iio: adc: mcp3911: simplify code with guard macro

Use the guard(mutex) macro for handle mutex lock/unlocks.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20231206-mcp3911-guard-v4-1-30c3c5d4340f@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index d864558..7a32e7a 100644 (file)
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -7,6 +7,7 @@
  */
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -316,47 +317,37 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
                            int *val2, long mask)
 {
        struct mcp3911 *adc = iio_priv(indio_dev);
-       int ret = -EINVAL;
+       int ret;
 
-       mutex_lock(&adc->lock);
+       guard(mutex)(&adc->lock);
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = mcp3911_read(adc,
                                   MCP3911_CHANNEL(channel->channel), val, 3);
                if (ret)
-                       goto out;
+                       return ret;
 
                *val = sign_extend32(*val, 23);
-
-               ret = IIO_VAL_INT;
-               break;
-
+               return IIO_VAL_INT;
        case IIO_CHAN_INFO_OFFSET:
-
                ret = adc->chip->get_offset(adc, channel->channel, val);
                if (ret)
-                       goto out;
+                       return ret;
 
-               ret = IIO_VAL_INT;
-               break;
+               return IIO_VAL_INT;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                ret = adc->chip->get_osr(adc, val);
                if (ret)
-                       goto out;
-
-               ret = IIO_VAL_INT;
-               break;
+                       return ret;
 
+               return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0];
                *val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1];
-               ret = IIO_VAL_INT_PLUS_NANO;
-               break;
+               return IIO_VAL_INT_PLUS_NANO;
+       default:
+               return -EINVAL;
        }
-
-out:
-       mutex_unlock(&adc->lock);
-       return ret;
 }
 
 static int mcp3911_write_raw(struct iio_dev *indio_dev,
@@ -364,9 +355,8 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
                             int val2, long mask)
 {
        struct mcp3911 *adc = iio_priv(indio_dev);
-       int ret = -EINVAL;
 
-       mutex_lock(&adc->lock);
+       guard(mutex)(&adc->lock);
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
@@ -374,32 +364,25 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
                            val2 == mcp3911_scale_table[i][1]) {
 
                                adc->gain[channel->channel] = BIT(i);
-                               ret = adc->chip->set_scale(adc, channel->channel, i);
+                               return adc->chip->set_scale(adc, channel->channel, i);
                        }
                }
-               break;
+               return -EINVAL;
        case IIO_CHAN_INFO_OFFSET:
-               if (val2 != 0) {
-                       ret = -EINVAL;
-                       goto out;
-               }
-
-               ret = adc->chip->set_offset(adc, channel->channel, val);
-               break;
+               if (val2 != 0)
+                       return -EINVAL;
 
+               return adc->chip->set_offset(adc, channel->channel, val);
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
                for (int i = 0; i < ARRAY_SIZE(mcp3911_osr_table); i++) {
                        if (val == mcp3911_osr_table[i]) {
-                               ret = adc->chip->set_osr(adc, i);
-                               break;
+                               return adc->chip->set_osr(adc, i);
                        }
                }
-               break;
+               return -EINVAL;
+       default:
+               return -EINVAL;
        }
-
-out:
-       mutex_unlock(&adc->lock);
-       return ret;
 }
 
 static int mcp3911_calc_scale_table(struct mcp3911 *adc)
@@ -532,7 +515,7 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
        int i = 0;
        int ret;
 
-       mutex_lock(&adc->lock);
+       guard(mutex)(&adc->lock);
        adc->tx_buf = MCP3911_REG_READ(MCP3911_CHANNEL(0), adc->dev_addr);
        ret = spi_sync_transfer(adc->spi, xfer, ARRAY_SIZE(xfer));
        if (ret < 0) {
@@ -549,7 +532,6 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
        iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan,
                                           iio_get_time_ns(indio_dev));
 out:
-       mutex_unlock(&adc->lock);
        iio_trigger_notify_done(indio_dev->trig);
 
        return IRQ_HANDLED;