On 09/05/2017 02:14 PM, Dragos Bogdan wrote:
> Since most of the SD ADCs have the option of reseting the serial
> interface by sending a number of SCLKs with CS = 0 and DIN = 1,
> a dedicated function that can do this is usefull.
>
> Signed-off-by: Dragos Bogdan <dragos.bog...@analog.com>
Acked-by: Lars-Peter Clausen <l...@metafoo.de>
> ---
> drivers/iio/adc/ad_sigma_delta.c | 28 ++++++++++++++++++++++++++++
> include/linux/iio/adc/ad_sigma_delta.h | 3 +++
> 2 files changed, 31 insertions(+)
>
> diff --git a/drivers/iio/adc/ad_sigma_delta.c
> b/drivers/iio/adc/ad_sigma_delta.c
> index d10bd0c97233..22c4c17cd996 100644
> --- a/drivers/iio/adc/ad_sigma_delta.c
> +++ b/drivers/iio/adc/ad_sigma_delta.c
> @@ -177,6 +177,34 @@ int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta,
> }
> EXPORT_SYMBOL_GPL(ad_sd_read_reg);
>
> +/**
> + * ad_sd_reset() - Reset the serial interface
> + *
> + * @sigma_delta: The sigma delta device
> + * @reset_length: Number of SCLKs with DIN = 1
> + *
> + * Returns 0 on success, an error code otherwise.
> + **/
> +int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
> + unsigned int reset_length)
> +{
> + uint8_t *buf;
> + unsigned int size;
> + int ret;
> +
> + size = DIV_ROUND_UP(reset_length, 8);
> + buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + memset(buf, 0xff, size);
> + ret = spi_write(sigma_delta->spi, buf, size);
> + kfree(buf);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(ad_sd_reset);
> +
> static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
> unsigned int mode, unsigned int channel)
> {
> diff --git a/include/linux/iio/adc/ad_sigma_delta.h
> b/include/linux/iio/adc/ad_sigma_delta.h
> index 5ba430cc9a87..1fc7abd28b0b 100644
> --- a/include/linux/iio/adc/ad_sigma_delta.h
> +++ b/include/linux/iio/adc/ad_sigma_delta.h
> @@ -111,6 +111,9 @@ int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta,
> unsigned int reg,
> int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
> unsigned int size, unsigned int *val);
>
> +int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
> + unsigned int reset_length);
> +
> int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
> const struct iio_chan_spec *chan, int *val);
> int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
>
