Merge tag 'qcom-soc-for-4.3' into v4.2-rc2

Qualcomm ARM Based SoC Updates for 4.3

* Add SMEM driver
* Add SMD driver
* Add RPM over SMD driver
* Select QCOM_SCM by default

Documentation/devicetree/bindings/soc/qcom,smd-rpm.txt

···
+Qualcomm Resource Power Manager (RPM) over SMD
+
+This driver is used to interface with the Resource Power Manager (RPM) found in
+various Qualcomm platforms. The RPM allows each component in the system to vote
+for state of the system resources, such as clocks, regulators and bus
+frequencies.
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be one of:
+		    "qcom,rpm-msm8974"
+
+- qcom,smd-channels:
+	Usage: required
+	Value type: <stringlist>
+	Definition: Shared Memory channel used for communication with the RPM
+
+= SUBDEVICES
+
+The RPM exposes resources to its subnodes. The below bindings specify the set
+of valid subnodes that can operate on these resources.
+
+== Regulators
+
+Regulator nodes are identified by their compatible:
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be one of:
+		    "qcom,rpm-pm8841-regulators"
+		    "qcom,rpm-pm8941-regulators"
+
+- vdd_s1-supply:
+- vdd_s2-supply:
+- vdd_s3-supply:
+- vdd_s4-supply:
+- vdd_s5-supply:
+- vdd_s6-supply:
+- vdd_s7-supply:
+- vdd_s8-supply:
+	Usage: optional (pm8841 only)
+	Value type: <phandle>
+	Definition: reference to regulator supplying the input pin, as
+		    described in the data sheet
+
+- vdd_s1-supply:
+- vdd_s2-supply:
+- vdd_s3-supply:
+- vdd_l1_l3-supply:
+- vdd_l2_lvs1_2_3-supply:
+- vdd_l4_l11-supply:
+- vdd_l5_l7-supply:
+- vdd_l6_l12_l14_l15-supply:
+- vdd_l8_l16_l18_l19-supply:
+- vdd_l9_l10_l17_l22-supply:
+- vdd_l13_l20_l23_l24-supply:
+- vdd_l21-supply:
+- vin_5vs-supply:
+	Usage: optional (pm8941 only)
+	Value type: <phandle>
+	Definition: reference to regulator supplying the input pin, as
+		    described in the data sheet
+
+The regulator node houses sub-nodes for each regulator within the device. Each
+sub-node is identified using the node's name, with valid values listed for each
+of the pmics below.
+
+pm8841:
+	s1, s2, s3, s4, s5, s6, s7, s8
+
+pm8941:
+	s1, s2, s3, s4, l1, l2, l3, l4, l5, l6, l7, l8, l9, l10, l11, l12, l13,
+	l14, l15, l16, l17, l18, l19, l20, l21, l22, l23, l24, lvs1, lvs2,
+	lvs3, 5vs1, 5vs2
+
+The content of each sub-node is defined by the standard binding for regulators -
+see regulator.txt.
+
+= EXAMPLE
+
+	smd {
+		compatible = "qcom,smd";
+
+		rpm {
+			interrupts = <0 168 1>;
+			qcom,ipc = <&apcs 8 0>;
+			qcom,smd-edge = <15>;
+
+			rpm_requests {
+				compatible = "qcom,rpm-msm8974";
+				qcom,smd-channels = "rpm_requests";
+
+				pm8941-regulators {
+					compatible = "qcom,rpm-pm8941-regulators";
+					vdd_l13_l20_l23_l24-supply = <&pm8941_boost>;
+
+					pm8941_s3: s3 {
+						regulator-min-microvolt = <1800000>;
+						regulator-max-microvolt = <1800000>;
+					};
+
+					pm8941_boost: s4 {
+						regulator-min-microvolt = <5000000>;
+						regulator-max-microvolt = <5000000>;
+					};
+
+					pm8941_l20: l20 {
+						regulator-min-microvolt = <2950000>;
+						regulator-max-microvolt = <2950000>;
+					};
+				};
+			};
+		};
+	};
+

Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt

···
+Qualcomm Shared Memory Driver (SMD) binding
+
+This binding describes the Qualcomm Shared Memory Driver, a fifo based
+communication channel for sending data between the various subsystems in
+Qualcomm platforms.
+
+- compatible:
+	Usage: required
+	Value type: <stringlist>
+	Definition: must be "qcom,smd"
+
+= EDGES
+
+Each subnode of the SMD node represents a remote subsystem or a remote
+processor of some sort - or in SMD language an "edge". The name of the edges
+are not important.
+The edge is described by the following properties:
+
+- interrupts:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify the IRQ used by the remote processor to
+		    signal this processor about communication related updates
+
+- qcom,ipc:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: three entries specifying the outgoing ipc bit used for
+		    signaling the remote processor:
+		    - phandle to a syscon node representing the apcs registers
+		    - u32 representing offset to the register within the syscon
+		    - u32 representing the ipc bit within the register
+
+- qcom,smd-edge:
+	Usage: required
+	Value type: <u32>
+	Definition: the identifier of the remote processor in the smd channel
+		    allocation table
+
+= SMD DEVICES
+
+In turn, subnodes of the "edges" represent devices tied to SMD channels on that
+"edge". The names of the devices are not important. The properties of these
+nodes are defined by the individual bindings for the SMD devices - but must
+contain the following property:
+
+- qcom,smd-channels:
+	Usage: required
+	Value type: <stringlist>
+	Definition: a list of channels tied to this device, used for matching
+		    the device to channels
+
+= EXAMPLE
+
+The following example represents a smd node, with one edge representing the
+"rpm" subsystem. For the "rpm" subsystem we have a device tied to the
+"rpm_request" channel.
+
+	apcs: syscon@f9011000 {
+		compatible = "syscon";
+		reg = <0xf9011000 0x1000>;
+	};
+
+	smd {
+		compatible = "qcom,smd";
+
+		rpm {
+			interrupts = <0 168 1>;
+			qcom,ipc = <&apcs 8 0>;
+			qcom,smd-edge = <15>;
+
+			rpm_requests {
+				compatible = "qcom,rpm-msm8974";
+				qcom,smd-channels = "rpm_requests";
+
+				...
+			};
+		};
+	};

drivers/soc/qcom/Kconfig

···
 config QCOM_PM
 	bool "Qualcomm Power Management"
 	depends on ARCH_QCOM && !ARM64
+	select QCOM_SCM
 	help
 	  QCOM Platform specific power driver to manage cores and L2 low power
 	  modes. It interface with various system drivers to put the cores in
 	  low power modes.
+
+config QCOM_SMD
+	tristate "Qualcomm Shared Memory Driver (SMD)"
+	depends on QCOM_SMEM
+	help
+	  Say y here to enable support for the Qualcomm Shared Memory Driver
+	  providing communication channels to remote processors in Qualcomm
+	  platforms.
+
+config QCOM_SMD_RPM
+	tristate "Qualcomm Resource Power Manager (RPM) over SMD"
+	depends on QCOM_SMD && OF
+	help
+	  If you say yes to this option, support will be included for the
+	  Resource Power Manager system found in the Qualcomm 8974 based
+	  devices.
+
+	  This is required to access many regulators, clocks and bus
+	  frequencies controlled by the RPM on these devices.
+
+	  Say M here if you want to include support for the Qualcomm RPM as a
+	  module. This will build a module called "qcom-smd-rpm".
+
+config QCOM_SMEM
+	tristate "Qualcomm Shared Memory Manager (SMEM)"
+	depends on ARCH_QCOM
+	help
+	  Say y here to enable support for the Qualcomm Shared Memory Manager.
+	  The driver provides an interface to items in a heap shared among all
+	  processors in a Qualcomm platform.

drivers/soc/qcom/Makefile

···
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
+obj-$(CONFIG_QCOM_SMD) +=	smd.o
+obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
+obj-$(CONFIG_QCOM_SMEM) +=	smem.o

