2022-07-04 17:21:30

by Marcus Folkesson

Subject: [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register

Keep using managed resources as much as possible.

Signed-off-by: Marcus Folkesson <[email protected]>
---
drivers/iio/adc/mcp3911.c | 43 ++++++++++++++++-----------------------
1 file changed, 18 insertions(+), 25 deletions(-)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 890af7dca62d..f5fd9da6ab55 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -258,6 +258,16 @@ static int mcp3911_config(struct mcp3911 *adc)
return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
}

+static void mcp3911_cleanup(void *_adc)
+{
+ struct mcp3911 *adc = _adc;
+
+ if (adc->clki)
+ clk_disable_unprepare(adc->clki);
+ if (adc->vref)
+ regulator_disable(adc->vref);
+}
+
static int mcp3911_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
@@ -271,6 +281,10 @@ static int mcp3911_probe(struct spi_device *spi)
adc = iio_priv(indio_dev);
adc->spi = spi;

+ ret = devm_add_action_or_reset(&spi->dev, mcp3911_cleanup, adc);
+ if (ret)
+ return ret;
+
adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
if (IS_ERR(adc->vref)) {
if (PTR_ERR(adc->vref) == -ENODEV) {
@@ -296,21 +310,20 @@ static int mcp3911_probe(struct spi_device *spi)
dev_err(&adc->spi->dev,
"failed to get adc clk (%ld)\n",
PTR_ERR(adc->clki));
- ret = PTR_ERR(adc->clki);
- goto reg_disable;
+ return PTR_ERR(adc->clki);
}
} else {
ret = clk_prepare_enable(adc->clki);
if (ret < 0) {
dev_err(&adc->spi->dev,
"Failed to enable clki: %d\n", ret);
- goto reg_disable;
+ return ret;
}
}

ret = mcp3911_config(adc);
if (ret)
- goto clk_disable;
+ return ret;

indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -322,31 +335,11 @@ static int mcp3911_probe(struct spi_device *spi)

mutex_init(&adc->lock);

- ret = iio_device_register(indio_dev);
- if (ret)
- goto clk_disable;
-
- return ret;
-
-clk_disable:
- clk_disable_unprepare(adc->clki);
-reg_disable:
- if (adc->vref)
- regulator_disable(adc->vref);
-
- return ret;
+ return devm_iio_device_register(&adc->spi->dev, indio_dev);
}

static void mcp3911_remove(struct spi_device *spi)
{
- struct iio_dev *indio_dev = spi_get_drvdata(spi);
- struct mcp3911 *adc = iio_priv(indio_dev);
-
- iio_device_unregister(indio_dev);
-
- clk_disable_unprepare(adc->clki);
- if (adc->vref)
- regulator_disable(adc->vref);
}

static const struct of_device_id mcp3911_dt_ids[] = {
--
2.36.1

2022-07-16 18:06:55

by Jonathan Cameron

Subject: Re: [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register

On Mon, 4 Jul 2022 19:21:11 +0200
Marcus Folkesson <[email protected]> wrote:

> Keep using managed resources as much as possible.
>
> Signed-off-by: Marcus Folkesson <[email protected]>
> ---
> drivers/iio/adc/mcp3911.c | 43 ++++++++++++++++-----------------------
> 1 file changed, 18 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
> index 890af7dca62d..f5fd9da6ab55 100644
> --- a/drivers/iio/adc/mcp3911.c
> +++ b/drivers/iio/adc/mcp3911.c
> @@ -258,6 +258,16 @@ static int mcp3911_config(struct mcp3911 *adc)
> return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
> }
>
> +static void mcp3911_cleanup(void *_adc)

Very rarely a good idea to cleanup more than one thing in a given
devm_ callback.

> +{
> + struct mcp3911 *adc = _adc;
> +
> + if (adc->clki)
> + clk_disable_unprepare(adc->clki);
> + if (adc->vref)
> + regulator_disable(adc->vref);
> +}
> +
> static int mcp3911_probe(struct spi_device *spi)
> {
> struct iio_dev *indio_dev;
> @@ -271,6 +281,10 @@ static int mcp3911_probe(struct spi_device *spi)
> adc = iio_priv(indio_dev);
> adc->spi = spi;
>
> + ret = devm_add_action_or_reset(&spi->dev, mcp3911_cleanup, adc);
> + if (ret)
> + return ret;

You should only register this 'after' what it cleans up. I want to see
a clear pairing between setup and tear down.

In this particular case register two callbacks, and only register them
if they have anything to do. i.e. the ->clki and ->vref are not null
respectively.

Jonathan


> +
> adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
> if (IS_ERR(adc->vref)) {
> if (PTR_ERR(adc->vref) == -ENODEV) {
> @@ -296,21 +310,20 @@ static int mcp3911_probe(struct spi_device *spi)
> dev_err(&adc->spi->dev,
> "failed to get adc clk (%ld)\n",
> PTR_ERR(adc->clki));
> - ret = PTR_ERR(adc->clki);
> - goto reg_disable;
> + return PTR_ERR(adc->clki);
> }
> } else {
> ret = clk_prepare_enable(adc->clki);
> if (ret < 0) {
> dev_err(&adc->spi->dev,
> "Failed to enable clki: %d\n", ret);
> - goto reg_disable;
> + return ret;
> }
> }
>
> ret = mcp3911_config(adc);
> if (ret)
> - goto clk_disable;
> + return ret;
>
> indio_dev->name = spi_get_device_id(spi)->name;
> indio_dev->modes = INDIO_DIRECT_MODE;
> @@ -322,31 +335,11 @@ static int mcp3911_probe(struct spi_device *spi)
>
> mutex_init(&adc->lock);
>
> - ret = iio_device_register(indio_dev);
> - if (ret)
> - goto clk_disable;
> -
> - return ret;
> -
> -clk_disable:
> - clk_disable_unprepare(adc->clki);
> -reg_disable:
> - if (adc->vref)
> - regulator_disable(adc->vref);
> -
> - return ret;
> + return devm_iio_device_register(&adc->spi->dev, indio_dev);
> }
>
> static void mcp3911_remove(struct spi_device *spi)
> {
> - struct iio_dev *indio_dev = spi_get_drvdata(spi);
> - struct mcp3911 *adc = iio_priv(indio_dev);
> -
> - iio_device_unregister(indio_dev);
> -
> - clk_disable_unprepare(adc->clki);
> - if (adc->vref)
> - regulator_disable(adc->vref);
> }
>
> static const struct of_device_id mcp3911_dt_ids[] = {