[SCSI] enclosure: add support for enclosure services

The enclosure misc device is really just a library providing sysfs
support for physical enclosure devices and their components.

Signed-off-by: James Bottomley <[e-mail]>

drivers/misc/Kconfig

···
 
 	  If unsure, say N.
 
+config ENCLOSURE_SERVICES
+	tristate "Enclosure Services"
+	default n
+	help
+	  Provides support for intelligent enclosures (bays which
+	  contain storage devices).  You also need either a host
+	  driver (SCSI/ATA) which supports enclosures
+	  or a SCSI enclosure device (SES) to use these services.
+
 endif # MISC_DEVICES

drivers/misc/Makefile

···
 obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
 obj-$(CONFIG_EEPROM_93CX6)	+= eeprom_93cx6.o
 obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o
+obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o

drivers/misc/enclosure.c

···
+/*
+ * Enclosure Services
+ *
+ * Copyright (C) 2008 James Bottomley <[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.
+**
+**  You should have received a copy of the GNU General Public License
+**  along with this program; if not, write to the Free Software
+**  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+**
+**-----------------------------------------------------------------------------
+*/
+#include <linux/device.h>
+#include <linux/enclosure.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+static LIST_HEAD(container_list);
+static DEFINE_MUTEX(container_list_lock);
+static struct class enclosure_class;
+static struct class enclosure_component_class;
+
+/**
+ * enclosure_find - find an enclosure given a device
+ * @dev:	the device to find for
+ *
+ * Looks through the list of registered enclosures to see
+ * if it can find a match for a device.  Returns NULL if no
+ * enclosure is found. Obtains a reference to the enclosure class
+ * device which must be released with class_device_put().
+ */
+struct enclosure_device *enclosure_find(struct device *dev)
+{
+	struct enclosure_device *edev = NULL;
+
+	mutex_lock(&container_list_lock);
+	list_for_each_entry(edev, &container_list, node) {
+		if (edev->cdev.dev == dev) {
+			class_device_get(&edev->cdev);
+			mutex_unlock(&container_list_lock);
+			return edev;
+		}
+	}
+	mutex_unlock(&container_list_lock);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(enclosure_find);
+
+/**
+ * enclosure_for_each_device - calls a function for each enclosure
+ * @fn:		the function to call
+ * @data:	the data to pass to each call
+ *
+ * Loops over all the enclosures calling the function.
+ *
+ * Note, this function uses a mutex which will be held across calls to
+ * @fn, so it must have non atomic context, and @fn may (although it
+ * should not) sleep or otherwise cause the mutex to be held for
+ * indefinite periods
+ */
+int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
+			      void *data)
+{
+	int error = 0;
+	struct enclosure_device *edev;
+
+	mutex_lock(&container_list_lock);
+	list_for_each_entry(edev, &container_list, node) {
+		error = fn(edev, data);
+		if (error)
+			break;
+	}
+	mutex_unlock(&container_list_lock);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(enclosure_for_each_device);
+
+/**
+ * enclosure_register - register device as an enclosure
+ *
+ * @dev:	device containing the enclosure
+ * @components:	number of components in the enclosure
+ *
+ * This sets up the device for being an enclosure.  Note that @dev does
+ * not have to be a dedicated enclosure device.  It may be some other type
+ * of device that additionally responds to enclosure services
+ */
+struct enclosure_device *
+enclosure_register(struct device *dev, const char *name, int components,
+		   struct enclosure_component_callbacks *cb)
+{
+	struct enclosure_device *edev =
+		kzalloc(sizeof(struct enclosure_device) +
+			sizeof(struct enclosure_component)*components,
+			GFP_KERNEL);
+	int err, i;
+
+	BUG_ON(!cb);
+
+	if (!edev)
+		return ERR_PTR(-ENOMEM);
+
+	edev->components = components;
+
+	edev->cdev.class = &enclosure_class;
+	edev->cdev.dev = get_device(dev);
+	edev->cb = cb;
+	snprintf(edev->cdev.class_id, BUS_ID_SIZE, "%s", name);
+	err = class_device_register(&edev->cdev);
+	if (err)
+		goto err;
+
+	for (i = 0; i < components; i++)
+		edev->component[i].number = -1;
+
+	mutex_lock(&container_list_lock);
+	list_add_tail(&edev->node, &container_list);