drivers/soc/qcom/smd-rpm.c

···
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+
+#include <linux/soc/qcom/smd.h>
+#include <linux/soc/qcom/smd-rpm.h>
+
+#define RPM_REQUEST_TIMEOUT     (5 * HZ)
+
+/**
+ * struct qcom_smd_rpm - state of the rpm device driver
+ * @rpm_channel:	reference to the smd channel
+ * @ack:		completion for acks
+ * @lock:		mutual exclusion around the send/complete pair
+ * @ack_status:		result of the rpm request
+ */
+struct qcom_smd_rpm {
+	struct qcom_smd_channel *rpm_channel;
+
+	struct completion ack;
+	struct mutex lock;
+	int ack_status;
+};
+
+/**
+ * struct qcom_rpm_header - header for all rpm requests and responses
+ * @service_type:	identifier of the service
+ * @length:		length of the payload
+ */
+struct qcom_rpm_header {
+	u32 service_type;
+	u32 length;
+};
+
+/**
+ * struct qcom_rpm_request - request message to the rpm
+ * @msg_id:	identifier of the outgoing message
+ * @flags:	active/sleep state flags
+ * @type:	resource type
+ * @id:		resource id
+ * @data_len:	length of the payload following this header
+ */
+struct qcom_rpm_request {
+	u32 msg_id;
+	u32 flags;
+	u32 type;
+	u32 id;
+	u32 data_len;
+};
+
+/**
+ * struct qcom_rpm_message - response message from the rpm
+ * @msg_type:	indicator of the type of message
+ * @length:	the size of this message, including the message header
+ * @msg_id:	message id
+ * @message:	textual message from the rpm
+ *
+ * Multiple of these messages can be stacked in an rpm message.
+ */
+struct qcom_rpm_message {
+	u32 msg_type;
+	u32 length;
+	union {
+		u32 msg_id;
+		u8 message[0];
+	};
+};
+
+#define RPM_SERVICE_TYPE_REQUEST	0x00716572 /* "req\0" */
+
+#define RPM_MSG_TYPE_ERR		0x00727265 /* "err\0" */
+#define RPM_MSG_TYPE_MSG_ID		0x2367736d /* "msg#" */
+
+/**
+ * qcom_rpm_smd_write - write @buf to @type:@id
+ * @rpm:	rpm handle
+ * @type:	resource type
+ * @id:		resource identifier
+ * @buf:	the data to be written
+ * @count:	number of bytes in @buf
+ */
+int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
+		       int state,
+		       u32 type, u32 id,
+		       void *buf,
+		       size_t count)
+{
+	static unsigned msg_id = 1;
+	int left;
+	int ret;
+
+	struct {
+		struct qcom_rpm_header hdr;
+		struct qcom_rpm_request req;
+		u8 payload[count];
+	} pkt;
+
+	/* SMD packets to the RPM may not exceed 256 bytes */
+	if (WARN_ON(sizeof(pkt) >= 256))
+		return -EINVAL;
+
+	mutex_lock(&rpm->lock);
+
+	pkt.hdr.service_type = RPM_SERVICE_TYPE_REQUEST;
+	pkt.hdr.length = sizeof(struct qcom_rpm_request) + count;
+
+	pkt.req.msg_id = msg_id++;
+	pkt.req.flags = BIT(state);
+	pkt.req.type = type;
+	pkt.req.id = id;
+	pkt.req.data_len = count;
+	memcpy(pkt.payload, buf, count);
+
+	ret = qcom_smd_send(rpm->rpm_channel, &pkt, sizeof(pkt));
+	if (ret)
+		goto out;
+
+	left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
+	if (!left)
+		ret = -ETIMEDOUT;
+	else
+		ret = rpm->ack_status;
+
+out:
+	mutex_unlock(&rpm->lock);
+	return ret;
+}
+EXPORT_SYMBOL(qcom_rpm_smd_write);
+
+static int qcom_smd_rpm_callback(struct qcom_smd_device *qsdev,
+				 const void *data,
+				 size_t count)
+{
+	const struct qcom_rpm_header *hdr = data;
+	const struct qcom_rpm_message *msg;
+	struct qcom_smd_rpm *rpm = dev_get_drvdata(&qsdev->dev);
+	const u8 *buf = data + sizeof(struct qcom_rpm_header);
+	const u8 *end = buf + hdr->length;
+	char msgbuf[32];
+	int status = 0;
+	u32 len;
+
+	if (hdr->service_type != RPM_SERVICE_TYPE_REQUEST ||
+	    hdr->length < sizeof(struct qcom_rpm_message)) {
+		dev_err(&qsdev->dev, "invalid request\n");
+		return 0;
+	}
+
+	while (buf < end) {
+		msg = (struct qcom_rpm_message *)buf;
+		switch (msg->msg_type) {
+		case RPM_MSG_TYPE_MSG_ID:
+			break;
+		case RPM_MSG_TYPE_ERR:
+			len = min_t(u32, ALIGN(msg->length, 4), sizeof(msgbuf));
+			memcpy_fromio(msgbuf, msg->message, len);
+			msgbuf[len - 1] = 0;
+
+			if (!strcmp(msgbuf, "resource does not exist"))
+				status = -ENXIO;
+			else
+				status = -EINVAL;
+			break;
+		}
+
+		buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg->length, 4);
+	}
+
+	rpm->ack_status = status;
+	complete(&rpm->ack);
+	return 0;
+}
+
+static int qcom_smd_rpm_probe(struct qcom_smd_device *sdev)
+{
+	struct qcom_smd_rpm *rpm;
+
+	rpm = devm_kzalloc(&sdev->dev, sizeof(*rpm), GFP_KERNEL);
+	if (!rpm)
+		return -ENOMEM;
+
+	mutex_init(&rpm->lock);
+	init_completion(&rpm->ack);
+
+	rpm->rpm_channel = sdev->channel;
+
+	dev_set_drvdata(&sdev->dev, rpm);
+
+	return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
+}
+
+static void qcom_smd_rpm_remove(struct qcom_smd_device *sdev)
+{
+	of_platform_depopulate(&sdev->dev);
+}
+
+static const struct of_device_id qcom_smd_rpm_of_match[] = {
+	{ .compatible = "qcom,rpm-msm8974" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
+
+static struct qcom_smd_driver qcom_smd_rpm_driver = {
+	.probe = qcom_smd_rpm_probe,
+	.remove = qcom_smd_rpm_remove,
+	.callback = qcom_smd_rpm_callback,
+	.driver  = {
+		.name  = "qcom_smd_rpm",
+		.owner = THIS_MODULE,
+		.of_match_table = qcom_smd_rpm_of_match,
+	},
+};
+
+static int __init qcom_smd_rpm_init(void)
+{
+	return qcom_smd_driver_register(&qcom_smd_rpm_driver);
+}
+arch_initcall(qcom_smd_rpm_init);
+
+static void __exit qcom_smd_rpm_exit(void)
+{
+	qcom_smd_driver_unregister(&qcom_smd_rpm_driver);
+}
+module_exit(qcom_smd_rpm_exit);
+
+MODULE_AUTHOR("Bjorn Andersson <[e-mail]>");
+MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
+MODULE_LICENSE("GPL v2");

