Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bc6815ab authored by Elliot Berman's avatar Elliot Berman
Browse files

power: reset: Add qcom-dload-mode driver 



Add a driver to manage download mode for Qualcomm SoCs. The driver can
force SoC to restart into a dump collection mode when panicking for
post-morten analysis, as controlled by
CONFIG_POWER_RESET_MSM_DOWNLOAD_MODE_DEFAULT. The driver also can reboot
into "emergency download mode," which restarts SoC into mode which
permits re-flashing storage via Qualcomm Sahara protocol.

Change-Id: I30c83bf020715b7a80c00faa19280aec7f708435
Signed-off-by: default avatarElliot Berman <eberman@codeaurora.org>
parent 8b8d4198

drivers/power/reset/Kconfig

+19 −0
Original line number Diff line number Diff line
@@ -105,6 +105,25 @@ config POWER_RESET_MSM 
	help

	  Power off and restart support for Qualcomm boards.



config POWER_RESET_QCOM_DOWNLOAD_MODE

	tristate "MSM download mode driver"

	depends on ARCH_QCOM

	help

	  MSM boards support booting to special download modes after a restart.

	  These modes could be a normal restart, restarting into a

	  ramdump collection mode (CrashDump), or restarting into "emergency

	  download mode".



config POWER_RESET_QCOM_DOWNLOAD_MODE_DEFAULT

	bool "MSM download mode enabled by default"

	help

	  A device with "download mode" enabled will upon an unexpected

	  warm-restart enter a special debug mode that allows the user to

	  "download" memory content over USB for offline postmortem analysis.

	  The feature can be enabled/disabled on the kernel command line.



	  Say Y here to enable "download mode" by default.



config POWER_RESET_QCOM_PON

	tristate "Qualcomm power-on driver"

	depends on ARCH_QCOM

drivers/power/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o 
obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o

obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o

obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o

obj-$(CONFIG_POWER_RESET_QCOM_DOWNLOAD_MODE) += qcom-dload-mode.o

obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o

obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o

obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o

drivers/power/reset/qcom-dload-mode.c

0 → 100644
+160 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright (c) 2020 The Linux Foundation. All rights reserved.

 */



#include <linux/delay.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/reboot.h>

#include <linux/pm.h>

#include <linux/qcom_scm.h>



struct qcom_dload {

	struct notifier_block panic_nb;

	struct notifier_block reboot_nb;



	bool in_panic;

};



static bool enable_dump =

	IS_ENABLED(CONFIG_POWER_RESET_QCOM_DOWNLOAD_MODE_DEFAULT);

static enum qcom_download_mode current_download_mode = QCOM_DOWNLOAD_NODUMP;



static int set_download_mode(enum qcom_download_mode mode)

{

	current_download_mode = mode;

	qcom_scm_set_download_mode(mode, 0);

	return 0;

}



static int param_set_download_mode(const char *val,

		const struct kernel_param *kp)

{

	int ret;



	/* update enable_dump according to user input */

	ret = param_set_bool(val, kp);

	if (ret)

		return ret;



	set_download_mode(QCOM_DOWNLOAD_FULLDUMP);



	return 0;

}

module_param_call(download_mode, param_set_download_mode, param_get_int,

			&enable_dump, 0644);



static int qcom_dload_panic(struct notifier_block *this, unsigned long event,

			      void *ptr)

{

	struct qcom_dload *poweroff = container_of(this, struct qcom_dload,

						     panic_nb);

	poweroff->in_panic = true;

	if (enable_dump)

		set_download_mode(QCOM_DOWNLOAD_FULLDUMP);

	return NOTIFY_OK;

}



static int qcom_dload_reboot(struct notifier_block *this, unsigned long event,

			      void *ptr)

{

	char *cmd = ptr;

	struct qcom_dload *poweroff = container_of(this, struct qcom_dload,

						     reboot_nb);



	/* Clean shutdown, disable dump mode to allow normal restart */

	if (!poweroff->in_panic)

		set_download_mode(QCOM_DOWNLOAD_NODUMP);



	if (cmd) {

		if (!strcmp(cmd, "edl"))

			set_download_mode(QCOM_DOWNLOAD_EDL);

		else if (!strcmp(cmd, "qcom_dload"))

			set_download_mode(QCOM_DOWNLOAD_FULLDUMP);

	}



	if (current_download_mode != QCOM_DOWNLOAD_NODUMP)

		reboot_mode = REBOOT_WARM;



	return NOTIFY_OK;

}





static int qcom_dload_probe(struct platform_device *pdev)

{

	struct qcom_dload *poweroff;



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

	if (!poweroff)

		return -ENOMEM;



	if (enable_dump)

		set_download_mode(QCOM_DOWNLOAD_FULLDUMP);

	else {

		set_download_mode(QCOM_DOWNLOAD_NODUMP);

		qcom_scm_disable_sdi();

	}



	poweroff->panic_nb.notifier_call = qcom_dload_panic;

	poweroff->panic_nb.priority = INT_MAX;

	atomic_notifier_chain_register(&panic_notifier_list,

				       &poweroff->panic_nb);



	poweroff->reboot_nb.notifier_call = qcom_dload_reboot;

	poweroff->reboot_nb.priority = 255;

	register_reboot_notifier(&poweroff->reboot_nb);



	platform_set_drvdata(pdev, poweroff);



	return 0;

}



static int qcom_dload_remove(struct platform_device *pdev)

{

	struct qcom_dload *poweroff = platform_get_drvdata(pdev);



	atomic_notifier_chain_unregister(&panic_notifier_list,

					 &poweroff->panic_nb);

	unregister_reboot_notifier(&poweroff->reboot_nb);



	return 0;

}



static const struct of_device_id of_qcom_dload_match[] = {

	{ .compatible = "qcom,dload-mode", },

	{},

};

MODULE_DEVICE_TABLE(of, of_qcom_dload_match);



static struct platform_driver qcom_dload_driver = {

	.probe = qcom_dload_probe,

	.remove = qcom_dload_remove,

	.driver = {

		.name = "qcom-dload-mode",

		.of_match_table = of_match_ptr(of_qcom_dload_match),

	},

};



static int __init qcom_dload_driver_init(void)

{

	return platform_driver_register(&qcom_dload_driver);

}

#if IS_MODULE(CONFIG_POWER_RESET_QCOM_DOWNLOAD_MODE)

module_init(qcom_dload_driver_init);

#else

pure_initcall(qcom_dload_driver_init);

#endif



static void __exit qcom_dload_driver_exit(void)

{

	return platform_driver_unregister(&qcom_dload_driver);

}

module_exit(qcom_dload_driver_exit);



MODULE_DESCRIPTION("MSM Download Mode Driver");

MODULE_LICENSE("GPL v2");