+	mutex_unlock(&container_list_lock);
+
+	return edev;
+
+ err:
+	put_device(edev->cdev.dev);
+	kfree(edev);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(enclosure_register);
+
+static struct enclosure_component_callbacks enclosure_null_callbacks;
+
+/**
+ * enclosure_unregister - remove an enclosure
+ *
+ * @edev:	the registered enclosure to remove;
+ */
+void enclosure_unregister(struct enclosure_device *edev)
+{
+	int i;
+
+	mutex_lock(&container_list_lock);
+	list_del(&edev->node);
+	mutex_unlock(&container_list_lock);
+
+	for (i = 0; i < edev->components; i++)
+		if (edev->component[i].number != -1)
+			class_device_unregister(&edev->component[i].cdev);
+
+	/* prevent any callbacks into service user */
+	edev->cb = &enclosure_null_callbacks;
+	class_device_unregister(&edev->cdev);
+}
+EXPORT_SYMBOL_GPL(enclosure_unregister);
+
+static void enclosure_release(struct class_device *cdev)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	put_device(cdev->dev);
+	kfree(edev);
+}
+
+static void enclosure_component_release(struct class_device *cdev)
+{
+	if (cdev->dev)
+		put_device(cdev->dev);
+	class_device_put(cdev->parent);
+}
+
+/**
+ * enclosure_component_register - add a particular component to an enclosure
+ * @edev:	the enclosure to add the component
+ * @num:	the device number
+ * @type:	the type of component being added
+ * @name:	an optional name to appear in sysfs (leave NULL if none)
+ *
+ * Registers the component.  The name is optional for enclosures that
+ * give their components a unique name.  If not, leave the field NULL
+ * and a name will be assigned.
+ *
+ * Returns a pointer to the enclosure component or an error.
+ */
+struct enclosure_component *
+enclosure_component_register(struct enclosure_device *edev,
+			     unsigned int number,
+			     enum enclosure_component_type type,
+			     const char *name)
+{
+	struct enclosure_component *ecomp;
+	struct class_device *cdev;
+	int err;
+
+	if (number >= edev->components)
+		return ERR_PTR(-EINVAL);
+
+	ecomp = &edev->component[number];
+
+	if (ecomp->number != -1)
+		return ERR_PTR(-EINVAL);
+
+	ecomp->type = type;
+	ecomp->number = number;
+	cdev = &ecomp->cdev;
+	cdev->parent = class_device_get(&edev->cdev);
+	cdev->class = &enclosure_component_class;
+	if (name)
+		snprintf(cdev->class_id, BUS_ID_SIZE, "%s", name);
+	else
+		snprintf(cdev->class_id, BUS_ID_SIZE, "%u", number);
+
+	err = class_device_register(cdev);
+	if (err)
+		ERR_PTR(err);
+
+	return ecomp;
+}
+EXPORT_SYMBOL_GPL(enclosure_component_register);
+
+/**
+ * enclosure_add_device - add a device as being part of an enclosure
+ * @edev:	the enclosure device being added to.
+ * @num:	the number of the component
+ * @dev:	the device being added
+ *
+ * Declares a real device to reside in slot (or identifier) @num of an
+ * enclosure.  This will cause the relevant sysfs links to appear.
+ * This function may also be used to change a device associated with
+ * an enclosure without having to call enclosure_remove_device() in
+ * between.
+ *
+ * Returns zero on success or an error.
+ */
+int enclosure_add_device(struct enclosure_device *edev, int component,
+			 struct device *dev)
+{
+	struct class_device *cdev;
+
+	if (!edev || component >= edev->components)
+		return -EINVAL;
+
+	cdev = &edev->component[component].cdev;
+
+	class_device_del(cdev);
+	if (cdev->dev)
+		put_device(cdev->dev);
+	cdev->dev = get_device(dev);
+	return class_device_add(cdev);
+}
+EXPORT_SYMBOL_GPL(enclosure_add_device);
+
+/**
+ * enclosure_remove_device - remove a device from an enclosure
+ * @edev:	the enclosure device
+ * @num:	the number of the component to remove
+ *
+ * Returns zero on success or an error.
+ *
+ */
+int enclosure_remove_device(struct enclosure_device *edev, int component)
+{
+	struct class_device *cdev;
+
+	if (!edev || component >= edev->components)
+		return -EINVAL;
+
+	cdev = &edev->component[component].cdev;
+
+	class_device_del(cdev);
+	if (cdev->dev)
+		put_device(cdev->dev);
+	cdev->dev = NULL;
+	return class_device_add(cdev);
+}
+EXPORT_SYMBOL_GPL(enclosure_remove_device);
+
+/*
+ * sysfs pieces below
+ */
+
+static ssize_t enclosure_show_components(struct class_device *cdev, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	return snprintf(buf, 40, "%d\n", edev->components);
+}
+
+static struct class_device_attribute enclosure_attrs[] = {