drivers/soc/qcom/smd.c

···
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smd.h>
+#include <linux/soc/qcom/smem.h>
+#include <linux/wait.h>
+
+/*
+ * The Qualcomm Shared Memory communication solution provides point-to-point
+ * channels for clients to send and receive streaming or packet based data.
+ *
+ * Each channel consists of a control item (channel info) and a ring buffer
+ * pair. The channel info carry information related to channel state, flow
+ * control and the offsets within the ring buffer.
+ *
+ * All allocated channels are listed in an allocation table, identifying the
+ * pair of items by name, type and remote processor.
+ *
+ * Upon creating a new channel the remote processor allocates channel info and
+ * ring buffer items from the smem heap and populate the allocation table. An
+ * interrupt is sent to the other end of the channel and a scan for new
+ * channels should be done. A channel never goes away, it will only change
+ * state.
+ *
+ * The remote processor signals it intent for bring up the communication
+ * channel by setting the state of its end of the channel to "opening" and
+ * sends out an interrupt. We detect this change and register a smd device to
+ * consume the channel. Upon finding a consumer we finish the handshake and the
+ * channel is up.
+ *
+ * Upon closing a channel, the remote processor will update the state of its
+ * end of the channel and signal us, we will then unregister any attached
+ * device and close our end of the channel.
+ *
+ * Devices attached to a channel can use the qcom_smd_send function to push
+ * data to the channel, this is done by copying the data into the tx ring
+ * buffer, updating the pointers in the channel info and signaling the remote
+ * processor.
+ *
+ * The remote processor does the equivalent when it transfer data and upon
+ * receiving the interrupt we check the channel info for new data and delivers
+ * this to the attached device. If the device is not ready to receive the data
+ * we leave it in the ring buffer for now.
+ */
+
+struct smd_channel_info;
+struct smd_channel_info_word;
+
+#define SMD_ALLOC_TBL_COUNT	2
+#define SMD_ALLOC_TBL_SIZE	64
+
+/*
+ * This lists the various smem heap items relevant for the allocation table and
+ * smd channel entries.
+ */
+static const struct {
+	unsigned alloc_tbl_id;
+	unsigned info_base_id;
+	unsigned fifo_base_id;
+} smem_items[SMD_ALLOC_TBL_COUNT] = {
+	{
+		.alloc_tbl_id = 13,
+		.info_base_id = 14,
+		.fifo_base_id = 338
+	},
+	{
+		.alloc_tbl_id = 14,
+		.info_base_id = 266,
+		.fifo_base_id = 202,
+	},
+};
+
+/**
+ * struct qcom_smd_edge - representing a remote processor
+ * @smd:		handle to qcom_smd
+ * @of_node:		of_node handle for information related to this edge
+ * @edge_id:		identifier of this edge
+ * @irq:		interrupt for signals on this edge
+ * @ipc_regmap:		regmap handle holding the outgoing ipc register
+ * @ipc_offset:		offset within @ipc_regmap of the register for ipc
+ * @ipc_bit:		bit in the register at @ipc_offset of @ipc_regmap
+ * @channels:		list of all channels detected on this edge
+ * @channels_lock:	guard for modifications of @channels
+ * @allocated:		array of bitmaps representing already allocated channels
+ * @need_rescan:	flag that the @work needs to scan smem for new channels
+ * @smem_available:	last available amount of smem triggering a channel scan
+ * @work:		work item for edge house keeping
+ */
+struct qcom_smd_edge {
+	struct qcom_smd *smd;
+	struct device_node *of_node;
+	unsigned edge_id;
+
+	int irq;
+
+	struct regmap *ipc_regmap;
+	int ipc_offset;
+	int ipc_bit;
+
+	struct list_head channels;
+	spinlock_t channels_lock;
+
+	DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
+
+	bool need_rescan;
+	unsigned smem_available;
+
+	struct work_struct work;
+};
+
+/*
+ * SMD channel states.
+ */
+enum smd_channel_state {
+	SMD_CHANNEL_CLOSED,
+	SMD_CHANNEL_OPENING,
+	SMD_CHANNEL_OPENED,
+	SMD_CHANNEL_FLUSHING,
+	SMD_CHANNEL_CLOSING,
+	SMD_CHANNEL_RESET,
+	SMD_CHANNEL_RESET_OPENING
+};
+
+/**
+ * struct qcom_smd_channel - smd channel struct
+ * @edge:		qcom_smd_edge this channel is living on
+ * @qsdev:		reference to a associated smd client device
+ * @name:		name of the channel
+ * @state:		local state of the channel
+ * @remote_state:	remote state of the channel
+ * @tx_info:		byte aligned outgoing channel info
+ * @rx_info:		byte aligned incoming channel info
+ * @tx_info_word:	word aligned outgoing channel info
+ * @rx_info_word:	word aligned incoming channel info
+ * @tx_lock:		lock to make writes to the channel mutually exclusive
+ * @fblockread_event:	wakeup event tied to tx fBLOCKREADINTR
+ * @tx_fifo:		pointer to the outgoing ring buffer
+ * @rx_fifo:		pointer to the incoming ring buffer
+ * @fifo_size:		size of each ring buffer
+ * @bounce_buffer:	bounce buffer for reading wrapped packets
+ * @cb:			callback function registered for this channel
+ * @recv_lock:		guard for rx info modifications and cb pointer
+ * @pkt_size:		size of the currently handled packet
+ * @list:		lite entry for @channels in qcom_smd_edge
+ */
+struct qcom_smd_channel {
+	struct qcom_smd_edge *edge;
+
+	struct qcom_smd_device *qsdev;
+
+	char *name;
+	enum smd_channel_state state;
+	enum smd_channel_state remote_state;
+
+	struct smd_channel_info *tx_info;
+	struct smd_channel_info *rx_info;
+
+	struct smd_channel_info_word *tx_info_word;
+	struct smd_channel_info_word *rx_info_word;
+
+	struct mutex tx_lock;
+	wait_queue_head_t fblockread_event;
+
+	void *tx_fifo;
+	void *rx_fifo;
+	int fifo_size;
+
+	void *bounce_buffer;
+	int (*cb)(struct qcom_smd_device *, const void *, size_t);
+
+	spinlock_t recv_lock;
+
+	int pkt_size;
+
+	struct list_head list;
+};
+
+/**
+ * struct qcom_smd - smd struct
+ * @dev:	device struct
+ * @num_edges:	number of entries in @edges
+ * @edges:	array of edges to be handled
+ */
+struct qcom_smd {
+	struct device *dev;
+
+	unsigned num_edges;
+	struct qcom_smd_edge edges[0];
+};
+
+/*
+ * Format of the smd_info smem items, for byte aligned channels.
+ */
+struct smd_channel_info {
+	u32 state;
+	u8  fDSR;
+	u8  fCTS;
+	u8  fCD;
+	u8  fRI;
+	u8  fHEAD;
+	u8  fTAIL;
+	u8  fSTATE;
+	u8  fBLOCKREADINTR;
+	u32 tail;
+	u32 head;
+};
+
+/*
+ * Format of the smd_info smem items, for word aligned channels.
+ */
+struct smd_channel_info_word {
+	u32 state;
+	u32 fDSR;
+	u32 fCTS;
+	u32 fCD;
+	u32 fRI;
+	u32 fHEAD;
+	u32 fTAIL;
+	u32 fSTATE;
+	u32 fBLOCKREADINTR;
+	u32 tail;
+	u32 head;
+};
+
+#define GET_RX_CHANNEL_INFO(channel, param) \
+	(channel->rx_info_word ? \
+		channel->rx_info_word->param : \
+		channel->rx_info->param)
+
+#define SET_RX_CHANNEL_INFO(channel, param, value) \
+	(channel->rx_info_word ? \
+		(channel->rx_info_word->param = value) : \
+		(channel->rx_info->param = value))
+
+#define GET_TX_CHANNEL_INFO(channel, param) \
+	(channel->tx_info_word ? \
+		channel->tx_info_word->param : \
+		channel->tx_info->param)
+
+#define SET_TX_CHANNEL_INFO(channel, param, value) \
+	(channel->tx_info_word ? \
+		(channel->tx_info_word->param = value) : \
+		(channel->tx_info->param = value))
+
+/**
+ * struct qcom_smd_alloc_entry - channel allocation entry
+ * @name:	channel name
+ * @cid:	channel index
+ * @flags:	channel flags and edge id
+ * @ref_count:	reference count of the channel
+ */
+struct qcom_smd_alloc_entry {
+	u8 name[20];
+	u32 cid;
+	u32 flags;
+	u32 ref_count;
+} __packed;
+
+#define SMD_CHANNEL_FLAGS_EDGE_MASK	0xff
+#define SMD_CHANNEL_FLAGS_STREAM	BIT(8)
+#define SMD_CHANNEL_FLAGS_PACKET	BIT(9)
+
+/*
+ * Each smd packet contains a 20 byte header, with the first 4 being the length
+ * of the packet.
+ */
+#define SMD_PACKET_HEADER_LEN	20
+
+/*
+ * Signal the remote processor associated with 'channel'.
+ */
+static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
+{
+	struct qcom_smd_edge *edge = channel->edge;
+
+	regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
+}
+
+/*
+ * Initialize the tx channel info
+ */
+static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
+{
+	SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
+	SET_TX_CHANNEL_INFO(channel, fDSR, 0);
+	SET_TX_CHANNEL_INFO(channel, fCTS, 0);
+	SET_TX_CHANNEL_INFO(channel, fCD, 0);
+	SET_TX_CHANNEL_INFO(channel, fRI, 0);
+	SET_TX_CHANNEL_INFO(channel, fHEAD, 0);
+	SET_TX_CHANNEL_INFO(channel, fTAIL, 0);
+	SET_TX_CHANNEL_INFO(channel, fSTATE, 1);
+	SET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR, 0);
+	SET_TX_CHANNEL_INFO(channel, head, 0);
+	SET_TX_CHANNEL_INFO(channel, tail, 0);
+
+	qcom_smd_signal_channel(channel);
+
+	channel->state = SMD_CHANNEL_CLOSED;
+	channel->pkt_size = 0;
+}
+
+/*
+ * Calculate the amount of data available in the rx fifo
+ */
+static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
+{
+	unsigned head;
+	unsigned tail;
+
+	head = GET_RX_CHANNEL_INFO(channel, head);
+	tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+	return (head - tail) & (channel->fifo_size - 1);
+}
+
+/*
+ * Set tx channel state and inform the remote processor
+ */
+static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
+				       int state)
+{
+	struct qcom_smd_edge *edge = channel->edge;
+	bool is_open = state == SMD_CHANNEL_OPENED;
+
+	if (channel->state == state)
+		return;
+
+	dev_dbg(edge->smd->dev, "set_state(%s, %d)\n", channel->name, state);
+
+	SET_TX_CHANNEL_INFO(channel, fDSR, is_open);
+	SET_TX_CHANNEL_INFO(channel, fCTS, is_open);
+	SET_TX_CHANNEL_INFO(channel, fCD, is_open);
+
+	SET_TX_CHANNEL_INFO(channel, state, state);
+	SET_TX_CHANNEL_INFO(channel, fSTATE, 1);
+
+	channel->state = state;
+	qcom_smd_signal_channel(channel);
+}
+
+/*
+ * Copy count bytes of data using 32bit accesses, if that's required.
+ */
+static void smd_copy_to_fifo(void __iomem *_dst,
+			     const void *_src,
+			     size_t count,
+			     bool word_aligned)
+{
+	u32 *dst = (u32 *)_dst;
+	u32 *src = (u32 *)_src;
+
+	if (word_aligned) {
+		count /= sizeof(u32);
+		while (count--)
+			writel_relaxed(*src++, dst++);
+	} else {
+		memcpy_toio(_dst, _src, count);
+	}
+}
+
+/*
+ * Copy count bytes of data using 32bit accesses, if that is required.
+ */
+static void smd_copy_from_fifo(void *_dst,
+			       const void __iomem *_src,
+			       size_t count,
+			       bool word_aligned)
+{
+	u32 *dst = (u32 *)_dst;
+	u32 *src = (u32 *)_src;
+
+	if (word_aligned) {
+		count /= sizeof(u32);
+		while (count--)
+			*dst++ = readl_relaxed(src++);
+	} else {
+		memcpy_fromio(_dst, _src, count);
+	}
+}
+
+/*
+ * Read count bytes of data from the rx fifo into buf, but don't advance the
+ * tail.
+ */
+static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
+				    void *buf, size_t count)
+{
+	bool word_aligned;
+	unsigned tail;
+	size_t len;
+
+	word_aligned = channel->rx_info_word != NULL;
+	tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+	len = min_t(size_t, count, channel->fifo_size - tail);
+	if (len) {
+		smd_copy_from_fifo(buf,
+				   channel->rx_fifo + tail,
+				   len,
+				   word_aligned);
+	}
+
+	if (len != count) {
+		smd_copy_from_fifo(buf + len,
+				   channel->rx_fifo,
+				   count - len,
+				   word_aligned);
+	}
+
+	return count;
+}
+
