linux-kernel - [PATCH v2] iio: amplifiers: ada4250: clean up ada4250

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Message-Id: <20250418-iio-amplifiers-ada4250-simplify-data-buffer-in-init-v2-1-1bf9b033aaf5@baylibre.com>
Date: Fri, 18 Apr 2025 15:37:54 -0500
From: David Lechner <dlechner@...libre.com>
To: Lars-Peter Clausen <lars@...afoo.de>, 
 Michael Hennerich <Michael.Hennerich@...log.com>, 
 Antoniu Miclaus <antoniu.miclaus@...log.com>, 
 Jonathan Cameron <jic23@...nel.org>, David Lechner <dlechner@...libre.com>, 
 Nuno Sá <nuno.sa@...log.com>, 
 Andy Shevchenko <andy@...nel.org>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] iio: amplifiers: ada4250: clean up ada4250_init()

There are a few opportunities to simplify the code in ada4250_init():
* Replace local spi variable with dev since spi is not used directly.
* Drop the data variable and use chip_id directly with the regmap bulk
  read (__aligned() and initialization of the data variable were
  unnecessary).
* Don't use get_unaligned_le16() when not needed.
* Use dev_err_probe() instead of dev_err() and return.

Signed-off-by: David Lechner <dlechner@...libre.com>
---
In v1, I though we had a bug, but Andy set me straight. Still, since we
were already looking at this, there is some room for improvement, so I
changed this to a cleanup patch instead.

Changes in v2:
- Totally new patch.
- Link to v1: https://lore.kernel.org/r/20250418-iio-amplifiers-ada4250-simplify-data-buffer-in-init-v1-1-7e7bd6dad423@baylibre.com
---
 drivers/iio/amplifiers/ada4250.c | 34 ++++++++++++++--------------------
 1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/amplifiers/ada4250.c b/drivers/iio/amplifiers/ada4250.c
index 74f8429d652b17b4d1f38366e23ce6a2b3e9b218..13906e4b4842095717566781ad00cd58f3934510 100644
--- a/drivers/iio/amplifiers/ada4250.c
+++ b/drivers/iio/amplifiers/ada4250.c
@@ -13,8 +13,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
-
-#include <linux/unaligned.h>
+#include <linux/types.h>
 
 /* ADA4250 Register Map */
 #define ADA4250_REG_GAIN_MUX        0x00
@@ -299,25 +298,23 @@ static void ada4250_reg_disable(void *data)
 
 static int ada4250_init(struct ada4250_state *st)
 {
+	struct device *dev = &st->spi->dev;
 	int ret;
-	u16 chip_id;
-	u8 data[2] __aligned(8) = {};
-	struct spi_device *spi = st->spi;
+	__le16 chip_id;
 
-	st->refbuf_en = device_property_read_bool(&spi->dev, "adi,refbuf-enable");
+	st->refbuf_en = device_property_read_bool(dev, "adi,refbuf-enable");
 
-	st->reg = devm_regulator_get(&spi->dev, "avdd");
+	st->reg = devm_regulator_get(dev, "avdd");
 	if (IS_ERR(st->reg))
-		return dev_err_probe(&spi->dev, PTR_ERR(st->reg),
+		return dev_err_probe(dev, PTR_ERR(st->reg),
 				     "failed to get the AVDD voltage\n");
 
 	ret = regulator_enable(st->reg);
-	if (ret) {
-		dev_err(&spi->dev, "Failed to enable specified AVDD supply\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to enable specified AVDD supply\n");
 
-	ret = devm_add_action_or_reset(&spi->dev, ada4250_reg_disable, st->reg);
+	ret = devm_add_action_or_reset(dev, ada4250_reg_disable, st->reg);
 	if (ret)
 		return ret;
 
@@ -326,16 +323,13 @@ static int ada4250_init(struct ada4250_state *st)
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(st->regmap, ADA4250_REG_CHIP_ID, data, 2);
+	ret = regmap_bulk_read(st->regmap, ADA4250_REG_CHIP_ID, &chip_id,
+			       sizeof(chip_id));
 	if (ret)
 		return ret;
 
-	chip_id = get_unaligned_le16(data);
-
-	if (chip_id != ADA4250_CHIP_ID) {
-		dev_err(&spi->dev, "Invalid chip ID.\n");
-		return -EINVAL;
-	}
+	if (le16_to_cpu(chip_id) != ADA4250_CHIP_ID)
+		return dev_err_probe(dev, -EINVAL, "Invalid chip ID.\n");
 
 	return regmap_write(st->regmap, ADA4250_REG_REFBUF_EN,
 			    FIELD_PREP(ADA4250_REFBUF_MSK, st->refbuf_en));

---
base-commit: aff301f37e220970c2f301b5c65a8bfedf52058e
change-id: 20250418-iio-amplifiers-ada4250-simplify-data-buffer-in-init-93ebb1344295

Best regards,
-- 
David Lechner <dlechner@...libre.com>