[PATCH v5 09/11] iio: adc: hx711: pass iio_chan_spec to hx711_reset_read

[Piyush Patle <piyushpatle228@gmail.com>]

Change hx711_reset_read() to accept the channel descriptor directly and
update its callers accordingly.

Split the existing HX711 channel-selection work into a small helper so a
later variant-specific change can add a matching helper without growing
hx711_reset_read() further.

No functional change.

Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
---
Changes in v5:
- Use "change" instead of "patch" when referring to the later HX710B
  follow-up.
- Extract hx711_set_hx711_channel() so the HX710B patch can add a
  matching helper.
- Reindent the triggered-buffer call site as requested.
Changes in v4:
- New patch split out from the earlier refactor during review.
---
drivers/iio/adc/hx711.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c
index 15b9f78b6a25..914c6efd0f96 100644
--- a/drivers/iio/adc/hx711.c
+++ b/drivers/iio/adc/hx711.c
@@ -264,7 +264,22 @@ static int hx711_set_gain_for_channel(struct hx711_data *hx711_data, int chan)
 	return 0;
 }
 
-static int hx711_reset_read(struct hx711_data *hx711_data, int chan)
+static int hx711_set_hx711_channel(struct hx711_data *hx711_data,
+				   const struct iio_chan_spec *chan,
+				   int *trailing_pulses)
+{
+	int ret;
+
+	ret = hx711_set_gain_for_channel(hx711_data, chan->channel);
+	if (ret < 0)
+		return ret;
+
+	*trailing_pulses = hx711_get_gain_to_pulse(hx711_data->gain_set);
+	return 0;
+}
+
+static int hx711_reset_read(struct hx711_data *hx711_data,
+			    const struct iio_chan_spec *chan)
 {
 	int trailing_pulses;
 	int ret;
@@ -278,11 +293,10 @@ static int hx711_reset_read(struct hx711_data *hx711_data, int chan)
 		return -EIO;
 	}
 
-	ret = hx711_set_gain_for_channel(hx711_data, chan);
+	ret = hx711_set_hx711_channel(hx711_data, chan, &trailing_pulses);
 	if (ret < 0)
 		return ret;
 
-	trailing_pulses = hx711_get_gain_to_pulse(hx711_data->gain_set);
 	return hx711_read(hx711_data, trailing_pulses);
 }
 
@@ -296,7 +310,7 @@ static int hx711_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&hx711_data->lock);
 
-		*val = hx711_reset_read(hx711_data, chan->channel);
+		*val = hx711_reset_read(hx711_data, chan);
 
 		mutex_unlock(&hx711_data->lock);
 
@@ -386,8 +400,8 @@ static irqreturn_t hx711_trigger(int irq, void *p)
 	memset(&hx711_data->buffer, 0, sizeof(hx711_data->buffer));
 
 	iio_for_each_active_channel(indio_dev, i) {
-		hx711_data->buffer.channel[j] = hx711_reset_read(hx711_data,
-					indio_dev->channels[i].channel);
+		hx711_data->buffer.channel[j] =
+			hx711_reset_read(hx711_data, &indio_dev->channels[i]);
 		j++;
 	}
 
-- 
2.43.0