linux-kernel - [PATCH] iio: light: cm3232: Reset before reading HW ID

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Message-ID: <20241114131656.1707358-1-cibil.pankiras@aerq.com>
Date: Thu, 14 Nov 2024 14:16:56 +0100
From: Cibil <cibil.pankiras@...q.com>
To: jic23@...nel.org,
	ktsai@...ellamicro.com,
	lars@...afoo.de
CC: linux-iio@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Cibil Pankiras <cibil.pankiras@...q.com>
Subject: [PATCH] iio: light: cm3232: Reset before reading HW ID

From: Cibil Pankiras <cibil.pankiras@...q.com>

According to the datasheet, the chip requires a reset before any data
can be read. This commit moves the device identification logic to
occur after the reset to ensure proper initialization.

Cc: Kevin Tsai <ktsai@...ellamicro.com>
Signed-off-by: Cibil Pankiras <cibil.pankiras@...q.com>
---
 drivers/iio/light/cm3232.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/light/cm3232.c b/drivers/iio/light/cm3232.c
index 2c80a0535d2c..db33671c448c 100644
--- a/drivers/iio/light/cm3232.c
+++ b/drivers/iio/light/cm3232.c
@@ -89,6 +89,15 @@ static int cm3232_reg_init(struct cm3232_chip *chip)
 
 	chip->als_info = &cm3232_als_info_default;
 
+	/* Disable and reset device */
+	chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
+	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
+					chip->regs_cmd);
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "Error writing reg_cmd\n");
+		return ret;
+	}
+
 	/* Identify device */
 	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
 	if (ret < 0) {
@@ -99,15 +108,6 @@ static int cm3232_reg_init(struct cm3232_chip *chip)
 	if ((ret & 0xFF) != chip->als_info->hw_id)
 		return -ENODEV;
 
-	/* Disable and reset device */
-	chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
-	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
-					chip->regs_cmd);
-	if (ret < 0) {
-		dev_err(&chip->client->dev, "Error writing reg_cmd\n");
-		return ret;
-	}
-
 	/* Register default value */
 	chip->regs_cmd = chip->als_info->regs_cmd_default;
 
-- 
2.34.1

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