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

There are two ways to set the output voltage of the LD05
regulator. First by writing to the voltage selection registers
and second by toggling the SD_VSEL signal.

Usually board designers connect SD_VSEL to the VSELECT signal
controlled by the USDHC controller, but in some cases the
signal is hardwired to a fixed low level (therefore selecting
3.3V as initial value for allowing to boot from the SD card).

In these cases, the voltage is only determined by the value
of the LDO5CTRL_L register. Introduce a property
nxp,sd-vsel-fixed-low to let the driver know that SD_VSEL
is low and there is no GPIO to actually get that
information from dynamically.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
This was originally part of the series here: [1]. The other patches
were already applied, but this one is missing in regulator/for-next
and linux-next, which is why I'm resending.

[1] https://patchwork.kernel.org/project/linux-arm-kernel/cover/20241218152842.97483-1-frieder@fris.de/
---
---
 drivers/regulator/pca9450-regulator.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/regulator/pca9450-regulator.c b/drivers/regulator/pca9450-regulator.c
index 8f81d813640d..a56f3ab754fa 100644
--- a/drivers/regulator/pca9450-regulator.c
+++ b/drivers/regulator/pca9450-regulator.c
@@ -36,6 +36,7 @@ struct pca9450 {
 	enum pca9450_chip_type type;
 	unsigned int rcnt;
 	int irq;
+	bool sd_vsel_fixed_low;
 };
 
 static const struct regmap_range pca9450_status_range = {
@@ -102,6 +103,9 @@ static unsigned int pca9450_ldo5_get_reg_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pca9450 *pca9450 = rdev_get_drvdata(rdev);
 
+	if (pca9450->sd_vsel_fixed_low)
+		return PCA9450_REG_LDO5CTRL_L;
+
 	if (pca9450->sd_vsel_gpio && !gpiod_get_value(pca9450->sd_vsel_gpio))
 		return PCA9450_REG_LDO5CTRL_L;
 
@@ -1100,6 +1104,9 @@ static int pca9450_i2c_probe(struct i2c_client *i2c)
 		return ret;
 	}
 
+	pca9450->sd_vsel_fixed_low =
+		of_property_read_bool(ldo5->dev.of_node, "nxp,sd-vsel-fixed-low");
+
 	dev_info(&i2c->dev, "%s probed.\n",
 		type == PCA9450_TYPE_PCA9450A ? "pca9450a" :
 		(type == PCA9450_TYPE_PCA9451A ? "pca9451a" : "pca9450bc"));
-- 
2.48.1

On Mon, 03 Mar 2025 14:22:54 +0100, Frieder Schrempf wrote:
> There are two ways to set the output voltage of the LD05
> regulator. First by writing to the voltage selection registers
> and second by toggling the SD_VSEL signal.
> 
> Usually board designers connect SD_VSEL to the VSELECT signal
> controlled by the USDHC controller, but in some cases the
> signal is hardwired to a fixed low level (therefore selecting
> 3.3V as initial value for allowing to boot from the SD card).
> 
> [...]

Applied to

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

Thanks!

[1/1] regulator: pca9450: Handle hardware with fixed SD_VSEL for LDO5
      commit: c8c1ab2c5cb797fe455aa18b4ab7bf39897627f6

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