On Sun, 15 Sep 2019 13:59:48 +0100 Jonathan Cameron <[email protected]> wrote:
> On Mon, 9 Sep 2019 14:37:48 +0200 > Andreas Klinger <[email protected]> wrote: > > > Set gain in hx711_reset() to its default value after a reset cycle. This > > omits one precautionary read cycle, because the read is performed in > > hx711_set_gain_for_channel() anyway if gain has changed. > > > > Check for DOUT low and if its high wait some time if it goes down > > instead of doing a blind reset cycle when DOUT is not down. > > > > This is a performance optimization which allows to query the sensor with > > a higher frequency. > > > > Signed-off-by: Andreas Klinger <[email protected]> > Hi Andreas, > > This one seems to have a slightly non trivial interaction with patch 1 > so will have to wait until the fixes-togreg branch works it's way back > around to the upstream for the togreg branch. Give me a poke if I seem > to have lost it! Applied. Thanks, Jonathan > > Thanks, > > Jonathan > > > --- > > drivers/iio/adc/hx711.c | 23 +++++------------------ > > 1 file changed, 5 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c > > index 0678964dbd21..c8686558429b 100644 > > --- a/drivers/iio/adc/hx711.c > > +++ b/drivers/iio/adc/hx711.c > > @@ -23,6 +23,7 @@ > > > > /* gain to pulse and scale conversion */ > > #define HX711_GAIN_MAX 3 > > +#define HX711_RESET_GAIN 128 > > > > struct hx711_gain_to_scale { > > int gain; > > @@ -100,7 +101,6 @@ struct hx711_data { > > > > static int hx711_cycle(struct hx711_data *hx711_data) > > { > > - int val; > > unsigned long flags; > > > > /* > > @@ -186,8 +186,7 @@ static int hx711_wait_for_ready(struct hx711_data > > *hx711_data) > > > > static int hx711_reset(struct hx711_data *hx711_data) > > { > > - int ret; > > - int val = gpiod_get_value(hx711_data->gpiod_dout); > > + int val = hx711_wait_for_ready(hx711_data); > > > > if (val) { > > /* > > @@ -203,22 +202,10 @@ static int hx711_reset(struct hx711_data *hx711_data) > > msleep(10); > > gpiod_set_value(hx711_data->gpiod_pd_sck, 0); > > > > - ret = hx711_wait_for_ready(hx711_data); > > - if (ret) > > - return ret; > > - /* > > - * after a reset the gain is 128 so we do a dummy read > > - * to set the gain for the next read > > - */ > > - ret = hx711_read(hx711_data); > > - if (ret < 0) > > - return ret; > > - > > - /* > > - * after a dummy read we need to wait vor readiness > > - * for not mixing gain pulses with the clock > > - */ > > val = hx711_wait_for_ready(hx711_data); > > + > > + /* after a reset the gain is 128 */ > > + hx711_data->gain_set = HX711_RESET_GAIN; > > } > > > > return val; >
