[PATCH v2] regulator: pca9450: Clear PRESET_EN bit to fix BUCK1/2/3 voltage setting

[PATCH v2] regulator: pca9450: Clear PRESET_EN bit to fix BUCK1/2/3 voltage setting

[Schrempf Frieder]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

The driver uses the DVS registers PCA9450_REG_BUCKxOUT_DVS0 to set the
voltage for the buck regulators 1, 2 and 3. This has no effect as the
PRESET_EN bit is set by default and therefore the preset values are used
instead, which are set to 850 mV.

To fix this we clear the PRESET_EN bit at time of initialization.

Fixes: 0935ff5f1f0a ("regulator: pca9450: add pca9450 pmic driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
Changes in v2:
  * Improve comment and commit message
  * Use regmap_clear_bits() instead of regmap_update_bits()
  * Add error code to log message
---
 drivers/regulator/pca9450-regulator.c | 8 ++++++++
 include/linux/regulator/pca9450.h     | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/drivers/regulator/pca9450-regulator.c b/drivers/regulator/pca9450-regulator.c
index 833d398c6aa2..d38109cc3a01 100644
--- a/drivers/regulator/pca9450-regulator.c
+++ b/drivers/regulator/pca9450-regulator.c
@@ -797,6 +797,14 @@ static int pca9450_i2c_probe(struct i2c_client *i2c,
 		return ret;
 	}
 
+	/* Clear PRESET_EN bit in BUCK123_DVS to use DVS registers */
+	ret = regmap_clear_bits(pca9450->regmap, PCA9450_REG_BUCK123_DVS,
+				BUCK123_PRESET_EN);
+	if (ret) {
+		dev_err(&i2c->dev, "Failed to clear PRESET_EN bit: %d\n", ret);
+		return ret;
+	}
+
 	/* Set reset behavior on assertion of WDOG_B signal */
 	ret = regmap_update_bits(pca9450->regmap, PCA9450_REG_RESET_CTRL,
 				WDOG_B_CFG_MASK, WDOG_B_CFG_COLD_LDO12);
diff --git a/include/linux/regulator/pca9450.h b/include/linux/regulator/pca9450.h
index ccdb5320a240..71902f41c919 100644
--- a/include/linux/regulator/pca9450.h
+++ b/include/linux/regulator/pca9450.h
@@ -147,6 +147,9 @@ enum {
 #define BUCK6_FPWM			0x04
 #define BUCK6_ENMODE_MASK		0x03
 
+/* PCA9450_REG_BUCK123_PRESET_EN bit */
+#define BUCK123_PRESET_EN		0x80
+
 /* PCA9450_BUCK1OUT_DVS0 bits */
 #define BUCK1OUT_DVS0_MASK		0x7F
 #define BUCK1OUT_DVS0_DEFAULT		0x14
-- 
2.25.1

Re: [PATCH v2] regulator: pca9450: Clear PRESET_EN bit to fix BUCK1/2/3 voltage setting

[Mark Brown]

On Mon, 22 Feb 2021 12:52:20 +0100, Schrempf Frieder wrote:
> The driver uses the DVS registers PCA9450_REG_BUCKxOUT_DVS0 to set the
> voltage for the buck regulators 1, 2 and 3. This has no effect as the
> PRESET_EN bit is set by default and therefore the preset values are used
> instead, which are set to 850 mV.
> 
> To fix this we clear the PRESET_EN bit at time of initialization.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/1] regulator: pca9450: Clear PRESET_EN bit to fix BUCK1/2/3 voltage setting
      commit: 66f9f2d5d94f374605d829b9e690e8cdc9d0d05d

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