFGL_SRC_OPT_BL		(1 << 21)	/* optimize src burst length */
+
+/* Bitfields in CFG_HI */
+#define IDMA64C_CFGH_SRC_PER(x)		((x) << 0)	/* src peripheral */
+#define IDMA64C_CFGH_DST_PER(x)		((x) << 4)	/* dst peripheral */
+#define IDMA64C_CFGH_RD_ISSUE_THD(x)	((x) << 8)
+#define IDMA64C_CFGH_RW_ISSUE_THD(x)	((x) << 18)
+
+/* Interrupt registers */
+
+#define IDMA64_INT_XFER		0x00
+#define IDMA64_INT_BLOCK	0x08
+#define IDMA64_INT_SRC_TRAN	0x10
+#define IDMA64_INT_DST_TRAN	0x18
+#define IDMA64_INT_ERROR	0x20
+
+#define IDMA64_RAW(x)		(0x2c0 + IDMA64_INT_##x)	/* r */
+#define IDMA64_STATUS(x)	(0x2e8 + IDMA64_INT_##x)	/* r (raw & mask) */
+#define IDMA64_MASK(x)		(0x310 + IDMA64_INT_##x)	/* rw (set = irq enabled) */
+#define IDMA64_CLEAR(x)		(0x338 + IDMA64_INT_##x)	/* w (ack, affects "raw") */
+
+/* Common registers */
+
+#define IDMA64_STATUS_INT	0x360	/* r */
+#define IDMA64_CFG		0x398
+#define IDMA64_CH_EN		0x3a0
+
+/* Bitfields in CFG */
+#define IDMA64_CFG_DMA_EN		(1 << 0)
+
+/* Hardware descriptor for Linked LIst transfers */
+struct idma64_lli {
+	u64		sar;
+	u64		dar;
+	u64		llp;
+	u32		ctllo;
+	u32		ctlhi;
+	u32		sstat;
+	u32		dstat;
+};
+
+struct idma64_hw_desc {
+	struct idma64_lli *lli;
+	dma_addr_t llp;
+	dma_addr_t phys;
+	unsigned int len;
+};
+
+struct idma64_desc {
+	struct virt_dma_desc vdesc;
+	enum dma_transfer_direction direction;
+	struct idma64_hw_desc *hw;
+	unsigned int ndesc;
+	size_t length;
+	enum dma_status status;
+};
+
+static inline struct idma64_desc *to_idma64_desc(struct virt_dma_desc *vdesc)
+{
+	return container_of(vdesc, struct idma64_desc, vdesc);
+}
+
+struct idma64_chan {
+	struct virt_dma_chan vchan;
+
+	void __iomem *regs;
+
+	/* hardware configuration */
+	enum dma_transfer_direction direction;
+	unsigned int mask;
+	struct dma_slave_config config;
+
+	void *pool;
+	struct idma64_desc *desc;
+};
+
+static inline struct idma64_chan *to_idma64_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct idma64_chan, vchan.chan);
+}
+
+#define channel_set_bit(idma64, reg, mask)	\
+	dma_writel(idma64, reg, ((mask) << 8) | (mask))
+#define channel_clear_bit(idma64, reg, mask)	\
+	dma_writel(idma64, reg, ((mask) << 8) | 0)
+
+static inline u32 idma64c_readl(struct idma64_chan *idma64c, int offset)
+{
+	return readl(idma64c->regs + offset);
+}
+
+static inline void idma64c_writel(struct idma64_chan *idma64c, int offset,
+				  u32 value)
+{
+	writel(value, idma64c->regs + offset);
+}
+
+#define channel_readl(idma64c, reg)		\
+	idma64c_readl(idma64c, IDMA64_CH_##reg)
+#define channel_writel(idma64c, reg, value)	\
+	idma64c_writel(idma64c, IDMA64_CH_##reg, (value))
+
+static inline u64 idma64c_readq(struct idma64_chan *idma64c, int offset)
+{
+	u64 l, h;
+
+	l = idma64c_readl(idma64c, offset);
+	h = idma64c_readl(idma64c, offset + 4);
+
+	return l | (h << 32);
+}
+
+static inline void idma64c_writeq(struct idma64_chan *idma64c, int offset,
+				  u64 value)
+{
+	idma64c_writel(idma64c, offset, value);
+	idma64c_writel(idma64c, offset + 4, value >> 32);
+}
+
+#define channel_readq(idma64c, reg)		\
+	idma64c_readq(idma64c, IDMA64_CH_##reg)
+#define channel_writeq(idma64c, reg, value)	\
+	idma64c_writeq(idma64c, IDMA64_CH_##reg, (value))
+
+struct idma64 {
+	struct dma_device dma;
+
+	void __iomem *regs;
+
+	/* channels */
+	unsigned short all_chan_mask;
+	struct idma64_chan *chan;
+};
+
+static inline struct idma64 *to_idma64(struct dma_device *ddev)
+{
+	return container_of(ddev, struct idma64, dma);
+}
+
+static inline u32 idma64_readl(struct idma64 *idma64, int offset)
+{
+	return readl(idma64->regs + offset);
+}
+
+static inline void idma64_writel(struct idma64 *idma64, int offset, u32 value)
+{
+	writel(value, idma64->regs + offset);
+}
+
+#define dma_readl(idma64, reg)			\
+	idma64_readl(idma64, IDMA64_##reg)
+#define dma_writel(idma64, reg, value)		\
+	idma64_writel(idma64, IDMA64_##reg, (value))
+
+/**
+ * struct idma64_chip - representation of DesignWare DMA controller hardware
+ * @dev:		struct device of the DMA controller
+ * @irq:		irq line
+ * @regs:		memory mapped I/O space
+ * @idma64:		struct idma64 that is filed by idma64_probe()
+ */
+struct idma64_chip {
+	struct device	*dev;
+	int		irq;
+	void __iomem	*regs;
+	struct idma64	*idma64;
+};
+
+#endif /* __DMA_IDMA64_H__ */

