r8169: add support for the temperature sensor being available from RTL8125B

This adds support for the temperature sensor being available from
RTL8125B. Register information was taken from r8125 vendor driver.

Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: hkallweit

drivers/net/ethernet/realtek/r8169_main.c

@@ -16,6 +16,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/ethtool.h>
+#include <linux/hwmon.h>
 #include <linux/phy.h>
 #include <linux/if_vlan.h>
 #include <linux/in.h>
@@ -5363,6 +5364,43 @@ static bool rtl_aspm_is_safe(struct rtl8169_private *tp)
 	return false;
 }
 
+static umode_t r8169_hwmon_is_visible(const void *drvdata,
+				      enum hwmon_sensor_types type,
+				      u32 attr, int channel)
+{
+	return 0444;
+}
+
+static int r8169_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			    u32 attr, int channel, long *val)
+{
+	struct rtl8169_private *tp = dev_get_drvdata(dev);
+	int val_raw;
+
+	val_raw = phy_read_paged(tp->phydev, 0xbd8, 0x12) & 0x3ff;
+	if (val_raw >= 512)
+		val_raw -= 1024;
+
+	*val = 1000 * val_raw / 2;
+
+	return 0;
+}
+
+static const struct hwmon_ops r8169_hwmon_ops = {
+	.is_visible =  r8169_hwmon_is_visible,
+	.read = r8169_hwmon_read,
+};
+
+static const struct hwmon_channel_info * const r8169_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	NULL
+};
+
+static const struct hwmon_chip_info r8169_hwmon_chip_info = {
+	.ops = &r8169_hwmon_ops,
+	.info = r8169_hwmon_info,
+};
+
 static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	struct rtl8169_private *tp;
@@ -5537,6 +5575,12 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (rc)
 		return rc;
 
+	/* The temperature sensor is available from RTl8125B */
+	if (IS_REACHABLE(CONFIG_HWMON) && tp->mac_version >= RTL_GIGA_MAC_VER_63)
+		/* ignore errors */
+		devm_hwmon_device_register_with_info(&pdev->dev, "nic_temp", tp,
+						     &r8169_hwmon_chip_info,
+						     NULL);
 	rc = register_netdev(dev);
 	if (rc)
 		return rc;