On Fri, Jul 27, 2018 at 01:51:35AM +0000, Robin Gong wrote:

quoted

-----Original Message-----
From: Oleksij Rempel [mailto:o.rempel at pengutronix.de]
Sent: 2018?7?26? 19:38
To: Robin Gong <redacted>; Shawn Guo <shawnguo@kernel.org>;
Mark Brown [off-list ref]; Rafael J. Wysocki
[off-list ref]
Cc: kernel at pengutronix.de; devicetree at vger.kernel.org;
linux-arm-kernel at lists.infradead.org; linux-clk at vger.kernel.org;
linux-kernel at vger.kernel.org; Andrew Morton [off-list ref];
Liam Girdwood [off-list ref]; Leonard Crestez
[off-list ref]; Rob Herring [off-list ref]; Mark
Rutland [off-list ref]; Michael Turquette
[off-list ref]; Stephen Boyd [off-list ref]; Fabio
Estevam [off-list ref]; Russell King [off-list ref];
dl-linux-imx [off-list ref]; A.s. Dong [off-list ref]
Subject: Re: [PATCH v8 1/6] ARM: imx6q: provide documentation for new
fsl,pmic-stby-poweroff property

Hi,

On 26.07.2018 11:51, Robin Gong wrote:

quoted

quoted

-----Original Message-----
From: Oleksij Rempel [mailto:o.rempel at pengutronix.de]
Sent: 2018?7?26? 17:22
To: Shawn Guo <shawnguo@kernel.org>; Mark Brown

[off-list ref];

quoted

quoted

Rafael J. Wysocki [off-list ref]
Cc: Oleksij Rempel <o.rempel@pengutronix.de>; kernel at pengutronix.de;
devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
linux-clk at vger.kernel.org; linux-kernel at vger.kernel.org; Andrew
Morton [off-list ref]; Liam Girdwood
[off-list ref]; Leonard Crestez [off-list ref];

Rob

quoted

quoted

Herring [off-list ref]; Mark Rutland [off-list ref];
Michael Turquette [off-list ref]; Stephen Boyd
[off-list ref]; Fabio Estevam [off-list ref];
Russell King [off-list ref]; dl-linux-imx
[off-list ref]; Robin Gong [off-list ref]; A.s. Dong
[off-list ref]
Subject: [PATCH v8 1/6] ARM: imx6q: provide documentation for new
fsl,pmic-stby-poweroff property

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/clock/imx6q-clock.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/imx6q-clock.txt

b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
index a45ca67a9d5f..e1308346e00d 100644

--- a/Documentation/devicetree/bindings/clock/imx6q-clock.txt
+++ b/Documentation/devicetree/bindings/clock/imx6q-clock.txt

@@ -6,6 +6,14 @@ Required properties:
 - interrupts: Should contain CCM interrupt
 - #clock-cells: Should be <1>

+Optional properties:
+- fsl,pmic-stby-poweroff: Configure CCM to assert PMIC_STBY_REQ
+signal
+  on power off.
+  Use this property if the SoC should be powered off by external
+power
+  management IC (PMIC) triggered via PMIC_STBY_REQ signal.

PMIC_ON_REQ didn't connect to any pin of PMIC in your case?

No. First, it was only one customer specific issue. After some research I found
even publicly available boards (for example RioTboard) which has same/similar
design. After seeing this in imx6 documentation as valid power off way, I have
no doubts - there should be even more devices doin this in the wild.

Not sure why the customer didn't follow reference design, since PMIC_ON_REQ can
provide power off/on feature by pressing ONOFF key which connected ONOFF
pin of i.mx6(ONOFF will toggle PMIC_ON_REQ to power off/on PMIC). The official
power off/on way (PMIC_ON_REQ) can also power off all power rails of PFUZE except
snvs as your patch did on PMIC_STBY_REQ.  PMIC_STBY_REQ is used to notify pmic
switch power mode (PFM/APS) or decrease voltage to save power in kernel suspend,
not power off....I am not sure if we need this patchset to 'workaround' the board issue.

quoted

quoted

Don't understand
why not follow normal board design guide to power off pmic by

PMIC_ON_REQ.

quoted

How to power on board again then?

Power cycle. Without this patch, power of is not real power off. So, power cycle,
is expected behavior for user interaction. On usual PC, reset button will not
enable PC as well.

Your board can't support wakeup by RTC alarm if not use PMIC_ON_REQ to power off.
Again, why your board not follow the design guide?

Just wild assumption: you haven't read comment provided in patch:
Subject: [PATCH v8 2/6] ARM: imx6: register pm_power_off handler if
 "fsl,pmic-stby-poweroff" is set

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.

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