evie/android_kernel_oneplus_msm8998
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power: reset: msm: Deassert PS_HOLD via SCM if possible

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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: Stepan Moskovchenko <stepanm@codeaurora.org>
This commit is contained in:
Stepan Moskovchenko 2015-01-22 14:08:08 -08:00 • committed by David Keitel
parent 4a5aa46b78
commit 6c3bc79a39
1 changed files with 32 additions and 4 deletions
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36
drivers/power/reset/msm-poweroff.c
View file

@ -1,4 +1,4 @@
/* 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
@ -38,6 +38,7 @@
#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
@ -47,6 +48,7 @@
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;
@ -255,6 +257,30 @@ 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;
@ -289,7 +315,7 @@ 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);
}
@ -319,8 +345,7 @@ 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");
@ -383,6 +408,9 @@ 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: