[PATCH v2 2/6] staging: iio: ad9832: convert to guard(mutex)

[Tomas Borquez <tomasborquez13@gmail.com>]

Use guard(mutex) for cleaner lock handling and simpler error paths.

Signed-off-by: Tomas Borquez <tomasborquez13@gmail.com>
---
 drivers/staging/iio/frequency/ad9832.c | 41 +++++++++++---------------
 1 file changed, 17 insertions(+), 24 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index a5523e2210bf..35d8d51d5c2b 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -9,6 +9,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -179,20 +180,20 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 
 	ret = kstrtoul(buf, 10, &val);
 	if (ret)
-		goto error_ret;
+		return ret;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	switch ((u32)this_attr->address) {
 	case AD9832_FREQ0HM:
 	case AD9832_FREQ1HM:
 		ret = ad9832_write_frequency(st, this_attr->address, val);
-		break;
+		return ret ?: len;
 	case AD9832_PHASE0H:
 	case AD9832_PHASE1H:
 	case AD9832_PHASE2H:
 	case AD9832_PHASE3H:
 		ret = ad9832_write_phase(st, this_attr->address, val);
-		break;
+		return ret ?: len;
 	case AD9832_PINCTRL_EN:
 		st->ctrl_ss &= ~AD9832_SELSRC;
 		st->ctrl_ss |= FIELD_PREP(AD9832_SELSRC, val ? 0 : 1);
@@ -200,24 +201,20 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SYNCSELSRC) |
 						  st->ctrl_ss);
 		ret = spi_sync(st->spi, &st->msg);
-		break;
+		return ret ?: len;
 	case AD9832_FREQ_SYM:
-		if (val == 1 || val == 0) {
-			st->ctrl_fp &= ~AD9832_FREQ;
-			st->ctrl_fp |= FIELD_PREP(AD9832_FREQ, val ? 1 : 0);
-		} else {
-			ret = -EINVAL;
-			break;
-		}
+		if (val != 1 && val != 0)
+			return -EINVAL;
+
+		st->ctrl_fp &= ~AD9832_FREQ;
+		st->ctrl_fp |= FIELD_PREP(AD9832_FREQ, val ? 1 : 0);
 		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_FPSELECT) |
 						  st->ctrl_fp);
 		ret = spi_sync(st->spi, &st->msg);
-		break;
+		return ret ?: len;
 	case AD9832_PHASE_SYM:
-		if (val > 3) {
-			ret = -EINVAL;
-			break;
-		}
+		if (val > 3)
+			return -EINVAL;
 
 		st->ctrl_fp &= ~AD9832_PHASE_MASK;
 		st->ctrl_fp |= FIELD_PREP(AD9832_PHASE_MASK, val);
@@ -225,7 +222,7 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_FPSELECT) |
 						  st->ctrl_fp);
 		ret = spi_sync(st->spi, &st->msg);
-		break;
+		return ret ?: len;
 	case AD9832_OUTPUT_EN:
 		if (val)
 			st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP | AD9832_CLR);
@@ -235,14 +232,10 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
 		st->data = cpu_to_be16(FIELD_PREP(AD9832_CMD_MSK, AD9832_CMD_SLEEPRESCLR) |
 						  st->ctrl_src);
 		ret = spi_sync(st->spi, &st->msg);
-		break;
+		return ret ?: len;
 	default:
-		ret = -ENODEV;
+		return -ENODEV;
 	}
-	mutex_unlock(&st->lock);
-
-error_ret:
-	return ret ? ret : len;
 }
 
 /*
-- 
2.43.0