+	__ATTR(components, S_IRUGO, enclosure_show_components, NULL),
+	__ATTR_NULL
+};
+
+static struct class enclosure_class = {
+	.name			= "enclosure",
+	.owner			= THIS_MODULE,
+	.release		= enclosure_release,
+	.class_dev_attrs	= enclosure_attrs,
+};
+
+static const char *const enclosure_status [] = {
+	[ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
+	[ENCLOSURE_STATUS_OK] = "OK",
+	[ENCLOSURE_STATUS_CRITICAL] = "critical",
+	[ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
+	[ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
+	[ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
+	[ENCLOSURE_STATUS_UNKNOWN] = "unknown",
+	[ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
+};
+
+static const char *const enclosure_type [] = {
+	[ENCLOSURE_COMPONENT_DEVICE] = "device",
+	[ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
+};
+
+static ssize_t get_component_fault(struct class_device *cdev, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_fault)
+		edev->cb->get_fault(edev, ecomp);
+	return snprintf(buf, 40, "%d\n", ecomp->fault);
+}
+
+static ssize_t set_component_fault(struct class_device *cdev, const char *buf,
+				   size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_fault)
+		edev->cb->set_fault(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_status(struct class_device *cdev, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_status)
+		edev->cb->get_status(edev, ecomp);
+	return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
+}
+
+static ssize_t set_component_status(struct class_device *cdev, const char *buf,
+				   size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int i;
+
+	for (i = 0; enclosure_status[i]; i++) {
+		if (strncmp(buf, enclosure_status[i],
+			    strlen(enclosure_status[i])) == 0 &&
+		    (buf[strlen(enclosure_status[i])] == '\n' ||
+		     buf[strlen(enclosure_status[i])] == '\0'))
+			break;
+	}
+
+	if (enclosure_status[i] && edev->cb->set_status) {
+		edev->cb->set_status(edev, ecomp, i);
+		return count;
+	} else
+		return -EINVAL;
+}
+
+static ssize_t get_component_active(struct class_device *cdev, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_active)
+		edev->cb->get_active(edev, ecomp);
+	return snprintf(buf, 40, "%d\n", ecomp->active);
+}
+
+static ssize_t set_component_active(struct class_device *cdev, const char *buf,
+				   size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_active)
+		edev->cb->set_active(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_locate(struct class_device *cdev, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_locate)
+		edev->cb->get_locate(edev, ecomp);
+	return snprintf(buf, 40, "%d\n", ecomp->locate);
+}
+
+static ssize_t set_component_locate(struct class_device *cdev, const char *buf,
+				   size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_locate)
+		edev->cb->set_locate(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_type(struct class_device *cdev, char *buf)
+{
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
+}
+
+
+static struct class_device_attribute enclosure_component_attrs[] = {
+	__ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
+	       set_component_fault),
+	__ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
+	       set_component_status),
+	__ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
+	       set_component_active),
+	__ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
+	       set_component_locate),
+	__ATTR(type, S_IRUGO, get_component_type, NULL),
+	__ATTR_NULL
+};
+
+static struct class enclosure_component_class =  {
+	.name			= "enclosure_component",
+	.owner			= THIS_MODULE,
+	.class_dev_attrs	= enclosure_component_attrs,
+	.release		= enclosure_component_release,
+};
+
+static int __init enclosure_init(void)
+{
+	int err;
+
+	err = class_register(&enclosure_class);
+	if (err)
+		return err;
+	err = class_register(&enclosure_component_class);
+	if (err)
+		goto err_out;
+
+	return 0;
+ err_out:
+	class_unregister(&enclosure_class);
+
+	return err;
+}
+
+static void __exit enclosure_exit(void)
+{
+	class_unregister(&enclosure_component_class);
+	class_unregister(&enclosure_class);
+}
+
+module_init(enclosure_init);
+module_exit(enclosure_exit);
+
+MODULE_AUTHOR("James Bottomley");
+MODULE_DESCRIPTION("Enclosure Services");
+MODULE_LICENSE("GPL v2");

