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Commit 9a8aeef1 authored by Mahesh Sivasubramanian's avatar Mahesh Sivasubramanian
Browse files

soc: qcom: debugfs-qmp: Add a QMP client to send messages using debugfs 



Add support for a debugfs node that would allow clients to communicate
with the Always On Processor(AOP) using the QMP mailbox. Clients can
write the message to be sent directly into the nodes at
<debugfs>/aop_send_message.

Change-Id: If8d51cfd92a231b6d8a540c895f56290aa7a7342
Signed-off-by: default avatarMahesh Sivasubramanian <msivasub@codeaurora.org>
parent 285dbc85

Documentation/devicetree/bindings/arm/msm/qmp-debugfs-client.txt

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+17 −0
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QMP debugfs client:

-----------------



QTI Messaging Protocol(QMP) debugfs client is an interface for clients to

send data to the Always on processor using QMP.



Required properties :

- compatible : must be "qcom,debugfs-qmp-client"

- mboxes : list of QMP mailbox phandle and channel identifier tuples.

- mbox-names : names of the listed mboxes



Example :

	qcom,qmp-client {

		compatible = "qcom,debugfs-qmp-client";

		mboxes = <&qmp_aop 0>;

		mbox-names = "aop";

	};

drivers/soc/qcom/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -552,3 +552,11 @@ endif # MSM_IDLE_STATS 
endif # MSM_PM



endmenu



config QMP_DEBUGFS_CLIENT

	bool "Debugfs Client to communicate with AOP using QMP protocol"

	depends on DEBUG_FS

	default n

	help

	  This options enables a driver which allows clients to send messages

	  to Alway On processor using QMP transport.

drivers/soc/qcom/Makefile

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@@ -60,3 +60,4 @@ obj-$(CONFIG_MSM_EVENT_TIMER) += event_timer.o 
obj-$(CONFIG_MSM_IDLE_STATS)	+= lpm-stats.o

obj-$(CONFIG_QTI_RPM_STATS_LOG) += rpm_stats.o

obj-$(CONFIG_QCOM_FSA4480_I2C)	+= fsa4480-i2c.o

obj-$(CONFIG_QMP_DEBUGFS_CLIENT) += qmp-debugfs-client.o

drivers/soc/qcom/qmp-debugfs-client.c

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/* Copyright (c) 2017, 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/kernel.h>

#include <linux/init.h>

#include <linux/mailbox_client.h>

#include <linux/seq_file.h>

#include <linux/debugfs.h>

#include <linux/platform_device.h>

#include <linux/mailbox/qmp.h>

#include <linux/uaccess.h>



#define MAX_MSG_SIZE 96 /* Imposed by the remote*/



static struct mbox_chan *chan;

static struct mbox_client *cl;



static ssize_t aop_msg_write(struct file *file, const char __user *userstr,

		size_t len, loff_t *pos)

{

	char buf[MAX_MSG_SIZE + 1] = {0};

	struct qmp_pkt pkt;

	int rc;



	if (!len || (len > MAX_MSG_SIZE))

		return len;



	rc  = copy_from_user(buf, userstr, len);

	if (rc) {

		pr_err("%s copy from user failed, rc=%d\n", __func__, rc);

		return len;

	}



	/*

	 * Controller expects a 4 byte aligned buffer

	 */

	pkt.size = (len + 0x3) & ~0x3;

	pkt.data = buf;



	if (mbox_send_message(chan, &pkt) < 0)

		pr_err("Failed to send qmp request\n");



	return len;

}



static const struct file_operations aop_msg_fops = {

	.write = aop_msg_write,

};



static int qmp_msg_probe(struct platform_device *pdev)

{

	struct dentry *file;



	cl = devm_kzalloc(&pdev->dev, sizeof(*cl), GFP_KERNEL);

	if (!cl)

		return -ENOMEM;



	cl->dev = &pdev->dev;

	cl->tx_block = true;

	cl->tx_tout = 100;

	cl->knows_txdone = false;



	chan = mbox_request_channel(cl, 0);

	if (IS_ERR(chan)) {

		dev_err(&pdev->dev, "Failed to mbox channel\n");

		return PTR_ERR(chan);

	}



	file = debugfs_create_file("aop_send_message", 0220, NULL, NULL,

			&aop_msg_fops);

	if (!file)

		goto err;

	return 0;

err:

	mbox_free_channel(chan);

	chan = NULL;

	return -ENOMEM;

}



static const struct of_device_id aop_qmp_match_tbl[] = {

	{.compatible = "qcom,debugfs-qmp-client"},

	{},

};



static struct platform_driver aop_qmp_msg_driver = {

	.probe = qmp_msg_probe,

	.driver = {

		.name = "debugfs-qmp-client",

		.owner = THIS_MODULE,

		.of_match_table = aop_qmp_match_tbl,

	},

};



builtin_platform_driver(aop_qmp_msg_driver);