4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita <akinobu.mita@xxxxxxxxx> commit e8245c68350104b6022b6783719e843d69ea7c43 upstream. The ADS1015 device have two operating modes, continuous conversion mode and single-shot mode. This driver assumes that the continuous conversion mode is selected by runtime resume callback when the ADC result is requested. If CONFIG_PM is disabled, the device is always in the default single-shot mode and no one begins a single conversion. So the conversion register doesn't contain valid ADC result. Fix it by changing the continuous mode in probe function. 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 | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -617,6 +617,13 @@ static int ads1015_probe(struct i2c_clie dev_err(&client->dev, "iio triggered buffer setup failed\n"); return ret; } + + ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG, + ADS1015_CFG_MOD_MASK, + ADS1015_CONTINUOUS << ADS1015_CFG_MOD_SHIFT); + if (ret) + return ret; + ret = pm_runtime_set_active(&client->dev); if (ret) goto err_buffer_cleanup;