Re: [PATCH] iio: st_sensors: add debugfs register read hook

[Denis Ciocca <denis.ciocca@st.com>]

Hi Linus,

Thanks for your job! My comments inline.

> This adds a debugfs hook to read/write registers in the ST
> sensors using debugfs. Proved to be awesome help when trying
> to debug why IRQs do not arrive.
>
> Cc: Denis Ciocca <denis.ciocca@st.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>   drivers/iio/accel/st_accel_core.c               |  1 +
>   drivers/iio/common/st_sensors/st_sensors_core.c | 21 +++++++++++++++++++++
>   drivers/iio/gyro/st_gyro_core.c                 |  1 +
>   drivers/iio/magnetometer/st_magn_core.c         |  1 +
>   drivers/iio/pressure/st_pressure_core.c         |  1 +
>   include/linux/iio/common/st_sensors.h           |  4 ++++
>   6 files changed, 29 insertions(+)
>
> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
> index 6617e779aa87..f5f2684c0090 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -612,6 +612,7 @@ static const struct iio_info accel_info = {
>   	.attrs = &st_accel_attribute_group,
>   	.read_raw = &st_accel_read_raw,
>   	.write_raw = &st_accel_write_raw,
> +	.debugfs_reg_access = st_sensors_debugfs_reg_access,
To keep the style, can u use & before the function name?


>   };
>   
>   #ifdef CONFIG_IIO_TRIGGER
> diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
> index 8086cbcff87d..05b519ef111f 100644
> --- a/drivers/iio/common/st_sensors/st_sensors_core.c
> +++ b/drivers/iio/common/st_sensors/st_sensors_core.c
> @@ -44,6 +44,27 @@ st_sensors_write_data_with_mask_error:
>   	return err;
>   }
>   
> +int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
> +				  unsigned reg, unsigned writeval,
> +				  unsigned *readval)
> +{
> +	struct st_sensor_data *sdata = iio_priv(indio_dev);
> +	u8 readdata;
> +	int err;
> +
> +	if (!readval)
> +		return sdata->tf->write_byte(&sdata->tb, sdata->dev,
> +					     (u8)reg, (u8)writeval);
> +
> +	err = sdata->tf->read_byte(&sdata->tb, sdata->dev, (u8)reg, &readdata);
> +	if (err < 0)
> +		return err;
> +
> +	*readval = (unsigned)readdata;
> +
> +	return 0;
> +}
> +
This function should export the symbol when modules are in use...


>   static int st_sensors_match_odr(struct st_sensor_settings *sensor_settings,
>   			unsigned int odr, struct st_sensor_odr_avl *odr_out)
>   {
> diff --git a/drivers/iio/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
> index ffe96642b6d0..39138e53ba24 100644
> --- a/drivers/iio/gyro/st_gyro_core.c
> +++ b/drivers/iio/gyro/st_gyro_core.c
> @@ -380,6 +380,7 @@ static const struct iio_info gyro_info = {
>   	.attrs = &st_gyro_attribute_group,
>   	.read_raw = &st_gyro_read_raw,
>   	.write_raw = &st_gyro_write_raw,
> +	.debugfs_reg_access = st_sensors_debugfs_reg_access,
>   };
& same here

>   
>   #ifdef CONFIG_IIO_TRIGGER
> diff --git a/drivers/iio/magnetometer/st_magn_core.c b/drivers/iio/magnetometer/st_magn_core.c
> index b4bcfb790f49..e4da514efa9f 100644
> --- a/drivers/iio/magnetometer/st_magn_core.c
> +++ b/drivers/iio/magnetometer/st_magn_core.c
> @@ -475,6 +475,7 @@ static const struct iio_info magn_info = {
>   	.attrs = &st_magn_attribute_group,
>   	.read_raw = &st_magn_read_raw,
>   	.write_raw = &st_magn_write_raw,
> +	.debugfs_reg_access = st_sensors_debugfs_reg_access,
>   };
& same here

>   
>   int st_magn_common_probe(struct iio_dev *indio_dev)
> diff --git a/drivers/iio/pressure/st_pressure_core.c b/drivers/iio/pressure/st_pressure_core.c
> index e881fa6291e9..1306d8284bdd 100644
> --- a/drivers/iio/pressure/st_pressure_core.c
> +++ b/drivers/iio/pressure/st_pressure_core.c
> @@ -397,6 +397,7 @@ static const struct iio_info press_info = {
>   	.attrs = &st_press_attribute_group,
>   	.read_raw = &st_press_read_raw,
>   	.write_raw = &st_press_write_raw,
> +	.debugfs_reg_access = st_sensors_debugfs_reg_access,
>   };
& same here

>   
>   #ifdef CONFIG_IIO_TRIGGER
> diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h
> index 2c476acb87d9..d8b4a7bc4029 100644
> --- a/include/linux/iio/common/st_sensors.h
> +++ b/include/linux/iio/common/st_sensors.h
> @@ -269,6 +269,10 @@ void st_sensors_power_enable(struct iio_dev *indio_dev);
>   
>   void st_sensors_power_disable(struct iio_dev *indio_dev);
>   
> +int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
> +				  unsigned reg, unsigned writeval,
> +				  unsigned *readval);
> +
>   int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr);
>   
>   int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable);