[PATCH v3 7/8] iio: magnetometer: yas530: Apply minor cleanups

[Jakob Hauser <jahau@rocketmail.com>]

This commit gathers minor cleanups in the current driver.

In the device examples, "Xiaomi" is too generic, specific devices should be
listed here. E.g. Xiaomi Redmi 2 seems to have YAS537 but it's not fully clear
if this applies to all its variants. Samsung Galaxy S7 is often quoted in
conjunction with YAS537.

In the function yas530_get_calibration_data(), the debug dump was extended to
16 elements as this is the size of the calibration data array of YAS530.
---
 drivers/iio/magnetometer/yamaha-yas530.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/magnetometer/yamaha-yas530.c b/drivers/iio/magnetometer/yamaha-yas530.c
index 98c8d365fab7..72a75dc57e11 100644
--- a/drivers/iio/magnetometer/yamaha-yas530.c
+++ b/drivers/iio/magnetometer/yamaha-yas530.c
@@ -10,7 +10,7 @@
  * (YAS534 is a magnetic switch, not handled)
  * YAS535 MS-6C
  * YAS536 MS-3W
- * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5, Xiaomi)
+ * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5, Galaxy S7)
  * YAS539 MS-3S (2018 Samsung Galaxy A7 SM-A750FN)
  *
  * Code functions found in the MPU3050 YAS530 and YAS532 drivers
@@ -322,7 +322,7 @@ static int yas530_532_get_measure(struct yas5xx *yas5xx, s32 *to,
 {
 	struct yas5xx_calibration *c = &yas5xx->calibration;
 	u16 t_ref, t, x, y1, y2;
-	/* These are "signed x, signed y1 etc */
+	/* These are signed x, signed y1 etc */
 	s32 sx, sy1, sy2, sy, sz;
 	int ret;
 
@@ -656,9 +656,12 @@ static int yas530_get_calibration_data(struct yas5xx *yas5xx)
 	ret = regmap_bulk_read(yas5xx->map, YAS530_532_CAL, data, sizeof(data));
 	if (ret)
 		return ret;
-	dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data);
+	dev_dbg(yas5xx->dev, "calibration data: %16ph\n", data);
 
+	/* Contribute calibration data to the input pool for kernel entropy */
 	add_device_randomness(data, sizeof(data));
+
+	/* Extract version */
 	yas5xx->version = data[15] & GENMASK(1, 0);
 
 	/* Extract the calibration from the bitfield */
@@ -685,6 +688,7 @@ static int yas530_get_calibration_data(struct yas5xx *yas5xx)
 	c->r[0] = sign_extend32(FIELD_GET(GENMASK(28, 23), val), 5);
 	c->r[1] = sign_extend32(FIELD_GET(GENMASK(20, 15), val), 5);
 	c->r[2] = sign_extend32(FIELD_GET(GENMASK(12, 7), val), 5);
+
 	return 0;
 }
 
@@ -703,15 +707,17 @@ static int yas532_get_calibration_data(struct yas5xx *yas5xx)
 	ret = regmap_bulk_read(yas5xx->map, YAS530_532_CAL, data, sizeof(data));
 	if (ret)
 		return ret;
-	dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data);
+	dev_dbg(yas5xx->dev, "calibration data: %14ph\n", data);
 
 	/* Sanity check, is this all zeroes? */
-	if (memchr_inv(data, 0x00, 13) == NULL) {
+	if (!memchr_inv(data, 0x00, 13)) {
 		if (!(data[13] & BIT(7)))
 			dev_warn(yas5xx->dev, "calibration is blank!\n");
 	}
 
+	/* Contribute calibration data to the input pool for kernel entropy */
 	add_device_randomness(data, sizeof(data));
+
 	/* Only one bit of version info reserved here as far as we know */
 	yas5xx->version = data[13] & BIT(0);
 
@@ -720,6 +726,7 @@ static int yas532_get_calibration_data(struct yas5xx *yas5xx)
 	c->Cy1 = data[1] * 10 - 1280;
 	c->Cy2 = data[2] * 10 - 1280;
 	yas530_532_extract_calibration(&data[3], c);
+
 	/*
 	 * Extract linearization:
 	 * Linearization layout in the 32 bits at byte 10:
-- 
2.35.1