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Commit ff6f3afb authored by Stepan Moskovchenko's avatar Stepan Moskovchenko Committed by Gerrit - the friendly Code Review server
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power: reset: msm: Deassert PS_HOLD via SCM if possible 



Support a new SCM call which disables the PMIC arbiter and
deasserts PS_HOLD in a single operation. Fall back on the
legacy behavior of disabling the PMIC abriter and directly
deasserting PS_HOLD if this call is not available.

This is necessary comply with atomicity requirements of the
secure environment.

Change-Id: Ia3b13d469932edf94d3249fa3e7234a1c12eee1b
Signed-off-by: default avatarStepan Moskovchenko <stepanm@codeaurora.org>
parent dd586522

drivers/power/reset/msm-poweroff.c

+32 −4
Original line number Diff line number Diff line 
/* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.

/* Copyright (c) 2013-2015, 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
@@ -37,6 +37,7 @@ 
#define EMERGENCY_DLOAD_MAGIC3    0x77777777



#define SCM_IO_DISABLE_PMIC_ARBITER	1

#define SCM_IO_DEASSERT_PS_HOLD		2

#define SCM_WDOG_DEBUG_BOOT_PART	0x9

#define SCM_DLOAD_MODE			0X10

#define SCM_EDLOAD_MODE			0X01
@@ -46,6 +47,7 @@ 
static int restart_mode;

void *restart_reason;

static bool scm_pmic_arbiter_disable_supported;

static bool scm_deassert_ps_hold_supported;

/* Download mode master kill-switch */

static void __iomem *msm_ps_hold;
@@ -254,6 +256,30 @@ static void msm_restart_prepare(const char *cmd) 


}



/*

 * Deassert PS_HOLD to signal the PMIC that we are ready to power down or reset.

 * Do this by calling into the secure environment, if available, or by directly

 * writing to a hardware register.

 *

 * This function should never return.

 */

static void deassert_ps_hold(void)

{

	struct scm_desc desc = {

		.args[0] = 0,

		.arginfo = SCM_ARGS(1),

	};



	if (scm_deassert_ps_hold_supported) {

		/* This call will be available on ARMv8 only */

		scm_call2_atomic(SCM_SIP_FNID(SCM_SVC_PWR,

				 SCM_IO_DEASSERT_PS_HOLD), &desc);

	}



	/* Fall-through to the direct write in case the scm_call "returns" */

	__raw_writel(0, msm_ps_hold);

}



static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd)

{

	int ret;
@@ -288,7 +314,7 @@ static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd) 
		pr_err("Failed to disable secure wdog debug: %d\n", ret);



	halt_spmi_pmic_arbiter();

	__raw_writel(0, msm_ps_hold);

	deassert_ps_hold();



	mdelay(10000);

}
@@ -318,8 +344,7 @@ static void do_msm_poweroff(void) 
		pr_err("Failed to disable wdog debug: %d\n", ret);



	halt_spmi_pmic_arbiter();

	/* MSM initiated power off, lower ps_hold */

	__raw_writel(0, msm_ps_hold);

	deassert_ps_hold();



	mdelay(10000);

	pr_err("Powering off has failed\n");
@@ -382,6 +407,9 @@ static int msm_restart_probe(struct platform_device *pdev) 
	if (scm_is_call_available(SCM_SVC_PWR, SCM_IO_DISABLE_PMIC_ARBITER) > 0)

		scm_pmic_arbiter_disable_supported = true;



	if (scm_is_call_available(SCM_SVC_PWR, SCM_IO_DEASSERT_PS_HOLD) > 0)

		scm_deassert_ps_hold_supported = true;



	return 0;



err_restart_reason: