[PATCH v4 4/8] misc: amd-sbi: Consolidate Common SBTSI Probe Path

[Akshay Gupta <Akshay.Gupta@amd.com>]

From: Prathima <Prathima.Lk@amd.com>

Refactor shared probe procedures into sbtsi_probe_common() to ensure
that I2C and I3C probes focus solely on bus-specific allocation and
device configuration.
The utility function reads the configuration register via sbtsi_xfer(),
initializes ext_range_mode and read_order, assigns the driver data,
and registers the hwmon auxiliary device.
Routing register access through sbtsi_xfer() keeps the probe path
bus-agnostic, so no transfer logic has to be duplicated when SB-TSI over
I3C support is added in a later patch.

Reviewed-by: Akshay Gupta <Akshay.Gupta@amd.com>
Signed-off-by: Prathima <Prathima.Lk@amd.com>
---
Changes since v3:
- No functional changes.
- Revised the commit message to clearly detail the patch modifications.

Changes since v2:
- New patch to refactor SBTSI common probe

 drivers/misc/amd-sbi/tsi.c | 26 ++++++++++++++++++--------
 include/linux/misc/tsi.h   |  2 ++
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/amd-sbi/tsi.c b/drivers/misc/amd-sbi/tsi.c
index 67d08df28429..35b9f40741e7 100644
--- a/drivers/misc/amd-sbi/tsi.c
+++ b/drivers/misc/amd-sbi/tsi.c
@@ -79,31 +79,41 @@ static int sbtsi_create_hwmon_adev(struct device *dev, u8 dev_addr)
 	return devm_add_action_or_reset(dev, sbtsi_unregister_hwmon_adev, adev);
 }
 
+static int sbtsi_probe_common(struct device *dev, struct sbtsi_data *data)
+{
+	u8 val;
+	int err;
+
+	err = sbtsi_xfer(data, SBTSI_REG_CONFIG, &val, true);
+	if (err)
+		return err;
+
+	data->ext_range_mode = FIELD_GET(BIT(SBTSI_CONFIG_EXT_RANGE_SHIFT), val);
+	data->read_order = FIELD_GET(BIT(SBTSI_CONFIG_READ_ORDER_SHIFT), val);
+
+	dev_set_drvdata(dev, data);
+	return sbtsi_create_hwmon_adev(dev, data->dev_addr);
+}
+
 static int sbtsi_i2c_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct sbtsi_data *data;
-	int err;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
 	data->client = client;
-	err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG);
-	if (err < 0)
-		return err;
-	data->ext_range_mode = FIELD_GET(BIT(SBTSI_CONFIG_EXT_RANGE_SHIFT), err);
-	data->read_order = FIELD_GET(BIT(SBTSI_CONFIG_READ_ORDER_SHIFT), err);
 
-	dev_set_drvdata(dev, data);
 	/* In a multi-socket system, devices that are otherwise identical do not
 	 * share the same static address; each instance resides at a unique I2C
 	 * client address on the same or different bus. Use the I2C client
 	 * address as the auxiliary device instance ID to ensure each socket
 	 * receives a distinct auxiliary device name.
 	 */
-	return sbtsi_create_hwmon_adev(dev, client->addr);
+	data->dev_addr = client->addr;
+	return sbtsi_probe_common(dev, data);
 }
 
 static const struct i2c_device_id sbtsi_id[] = {
diff --git a/include/linux/misc/tsi.h b/include/linux/misc/tsi.h
index 2d2709f1ff32..6533879cc358 100644
--- a/include/linux/misc/tsi.h
+++ b/include/linux/misc/tsi.h
@@ -14,11 +14,13 @@
 /**
  * struct sbtsi_data - driver private data for an AMD SB-TSI device
  * @client:	underlying I2C client
+ * @dev_addr:	I2C device address, used as the auxiliary device instance id
  * @ext_range_mode:	sensor uses extended temperature range
  * @read_order:	if set, decimal part must be read before integer part
  */
 struct sbtsi_data {
 	struct i2c_client *client;
+	u8 dev_addr;
 	bool ext_range_mode;
 	bool read_order;
 };
-- 
2.34.1