4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita <akinobu.mita@xxxxxxxxx> commit 0d106b74c558e3000aa0e058b4725cacb70ce77a upstream. The ti-ads1015 driver has eight iio voltage channels and each iio channel can hold own sampling frequency information. The ADS1015 device only have a single config register which contains an input multiplexer selection, PGA and data rate settings. So the driver should load the correct settings when the input multiplexer selection is changed. However, regardless of which channlel is currently selected, changing any iio channel's sampling frequency information immediately overwrites the current data rate setting in the config register. It breaks the current data rate setting if the different channel's sampling frequency information is changed because the data rate setting is not reloaded when the input multiplexer is switched. This removes the unexpected config register update and correctly load the data rate setting before getting adc result. Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/adc/ti-ads1015.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -252,9 +252,11 @@ int ads1015_get_adc_result(struct ads101 ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG, ADS1015_CFG_MUX_MASK | - ADS1015_CFG_PGA_MASK, + ADS1015_CFG_PGA_MASK | + ADS1015_CFG_DR_MASK, chan << ADS1015_CFG_MUX_SHIFT | - pga << ADS1015_CFG_PGA_SHIFT, + pga << ADS1015_CFG_PGA_SHIFT | + dr << ADS1015_CFG_DR_SHIFT, &change); if (ret < 0) return ret; @@ -325,25 +327,16 @@ static int ads1015_set_scale(struct ads1 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate) { - int i, ret, rindex = -1; + int i; - for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) + for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) { if (data->data_rate[i] == rate) { - rindex = i; - break; + data->channel_data[chan].data_rate = i; + return 0; } - if (rindex < 0) - return -EINVAL; - - ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG, - ADS1015_CFG_DR_MASK, - rindex << ADS1015_CFG_DR_SHIFT); - if (ret < 0) - return ret; - - data->channel_data[chan].data_rate = rindex; + } - return 0; + return -EINVAL; } static int ads1015_read_raw(struct iio_dev *indio_dev,