drivers/mfd/Kconfig

···
 	  thermal, charger and related power management functions
 	  on these systems.
 
+config MFD_INTEL_LPSS
+	tristate
+	select COMMON_CLK
+	select MFD_CORE
+
+config MFD_INTEL_LPSS_ACPI
+	tristate "Intel Low Power Subsystem support in ACPI mode"
+	select MFD_INTEL_LPSS
+	depends on X86 && ACPI
+	help
+	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
+	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
+	  PCH) in ACPI mode.
+
+config MFD_INTEL_LPSS_PCI
+	tristate "Intel Low Power Subsystem support in PCI mode"
+	select MFD_INTEL_LPSS
+	depends on X86 && PCI
+	help
+	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
+	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
+	  PCH) in PCI mode.
+
 config MFD_INTEL_MSIC
 	bool "Intel MSIC"
 	depends on INTEL_SCU_IPC

drivers/mfd/Makefile

···
 obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
 obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
 obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
+obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
+obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
+obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
 obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
 obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o

drivers/mfd/intel-lpss-acpi.c

···
+/*
+ * Intel LPSS ACPI support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <[e-mail]>
+ *          Mika Westerberg <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+
+#include "intel-lpss.h"
+
+static const struct intel_lpss_platform_info spt_info = {
+	.clk_rate = 120000000,
+};
+
+static const struct acpi_device_id intel_lpss_acpi_ids[] = {
+	/* SPT */
+	{ "INT3446", (kernel_ulong_t)&spt_info },
+	{ "INT3447", (kernel_ulong_t)&spt_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, intel_lpss_acpi_ids);
+
+static int intel_lpss_acpi_probe(struct platform_device *pdev)
+{
+	struct intel_lpss_platform_info *info;
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(intel_lpss_acpi_ids, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
+	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	info->irq = platform_get_irq(pdev, 0);
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	return intel_lpss_probe(&pdev->dev, info);
+}
+
+static int intel_lpss_acpi_remove(struct platform_device *pdev)
+{
+	intel_lpss_remove(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static INTEL_LPSS_PM_OPS(intel_lpss_acpi_pm_ops);
+
+static struct platform_driver intel_lpss_acpi_driver = {
+	.probe = intel_lpss_acpi_probe,
+	.remove = intel_lpss_acpi_remove,
+	.driver = {
+		.name = "intel-lpss",
+		.acpi_match_table = intel_lpss_acpi_ids,
+		.pm = &intel_lpss_acpi_pm_ops,
+	},
+};
+
+module_platform_driver(intel_lpss_acpi_driver);
+
+MODULE_AUTHOR("Andy Shevchenko <[e-mail]>");
+MODULE_AUTHOR("Mika Westerberg <[e-mail]>");
+MODULE_DESCRIPTION("Intel LPSS ACPI driver");
+MODULE_LICENSE("GPL v2");

