3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Dragos Bogdan dragos.bogdan@analog.com
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: Ben Hutchings ben@decadent.org.uk --- drivers/iio/adc/ad_sigma_delta.c | 28 ++++++++++++++++++++++++++++ include/linux/iio/adc/ad_sigma_delta.h | 3 +++ 2 files changed, 31 insertions(+)
--- 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) { --- 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_delt 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,