linux-kernel - [PATCH v2 0/2] ARM: EXYNOS: Call regulator suspend prepare/finish

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Message-Id: <1413454410-23396-1-git-send-email-javier.martinez@collabora.co.uk>
Date:	Thu, 16 Oct 2014 12:13:28 +0200
From:	Javier Martinez Canillas <javier.martinez@...labora.co.uk>
To:	Kukjin Kim <kgene.kim@...sung.com>
Cc:	Lee Jones <lee.jones@...aro.org>,
	Doug Anderson <dianders@...omium.org>,
	Mark Brown <broonie@...nel.org>,
	Tomasz Figa <tomasz.figa@...il.com>,
	Chanwoo Choi <cw00.choi@...sung.com>,
	linux-samsung-soc@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Javier Martinez Canillas <javier.martinez@...labora.co.uk>
Subject: [PATCH v2 0/2] ARM: EXYNOS: Call regulator suspend prepare/finish

Hello,

This series add support for Exynos platforms to prepare regulators for
system suspend. The regulator core has a set of helpers functions to be
used when the system is entering and leaving from a suspend state but
currently there is only one user in mainline.

This user is drivers/mfd/sec-core.c but it calls regulator_suspend_prepare()
from within the driver power-management suspend function. This does not
seems to be correct since the regulator suspend prepare function affects all
regulators in the system and not only the ones managed by this device.

So patch #1 in this series revert the commit that introduced that change and
patch #2 calls the regulator framework suspend/finish functions from the
Exynos platform power-management code. The first patch should be queued through
the mfd tree and the second through the linux-samsung tree.

Changes since v1:
 - Remove the call to regulator_suspend_prepare() from drivers/mfd/sec-core.c
   as suggested by Doug Anderson.
 - Call regulator_suspend_prepare() before s3c_pm_check_prepare() as suggested
   by Doug Anderson.
 - Added Lee Jones to cc list since there is a change for the mfd framework.

Javier Martinez Canillas (2):
  Revert "mfd: sec-core: Prepare regulators for suspend state to reduce
    power-consumption"
  ARM: EXYNOS: Call regulator core suspend prepare and finish functions

 arch/arm/mach-exynos/suspend.c | 18 ++++++++++++++++++
 drivers/mfd/Kconfig            |  1 -
 drivers/mfd/sec-core.c         | 10 ----------
 3 files changed, 18 insertions(+), 11 deletions(-)

NOTES:

* The drivers/mfd/sec-core.c only called regulator_suspend_prepare() on
  suspend but did not call regulator_suspend_finish() on resume so this
  series changes the assumption the driver did that the regulators .enable
  functions won't be called on resume and the regulators should be recovered
  automatically from suspend. So it may cause issues on this device since
  the semantics are changed. But I think not calling suspend finish was not
  correct in the first place.

* This could also be made from the suspend core (kernel/power/suspend.c) to
  avoid each platform support having the same code but I was not sure about
  this so I decided to it at the platform level.
  Another option is that the regulator core register a pm_notifier that could
  handle the PM_SUSPEND_PREPARE and PM_POST_SUSPEND events.

Best regards,
Javier

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