drivers/mfd/intel-lpss-pci.c

···
+/*
+ * Intel LPSS PCI support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <[e-mail]>
+ *          Mika Westerberg <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+
+#include "intel-lpss.h"
+
+static int intel_lpss_pci_probe(struct pci_dev *pdev,
+				const struct pci_device_id *id)
+{
+	struct intel_lpss_platform_info *info;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->mem = &pdev->resource[0];
+	info->irq = pdev->irq;
+
+	/* Probably it is enough to set this for iDMA capable devices only */
+	pci_set_master(pdev);
+
+	ret = intel_lpss_probe(&pdev->dev, info);
+	if (ret)
+		return ret;
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_allow(&pdev->dev);
+
+	return 0;
+}
+
+static void intel_lpss_pci_remove(struct pci_dev *pdev)
+{
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	intel_lpss_remove(&pdev->dev);
+}
+
+static INTEL_LPSS_PM_OPS(intel_lpss_pci_pm_ops);
+
+static const struct intel_lpss_platform_info spt_info = {
+	.clk_rate = 120000000,
+};
+
+static const struct intel_lpss_platform_info spt_uart_info = {
+	.clk_rate = 120000000,
+	.clk_con_id = "baudclk",
+};
+
+static const struct pci_device_id intel_lpss_pci_ids[] = {
+	/* SPT-LP */
+	{ PCI_VDEVICE(INTEL, 0x9d27), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0x9d28), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0x9d29), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d2a), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d60), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d61), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d62), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d63), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d64), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d65), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d66), (kernel_ulong_t)&spt_uart_info },
+	/* SPT-H */
+	{ PCI_VDEVICE(INTEL, 0xa127), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0xa128), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0xa129), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa12a), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa160), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa161), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa166), (kernel_ulong_t)&spt_uart_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, intel_lpss_pci_ids);
+
+static struct pci_driver intel_lpss_pci_driver = {
+	.name = "intel-lpss",
+	.id_table = intel_lpss_pci_ids,
+	.probe = intel_lpss_pci_probe,
+	.remove = intel_lpss_pci_remove,
+	.driver = {
+		.pm = &intel_lpss_pci_pm_ops,
+	},
+};
+
+module_pci_driver(intel_lpss_pci_driver);
+
+MODULE_AUTHOR("Andy Shevchenko <[e-mail]>");
+MODULE_AUTHOR("Mika Westerberg <[e-mail]>");
+MODULE_DESCRIPTION("Intel LPSS PCI driver");
+MODULE_LICENSE("GPL v2");

