The controller is powered by an externally switched PVDD rail. Get and enable it in the i2c phy probe, before any of the chip's pins is driven or its clock started, so the chip's power does not depend on whatever state the bootloader or platform left the rail in. Boards that do not describe the supply resolve to a dummy regulator, so the existing users keep working; they gain the regulator core's dummy-supply warning until their DTs describe the rail. Assisted-by: Claude:claude-fable-5 Signed-off-by: Jorijn van der Graaf --- drivers/nfc/s3fwrn5/i2c.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/nfc/s3fwrn5/i2c.c b/drivers/nfc/s3fwrn5/i2c.c index c528c085b43e..f93d8b47b65e 100644 --- a/drivers/nfc/s3fwrn5/i2c.c +++ b/drivers/nfc/s3fwrn5/i2c.c @@ -11,6 +11,7 @@ #include #include #include +#include #include @@ -158,6 +159,11 @@ static int s3fwrn5_i2c_probe(struct i2c_client *client) phy->i2c_dev = client; i2c_set_clientdata(client, phy); + ret = devm_regulator_get_enable(&client->dev, "pvdd"); + if (ret) + return dev_err_probe(&client->dev, ret, + "failed to enable pvdd\n"); + phy->common.gpio_en = devm_gpiod_get(&client->dev, "en", GPIOD_OUT_HIGH); if (IS_ERR(phy->common.gpio_en)) return PTR_ERR(phy->common.gpio_en); -- 2.55.0