| Message ID | 20240208094339.82633-1-arturas.moskvinas@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: adc: mcp320x: Simplify device removal logic | expand |
On Thu, 8 Feb 2024 11:43:39 +0200 Arturas Moskvinas <arturas.moskvinas@gmail.com> wrote: > Use devm_* APIs to enable regulator and to register in IIO infrastructure. > > Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com> Don't get the same regulator twice so as automate turning it off. The devm_regulator_get_enable() call is carefully hiding the regulator for cases where the driver never accesses it. Here we need it to read the voltage. To convert such a case to fully devm managed, use a devm_add_action_or_reset() and a custom callback. > --- > drivers/iio/adc/mcp320x.c | 19 ++----------------- > 1 file changed, 2 insertions(+), 17 deletions(-) > > diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c > index f3b81798b3c9..4685eed35271 100644 > --- a/drivers/iio/adc/mcp320x.c > +++ b/drivers/iio/adc/mcp320x.c > @@ -388,7 +388,6 @@ static int mcp320x_probe(struct spi_device *spi) > indio_dev->name = spi_get_device_id(spi)->name; > indio_dev->modes = INDIO_DIRECT_MODE; > indio_dev->info = &mcp320x_info; > - spi_set_drvdata(spi, indio_dev); > > device_index = spi_get_device_id(spi)->driver_data; > chip_info = &mcp320x_chip_infos[device_index]; > @@ -441,31 +440,17 @@ static int mcp320x_probe(struct spi_device *spi) > if (IS_ERR(adc->reg)) > return PTR_ERR(adc->reg); Just above here is the first regulator get. Whilst it may work we should not get it twice as the logic gets confused at the very least. > > - ret = regulator_enable(adc->reg); > + ret = devm_regulator_get_enable(&spi->dev, "vref"); > if (ret < 0) > return ret; > > mutex_init(&adc->lock); > > - ret = iio_device_register(indio_dev); > - if (ret < 0) > - goto reg_disable; > - > - return 0; > - > -reg_disable: > - regulator_disable(adc->reg); > - > - return ret; > + return devm_iio_device_register(&spi->dev, indio_dev); > } > > static void mcp320x_remove(struct spi_device *spi) > { > - struct iio_dev *indio_dev = spi_get_drvdata(spi); > - struct mcp320x *adc = iio_priv(indio_dev); > - > - iio_device_unregister(indio_dev); > - regulator_disable(adc->reg); > } Had the change otherwise been ok... You should be able to remove this function completely now it is empty. https://elixir.bootlin.com/linux/latest/source/drivers/spi/spi.c#L446 checks it's existence before calling it. Thanks Jonathan > > static const struct of_device_id mcp320x_dt_ids[] = { > > base-commit: 047371968ffc470769f541d6933e262dc7085456
On 2/10/24 17:58, Jonathan Cameron wrote: >> Use devm_* APIs to enable regulator and to register in IIO infrastructure. >> >> Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com> > > Don't get the same regulator twice so as automate turning it off. > The devm_regulator_get_enable() call is carefully hiding the > regulator for cases where the driver never accesses it. > > Here we need it to read the voltage. > > To convert such a case to fully devm managed, use a > devm_add_action_or_reset() and a custom callback. This is exactly the reason I wanted to use devm_regulator_get_enable() instead of devm_add_action_or_reset + custom callback which I saw in other ADCs code. It seems quite repetitive. Wondering if this could be addressed by regulator subsystem to provide device managed method which gets _enabled_ regulator resource and an automated disabling + resource freeing? We will loose fine grained information where failure happened exactly - getting resource or enabling regulator though... >> static void mcp320x_remove(struct spi_device *spi) >> { >> - struct iio_dev *indio_dev = spi_get_drvdata(spi); >> - struct mcp320x *adc = iio_priv(indio_dev); >> - >> - iio_device_unregister(indio_dev); >> - regulator_disable(adc->reg); >> } > Had the change otherwise been ok... > > You should be able to remove this function completely now it is empty. > https://elixir.bootlin.com/linux/latest/source/drivers/spi/spi.c#L446 > checks it's existence before calling it. Ack, will address with V2 patch. Arturas Moskvinas
diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index f3b81798b3c9..4685eed35271 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -388,7 +388,6 @@ static int mcp320x_probe(struct spi_device *spi) indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &mcp320x_info; - spi_set_drvdata(spi, indio_dev); device_index = spi_get_device_id(spi)->driver_data; chip_info = &mcp320x_chip_infos[device_index]; @@ -441,31 +440,17 @@ static int mcp320x_probe(struct spi_device *spi) if (IS_ERR(adc->reg)) return PTR_ERR(adc->reg); - ret = regulator_enable(adc->reg); + ret = devm_regulator_get_enable(&spi->dev, "vref"); if (ret < 0) return ret; mutex_init(&adc->lock); - ret = iio_device_register(indio_dev); - if (ret < 0) - goto reg_disable; - - return 0; - -reg_disable: - regulator_disable(adc->reg); - - return ret; + return devm_iio_device_register(&spi->dev, indio_dev); } static void mcp320x_remove(struct spi_device *spi) { - struct iio_dev *indio_dev = spi_get_drvdata(spi); - struct mcp320x *adc = iio_priv(indio_dev); - - iio_device_unregister(indio_dev); - regulator_disable(adc->reg); } static const struct of_device_id mcp320x_dt_ids[] = {
Use devm_* APIs to enable regulator and to register in IIO infrastructure. Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com> --- drivers/iio/adc/mcp320x.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-) base-commit: 047371968ffc470769f541d6933e262dc7085456