linux-kernel - [PATCH] regulator: wm831x-ldo - fix the logic to set REGULATOR_MODE_IDLE and REGULATOR_MODE

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Date:	Mon, 06 Sep 2010 16:48:13 +0800
From:	Axel Lin <axel.lin@...il.com>
To:	linux-kernel <linux-kernel@...r.kernel.org>
Cc:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Liam Girdwood <lrg@...mlogic.co.uk>
Subject: [PATCH] regulator: wm831x-ldo - fix the logic to set
	REGULATOR_MODE_IDLE and REGULATOR_MODE_STANDBY modes

Problem description in current implementation:
When setting REGULATOR_MODE_IDLE mode, current implementation set
WM831X_LDO1_LP_MODE bit of ctrl_reg (which is wrong, it should clear the bit).
But due to a missing break statement for case REGULATOR_MODE_IDLE, the code
fall through to case REGULATOR_MODE_STANDBY and then clear
WM831X_LDO1_LP_MODE bit. So it still looks OK when checking the status
by wm831x_gp_ldo_get_mode().

When setting REGULATOR_MODE_STANDBY mode, it just does not work.
wm831x_gp_ldo_get_mode() will still return REGULATOR_MODE_IDLE because
the accordingly WM831X_LDO1_LP_MODE bit is clear.

Correct behavior should be:
Clear WM831X_LDO1_LP_MODE bit of ctrl_reg for REGULATOR_MODE_IDLE mode.
Set WM831X_LDO1_LP_MODE bit of ctrl_reg for REGULATOR_MODE_STANDBY mode.

Signed-off-by: Axel Lin <axel.lin@...il.com>
---
 drivers/regulator/wm831x-ldo.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/wm831x-ldo.c b/drivers/regulator/wm831x-ldo.c
index e686cdb..9edf8f6 100644
--- a/drivers/regulator/wm831x-ldo.c
+++ b/drivers/regulator/wm831x-ldo.c
@@ -215,8 +215,7 @@ static int wm831x_gp_ldo_set_mode(struct regulator_dev *rdev,

 	case REGULATOR_MODE_IDLE:
 		ret = wm831x_set_bits(wm831x, ctrl_reg,
-				      WM831X_LDO1_LP_MODE,
-				      WM831X_LDO1_LP_MODE);
+				      WM831X_LDO1_LP_MODE, 0);
 		if (ret < 0)
 			return ret;

@@ -225,10 +224,12 @@ static int wm831x_gp_ldo_set_mode(struct regulator_dev *rdev,
 				      WM831X_LDO1_ON_MODE);
 		if (ret < 0)
 			return ret;
+		break;

 	case REGULATOR_MODE_STANDBY:
 		ret = wm831x_set_bits(wm831x, ctrl_reg,
-				      WM831X_LDO1_LP_MODE, 0);
+				      WM831X_LDO1_LP_MODE,
+				      WM831X_LDO1_LP_MODE);
 		if (ret < 0)
 			return ret;

-- 
1.7.2

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