From 56b57a9eb853a5d1fc31d755b0b000c4bb4b1a2d Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 21 Jul 2017 00:24:23 +0900 Subject: [PATCH] iio: adc: ti-ads1015: remove unnecessary config register update The ti-ads1015 driver has eight iio voltage channels and each iio channel can hold own scale 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 scale information immediately overwrites the current PGA setting in the config register. It is harmless because the correct PGA settings are reloaded just before getting adc result anyway. But it is unnecessary register update and should be removed. Cc: Daniel Baluta Cc: Jonathan Cameron Signed-off-by: Akinobu Mita Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ti-ads1015.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c index ed911776e283..6f22f46000e2 100644 --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -312,28 +312,18 @@ static int ads1015_set_scale(struct ads1015_data *data, struct iio_chan_spec const *chan, int scale, int uscale) { - int i, ret, rindex = -1; + int i; int fullscale = div_s64((scale * 1000000LL + uscale) << (chan->scan_type.realbits - 1), 1000000); for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) { if (ads1015_fullscale_range[i] == fullscale) { - rindex = i; - break; + data->channel_data[chan->address].pga = i; + return 0; } } - if (rindex < 0) - return -EINVAL; - - ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG, - ADS1015_CFG_PGA_MASK, - rindex << ADS1015_CFG_PGA_SHIFT); - if (ret < 0) - return ret; - - data->channel_data[chan->address].pga = rindex; - return 0; + return -EINVAL; } static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate) -- 2.20.1