+/*
+ * Advance the rx tail by count bytes.
+ */
+static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
+				     size_t count)
+{
+	unsigned tail;
+
+	tail = GET_RX_CHANNEL_INFO(channel, tail);
+	tail += count;
+	tail &= (channel->fifo_size - 1);
+	SET_RX_CHANNEL_INFO(channel, tail, tail);
+}
+
+/*
+ * Read out a single packet from the rx fifo and deliver it to the device
+ */
+static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
+{
+	struct qcom_smd_device *qsdev = channel->qsdev;
+	unsigned tail;
+	size_t len;
+	void *ptr;
+	int ret;
+
+	if (!channel->cb)
+		return 0;
+
+	tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+	/* Use bounce buffer if the data wraps */
+	if (tail + channel->pkt_size >= channel->fifo_size) {
+		ptr = channel->bounce_buffer;
+		len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
+	} else {
+		ptr = channel->rx_fifo + tail;
+		len = channel->pkt_size;
+	}
+
+	ret = channel->cb(qsdev, ptr, len);
+	if (ret < 0)
+		return ret;
+
+	/* Only forward the tail if the client consumed the data */
+	qcom_smd_channel_advance(channel, len);
+
+	channel->pkt_size = 0;
+
+	return 0;
+}
+
+/*
+ * Per channel interrupt handling
+ */
+static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
+{
+	bool need_state_scan = false;
+	int remote_state;
+	u32 pktlen;
+	int avail;
+	int ret;
+
+	/* Handle state changes */
+	remote_state = GET_RX_CHANNEL_INFO(channel, state);
+	if (remote_state != channel->remote_state) {
+		channel->remote_state = remote_state;
+		need_state_scan = true;
+	}
+	/* Indicate that we have seen any state change */
+	SET_RX_CHANNEL_INFO(channel, fSTATE, 0);
+
+	/* Signal waiting qcom_smd_send() about the interrupt */
+	if (!GET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR))
+		wake_up_interruptible(&channel->fblockread_event);
+
+	/* Don't consume any data until we've opened the channel */
+	if (channel->state != SMD_CHANNEL_OPENED)
+		goto out;
+
+	/* Indicate that we've seen the new data */
+	SET_RX_CHANNEL_INFO(channel, fHEAD, 0);
+
+	/* Consume data */
+	for (;;) {
+		avail = qcom_smd_channel_get_rx_avail(channel);
+
+		if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
+			qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
+			qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
+			channel->pkt_size = pktlen;
+		} else if (channel->pkt_size && avail >= channel->pkt_size) {
+			ret = qcom_smd_channel_recv_single(channel);
+			if (ret)
+				break;
+		} else {
+			break;
+		}
+	}
+
+	/* Indicate that we have seen and updated tail */
+	SET_RX_CHANNEL_INFO(channel, fTAIL, 1);
+
+	/* Signal the remote that we've consumed the data (if requested) */
+	if (!GET_RX_CHANNEL_INFO(channel, fBLOCKREADINTR)) {
+		/* Ensure ordering of channel info updates */
+		wmb();
+
+		qcom_smd_signal_channel(channel);
+	}
+
+out:
+	return need_state_scan;
+}
+
+/*
+ * The edge interrupts are triggered by the remote processor on state changes,
+ * channel info updates or when new channels are created.
+ */
+static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
+{
+	struct qcom_smd_edge *edge = data;
+	struct qcom_smd_channel *channel;
+	unsigned available;
+	bool kick_worker = false;
+
+	/*
+	 * Handle state changes or data on each of the channels on this edge
+	 */
+	spin_lock(&edge->channels_lock);
+	list_for_each_entry(channel, &edge->channels, list) {
+		spin_lock(&channel->recv_lock);
+		kick_worker |= qcom_smd_channel_intr(channel);
+		spin_unlock(&channel->recv_lock);
+	}
+	spin_unlock(&edge->channels_lock);
+
+	/*
+	 * Creating a new channel requires allocating an smem entry, so we only
+	 * have to scan if the amount of available space in smem have changed
+	 * since last scan.
+	 */
+	available = qcom_smem_get_free_space(edge->edge_id);
+	if (available != edge->smem_available) {
+		edge->smem_available = available;
+		edge->need_rescan = true;
+		kick_worker = true;
+	}
+
+	if (kick_worker)
+		schedule_work(&edge->work);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Delivers any outstanding packets in the rx fifo, can be used after probe of
+ * the clients to deliver any packets that wasn't delivered before the client
+ * was setup.
+ */
+static void qcom_smd_channel_resume(struct qcom_smd_channel *channel)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&channel->recv_lock, flags);
+	qcom_smd_channel_intr(channel);
+	spin_unlock_irqrestore(&channel->recv_lock, flags);
+}
+
+/*
+ * Calculate how much space is available in the tx fifo.
+ */
+static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
+{
+	unsigned head;
+	unsigned tail;
+	unsigned mask = channel->fifo_size - 1;
+
+	head = GET_TX_CHANNEL_INFO(channel, head);
+	tail = GET_TX_CHANNEL_INFO(channel, tail);
+
+	return mask - ((head - tail) & mask);
+}
+
+/*
+ * Write count bytes of data into channel, possibly wrapping in the ring buffer
+ */
+static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
+			       const void *data,
+			       size_t count)
+{
+	bool word_aligned;
+	unsigned head;
+	size_t len;
+
+	word_aligned = channel->tx_info_word != NULL;
+	head = GET_TX_CHANNEL_INFO(channel, head);
+
+	len = min_t(size_t, count, channel->fifo_size - head);
+	if (len) {
+		smd_copy_to_fifo(channel->tx_fifo + head,
+				 data,
+				 len,
+				 word_aligned);
+	}
+
+	if (len != count) {
+		smd_copy_to_fifo(channel->tx_fifo,
+				 data + len,
+				 count - len,
+				 word_aligned);
+	}
+
+	head += count;
+	head &= (channel->fifo_size - 1);
+	SET_TX_CHANNEL_INFO(channel, head, head);
+
+	return count;
+}
+
+/**
+ * qcom_smd_send - write data to smd channel
+ * @channel:	channel handle
+ * @data:	buffer of data to write
+ * @len:	number of bytes to write
+ *
+ * This is a blocking write of len bytes into the channel's tx ring buffer and
+ * signal the remote end. It will sleep until there is enough space available
+ * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
+ * polling.
+ */
+int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len)
+{
+	u32 hdr[5] = {len,};
+	int tlen = sizeof(hdr) + len;
+	int ret;
+
+	/* Word aligned channels only accept word size aligned data */
+	if (channel->rx_info_word != NULL && len % 4)
+		return -EINVAL;
+
+	ret = mutex_lock_interruptible(&channel->tx_lock);
+	if (ret)
+		return ret;
+
+	while (qcom_smd_get_tx_avail(channel) < tlen) {
+		if (channel->state != SMD_CHANNEL_OPENED) {
+			ret = -EPIPE;
+			goto out;
+		}
+
+		SET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR, 1);
+
+		ret = wait_event_interruptible(channel->fblockread_event,
+				       qcom_smd_get_tx_avail(channel) >= tlen ||
+				       channel->state != SMD_CHANNEL_OPENED);
+		if (ret)
+			goto out;
+
+		SET_TX_CHANNEL_INFO(channel, fBLOCKREADINTR, 0);
+	}
+
+	SET_TX_CHANNEL_INFO(channel, fTAIL, 0);
+
+	qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
+	qcom_smd_write_fifo(channel, data, len);
+
+	SET_TX_CHANNEL_INFO(channel, fHEAD, 1);
+
+	/* Ensure ordering of channel info updates */
+	wmb();
+
+	qcom_smd_signal_channel(channel);
+
+out:
+	mutex_unlock(&channel->tx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_smd_send);
+
+static struct qcom_smd_device *to_smd_device(struct device *dev)
+{
+	return container_of(dev, struct qcom_smd_device, dev);
+}
+
+static struct qcom_smd_driver *to_smd_driver(struct device *dev)
+{
+	struct qcom_smd_device *qsdev = to_smd_device(dev);
+
+	return container_of(qsdev->dev.driver, struct qcom_smd_driver, driver);
+}
+
+static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv)
+{
+	return of_driver_match_device(dev, drv);
+}
+
+/*
+ * Probe the smd client.
+ *
+ * The remote side have indicated that it want the channel to be opened, so
+ * complete the state handshake and probe our client driver.
+ */
+static int qcom_smd_dev_probe(struct device *dev)
+{
+	struct qcom_smd_device *qsdev = to_smd_device(dev);
+	struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
+	struct qcom_smd_channel *channel = qsdev->channel;
+	size_t bb_size;
+	int ret;
+
+	/*
+	 * Packets are maximum 4k, but reduce if the fifo is smaller
+	 */
+	bb_size = min(channel->fifo_size, SZ_4K);
+	channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
+	if (!channel->bounce_buffer)
+		return -ENOMEM;
+
+	channel->cb = qsdrv->callback;
+
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
+
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
+
+	ret = qsdrv->probe(qsdev);
+	if (ret)
+		goto err;
+
+	qcom_smd_channel_resume(channel);
+
+	return 0;
+
+err:
+	dev_err(&qsdev->dev, "probe failed\n");
+
+	channel->cb = NULL;
+	kfree(channel->bounce_buffer);
+	channel->bounce_buffer = NULL;
+
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+	return ret;
+}
+
+/*
+ * Remove the smd client.
+ *
+ * The channel is going away, for some reason, so remove the smd client and
+ * reset the channel state.
+ */
+static int qcom_smd_dev_remove(struct device *dev)
+{
+	struct qcom_smd_device *qsdev = to_smd_device(dev);
+	struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
+	struct qcom_smd_channel *channel = qsdev->channel;
+	unsigned long flags;
+
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);
+
+	/*
+	 * Make sure we don't race with the code receiving data.
+	 */
+	spin_lock_irqsave(&channel->recv_lock, flags);
+	channel->cb = NULL;
+	spin_unlock_irqrestore(&channel->recv_lock, flags);
+
+	/* Wake up any sleepers in qcom_smd_send() */
+	wake_up_interruptible(&channel->fblockread_event);
+
+	/*
+	 * We expect that the client might block in remove() waiting for any
+	 * outstanding calls to qcom_smd_send() to wake up and finish.
+	 */
+	if (qsdrv->remove)
+		qsdrv->remove(qsdev);
+
+	/*
+	 * The client is now gone, cleanup and reset the channel state.
+	 */
+	channel->qsdev = NULL;
+	kfree(channel->bounce_buffer);
+	channel->bounce_buffer = NULL;
+
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+
+	qcom_smd_channel_reset(channel);
+
+	return 0;
+}
+
+static struct bus_type qcom_smd_bus = {
+	.name = "qcom_smd",
+	.match = qcom_smd_dev_match,
+	.probe = qcom_smd_dev_probe,
+	.remove = qcom_smd_dev_remove,
+};
+
+/*
+ * Release function for the qcom_smd_device object.
+ */
+static void qcom_smd_release_device(struct device *dev)
+{
+	struct qcom_smd_device *qsdev = to_smd_device(dev);
+
+	kfree(qsdev);
+}
+
+/*
+ * Finds the device_node for the smd child interested in this channel.
+ */
+static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
+						  const char *channel)
+{
+	struct device_node *child;
+	const char *name;
+	const char *key;
+	int ret;
+
+	for_each_available_child_of_node(edge_node, child) {
+		key = "qcom,smd-channels";
+		ret = of_property_read_string(child, key, &name);
+		if (ret) {
+			of_node_put(child);
+			continue;
+		}
+
+		if (strcmp(name, channel) == 0)
+			return child;
+	}
+
+	return NULL;
+}
+
+/*
+ * Create a smd client device for channel that is being opened.
+ */
+static int qcom_smd_create_device(struct qcom_smd_channel *channel)
+{
+	struct qcom_smd_device *qsdev;
+	struct qcom_smd_edge *edge = channel->edge;
+	struct device_node *node;
+	struct qcom_smd *smd = edge->smd;
+	int ret;
+
+	if (channel->qsdev)
+		return -EEXIST;
