Re: [PATCH 07/16] iio: adc: at91-sama5d2_adc: simplify the code in at91_adc_read_info_raw()
From: Jonathan Cameron <jic23@kernel.org>
Date: 2022-06-11 17:45:03
Also in:
linux-devicetree, linux-iio, lkml
On Thu, 9 Jun 2022 11:32:04 +0300 Claudiu Beznea [off-list ref] wrote:
Simplify a bit the code in at91_adc_read_info_raw() by reducing the number of lines of code. Signed-off-by: Claudiu Beznea <redacted>
I'm not convinced this is worth while, but there are some lesser steps visible in this patch that probably are. Given your earlier reorg to move at01_adc_adjust_val_osr() under the locks, you can now move the locks to the caller, thus not needing to handle them separately in all the exit paths.
quoted hunk ↗ jump to hunk
--- drivers/iio/adc/at91-sama5d2_adc.c | 35 +++++++++--------------------- 1 file changed, 10 insertions(+), 25 deletions(-)diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index b52f1020feaf..fbb98e216e70 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c@@ -1576,6 +1576,7 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val) { struct at91_adc_state *st = iio_priv(indio_dev); + int (*fn)(struct at91_adc_state *, int, u16 *) = NULL; u16 tmp_val; int ret;@@ -1583,29 +1584,18 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, * Keep in mind that we cannot use software trigger or touchscreen * if external trigger is enabled */ - if (chan->type == IIO_POSITIONRELATIVE) { - ret = iio_device_claim_direct_mode(indio_dev); - if (ret) - return ret;
You can drop this out of the if statements as it happens in all paths. Or even better, move it to the caller..
- mutex_lock(&st->lock); - - ret = at91_adc_read_position(st, chan->channel, - &tmp_val);
huh? ret not checked?
- *val = tmp_val; - ret = at91_adc_adjust_val_osr(st, val);
Sure this is duplicated, but meh it's only a few lines.
- mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev);
this early release (compared to the long path) is the only bit really gets duplicated in all paths..
+ if (chan->type == IIO_POSITIONRELATIVE)
+ fn = at91_adc_read_position;
+ if (chan->type == IIO_PRESSURE)
+ fn = at91_adc_read_pressure;
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
return ret;
- }
- if (chan->type == IIO_PRESSURE) {this should always have been an else if () as the chan->type couldn't be both.
- ret = iio_device_claim_direct_mode(indio_dev); - if (ret) - return ret; - mutex_lock(&st->lock);
hence this lot can be shared with the above.
quoted hunk ↗ jump to hunk
+ mutex_lock(&st->lock); - ret = at91_adc_read_pressure(st, chan->channel, - &tmp_val); + if (fn) { + ret = fn(st, chan->channel, &tmp_val); *val = tmp_val; ret = at91_adc_adjust_val_osr(st, val); mutex_unlock(&st->lock);@@ -1616,11 +1606,6 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, /* in this case we have a voltage channel */ - ret = iio_device_claim_direct_mode(indio_dev); - if (ret) - return ret; - mutex_lock(&st->lock); - st->chan = chan; at91_adc_cor(st, chan);
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