[PATCH v2 15/19] iio: adc: at91-sama5d2_adc: lock around at91_adc_read_info_raw()

Claudiu Beznea
2022-06-28T15:23:30Z

Remove iio_device_{claim, release}_direct_mode() and lock/unlock to
&st->lock from at91_adc_read_info_raw(). Instead add a wrapper around
at91_adc_read_info_raw() and do there the lock/unlock. This will allow
using the at91_adc_read_info_raw() in patch that add support for
temperature sensor.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
drivers/iio/adc/at91-sama5d2_adc.c | 39 +++++++++++++++---------------
1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 3de5d1cb8a12..04c44b2d574c 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -1579,6 +1579,7 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
return IRQ_HANDLED;
}

+/* This needs to be called with direct mode claimed and st->lock locked. */
static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val)
{
@@ -1591,45 +1592,26 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
* if external trigger is enabled
*/
if (chan->type == IIO_POSITIONRELATIVE) {
- ret = iio_device_claim_direct_mode(indio_dev);
- if (ret)
- return ret;
- mutex_lock(&st->lock);
-
ret = at91_adc_read_position(st, chan->channel,
&tmp_val);
*val = tmp_val;
if (ret > 0)
ret = at91_adc_adjust_val_osr(st, val);
- mutex_unlock(&st->lock);
- iio_device_release_direct_mode(indio_dev);

return ret;
}
if (chan->type == IIO_PRESSURE) {
- ret = iio_device_claim_direct_mode(indio_dev);
- if (ret)
- return ret;
- mutex_lock(&st->lock);
-
ret = at91_adc_read_pressure(st, chan->channel,
&tmp_val);
*val = tmp_val;
if (ret > 0)
ret = at91_adc_adjust_val_osr(st, val);
- mutex_unlock(&st->lock);
- iio_device_release_direct_mode(indio_dev);

return ret;
}

/* 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);
@@ -1658,9 +1640,25 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
/* Needed to ACK the DRDY interruption */
at91_adc_readl(st, LCDR);

+ return ret;
+}
+
+static int at91_adc_read_info_locked(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct at91_adc_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ mutex_lock(&st->lock);
+ ret = at91_adc_read_info_raw(indio_dev, chan, val);
mutex_unlock(&st->lock);

iio_device_release_direct_mode(indio_dev);
+
return ret;
}

@@ -1672,7 +1670,8 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_RAW:
- return at91_adc_read_info_raw(indio_dev, chan, val);
+ return at91_adc_read_info_locked(indio_dev, chan, val);
+
case IIO_CHAN_INFO_SCALE:
*val = st->vref_uv / 1000;
if (chan->differential)