+
+	node = qcom_smd_match_channel(edge->of_node, channel->name);
+	if (!node) {
+		dev_dbg(smd->dev, "no match for '%s'\n", channel->name);
+		return -ENXIO;
+	}
+
+	dev_dbg(smd->dev, "registering '%s'\n", channel->name);
+
+	qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
+	if (!qsdev)
+		return -ENOMEM;
+
+	dev_set_name(&qsdev->dev, "%s.%s", edge->of_node->name, node->name);
+	qsdev->dev.parent = smd->dev;
+	qsdev->dev.bus = &qcom_smd_bus;
+	qsdev->dev.release = qcom_smd_release_device;
+	qsdev->dev.of_node = node;
+
+	qsdev->channel = channel;
+
+	channel->qsdev = qsdev;
+
+	ret = device_register(&qsdev->dev);
+	if (ret) {
+		dev_err(smd->dev, "device_register failed: %d\n", ret);
+		put_device(&qsdev->dev);
+	}
+
+	return ret;
+}
+
+/*
+ * Destroy a smd client device for a channel that's going away.
+ */
+static void qcom_smd_destroy_device(struct qcom_smd_channel *channel)
+{
+	struct device *dev;
+
+	BUG_ON(!channel->qsdev);
+
+	dev = &channel->qsdev->dev;
+
+	device_unregister(dev);
+	of_node_put(dev->of_node);
+	put_device(dev);
+}
+
+/**
+ * qcom_smd_driver_register - register a smd driver
+ * @qsdrv:	qcom_smd_driver struct
+ */
+int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv)
+{
+	qsdrv->driver.bus = &qcom_smd_bus;
+	return driver_register(&qsdrv->driver);
+}
+EXPORT_SYMBOL(qcom_smd_driver_register);
+
+/**
+ * qcom_smd_driver_unregister - unregister a smd driver
+ * @qsdrv:	qcom_smd_driver struct
+ */
+void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv)
+{
+	driver_unregister(&qsdrv->driver);
+}
+EXPORT_SYMBOL(qcom_smd_driver_unregister);
+
+/*
+ * Allocate the qcom_smd_channel object for a newly found smd channel,
+ * retrieving and validating the smem items involved.
+ */
+static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
+							unsigned smem_info_item,
+							unsigned smem_fifo_item,
+							char *name)
+{
+	struct qcom_smd_channel *channel;
+	struct qcom_smd *smd = edge->smd;
+	size_t fifo_size;
+	size_t info_size;
+	void *fifo_base;
+	void *info;
+	int ret;
+
+	channel = devm_kzalloc(smd->dev, sizeof(*channel), GFP_KERNEL);
+	if (!channel)
+		return ERR_PTR(-ENOMEM);
+
+	channel->edge = edge;
+	channel->name = devm_kstrdup(smd->dev, name, GFP_KERNEL);
+	if (!channel->name)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&channel->tx_lock);
+	spin_lock_init(&channel->recv_lock);
+	init_waitqueue_head(&channel->fblockread_event);
+
+	ret = qcom_smem_get(edge->edge_id, smem_info_item, (void **)&info, &info_size);
+	if (ret)
+		goto free_name_and_channel;
+
+	/*
+	 * Use the size of the item to figure out which channel info struct to
+	 * use.
+	 */
+	if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
+		channel->tx_info_word = info;
+		channel->rx_info_word = info + sizeof(struct smd_channel_info_word);
+	} else if (info_size == 2 * sizeof(struct smd_channel_info)) {
+		channel->tx_info = info;
+		channel->rx_info = info + sizeof(struct smd_channel_info);
+	} else {
+		dev_err(smd->dev,
+			"channel info of size %zu not supported\n", info_size);
+		ret = -EINVAL;
+		goto free_name_and_channel;
+	}
+
+	ret = qcom_smem_get(edge->edge_id, smem_fifo_item, &fifo_base, &fifo_size);
+	if (ret)
+		goto free_name_and_channel;
+
+	/* The channel consist of a rx and tx fifo of equal size */
+	fifo_size /= 2;
+
+	dev_dbg(smd->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
+			  name, info_size, fifo_size);
+
+	channel->tx_fifo = fifo_base;
+	channel->rx_fifo = fifo_base + fifo_size;
+	channel->fifo_size = fifo_size;
+
+	qcom_smd_channel_reset(channel);
+
+	return channel;
+
+free_name_and_channel:
+	devm_kfree(smd->dev, channel->name);
+	devm_kfree(smd->dev, channel);
+
+	return ERR_PTR(ret);
+}
+
+/*
+ * Scans the allocation table for any newly allocated channels, calls
+ * qcom_smd_create_channel() to create representations of these and add
+ * them to the edge's list of channels.
+ */
+static void qcom_discover_channels(struct qcom_smd_edge *edge)
+{
+	struct qcom_smd_alloc_entry *alloc_tbl;
+	struct qcom_smd_alloc_entry *entry;
+	struct qcom_smd_channel *channel;
+	struct qcom_smd *smd = edge->smd;
+	unsigned long flags;
+	unsigned fifo_id;
+	unsigned info_id;
+	int ret;
+	int tbl;
+	int i;
+
+	for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
+		ret = qcom_smem_get(edge->edge_id,
+				    smem_items[tbl].alloc_tbl_id,
+				    (void **)&alloc_tbl,
+				    NULL);
+		if (ret < 0)
+			continue;
+
+		for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
+			entry = &alloc_tbl[i];
+			if (test_bit(i, edge->allocated[tbl]))
+				continue;
+
+			if (entry->ref_count == 0)
+				continue;
+
+			if (!entry->name[0])
+				continue;
+
+			if (!(entry->flags & SMD_CHANNEL_FLAGS_PACKET))
+				continue;
+
+			if ((entry->flags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
+				continue;
+
+			info_id = smem_items[tbl].info_base_id + entry->cid;
+			fifo_id = smem_items[tbl].fifo_base_id + entry->cid;
+
+			channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
+			if (IS_ERR(channel))
+				continue;
+
+			spin_lock_irqsave(&edge->channels_lock, flags);
+			list_add(&channel->list, &edge->channels);
+			spin_unlock_irqrestore(&edge->channels_lock, flags);
+
+			dev_dbg(smd->dev, "new channel found: '%s'\n", channel->name);
+			set_bit(i, edge->allocated[tbl]);
+		}
+	}
+
+	schedule_work(&edge->work);
+}
+
+/*
+ * This per edge worker scans smem for any new channels and register these. It
+ * then scans all registered channels for state changes that should be handled
+ * by creating or destroying smd client devices for the registered channels.
+ *
+ * LOCKING: edge->channels_lock is not needed to be held during the traversal
+ * of the channels list as it's done synchronously with the only writer.
+ */
+static void qcom_channel_state_worker(struct work_struct *work)
+{
+	struct qcom_smd_channel *channel;
+	struct qcom_smd_edge *edge = container_of(work,
+						  struct qcom_smd_edge,
+						  work);
+	unsigned remote_state;
+
+	/*
+	 * Rescan smem if we have reason to belive that there are new channels.
+	 */
+	if (edge->need_rescan) {
+		edge->need_rescan = false;
+		qcom_discover_channels(edge);
+	}
+
+	/*
+	 * Register a device for any closed channel where the remote processor
+	 * is showing interest in opening the channel.
+	 */
+	list_for_each_entry(channel, &edge->channels, list) {
+		if (channel->state != SMD_CHANNEL_CLOSED)
+			continue;
+
+		remote_state = GET_RX_CHANNEL_INFO(channel, state);
+		if (remote_state != SMD_CHANNEL_OPENING &&
+		    remote_state != SMD_CHANNEL_OPENED)
+			continue;
+
+		qcom_smd_create_device(channel);
+	}
+
+	/*
+	 * Unregister the device for any channel that is opened where the
+	 * remote processor is closing the channel.
+	 */
+	list_for_each_entry(channel, &edge->channels, list) {
+		if (channel->state != SMD_CHANNEL_OPENING &&
+		    channel->state != SMD_CHANNEL_OPENED)
+			continue;
+
+		remote_state = GET_RX_CHANNEL_INFO(channel, state);
+		if (remote_state == SMD_CHANNEL_OPENING ||
+		    remote_state == SMD_CHANNEL_OPENED)
+			continue;
+
+		qcom_smd_destroy_device(channel);
+	}
+}
+
+/*
+ * Parses an of_node describing an edge.
+ */
+static int qcom_smd_parse_edge(struct device *dev,
+			       struct device_node *node,
+			       struct qcom_smd_edge *edge)
+{
+	struct device_node *syscon_np;
+	const char *key;
+	int irq;
+	int ret;
+
+	INIT_LIST_HEAD(&edge->channels);
+	spin_lock_init(&edge->channels_lock);
+
+	INIT_WORK(&edge->work, qcom_channel_state_worker);
+
+	edge->of_node = of_node_get(node);
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (irq < 0) {
+		dev_err(dev, "required smd interrupt missing\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(dev, irq,
+			       qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
+			       node->name, edge);
+	if (ret) {
+		dev_err(dev, "failed to request smd irq\n");
+		return ret;
+	}
+
+	edge->irq = irq;
+
+	key = "qcom,smd-edge";
+	ret = of_property_read_u32(node, key, &edge->edge_id);
+	if (ret) {
+		dev_err(dev, "edge missing %s property\n", key);
+		return -EINVAL;
+	}
+
+	syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
+	if (!syscon_np) {
+		dev_err(dev, "no qcom,ipc node\n");
+		return -ENODEV;
+	}
+
+	edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
+	if (IS_ERR(edge->ipc_regmap))
+		return PTR_ERR(edge->ipc_regmap);
+
+	key = "qcom,ipc";
+	ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
+	if (ret < 0) {
+		dev_err(dev, "no offset in %s\n", key);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
+	if (ret < 0) {
+		dev_err(dev, "no bit in %s\n", key);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int qcom_smd_probe(struct platform_device *pdev)
+{
+	struct qcom_smd_edge *edge;
+	struct device_node *node;
+	struct qcom_smd *smd;
+	size_t array_size;
+	int num_edges;
+	int ret;
+	int i = 0;
+
+	/* Wait for smem */
+	ret = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL, NULL);
+	if (ret == -EPROBE_DEFER)
+		return ret;
+
+	num_edges = of_get_available_child_count(pdev->dev.of_node);
+	array_size = sizeof(*smd) + num_edges * sizeof(struct qcom_smd_edge);
+	smd = devm_kzalloc(&pdev->dev, array_size, GFP_KERNEL);
+	if (!smd)
+		return -ENOMEM;
+	smd->dev = &pdev->dev;
+
+	smd->num_edges = num_edges;
+	for_each_available_child_of_node(pdev->dev.of_node, node) {
+		edge = &smd->edges[i++];
+		edge->smd = smd;
+
+		ret = qcom_smd_parse_edge(&pdev->dev, node, edge);
+		if (ret)
+			continue;
+
+		edge->need_rescan = true;
+		schedule_work(&edge->work);
+	}
+
+	platform_set_drvdata(pdev, smd);
+
+	return 0;
+}
+
+/*
+ * Shut down all smd clients by making sure that each edge stops processing
+ * events and scanning for new channels, then call destroy on the devices.
+ */
+static int qcom_smd_remove(struct platform_device *pdev)
+{
+	struct qcom_smd_channel *channel;
+	struct qcom_smd_edge *edge;
+	struct qcom_smd *smd = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < smd->num_edges; i++) {
+		edge = &smd->edges[i];
+
+		disable_irq(edge->irq);
+		cancel_work_sync(&edge->work);
+
+		list_for_each_entry(channel, &edge->channels, list) {
+			if (!channel->qsdev)
+				continue;
+
+			qcom_smd_destroy_device(channel);
+		}
+	}
+
+	return 0;
+}
+
+static const struct of_device_id qcom_smd_of_match[] = {
+	{ .compatible = "qcom,smd" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
+
+static struct platform_driver qcom_smd_driver = {
+	.probe = qcom_smd_probe,
+	.remove = qcom_smd_remove,
+	.driver = {
+		.name = "qcom-smd",
+		.of_match_table = qcom_smd_of_match,
+	},
+};
+
+static int __init qcom_smd_init(void)
+{
+	int ret;
+
+	ret = bus_register(&qcom_smd_bus);
+	if (ret) {
+		pr_err("failed to register smd bus: %d\n", ret);
+		return ret;
+	}
+
+	return platform_driver_register(&qcom_smd_driver);
+}
+postcore_initcall(qcom_smd_init);
+
+static void __exit qcom_smd_exit(void)
+{
+	platform_driver_unregister(&qcom_smd_driver);
+	bus_unregister(&qcom_smd_bus);
+}
+module_exit(qcom_smd_exit);
+
+MODULE_AUTHOR("Bjorn Andersson <[e-mail]>");
+MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
+MODULE_LICENSE("GPL v2");