include/linux/enclosure.h

···
+/*
+ * Enclosure Services
+ *
+ * Copyright (C) 2008 James Bottomley <[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.
+**
+**  You should have received a copy of the GNU General Public License
+**  along with this program; if not, write to the Free Software
+**  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+**
+**-----------------------------------------------------------------------------
+*/
+#ifndef _LINUX_ENCLOSURE_H_
+#define _LINUX_ENCLOSURE_H_
+
+#include <linux/device.h>
+#include <linux/list.h>
+
+/* A few generic types ... taken from ses-2 */
+enum enclosure_component_type {
+	ENCLOSURE_COMPONENT_DEVICE = 0x01,
+	ENCLOSURE_COMPONENT_ARRAY_DEVICE = 0x17,
+};
+
+/* ses-2 common element status */
+enum enclosure_status {
+	ENCLOSURE_STATUS_UNSUPPORTED = 0,
+	ENCLOSURE_STATUS_OK,
+	ENCLOSURE_STATUS_CRITICAL,
+	ENCLOSURE_STATUS_NON_CRITICAL,
+	ENCLOSURE_STATUS_UNRECOVERABLE,
+	ENCLOSURE_STATUS_NOT_INSTALLED,
+	ENCLOSURE_STATUS_UNKNOWN,
+	ENCLOSURE_STATUS_UNAVAILABLE,
+};
+
+/* SFF-8485 activity light settings */
+enum enclosure_component_setting {
+	ENCLOSURE_SETTING_DISABLED = 0,
+	ENCLOSURE_SETTING_ENABLED = 1,
+	ENCLOSURE_SETTING_BLINK_A_ON_OFF = 2,
+	ENCLOSURE_SETTING_BLINK_A_OFF_ON = 3,
+	ENCLOSURE_SETTING_BLINK_B_ON_OFF = 6,
+	ENCLOSURE_SETTING_BLINK_B_OFF_ON = 7,
+};
+
+struct enclosure_device;
+struct enclosure_component;
+struct enclosure_component_callbacks {
+	void (*get_status)(struct enclosure_device *,
+			     struct enclosure_component *);
+	int (*set_status)(struct enclosure_device *,
+			  struct enclosure_component *,
+			  enum enclosure_status);
+	void (*get_fault)(struct enclosure_device *,
+			  struct enclosure_component *);
+	int (*set_fault)(struct enclosure_device *,
+			 struct enclosure_component *,
+			 enum enclosure_component_setting);
+	void (*get_active)(struct enclosure_device *,
+			   struct enclosure_component *);
+	int (*set_active)(struct enclosure_device *,
+			  struct enclosure_component *,
+			  enum enclosure_component_setting);
+	void (*get_locate)(struct enclosure_device *,
+			   struct enclosure_component *);
+	int (*set_locate)(struct enclosure_device *,
+			  struct enclosure_component *,
+			  enum enclosure_component_setting);
+};
+
+
+struct enclosure_component {
+	void *scratch;
+	struct class_device cdev;
+	enum enclosure_component_type type;
+	int number;
+	int fault;
+	int active;
+	int locate;
+	enum enclosure_status status;
+};
+
+struct enclosure_device {
+	void *scratch;
+	struct list_head node;
+	struct class_device cdev;
+	struct enclosure_component_callbacks *cb;
+	int components;
+	struct enclosure_component component[0];
+};
+
+static inline struct enclosure_device *
+to_enclosure_device(struct class_device *dev)
+{
+	return container_of(dev, struct enclosure_device, cdev);
+}
+
+static inline struct enclosure_component *
+to_enclosure_component(struct class_device *dev)
+{
+	return container_of(dev, struct enclosure_component, cdev);
+}
+
+struct enclosure_device *
+enclosure_register(struct device *, const char *, int,
+		   struct enclosure_component_callbacks *);
+void enclosure_unregister(struct enclosure_device *);
+struct enclosure_component *
+enclosure_component_register(struct enclosure_device *, unsigned int,
+				 enum enclosure_component_type, const char *);
+int enclosure_add_device(struct enclosure_device *enclosure, int component,
+			 struct device *dev);
+int enclosure_remove_device(struct enclosure_device *enclosure, int component);
+struct enclosure_device *enclosure_find(struct device *dev);
+int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
+			      void *data);
+
+#endif /* _LINUX_ENCLOSURE_H_ */