From: Matti Vaittinen <mazziesaccount@gmail.com>

The ROHM BD72720 supports so called LDON-HEAD -mode, in which the buck10
is expected to be supplying power for an LDO. In this mode, the buck10
voltage will follow what is set for the LDO, on order to lower the
power-loss in the LDO.

This hardware configuration can be adverticed via the device-tree. When
this is done, the Linux driver should omit registering the voltage
control operations for the buck10, because the voltage control is now
done by the hardware.

This is done by modifying the buck10 regulator descriptor, before
passing it to the regulator registration functions. There is an
off-by-one error when the regulator descriptor array is indexed, and
wrong descriptor is modified causing the LDO1 operations to be modified
instead of the BUCK10 operations.

Fix this by correcting the indexing.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: f16a9d76a71d ("regulator: bd71828: Support ROHM BD72720")
---
 drivers/regulator/bd71828-regulator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/regulator/bd71828-regulator.c b/drivers/regulator/bd71828-regulator.c
index c8f3343cfe23..473beb4399d9 100644
--- a/drivers/regulator/bd71828-regulator.c
+++ b/drivers/regulator/bd71828-regulator.c
@@ -785,7 +785,7 @@ static const struct bd71828_regulator_data bd71828_rdata[] = {
 	},
 };
 
-#define BD72720_BUCK10_DESC_INDEX 10
+#define BD72720_BUCK10_DESC_INDEX 9
 #define BD72720_NUM_BUCK_VOLTS 0x100
 #define BD72720_NUM_LDO_VOLTS 0x100
 #define BD72720_NUM_LDO12346_VOLTS 0x80

base-commit: f338e77383789c0cae23ca3d48adcc5e9e137e3c
-- 
2.53.0

On Tue, 07 Apr 2026 16:27:19 +0300, Matti Vaittinen wrote:
> regulator: bd71828-regulator.c: Fix LDON-HEAD mode

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-7.0

Thanks!

[1/1] regulator: bd71828-regulator.c: Fix LDON-HEAD mode
      https://git.kernel.org/broonie/regulator/c/b1baaff4e523

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