drivers/soc/qcom/smem.c

···
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smem.h>
+
+/*
+ * The Qualcomm shared memory system is a allocate only heap structure that
+ * consists of one of more memory areas that can be accessed by the processors
+ * in the SoC.
+ *
+ * All systems contains a global heap, accessible by all processors in the SoC,
+ * with a table of contents data structure (@smem_header) at the beginning of
+ * the main shared memory block.
+ *
+ * The global header contains meta data for allocations as well as a fixed list
+ * of 512 entries (@smem_global_entry) that can be initialized to reference
+ * parts of the shared memory space.
+ *
+ *
+ * In addition to this global heap a set of "private" heaps can be set up at
+ * boot time with access restrictions so that only certain processor pairs can
+ * access the data.
+ *
+ * These partitions are referenced from an optional partition table
+ * (@smem_ptable), that is found 4kB from the end of the main smem region. The
+ * partition table entries (@smem_ptable_entry) lists the involved processors
+ * (or hosts) and their location in the main shared memory region.
+ *
+ * Each partition starts with a header (@smem_partition_header) that identifies
+ * the partition and holds properties for the two internal memory regions. The
+ * two regions are cached and non-cached memory respectively. Each region
+ * contain a link list of allocation headers (@smem_private_entry) followed by
+ * their data.
+ *
+ * Items in the non-cached region are allocated from the start of the partition
+ * while items in the cached region are allocated from the end. The free area
+ * is hence the region between the cached and non-cached offsets.
+ *
+ *
+ * To synchronize allocations in the shared memory heaps a remote spinlock must
+ * be held - currently lock number 3 of the sfpb or tcsr is used for this on all
+ * platforms.
+ *
+ */
+
+/*
+ * Item 3 of the global heap contains an array of versions for the various
+ * software components in the SoC. We verify that the boot loader version is
+ * what the expected version (SMEM_EXPECTED_VERSION) as a sanity check.
+ */
+#define SMEM_ITEM_VERSION	3
+#define  SMEM_MASTER_SBL_VERSION_INDEX	7
+#define  SMEM_EXPECTED_VERSION		11
+
+/*
+ * The first 8 items are only to be allocated by the boot loader while
+ * initializing the heap.
+ */
+#define SMEM_ITEM_LAST_FIXED	8
+
+/* Highest accepted item number, for both global and private heaps */
+#define SMEM_ITEM_COUNT		512
+
+/* Processor/host identifier for the application processor */
+#define SMEM_HOST_APPS		0
+
+/* Max number of processors/hosts in a system */
+#define SMEM_HOST_COUNT		9
+
+/**
+  * struct smem_proc_comm - proc_comm communication struct (legacy)
+  * @command:	current command to be executed
+  * @status:	status of the currently requested command
+  * @params:	parameters to the command
+  */
+struct smem_proc_comm {
+	u32 command;
+	u32 status;
+	u32 params[2];
+};
+
+/**
+ * struct smem_global_entry - entry to reference smem items on the heap
+ * @allocated:	boolean to indicate if this entry is used
+ * @offset:	offset to the allocated space
+ * @size:	size of the allocated space, 8 byte aligned
+ * @aux_base:	base address for the memory region used by this unit, or 0 for
+ *		the default region. bits 0,1 are reserved
+ */
+struct smem_global_entry {
+	u32 allocated;
+	u32 offset;
+	u32 size;
+	u32 aux_base; /* bits 1:0 reserved */
+};
+#define AUX_BASE_MASK		0xfffffffc
+
+/**
+ * struct smem_header - header found in beginning of primary smem region
+ * @proc_comm:		proc_comm communication interface (legacy)
+ * @version:		array of versions for the various subsystems
+ * @initialized:	boolean to indicate that smem is initialized
+ * @free_offset:	index of the first unallocated byte in smem
+ * @available:		number of bytes available for allocation
+ * @reserved:		reserved field, must be 0
+ * toc:			array of references to items
+ */
+struct smem_header {
+	struct smem_proc_comm proc_comm[4];
+	u32 version[32];
+	u32 initialized;
+	u32 free_offset;
+	u32 available;
+	u32 reserved;
+	struct smem_global_entry toc[SMEM_ITEM_COUNT];
+};
+
+/**
+ * struct smem_ptable_entry - one entry in the @smem_ptable list
+ * @offset:	offset, within the main shared memory region, of the partition
+ * @size:	size of the partition
+ * @flags:	flags for the partition (currently unused)
+ * @host0:	first processor/host with access to this partition
+ * @host1:	second processor/host with access to this partition
+ * @reserved:	reserved entries for later use
+ */
+struct smem_ptable_entry {
+	u32 offset;
+	u32 size;
+	u32 flags;
+	u16 host0;
+	u16 host1;
+	u32 reserved[8];
+};
+
+/**
+ * struct smem_ptable - partition table for the private partitions
+ * @magic:	magic number, must be SMEM_PTABLE_MAGIC
+ * @version:	version of the partition table
+ * @num_entries: number of partitions in the table
+ * @reserved:	for now reserved entries
+ * @entry:	list of @smem_ptable_entry for the @num_entries partitions
+ */
+struct smem_ptable {
+	u32 magic;
+	u32 version;
+	u32 num_entries;
+	u32 reserved[5];
+	struct smem_ptable_entry entry[];
+};
+#define SMEM_PTABLE_MAGIC	0x434f5424 /* "$TOC" */
+
+/**
+ * struct smem_partition_header - header of the partitions
+ * @magic:	magic number, must be SMEM_PART_MAGIC
+ * @host0:	first processor/host with access to this partition
+ * @host1:	second processor/host with access to this partition
+ * @size:	size of the partition
+ * @offset_free_uncached: offset to the first free byte of uncached memory in
+ *		this partition
+ * @offset_free_cached: offset to the first free byte of cached memory in this
+ *		partition
+ * @reserved:	for now reserved entries
+ */
+struct smem_partition_header {
+	u32 magic;
+	u16 host0;
+	u16 host1;
+	u32 size;
+	u32 offset_free_uncached;
+	u32 offset_free_cached;
+	u32 reserved[3];
+};
+#define SMEM_PART_MAGIC		0x54525024 /* "$PRT" */
+
+/**
+ * struct smem_private_entry - header of each item in the private partition
+ * @canary:	magic number, must be SMEM_PRIVATE_CANARY
+ * @item:	identifying number of the smem item
+ * @size:	size of the data, including padding bytes
+ * @padding_data: number of bytes of padding of data
+ * @padding_hdr: number of bytes of padding between the header and the data
+ * @reserved:	for now reserved entry
+ */
+struct smem_private_entry {
+	u16 canary;
+	u16 item;
+	u32 size; /* includes padding bytes */
+	u16 padding_data;
+	u16 padding_hdr;
+	u32 reserved;
+};
+#define SMEM_PRIVATE_CANARY	0xa5a5
+
+/**
+ * struct smem_region - representation of a chunk of memory used for smem
+ * @aux_base:	identifier of aux_mem base
+ * @virt_base:	virtual base address of memory with this aux_mem identifier
+ * @size:	size of the memory region
+ */
+struct smem_region {
+	u32 aux_base;
+	void __iomem *virt_base;
+	size_t size;
+};
+
+/**
+ * struct qcom_smem - device data for the smem device
+ * @dev:	device pointer
+ * @hwlock:	reference to a hwspinlock
+ * @partitions:	list of pointers to partitions affecting the current
+ *		processor/host
+ * @num_regions: number of @regions
+ * @regions:	list of the memory regions defining the shared memory
+ */
+struct qcom_smem {
+	struct device *dev;
+
+	struct hwspinlock *hwlock;
+
+	struct smem_partition_header *partitions[SMEM_HOST_COUNT];
+
+	unsigned num_regions;
+	struct smem_region regions[0];
+};
+
+/* Pointer to the one and only smem handle */
+static struct qcom_smem *__smem;
+
+/* Timeout (ms) for the trylock of remote spinlocks */
+#define HWSPINLOCK_TIMEOUT	1000
+
+static int qcom_smem_alloc_private(struct qcom_smem *smem,
+				   unsigned host,
+				   unsigned item,
+				   size_t size)
+{
+	struct smem_partition_header *phdr;
+	struct smem_private_entry *hdr;
+	size_t alloc_size;
+	void *p;
+
+	/* We're not going to find it if there's no matching partition */
+	if (host >= SMEM_HOST_COUNT || !smem->partitions[host])
+		return -ENOENT;
+
+	phdr = smem->partitions[host];
+
+	p = (void *)phdr + sizeof(*phdr);
+	while (p < (void *)phdr + phdr->offset_free_uncached) {
+		hdr = p;
+
+		if (hdr->canary != SMEM_PRIVATE_CANARY) {
+			dev_err(smem->dev,
+				"Found invalid canary in host %d partition\n",
+				host);
+			return -EINVAL;
+		}
+
+		if (hdr->item == item)
+			return -EEXIST;
+
+		p += sizeof(*hdr) + hdr->padding_hdr + hdr->size;
+	}
+
+	/* Check that we don't grow into the cached region */
+	alloc_size = sizeof(*hdr) + ALIGN(size, 8);
+	if (p + alloc_size >= (void *)phdr + phdr->offset_free_cached) {
+		dev_err(smem->dev, "Out of memory\n");
+		return -ENOSPC;
+	}
+
+	hdr = p;
+	hdr->canary = SMEM_PRIVATE_CANARY;
+	hdr->item = item;
+	hdr->size = ALIGN(size, 8);
+	hdr->padding_data = hdr->size - size;
+	hdr->padding_hdr = 0;
+
+	/*
+	 * Ensure the header is written before we advance the free offset, so
+	 * that remote processors that does not take the remote spinlock still
+	 * gets a consistent view of the linked list.
+	 */
+	wmb();
+	phdr->offset_free_uncached += alloc_size;
+
+	return 0;
+}
+
+static int qcom_smem_alloc_global(struct qcom_smem *smem,
+				  unsigned item,
+				  size_t size)
+{
+	struct smem_header *header;
+	struct smem_global_entry *entry;
+
+	if (WARN_ON(item >= SMEM_ITEM_COUNT))
+		return -EINVAL;
+
+	header = smem->regions[0].virt_base;
+	entry = &header->toc[item];
+	if (entry->allocated)
+		return -EEXIST;
+
+	size = ALIGN(size, 8);
+	if (WARN_ON(size > header->available))
+		return -ENOMEM;
+
+	entry->offset = header->free_offset;
+	entry->size = size;
+
+	/*
+	 * Ensure the header is consistent before we mark the item allocated,
+	 * so that remote processors will get a consistent view of the item
+	 * even though they do not take the spinlock on read.
+	 */
+	wmb();
+	entry->allocated = 1;
+
+	header->free_offset += size;
+	header->available -= size;
+
+	return 0;
+}
+
+/**
+ * qcom_smem_alloc() - allocate space for a smem item
+ * @host:	remote processor id, or -1
+ * @item:	smem item handle
+ * @size:	number of bytes to be allocated
+ *