drivers/mfd/intel-lpss.c

···
+/*
+ * Intel Sunrisepoint LPSS core support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <[e-mail]>
+ *          Mika Westerberg <[e-mail]>
+ *          Heikki Krogerus <[e-mail]>
+ *          Jarkko Nikula <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/idr.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
+
+#include "intel-lpss.h"
+
+#define LPSS_DEV_OFFSET		0x000
+#define LPSS_DEV_SIZE		0x200
+#define LPSS_PRIV_OFFSET	0x200
+#define LPSS_PRIV_SIZE		0x100
+#define LPSS_IDMA64_OFFSET	0x800
+#define LPSS_IDMA64_SIZE	0x800
+
+/* Offsets from lpss->priv */
+#define LPSS_PRIV_RESETS		0x04
+#define LPSS_PRIV_RESETS_FUNC		BIT(2)
+#define LPSS_PRIV_RESETS_IDMA		0x3
+
+#define LPSS_PRIV_ACTIVELTR		0x10
+#define LPSS_PRIV_IDLELTR		0x14
+
+#define LPSS_PRIV_LTR_REQ		BIT(15)
+#define LPSS_PRIV_LTR_SCALE_MASK	0xc00
+#define LPSS_PRIV_LTR_SCALE_1US		0x800
+#define LPSS_PRIV_LTR_SCALE_32US	0xc00
+#define LPSS_PRIV_LTR_VALUE_MASK	0x3ff
+
+#define LPSS_PRIV_SSP_REG		0x20
+#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN	BIT(0)
+
+#define LPSS_PRIV_REMAP_ADDR_LO		0x40
+#define LPSS_PRIV_REMAP_ADDR_HI		0x44
+
+#define LPSS_PRIV_CAPS			0xfc
+#define LPSS_PRIV_CAPS_NO_IDMA		BIT(8)
+#define LPSS_PRIV_CAPS_TYPE_SHIFT	4
+#define LPSS_PRIV_CAPS_TYPE_MASK	(0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
+
+/* This matches the type field in CAPS register */
+enum intel_lpss_dev_type {
+	LPSS_DEV_I2C = 0,
+	LPSS_DEV_UART,
+	LPSS_DEV_SPI,
+};
+
+struct intel_lpss {
+	const struct intel_lpss_platform_info *info;
+	enum intel_lpss_dev_type type;
+	struct clk *clk;
+	struct clk_lookup *clock;
+	const struct mfd_cell *cell;
+	struct device *dev;
+	void __iomem *priv;
+	int devid;
+	u32 caps;
+	u32 active_ltr;
+	u32 idle_ltr;
+	struct dentry *debugfs;
+};
+
+static const struct resource intel_lpss_dev_resources[] = {
+	DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
+	DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
+	DEFINE_RES_IRQ(0),
+};
+
+static const struct resource intel_lpss_idma64_resources[] = {
+	DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
+	DEFINE_RES_IRQ(0),
+};
+
+#define LPSS_IDMA64_DRIVER_NAME		"idma64"
+
+/*
+ * Cells needs to be ordered so that the iDMA is created first. This is
+ * because we need to be sure the DMA is available when the host controller
+ * driver is probed.
+ */
+static const struct mfd_cell intel_lpss_idma64_cell = {
+	.name = LPSS_IDMA64_DRIVER_NAME,
+	.num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
+	.resources = intel_lpss_idma64_resources,
+};
+
+static const struct mfd_cell intel_lpss_i2c_cell = {
+	.name = "i2c_designware",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_uart_cell = {
+	.name = "dw-apb-uart",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_spi_cell = {
+	.name = "pxa2xx-spi",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static DEFINE_IDA(intel_lpss_devid_ida);
+static struct dentry *intel_lpss_debugfs;
+
+static int intel_lpss_request_dma_module(const char *name)
+{
+	static bool intel_lpss_dma_requested;
+
+	if (intel_lpss_dma_requested)
+		return 0;
+
+	intel_lpss_dma_requested = true;
+	return request_module("%s", name);
+}
+
+static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
+{
+	lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+	lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
+}
+
+static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+
+	debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
+	debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
+	debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
+
+	lpss->debugfs = dir;
+	return 0;
+}
+
+static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
+{
+	debugfs_remove_recursive(lpss->debugfs);
+}
+
+static void intel_lpss_ltr_set(struct device *dev, s32 val)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	u32 ltr;
+
+	/*
+	 * Program latency tolerance (LTR) accordingly what has been asked
