diff options
| author | Dragos Bogdan <dragos.bogdan@analog.com> | 2017-09-05 15:14:45 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-12 11:27:34 +0200 |
| commit | 4b9c62a00aeae875cecbc9ac67753534e2681e4b (patch) | |
| tree | b51515dc2b622f1d36b14e9bef584263b99dce5c /drivers | |
| parent | 0bab54141bac4025534795eb83c70a69ce6e91b3 (diff) | |
iio: ad_sigma_delta: Implement a dedicated reset function
commit 7fc10de8d49a748c476532c9d8e8fe19e548dd67 upstream.
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: Dragos Bogdan <dragos.bogdan@analog.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/adc/ad_sigma_delta.c | 28 |
1 files changed, 28 insertions, 0 deletions
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 @@ out: } 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) { |