linux-kernel - [PATCH v2 1/3] iio: magnetometer: ak8975: Fix reading for ak099xx sensors

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Message-Id: <20240806-ak09918-v2-1-c300da66c198@mainlining.org>
Date: Tue, 06 Aug 2024 08:10:18 +0200
From: Barnabás Czémán <barnabas.czeman@...nlining.org>
To: Jonathan Cameron <jic23@...nel.org>, 
 Lars-Peter Clausen <lars@...afoo.de>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, 
 Jonathan Albrieux <jonathan.albrieux@...il.com>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 devicetree@...r.kernel.org, linux@...nlining.org, 
 Barnabás Czémán <barnabas.czeman@...nlining.org>
Subject: [PATCH v2 1/3] iio: magnetometer: ak8975: Fix reading for ak099xx
 sensors

ST2 register read should be placed after read measurment data,
because it will get correct values after it.

Signed-off-by: Barnabás Czémán <barnabas.czeman@...nlining.org>
---
 drivers/iio/magnetometer/ak8975.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index dd466c5fa621..925d76062b3e 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -692,22 +692,7 @@ static int ak8975_start_read_axis(struct ak8975_data *data,
 	if (ret < 0)
 		return ret;
 
-	/* This will be executed only for non-interrupt based waiting case */
-	if (ret & data->def->ctrl_masks[ST1_DRDY]) {
-		ret = i2c_smbus_read_byte_data(client,
-					       data->def->ctrl_regs[ST2]);
-		if (ret < 0) {
-			dev_err(&client->dev, "Error in reading ST2\n");
-			return ret;
-		}
-		if (ret & (data->def->ctrl_masks[ST2_DERR] |
-			   data->def->ctrl_masks[ST2_HOFL])) {
-			dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
-			return -EINVAL;
-		}
-	}
-
-	return 0;
+	return !(ret & data->def->ctrl_masks[ST1_DRDY]);
 }
 
 /* Retrieve raw flux value for one of the x, y, or z axis.  */
@@ -731,6 +716,20 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
 	ret = i2c_smbus_read_i2c_block_data_or_emulated(
 			client, def->data_regs[index],
 			sizeof(rval), (u8*)&rval);
+	ret = i2c_smbus_read_byte_data(client,
+				       data->def->ctrl_regs[ST2]);
+	if (ret < 0) {
+		dev_err(&client->dev, "Error in reading ST2\n");
+		goto exit;
+	}
+
+	if (ret & (data->def->ctrl_masks[ST2_DERR] |
+		   data->def->ctrl_masks[ST2_HOFL])) {
+		dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
+		ret = -EINVAL;
+		goto exit;
+	}
+
 	if (ret < 0)
 		goto exit;
 

-- 
2.46.0