+	 * by the PM QoS layer or disable it in case we were passed
+	 * negative value or PM_QOS_LATENCY_ANY.
+	 */
+	ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+
+	if (val == PM_QOS_LATENCY_ANY || val < 0) {
+		ltr &= ~LPSS_PRIV_LTR_REQ;
+	} else {
+		ltr |= LPSS_PRIV_LTR_REQ;
+		ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
+		ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
+
+		if (val > LPSS_PRIV_LTR_VALUE_MASK)
+			ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
+		else
+			ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
+	}
+
+	if (ltr == lpss->active_ltr)
+		return;
+
+	writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
+	writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+}
+
+static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
+{
+	lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
+	dev_pm_qos_expose_latency_tolerance(lpss->dev);
+}
+
+static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
+{
+	dev_pm_qos_hide_latency_tolerance(lpss->dev);
+	lpss->dev->power.set_latency_tolerance = NULL;
+}
+
+static int intel_lpss_assign_devs(struct intel_lpss *lpss)
+{
+	unsigned int type;
+
+	type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
+	type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
+
+	switch (type) {
+	case LPSS_DEV_I2C:
+		lpss->cell = &intel_lpss_i2c_cell;
+		break;
+	case LPSS_DEV_UART:
+		lpss->cell = &intel_lpss_uart_cell;
+		break;
+	case LPSS_DEV_SPI:
+		lpss->cell = &intel_lpss_spi_cell;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	lpss->type = type;
+
+	return 0;
+}
+
+static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
+{
+	return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
+}
+
+static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
+{
+	resource_size_t addr = lpss->info->mem->start;
+
+	writel(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR_LO);
+#if BITS_PER_LONG > 32
+	writel(addr >> 32, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
+#else
+	writel(0, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
+#endif
+}
+
+static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
+
+	/* Bring out the device from reset */
+	writel(value, lpss->priv + LPSS_PRIV_RESETS);
+}
+
+static void intel_lpss_init_dev(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
+
+	intel_lpss_deassert_reset(lpss);
+
+	if (!intel_lpss_has_idma(lpss))
+		return;
+
+	intel_lpss_set_remap_addr(lpss);
+
+	/* Make sure that SPI multiblock DMA transfers are re-enabled */
+	if (lpss->type == LPSS_DEV_SPI)
+		writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
+}
+
+static void intel_lpss_unregister_clock_tree(struct clk *clk)
+{
+	struct clk *parent;
+
+	while (clk) {
+		parent = clk_get_parent(clk);
+		clk_unregister(clk);
+		clk = parent;
+	}
+}
+
+static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
+					     const char *devname,
+					     struct clk **clk)
+{
+	char name[32];
+	struct clk *tmp = *clk;
+
+	snprintf(name, sizeof(name), "%s-enable", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
+				lpss->priv, 0, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	snprintf(name, sizeof(name), "%s-div", devname);
+	tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
+					      0, lpss->priv, 1, 15, 16, 15, 0,
+					      NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	snprintf(name, sizeof(name), "%s-update", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
+				CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	return 0;
+}
+
+static int intel_lpss_register_clock(struct intel_lpss *lpss)
+{
+	const struct mfd_cell *cell = lpss->cell;
+	struct clk *clk;
+	char devname[24];
+	int ret;
+
+	if (!lpss->info->clk_rate)
+		return 0;
+
+	/* Root clock */
+	clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
+				      CLK_IS_ROOT, lpss->info->clk_rate);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
+
+	/*
+	 * Support for clock divider only if it has some preset value.
