soc: qcom: Driver for the Qualcomm RPM over SMD

	  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

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

/*

 * 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 <bjorn.andersson@sonymobile.com>");

MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");

MODULE_LICENSE("GPL v2");

#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