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Commit 7fc10de8 authored by Dragos Bogdan's avatar Dragos Bogdan Committed by Jonathan Cameron
Browse files

iio: ad_sigma_delta: Implement a dedicated reset function 



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.

Needed for the patch:  iio: ad7793: Fix the serial interface reset
Signed-off-by: default avatarDragos Bogdan <dragos.bogdan@analog.com>
Acked-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 4b1f0c31

drivers/iio/adc/ad_sigma_delta.c

+28 −0
Original line number Diff line number Diff line
@@ -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)

{

include/linux/iio/adc/ad_sigma_delta.h

+3 −0
Original line number Diff line number Diff line
@@ -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,