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Commit 93053700 authored by Isaac J. Manjarres's avatar Isaac J. Manjarres
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soc: qcom: aop_msg: Add support for sending DDR freq msg to AOP 



To ensure that a clean power off is performed, APPS must
communicate to AOP to lower the DDR frequency. Add
functionality for using the mailbox interface to communicate
the desired DDR frequency with AOP when powering off the
device.

Change-Id: I404ca770e1a3413e0febfd1f446fe01113600dc0
Signed-off-by: default avatarIsaac J. Manjarres <isaacm@codeaurora.org>
parent 78204b52

Documentation/devicetree/bindings/arm/msm/msm_aop_ddr_msgs.txt

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AOP (Always-On-Processor) DDR Related Messaging



The AOP DDR messaging driver is used to send messages to the AOP,

using the mailbox interface, to lower the DDR frequency during reboot.



Required properties



- compatible : "qcom,aop-ddr-msgs"

- mbox : QMP mailbox phandle and channel identifier



Optional properties:

-mbox-name: name of the mailbox



Example:

	qcom,aop-ddr-msgs {

		compatible = "qcom,aop-ddr-msgs";

		mboxes = <&qmp_aop 0>;

	};

drivers/soc/qcom/Kconfig

+7 −0
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@@ -833,4 +833,11 @@ config QCOM_CX_IPEAK 
	  bit in tcsr register if it is going to cross its own threshold. If all

	  clients are going to cross their thresholds then Cx ipeak hw module will raise

	  an interrupt to cDSP block to throttle cDSP fmax.



config QCOM_AOP_DDR_MESSAGING

	bool "Send messages to AOP about the DDR frequency during reboot"

	help

	  This driver sends messages to the AOP to adjust the DDR frequency when

	  the device is rebooting, to ensure that the device is powered off

	  cleanly.

endmenu

drivers/soc/qcom/Makefile

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@@ -93,3 +93,4 @@ obj-$(CONFIG_QCOM_SMP2P_SLEEPSTATE) += smp2p_sleepstate.o 
obj-$(CONFIG_QCOM_MEM_OFFLINE) += mem-offline.o

obj-$(CONFIG_QCOM_CDSP_RM) += cdsprm.o

obj-$(CONFIG_QCOM_CX_IPEAK) += cx_ipeak.o

obj-$(CONFIG_QCOM_AOP_DDR_MESSAGING) += aop_ddr_msgs.o

drivers/soc/qcom/aop_ddr_msgs.c

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/* Copyright (c) 2018, 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/init.h>

#include <linux/kernel.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/reboot.h>

#include <linux/mailbox_client.h>

#include <linux/mailbox/qmp.h>

#include <linux/slab.h>



#define MAX_AOP_MSG_LEN			96

#define AOP_DDR_TARG_FREQ_MHZ		300



struct mbox_data {

	struct mbox_client cl;

	struct mbox_chan *mbox;

	struct notifier_block reboot_notif_blk;

};



static void send_aop_ddr_freq_msg(struct mbox_data *aop_mbox, int freq_mhz)

{

	struct qmp_pkt pkt;

	char mbox_msg[MAX_AOP_MSG_LEN + 1] = {0};

	int rc;



	scnprintf(mbox_msg, MAX_AOP_MSG_LEN,

		  "{class: ddr, res: fixed, val: %d}", freq_mhz);

	pkt.size = MAX_AOP_MSG_LEN;

	pkt.data = mbox_msg;



	rc = mbox_send_message(aop_mbox->mbox, &pkt);



	if (rc < 0)

		pr_err("Failed to send AOP DDR freq msg: %d rc: %d\n", freq_mhz,

		       rc);

}



static int aop_ddr_freq_msg_handler(struct notifier_block *this,

				    unsigned long event, void *ptr)

{

	struct mbox_data *aop_mbox = container_of(this, struct mbox_data,

						  reboot_notif_blk);



	if (event == SYS_HALT || event == SYS_POWER_OFF)

		send_aop_ddr_freq_msg(aop_mbox, AOP_DDR_TARG_FREQ_MHZ);



	return NOTIFY_DONE;

}



static int aop_ddr_msgs_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	int rc;

	struct mbox_data *aop_mbox = devm_kzalloc(dev, sizeof(*aop_mbox),

						  GFP_KERNEL);



	if (!aop_mbox)

		return -ENOMEM;



	aop_mbox->cl.dev = dev;

	aop_mbox->cl.tx_block = true;

	aop_mbox->cl.tx_tout = 1000;

	aop_mbox->cl.knows_txdone = false;

	aop_mbox->mbox = mbox_request_channel(&aop_mbox->cl, 0);

	if (IS_ERR(aop_mbox->mbox)) {

		rc = PTR_ERR(aop_mbox->mbox);

		pr_err("Failed to get mailbox channel rc: %d\n", rc);

		return rc;

	}



	aop_mbox->reboot_notif_blk.notifier_call = aop_ddr_freq_msg_handler;

	platform_set_drvdata(pdev, aop_mbox);

	rc = register_reboot_notifier(&aop_mbox->reboot_notif_blk);

	if (rc < 0) {

		pr_err("Failed to register to the reboot notifier rc: %d\n",

		       rc);

		mbox_free_channel(aop_mbox->mbox);

		platform_set_drvdata(pdev, NULL);

	}

	return rc;

}



static int aop_ddr_msgs_remove(struct platform_device *pdev)

{

	struct mbox_data *aop_mbox = platform_get_drvdata(pdev);



	mbox_free_channel(aop_mbox->mbox);

	platform_set_drvdata(pdev, NULL);



	return 0;

}



static const struct of_device_id of_aop_ddr_match_tbl[] = {

	{ .compatible = "qcom,aop-ddr-msgs", },

	{},

};

MODULE_DEVICE_TABLE(of, of_aop_ddr_match_tbl);



static struct platform_driver aop_ddr_msgs_driver = {

	.probe = aop_ddr_msgs_probe,

	.remove = aop_ddr_msgs_remove,

	.driver = {

		.name = "aop-ddr-msgs",

		.of_match_table = of_match_ptr(of_aop_ddr_match_tbl),

	},

};

module_platform_driver(aop_ddr_msgs_driver);



MODULE_DESCRIPTION("Qualcomm Technologies Inc AOP DDR Messaging driver");

MODULE_LICENSE("GPL v2");