+	 * Otherwise we assume that the divider is not used.
+	 */
+	if (lpss->type != LPSS_DEV_I2C) {
+		ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
+		if (ret)
+			goto err_clk_register;
+	}
+
+	ret = -ENOMEM;
+
+	/* Clock for the host controller */
+	lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
+	if (!lpss->clock)
+		goto err_clk_register;
+
+	lpss->clk = clk;
+
+	return 0;
+
+err_clk_register:
+	intel_lpss_unregister_clock_tree(clk);
+
+	return ret;
+}
+
+static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
+{
+	if (IS_ERR_OR_NULL(lpss->clk))
+		return;
+
+	clkdev_drop(lpss->clock);
+	intel_lpss_unregister_clock_tree(lpss->clk);
+}
+
+int intel_lpss_probe(struct device *dev,
+		     const struct intel_lpss_platform_info *info)
+{
+	struct intel_lpss *lpss;
+	int ret;
+
+	if (!info || !info->mem || info->irq <= 0)
+		return -EINVAL;
+
+	lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
+	if (!lpss)
+		return -ENOMEM;
+
+	lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
+				  LPSS_PRIV_SIZE);
+	if (!lpss->priv)
+		return -ENOMEM;
+
+	lpss->info = info;
+	lpss->dev = dev;
+	lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
+
+	dev_set_drvdata(dev, lpss);
+
+	ret = intel_lpss_assign_devs(lpss);
+	if (ret)
+		return ret;
+
+	intel_lpss_init_dev(lpss);
+
+	lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
+	if (lpss->devid < 0)
+		return lpss->devid;
+
+	ret = intel_lpss_register_clock(lpss);
+	if (ret)
+		goto err_clk_register;
+
+	intel_lpss_ltr_expose(lpss);
+
+	ret = intel_lpss_debugfs_add(lpss);
+	if (ret)
+		dev_warn(dev, "Failed to create debugfs entries\n");
+
+	if (intel_lpss_has_idma(lpss)) {
+		/*
+		 * Ensure the DMA driver is loaded before the host
+		 * controller device appears, so that the host controller
+		 * driver can request its DMA channels as early as
+		 * possible.
+		 *
+		 * If the DMA module is not there that's OK as well.
+		 */
+		intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
+
+		ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
+				      1, info->mem, info->irq, NULL);
+		if (ret)
+			dev_warn(dev, "Failed to add %s, fallback to PIO\n",
+				 LPSS_IDMA64_DRIVER_NAME);
+	}
+
+	ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
+			      1, info->mem, info->irq, NULL);
+	if (ret)
+		goto err_remove_ltr;
+
+	return 0;
+
+err_remove_ltr:
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+
+err_clk_register:
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_probe);
+
+void intel_lpss_remove(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+
+	mfd_remove_devices(dev);
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+	intel_lpss_unregister_clock(lpss);
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+}
+EXPORT_SYMBOL_GPL(intel_lpss_remove);
+
+static int resume_lpss_device(struct device *dev, void *data)
+{
+	pm_runtime_resume(dev);
+	return 0;
+}
+
+int intel_lpss_prepare(struct device *dev)
+{
+	/*
+	 * Resume both child devices before entering system sleep. This
+	 * ensures that they are in proper state before they get suspended.
+	 */
+	device_for_each_child_reverse(dev, NULL, resume_lpss_device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_prepare);
+
+int intel_lpss_suspend(struct device *dev)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_suspend);
+
+int intel_lpss_resume(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+
+	intel_lpss_init_dev(lpss);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_resume);
+
+static int __init intel_lpss_init(void)
+{
+	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
+	return 0;
+}
+module_init(intel_lpss_init);
+
+static void __exit intel_lpss_exit(void)
+{
+	debugfs_remove(intel_lpss_debugfs);
+}
+module_exit(intel_lpss_exit);
+
+MODULE_AUTHOR("Andy Shevchenko <[e-mail]>");
+MODULE_AUTHOR("Mika Westerberg <[e-mail]>");
+MODULE_AUTHOR("Heikki Krogerus <[e-mail]>");
+MODULE_AUTHOR("Jarkko Nikula <[e-mail]>");
+MODULE_DESCRIPTION("Intel LPSS core driver");
+MODULE_LICENSE("GPL v2");

