On Mon, Oct 27, 2014 at 11:45:44AM -0500, Felipe Balbi wrote:

On Mon, Oct 27, 2014 at 09:09:28AM +0100, Johan Hovold wrote:

quoted

Add new property "ti,system-power-controller" to register the RTC as a
power-off handler.

Some RTC IP revisions can control an external PMIC via the pmic_power_en
pin, which can be configured to transition to OFF on ALARM2 events and
back to ON on subsequent ALARM (wakealarm) events.

This is based on earlier work by Colin Foe-Parker and AnilKumar Ch. [1]

[1] https://www.mail-archive.com/linux-omap at vger.kernel.org/msg82127.html

Tested-by: Felipe Balbi <redacted>
Signed-off-by: Johan Hovold <johan@kernel.org>
---

Changes since v2:
 - add two-second delay to allow alarm to trigger before returning

Andrew, can you replace just this patch in the series that you already
have in your tree, or do you prefer I resend the whole series (with
Felipe's Tested-by tags)?

Thanks,
Johan


 Documentation/devicetree/bindings/rtc/rtc-omap.txt |  9 +-
 drivers/rtc/rtc-omap.c                             | 95 ++++++++++++++++++++++
 2 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/rtc/rtc-omap.txt b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
index 5a0f02d34d95..750efd40c72e 100644
--- a/Documentation/devicetree/bindings/rtc/rtc-omap.txt
+++ b/Documentation/devicetree/bindings/rtc/rtc-omap.txt

@@ -5,11 +5,17 @@ Required properties:
 	- "ti,da830-rtc"  - for RTC IP used similar to that on DA8xx SoC family.
 	- "ti,am3352-rtc" - for RTC IP used similar to that on AM335x SoC family.
 			    This RTC IP has special WAKE-EN Register to enable
-			    Wakeup generation for event Alarm.
+			    Wakeup generation for event Alarm. It can also be
+			    used to control an external PMIC via the
+			    pmic_power_en pin.
 - reg: Address range of rtc register set
 - interrupts: rtc timer, alarm interrupts in order
 - interrupt-parent: phandle for the interrupt controller
 
+Optional properties:
+- ti,system-power-controller: whether the rtc is controlling the system power

isn't there a discussion going on to drop the vendor prefix ? I wonder
if we should just use the final binding to avoid supporting this for
rtc-omap too. OTOH, all of that can be hidden under
of_is_system_power_controller() itself.

Exactly, Romain intends to support both versions (i.e. with and without
the prefix) with his helper function as there are already other uses of
this variant in the wild.

As I believe I mentioned in my cover letter, I suggest simply updating
to the generic property name (i.e. use the helper and drop the prefix)
once that code has been merged. Either way, we should always be able
to change the property name before it has been used in a mainline
release (as long as we update the driver and any dts use in one commit
in order not to break bisectability).

Johan