linux-kernel - [PATCH RFT v2] regulator: ab8500: Update info->update_val only when successfully update register

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Message-ID: <1364462580.17483.1.camel@phoenix>
Date:	Thu, 28 Mar 2013 17:23:00 +0800
From:	Axel Lin <axel.lin@...ics.com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	Bengt Jonsson <bengt.g.jonsson@...ricsson.com>,
	Lee Jones <lee.jones@...aro.org>,
	Yvan FILLION <yvan.fillion@...ricsson.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH RFT v2] regulator: ab8500: Update info->update_val only when
 successfully update register

Don't update info->update_val if write to the register fails.

Signed-off-by: Axel Lin <axel.lin@...ics.com>
---
v2:
On the second thought, I think it's ok to update info->update_val when
regulator is disabled, the mode will change when the regulator is enabled.

Hi Bengt,
I just got your Ack for v1.
Can you review this v2 again, and let Mark know which version do you prefer.

Thanks.
Axel
 drivers/regulator/ab8500.c |   27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index 12e2740..7814ac3 100644
--- a/drivers/regulator/ab8500.c
+++ b/drivers/regulator/ab8500.c
@@ -182,8 +182,8 @@ static unsigned int ab8500_regulator_get_optimum_mode(
 static int ab8500_regulator_set_mode(struct regulator_dev *rdev,
 				     unsigned int mode)
 {
-	int ret = 0;
-
+	int ret;
+	u8 update_val;
 	struct ab8500_regulator_info *info = rdev_get_drvdata(rdev);
 
 	if (info == NULL) {
@@ -193,31 +193,42 @@ static int ab8500_regulator_set_mode(struct regulator_dev *rdev,
 
 	switch (mode) {
 	case REGULATOR_MODE_NORMAL:
-		info->update_val = info->update_val_normal;
+		update_val = info->update_val_normal;
 		break;
 	case REGULATOR_MODE_IDLE:
-		info->update_val = info->update_val_idle;
+		update_val = info->update_val_idle;
 		break;
 	default:
 		return -EINVAL;
 	}
 
+	/* ab8500 regulators share mode and enable in the same register bits.
+	   off = 0b00
+	   low power mode= 0b11
+	   full powermode = 0b01
+	   (HW control mode = 0b10)
+	   Thus we don't write to the register when regulator is disabled.
+	*/
 	if (info->is_enabled) {
 		ret = abx500_mask_and_set_register_interruptible(info->dev,
 			info->update_bank, info->update_reg,
-			info->update_mask, info->update_val);
-		if (ret < 0)
+			info->update_mask, update_val);
+		if (ret < 0) {
 			dev_err(rdev_get_dev(rdev),
 				"couldn't set regulator mode\n");
+			return ret;
+		}
 
 		dev_vdbg(rdev_get_dev(rdev),
 			"%s-set_mode (bank, reg, mask, value): "
 			"0x%x, 0x%x, 0x%x, 0x%x\n",
 			info->desc.name, info->update_bank, info->update_reg,
-			info->update_mask, info->update_val);
+			info->update_mask, update_val);
 	}
 
-	return ret;
+	info->update_val = update_val;
+
+	return 0;
 }
 
 static unsigned int ab8500_regulator_get_mode(struct regulator_dev *rdev)
-- 
1.7.10.4



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