drivers/mfd/intel-lpss.h

···
+/*
+ * Intel LPSS core support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <[e-mail]>
+ *          Mika Westerberg <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __MFD_INTEL_LPSS_H
+#define __MFD_INTEL_LPSS_H
+
+struct device;
+struct resource;
+
+struct intel_lpss_platform_info {
+	struct resource *mem;
+	int irq;
+	unsigned long clk_rate;
+	const char *clk_con_id;
+};
+
+int intel_lpss_probe(struct device *dev,
+		     const struct intel_lpss_platform_info *info);
+void intel_lpss_remove(struct device *dev);
+
+#ifdef CONFIG_PM
+int intel_lpss_prepare(struct device *dev);
+int intel_lpss_suspend(struct device *dev);
+int intel_lpss_resume(struct device *dev);
+
+#ifdef CONFIG_PM_SLEEP
+#define INTEL_LPSS_SLEEP_PM_OPS			\
+	.prepare = intel_lpss_prepare,		\
+	.suspend = intel_lpss_suspend,		\
+	.resume = intel_lpss_resume,		\
+	.freeze = intel_lpss_suspend,		\
+	.thaw = intel_lpss_resume,		\
+	.poweroff = intel_lpss_suspend,		\
+	.restore = intel_lpss_resume,
+#endif
+
+#define INTEL_LPSS_RUNTIME_PM_OPS		\
+	.runtime_suspend = intel_lpss_suspend,	\
+	.runtime_resume = intel_lpss_resume,
+
+#else /* !CONFIG_PM */
+#define INTEL_LPSS_SLEEP_PM_OPS
+#define INTEL_LPSS_RUNTIME_PM_OPS
+#endif /* CONFIG_PM */
+
+#define INTEL_LPSS_PM_OPS(name)			\
+const struct dev_pm_ops name = {		\
+	INTEL_LPSS_SLEEP_PM_OPS			\
+	INTEL_LPSS_RUNTIME_PM_OPS		\
+}
+
+#endif /* __MFD_INTEL_LPSS_H */

drivers/mfd/mfd-core.c

···
 {
 	atomic_t *cnts = NULL;
 
-	device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
+	device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn);
 	kfree(cnts);
 }
 EXPORT_SYMBOL(mfd_remove_devices);

include/linux/device.h

···
 extern void device_del(struct device *dev);
 extern int device_for_each_child(struct device *dev, void *data,
 		     int (*fn)(struct device *dev, void *data));
+extern int device_for_each_child_reverse(struct device *dev, void *data,
+		     int (*fn)(struct device *dev, void *data));
 extern struct device *device_find_child(struct device *dev, void *data,
 				int (*match)(struct device *dev, void *data));
 extern int device_rename(struct device *dev, const char *new_name);

include/linux/klist.h

···
 extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
 				 struct klist_node *n);
 extern void klist_iter_exit(struct klist_iter *i);
+extern struct klist_node *klist_prev(struct klist_iter *i);
 extern struct klist_node *klist_next(struct klist_iter *i);
 
 #endif

include/linux/pm_qos.h

···
 int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
 s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev);
 int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val);
+int dev_pm_qos_expose_latency_tolerance(struct device *dev);
+void dev_pm_qos_hide_latency_tolerance(struct device *dev);
 
 static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 {
···
 			{ return PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; }
 static inline int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 			{ return 0; }
+static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev)
+			{ return 0; }
+static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
 
 static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev) { return 0; }
 static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }

lib/klist.c

···
 }
 
 /**
+ * klist_prev - Ante up prev node in list.
+ * @i: Iterator structure.
+ *
+ * First grab list lock. Decrement the reference count of the previous
+ * node, if there was one. Grab the prev node, increment its reference
+ * count, drop the lock, and return that prev node.
+ */
+struct klist_node *klist_prev(struct klist_iter *i)
+{
+	void (*put)(struct klist_node *) = i->i_klist->put;
+	struct klist_node *last = i->i_cur;
+	struct klist_node *prev;
+
+	spin_lock(&i->i_klist->k_lock);
+
+	if (last) {
+		prev = to_klist_node(last->n_node.prev);
+		if (!klist_dec_and_del(last))
+			put = NULL;
+	} else
+		prev = to_klist_node(i->i_klist->k_list.prev);
+
+	i->i_cur = NULL;
+	while (prev != to_klist_node(&i->i_klist->k_list)) {
+		if (likely(!knode_dead(prev))) {
+			kref_get(&prev->n_ref);
+			i->i_cur = prev;
+			break;
+		}
+		prev = to_klist_node(prev->n_node.prev);
+	}
+
+	spin_unlock(&i->i_klist->k_lock);
+
+	if (put && last)
+		put(last);
+	return i->i_cur;
+}
+EXPORT_SYMBOL_GPL(klist_prev);
+
+/**
  * klist_next - Ante up next node in list.
  * @i: Iterator structure.
  *