+ * Allocate space for a given smem item of size @size, given that the item is
+ * not yet allocated.
+ */
+int qcom_smem_alloc(unsigned host, unsigned item, size_t size)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!__smem)
+		return -EPROBE_DEFER;
+
+	if (item < SMEM_ITEM_LAST_FIXED) {
+		dev_err(__smem->dev,
+			"Rejecting allocation of static entry %d\n", item);
+		return -EINVAL;
+	}
+
+	ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
+					  HWSPINLOCK_TIMEOUT,
+					  &flags);
+	if (ret)
+		return ret;
+
+	ret = qcom_smem_alloc_private(__smem, host, item, size);
+	if (ret == -ENOENT)
+		ret = qcom_smem_alloc_global(__smem, item, size);
+
+	hwspin_unlock_irqrestore(__smem->hwlock, &flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_smem_alloc);
+
+static int qcom_smem_get_global(struct qcom_smem *smem,
+				unsigned item,
+				void **ptr,
+				size_t *size)
+{
+	struct smem_header *header;
+	struct smem_region *area;
+	struct smem_global_entry *entry;
+	u32 aux_base;
+	unsigned i;
+
+	if (WARN_ON(item >= SMEM_ITEM_COUNT))
+		return -EINVAL;
+
+	header = smem->regions[0].virt_base;
+	entry = &header->toc[item];
+	if (!entry->allocated)
+		return -ENXIO;
+
+	if (ptr != NULL) {
+		aux_base = entry->aux_base & AUX_BASE_MASK;
+
+		for (i = 0; i < smem->num_regions; i++) {
+			area = &smem->regions[i];
+
+			if (area->aux_base == aux_base || !aux_base) {
+				*ptr = area->virt_base + entry->offset;
+				break;
+			}
+		}
+	}
+	if (size != NULL)
+		*size = entry->size;
+
+	return 0;
+}
+
+static int qcom_smem_get_private(struct qcom_smem *smem,
+				 unsigned host,
+				 unsigned item,
+				 void **ptr,
+				 size_t *size)
+{
+	struct smem_partition_header *phdr;
+	struct smem_private_entry *hdr;
+	void *p;
+
+	/* We're not going to find it if there's no matching partition */
+	if (host >= SMEM_HOST_COUNT || !smem->partitions[host])
+		return -ENOENT;
+
+	phdr = smem->partitions[host];
+
+	p = (void *)phdr + sizeof(*phdr);
+	while (p < (void *)phdr + phdr->offset_free_uncached) {
+		hdr = p;
+
+		if (hdr->canary != SMEM_PRIVATE_CANARY) {
+			dev_err(smem->dev,
+				"Found invalid canary in host %d partition\n",
+				host);
+			return -EINVAL;
+		}
+
+		if (hdr->item == item) {
+			if (ptr != NULL)
+				*ptr = p + sizeof(*hdr) + hdr->padding_hdr;
+
+			if (size != NULL)
+				*size = hdr->size - hdr->padding_data;
+
+			return 0;
+		}
+
+		p += sizeof(*hdr) + hdr->padding_hdr + hdr->size;
+	}
+
+	return -ENOENT;
+}
+
+/**
+ * qcom_smem_get() - resolve ptr of size of a smem item
+ * @host:	the remote processor, or -1
+ * @item:	smem item handle
+ * @ptr:	pointer to be filled out with address of the item
+ * @size:	pointer to be filled out with size of the item
+ *
+ * Looks up pointer and size of a smem item.
+ */
+int qcom_smem_get(unsigned host, unsigned item, void **ptr, size_t *size)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!__smem)
+		return -EPROBE_DEFER;
+
+	ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
+					  HWSPINLOCK_TIMEOUT,
+					  &flags);
+	if (ret)
+		return ret;
+
+	ret = qcom_smem_get_private(__smem, host, item, ptr, size);
+	if (ret == -ENOENT)
+		ret = qcom_smem_get_global(__smem, item, ptr, size);
+
+	hwspin_unlock_irqrestore(__smem->hwlock, &flags);
+	return ret;
+
+}
+EXPORT_SYMBOL(qcom_smem_get);
+
+/**
+ * qcom_smem_get_free_space() - retrieve amount of free space in a partition
+ * @host:	the remote processor identifying a partition, or -1
+ *
+ * To be used by smem clients as a quick way to determine if any new
+ * allocations has been made.
+ */
+int qcom_smem_get_free_space(unsigned host)
+{
+	struct smem_partition_header *phdr;
+	struct smem_header *header;
+	unsigned ret;
+
+	if (!__smem)
+		return -EPROBE_DEFER;
+
+	if (host < SMEM_HOST_COUNT && __smem->partitions[host]) {
+		phdr = __smem->partitions[host];
+		ret = phdr->offset_free_cached - phdr->offset_free_uncached;
+	} else {
+		header = __smem->regions[0].virt_base;
+		ret = header->available;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_smem_get_free_space);
+
+static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
+{
+	unsigned *versions;
+	size_t size;
+	int ret;
+
+	ret = qcom_smem_get_global(smem, SMEM_ITEM_VERSION,
+				   (void **)&versions, &size);
+	if (ret < 0) {
+		dev_err(smem->dev, "Unable to read the version item\n");
+		return -ENOENT;
+	}
+
+	if (size < sizeof(unsigned) * SMEM_MASTER_SBL_VERSION_INDEX) {
+		dev_err(smem->dev, "Version item is too small\n");
+		return -EINVAL;
+	}
+
+	return versions[SMEM_MASTER_SBL_VERSION_INDEX];
+}
+
+static int qcom_smem_enumerate_partitions(struct qcom_smem *smem,
+					  unsigned local_host)
+{
+	struct smem_partition_header *header;
+	struct smem_ptable_entry *entry;
+	struct smem_ptable *ptable;
+	unsigned remote_host;
+	int i;
+
+	ptable = smem->regions[0].virt_base + smem->regions[0].size - SZ_4K;
+	if (ptable->magic != SMEM_PTABLE_MAGIC)
+		return 0;
+
+	if (ptable->version != 1) {
+		dev_err(smem->dev,
+			"Unsupported partition header version %d\n",
+			ptable->version);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < ptable->num_entries; i++) {
+		entry = &ptable->entry[i];
+
+		if (entry->host0 != local_host && entry->host1 != local_host)
+			continue;
+
+		if (!entry->offset)
+			continue;
+
+		if (!entry->size)
+			continue;
+
+		if (entry->host0 == local_host)
+			remote_host = entry->host1;
+		else
+			remote_host = entry->host0;
+
+		if (remote_host >= SMEM_HOST_COUNT) {
+			dev_err(smem->dev,
+				"Invalid remote host %d\n",
+				remote_host);
+			return -EINVAL;
+		}
+
+		if (smem->partitions[remote_host]) {
+			dev_err(smem->dev,
+				"Already found a partition for host %d\n",
+				remote_host);
+			return -EINVAL;
+		}
+
+		header = smem->regions[0].virt_base + entry->offset;
+
+		if (header->magic != SMEM_PART_MAGIC) {
+			dev_err(smem->dev,
+				"Partition %d has invalid magic\n", i);
+			return -EINVAL;
+		}
+
+		if (header->host0 != local_host && header->host1 != local_host) {
+			dev_err(smem->dev,
+				"Partition %d hosts are invalid\n", i);
+			return -EINVAL;
+		}
+
+		if (header->host0 != remote_host && header->host1 != remote_host) {
+			dev_err(smem->dev,
+				"Partition %d hosts are invalid\n", i);
+			return -EINVAL;
+		}
+
+		if (header->size != entry->size) {
+			dev_err(smem->dev,
+				"Partition %d has invalid size\n", i);
+			return -EINVAL;
+		}
+
+		if (header->offset_free_uncached > header->size) {
+			dev_err(smem->dev,
+				"Partition %d has invalid free pointer\n", i);
+			return -EINVAL;
+		}
+
+		smem->partitions[remote_host] = header;
+	}
+
+	return 0;
+}
+
+static int qcom_smem_count_mem_regions(struct platform_device *pdev)
+{
+	struct resource *res;
+	int num_regions = 0;
+	int i;
+
+	for (i = 0; i < pdev->num_resources; i++) {
+		res = &pdev->resource[i];
+
+		if (resource_type(res) == IORESOURCE_MEM)
+			num_regions++;
+	}
+
+	return num_regions;
+}
+
+static int qcom_smem_probe(struct platform_device *pdev)
+{
+	struct smem_header *header;
+	struct device_node *np;
+	struct qcom_smem *smem;
+	struct resource *res;
+	struct resource r;
+	size_t array_size;
+	int num_regions = 0;
+	int hwlock_id;
+	u32 version;
+	int ret;
+	int i;
+
+	num_regions = qcom_smem_count_mem_regions(pdev) + 1;
+
+	array_size = num_regions * sizeof(struct smem_region);
+	smem = devm_kzalloc(&pdev->dev, sizeof(*smem) + array_size, GFP_KERNEL);
+	if (!smem)
+		return -ENOMEM;
+
+	smem->dev = &pdev->dev;
+	smem->num_regions = num_regions;
+
+	np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
+	if (!np) {
+		dev_err(&pdev->dev, "No memory-region specified\n");
+		return -EINVAL;
+	}
+
+	ret = of_address_to_resource(np, 0, &r);
+	of_node_put(np);
+	if (ret)
+		return ret;
+
+	smem->regions[0].aux_base = (u32)r.start;
+	smem->regions[0].size = resource_size(&r);
+	smem->regions[0].virt_base = devm_ioremap_nocache(&pdev->dev,
+							  r.start,
+							  resource_size(&r));
+	if (!smem->regions[0].virt_base)
+		return -ENOMEM;
+
+	for (i = 1; i < num_regions; i++) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, i - 1);
+
+		smem->regions[i].aux_base = (u32)res->start;
+		smem->regions[i].size = resource_size(res);
+		smem->regions[i].virt_base = devm_ioremap_nocache(&pdev->dev,
+								  res->start,
+								  resource_size(res));
+		if (!smem->regions[i].virt_base)
+			return -ENOMEM;
+	}
+
+	header = smem->regions[0].virt_base;
+	if (header->initialized != 1 || header->reserved) {
+		dev_err(&pdev->dev, "SMEM is not initialized by SBL\n");
+		return -EINVAL;
+	}
+
+	version = qcom_smem_get_sbl_version(smem);
+	if (version >> 16 != SMEM_EXPECTED_VERSION) {
+		dev_err(&pdev->dev, "Unsupported SMEM version 0x%x\n", version);
+		return -EINVAL;
+	}
+
+	ret = qcom_smem_enumerate_partitions(smem, SMEM_HOST_APPS);
+	if (ret < 0)
+		return ret;
+
+	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);
+	if (hwlock_id < 0) {
+		dev_err(&pdev->dev, "failed to retrieve hwlock\n");
+		return hwlock_id;
+	}
+
+	smem->hwlock = hwspin_lock_request_specific(hwlock_id);
+	if (!smem->hwlock)
+		return -ENXIO;
+
+	__smem = smem;
+
+	return 0;
+}
+
+static int qcom_smem_remove(struct platform_device *pdev)
+{
+	__smem = NULL;
+	hwspin_lock_free(__smem->hwlock);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_smem_of_match[] = {
+	{ .compatible = "qcom,smem" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_smem_of_match);
+
+static struct platform_driver qcom_smem_driver = {
+	.probe = qcom_smem_probe,
+	.remove = qcom_smem_remove,
+	.driver  = {
+		.name = "qcom-smem",
+		.of_match_table = qcom_smem_of_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init qcom_smem_init(void)
+{
+	return platform_driver_register(&qcom_smem_driver);
+}
+arch_initcall(qcom_smem_init);
+
+static void __exit qcom_smem_exit(void)
+{
+	platform_driver_unregister(&qcom_smem_driver);
+}
+module_exit(qcom_smem_exit)
+
+MODULE_AUTHOR("Bjorn Andersson <[e-mail]>");
+MODULE_DESCRIPTION("Qualcomm Shared Memory Manager");
+MODULE_LICENSE("GPL v2");

