[PATCH AUTOSEL 4.9 42/64] ARM: imx6: register pm_power_off handler if "fsl,pmic-stby-poweroff" is set

Sasha Levin
2019-11-08T11:53:30Z

From: Oleksij Rempel <o.rempel@pengutronix.de>

[ Upstream commit 8148d2136002da2e2887caf6a07bbd9c033f14f3 ]

One of the Freescale recommended sequences for power off with external
PMIC is the following:
...
3. SoC is programming PMIC for power off when standby is asserted.
4. In CCM STOP mode, Standby is asserted, PMIC gates SoC supplies.

See:
http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf
page 5083

This patch implements step 4. of this sequence.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/mach-imx/pm-imx6.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index 1515e498d348c..dd9eb3f14f45c 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c
@@ -602,6 +602,28 @@ static void __init imx6_pm_common_init(const struct imx6_pm_socdata
IMX6Q_GPR1_GINT);
}

+static void imx6_pm_stby_poweroff(void)
+{
+ imx6_set_lpm(STOP_POWER_OFF);
+ imx6q_suspend_finish(0);
+
+ mdelay(1000);
+
+ pr_emerg("Unable to poweroff system\n");
+}
+
+static int imx6_pm_stby_poweroff_probe(void)
+{
+ if (pm_power_off) {
+ pr_warn("%s: pm_power_off already claimed %p %pf!\n",
+ __func__, pm_power_off, pm_power_off);
+ return -EBUSY;
+ }
+
+ pm_power_off = imx6_pm_stby_poweroff;
+ return 0;
+}
+
void __init imx6_pm_ccm_init(const char *ccm_compat)
{
struct device_node *np;
@@ -618,6 +640,9 @@ void __init imx6_pm_ccm_init(const char *ccm_compat)
val = readl_relaxed(ccm_base + CLPCR);
val &= ~BM_CLPCR_LPM;
writel_relaxed(val, ccm_base + CLPCR);
+
+ if (of_property_read_bool(np, "fsl,pmic-stby-poweroff"))
+ imx6_pm_stby_poweroff_probe();
}

void __init imx6q_pm_init(void)
--
2.20.1