mt76: mt7915: add thermal sensor device support

This provides userspace with a unified interface, hwmon sysfs, to monitor
temperature in the hardware and can be adapted to system monitoring tools.

For reading temperature, cat /sys/class/ieee80211/phy*/hwmon*/temp1_input
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c

@@ -224,18 +224,6 @@ mt7915_tx_stats_show(struct seq_file *file, void *data)
 
 DEFINE_SHOW_ATTRIBUTE(mt7915_tx_stats);
 
-static int mt7915_read_temperature(struct seq_file *s, void *data)
-{
-	struct mt7915_dev *dev = dev_get_drvdata(s->private);
-	int temp;
-
-	/* cpu */
-	temp = mt7915_mcu_get_temperature(dev, 0);
-	seq_printf(s, "Temperature: %d\n", temp);
-
-	return 0;
-}
-
 static int
 mt7915_queues_acq(struct seq_file *s, void *data)
 {
@@ -390,8 +378,6 @@ int mt7915_init_debugfs(struct mt7915_dev *dev)
 	debugfs_create_file("radar_trigger", 0200, dir, dev,
 			    &fops_radar_trigger);
 	debugfs_create_file("ser_trigger", 0200, dir, dev, &fops_ser_trigger);
-	debugfs_create_devm_seqfile(dev->mt76.dev, "temperature", dir,
-				    mt7915_read_temperature);
 	debugfs_create_devm_seqfile(dev->mt76.dev, "txpower_sku", dir,
 				    mt7915_read_rate_txpower);
 

drivers/net/wireless/mediatek/mt76/mt7915/init.c

@@ -2,6 +2,8 @@
 /* Copyright (C) 2020 MediaTek Inc. */
 
 #include <linux/etherdevice.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 #include "mt7915.h"
 #include "mac.h"
 #include "mcu.h"
@@ -39,6 +41,47 @@ static const struct ieee80211_iface_combination if_comb[] = {
 	}
 };
 
+static ssize_t mt7915_thermal_show_temp(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct mt7915_phy *phy = dev_get_drvdata(dev);
+	int temperature;
+
+	temperature = mt7915_mcu_get_temperature(phy);
+	if (temperature < 0)
+		return temperature;
+
+	/* display in millidegree celcius */
+	return sprintf(buf, "%u\n", temperature * 1000);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, 0444, mt7915_thermal_show_temp,
+			  NULL, 0);
+
+static struct attribute *mt7915_hwmon_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(mt7915_hwmon);
+
+static int mt7915_thermal_init(struct mt7915_phy *phy)
+{
+	struct wiphy *wiphy = phy->mt76->hw->wiphy;
+	struct device *hwmon;
+
+	if (!IS_REACHABLE(CONFIG_HWMON))
+		return 0;
+
+	hwmon = devm_hwmon_device_register_with_groups(&wiphy->dev,
+						       wiphy_name(wiphy), phy,
+						       mt7915_hwmon_groups);
+	if (IS_ERR(hwmon))
+		return PTR_ERR(hwmon);
+
+	return 0;
+}
+
 static void
 mt7915_init_txpower(struct mt7915_dev *dev,
 		    struct ieee80211_supported_band *sband)
@@ -258,6 +301,10 @@ static int mt7915_register_ext_phy(struct mt7915_dev *dev)
 	if (ret)
 		goto error;
 
+	ret = mt7915_thermal_init(phy);
+	if (ret)
+		goto error;
+
 	return 0;
 
 error:
@@ -708,6 +755,10 @@ int mt7915_register_device(struct mt7915_dev *dev)
 	if (ret)
 		return ret;
 
+	ret = mt7915_thermal_init(&dev->phy);
+	if (ret)
+		return ret;
+
 	ieee80211_queue_work(mt76_hw(dev), &dev->init_work);
 
 	ret = mt7915_register_ext_phy(dev);

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c

@@ -3559,16 +3559,17 @@ int mt7915_mcu_apply_tx_dpd(struct mt7915_phy *phy)
 	return 0;
 }
 
-int mt7915_mcu_get_temperature(struct mt7915_dev *dev, int index)
+int mt7915_mcu_get_temperature(struct mt7915_phy *phy)
 {
+	struct mt7915_dev *dev = phy->dev;
 	struct {
 		u8 ctrl_id;
 		u8 action;
-		u8 band;
+		u8 dbdc_idx;
 		u8 rsv[5];
 	} req = {
 		.ctrl_id = THERMAL_SENSOR_TEMP_QUERY,
-		.action = index,
+		.dbdc_idx = phy != &dev->phy,
 	};
 
 	return mt76_mcu_send_msg(&dev->mt76, MCU_EXT_CMD(THERMAL_CTRL), &req,

drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h

@@ -356,7 +356,7 @@ int mt7915_mcu_set_radar_th(struct mt7915_dev *dev, int index,
 			    const struct mt7915_dfs_pattern *pattern);
 int mt7915_mcu_apply_group_cal(struct mt7915_dev *dev);
 int mt7915_mcu_apply_tx_dpd(struct mt7915_phy *phy);
-int mt7915_mcu_get_temperature(struct mt7915_dev *dev, int index);
+int mt7915_mcu_get_temperature(struct mt7915_phy *phy);
 int mt7915_mcu_get_tx_rate(struct mt7915_dev *dev, u32 cmd, u16 wlan_idx);
 int mt7915_mcu_get_rx_rate(struct mt7915_phy *phy, struct ieee80211_vif *vif,
 			   struct ieee80211_sta *sta, struct rate_info *rate);