regulator: tps51632: Fix setting ramp delay

According to the datasheet:

SLEW Register(Address = 07h)
b7 b6 b5 b4 b3 b2 b1 b0
48mV/us 42mV/us 36mV/us 30mV/us 24mV/us 18mV/us 12mV/us 6mV/us

Current code does not set correct slew rate in some cases:
e.g. Assume ramp_delay is 10000, current code sets slew register to 6mV/us. Fix the logic to set slew register.

---
 drivers/regulator/tps51632-regulator.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

index 572816e..c139890 100644
@@ -94,11 +94,14 @@ static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
 		int ramp_delay)
 {
 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
-	int bit = ramp_delay/6000;
+	int bit;
 	int ret;
 
-	if (bit)
-		bit--;
+	if (ramp_delay == 0)
+		bit = 0;
+	else
+		bit = DIV_ROUND_UP(ramp_delay, 6000) - 1;
+
 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
 	if (ret < 0)
 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);

2.5.0

Setting register to nearest faster ramp side, the change looks fine.

The patch

regulator: tps51632: Fix setting ramp delay

has been applied to the regulator tree at

git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks,
Mark

From: Axel Lin <[email protected]>
Date: Tue, 31 May 2016 17:26:00 +0800
Subject: [PATCH] regulator: tps51632: Fix setting ramp delay

According to the datasheet:

SLEW Register(Address = 07h)
b7 b6 b5 b4 b3 b2 b1 b0
48mV/us 42mV/us 36mV/us 30mV/us 24mV/us 18mV/us 12mV/us 6mV/us

Current code does not set correct slew rate in some cases:
e.g. Assume ramp_delay is 10000, current code sets slew register to 6mV/us. Fix the logic to set slew register.

---
 drivers/regulator/tps51632-regulator.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

index 572816e30095..c139890c1514 100644
@@ -94,11 +94,14 @@ static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
 		int ramp_delay)
 {
 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
-	int bit = ramp_delay/6000;
+	int bit;
 	int ret;
 
-	if (bit)
-		bit--;
+	if (ramp_delay == 0)
+		bit = 0;
+	else
+		bit = DIV_ROUND_UP(ramp_delay, 6000) - 1;
+
 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
 	if (ret < 0)
 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);

2.8.1