Re: [PATCH v5 2/6] ARM: imx6: register pm_power_off handler if "fsl,pmic-stby-poweroff" is set

From: Oleksij Rempel
Date: Tue Jun 20 2017 - 00:55:49 EST


Hi Leonard,

On 19.06.2017 13:35, Leonard Crestez wrote:
On Mon, 2017-06-19 at 07:02 +0200, Oleksij Rempel wrote:
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:
https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww
.nxp.com%2Fassets%2Fdocuments%2Fdata%2Fen%2Freference-
manuals%2FIMX6DQRM.pdf&data=01%7C01%7Cleonard.crestez%40nxp.com%7C32c
df19d0ab44ed8e24d08d4b6d097f4%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0&
sdata=CWDpnEGikPGmSTM3dQH8IMxQCVzcIvHL69nu962d8M0%3D&reserved=0
page 5083

This patch implements step 4. of this sequence.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
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 e61b1d1027e1..cb76832935f0 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_poweroff(void)
+{
+ imx6_set_lpm(STOP_POWER_OFF);
+ cpu_suspend(0, imx6q_suspend_finish);

It's a bit strange that you're using parts of the suspend code for
this. Perhaps you could just write your bits to CLPCR and then execute
a WFI?

Well, every thing in this patch set, yell about using standby/suspend path in HW for power off. Even iMX code use STOP_POWER_OFF for configuring this regs. How can it be more strange? :) Should i really duplicate code to hide this?

It would also be nice to rename this to something like
imx6_pm_stby_poweroff to make it clear that it's only for a certain
power off path.

ok.