include/linux/soc/qcom/smd-rpm.h

···
+#ifndef __QCOM_SMD_RPM_H__
+#define __QCOM_SMD_RPM_H__
+
+struct qcom_smd_rpm;
+
+#define QCOM_SMD_RPM_ACTIVE_STATE        0
+#define QCOM_SMD_RPM_SLEEP_STATE         1
+
+/*
+ * Constants used for addressing resources in the RPM.
+ */
+#define QCOM_SMD_RPM_BOOST	0x61747362
+#define QCOM_SMD_RPM_BUS_CLK	0x316b6c63
+#define QCOM_SMD_RPM_BUS_MASTER	0x73616d62
+#define QCOM_SMD_RPM_BUS_SLAVE	0x766c7362
+#define QCOM_SMD_RPM_CLK_BUF_A	0x616B6C63
+#define QCOM_SMD_RPM_LDOA	0x616f646c
+#define QCOM_SMD_RPM_LDOB	0x626F646C
+#define QCOM_SMD_RPM_MEM_CLK	0x326b6c63
+#define QCOM_SMD_RPM_MISC_CLK	0x306b6c63
+#define QCOM_SMD_RPM_NCPA	0x6170636E
+#define QCOM_SMD_RPM_NCPB	0x6270636E
+#define QCOM_SMD_RPM_OCMEM_PWR	0x706d636f
+#define QCOM_SMD_RPM_QPIC_CLK	0x63697071
+#define QCOM_SMD_RPM_SMPA	0x61706d73
+#define QCOM_SMD_RPM_SMPB	0x62706d73
+#define QCOM_SMD_RPM_SPDM	0x63707362
+#define QCOM_SMD_RPM_VSA	0x00617376
+
+int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
+		       int state,
+		       u32 resource_type, u32 resource_id,
+		       void *buf, size_t count);
+
+#endif

include/linux/soc/qcom/smd.h

···
+#ifndef __QCOM_SMD_H__
+#define __QCOM_SMD_H__
+
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+
+struct qcom_smd;
+struct qcom_smd_channel;
+struct qcom_smd_lookup;
+
+/**
+ * struct qcom_smd_device - smd device struct
+ * @dev:	the device struct
+ * @channel:	handle to the smd channel for this device
+ */
+struct qcom_smd_device {
+	struct device dev;
+	struct qcom_smd_channel *channel;
+};
+
+/**
+ * struct qcom_smd_driver - smd driver struct
+ * @driver:	underlying device driver
+ * @probe:	invoked when the smd channel is found
+ * @remove:	invoked when the smd channel is closed
+ * @callback:	invoked when an inbound message is received on the channel,
+ *		should return 0 on success or -EBUSY if the data cannot be
+ *		consumed at this time
+ */
+struct qcom_smd_driver {
+	struct device_driver driver;
+	int (*probe)(struct qcom_smd_device *dev);
+	void (*remove)(struct qcom_smd_device *dev);
+	int (*callback)(struct qcom_smd_device *, const void *, size_t);
+};
+
+int qcom_smd_driver_register(struct qcom_smd_driver *drv);
+void qcom_smd_driver_unregister(struct qcom_smd_driver *drv);
+
+#define module_qcom_smd_driver(__smd_driver) \
+	module_driver(__smd_driver, qcom_smd_driver_register, \
+		      qcom_smd_driver_unregister)
+
+int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len);
+
+#endif

include/linux/soc/qcom/smem.h

···
+#ifndef __QCOM_SMEM_H__
+#define __QCOM_SMEM_H__
+
+#define QCOM_SMEM_HOST_ANY -1
+
+int qcom_smem_alloc(unsigned host, unsigned item, size_t size);
+int qcom_smem_get(unsigned host, unsigned item, void **ptr, size_t *size);
+
+int qcom_smem_get_free_space(unsigned host);
+
+#endif