ath11k: add thermal sensor device support

Temperature sensor generates electrical analog voltage from temperature
of each chain. The analog voltage is converted to digital value through
ADC. For reading temperature values fom user space, hw monitoring device
is used.

Whenever the user requests for current temperature, the driver sends WMI
command and wait for response. For reading temperature,

cat /sys/class/ieee80211/phy*/device/hwmon/hwmon2/temp1_input

Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath11k/thermal.c b/drivers/net/wireless/ath/ath11k/thermal.c
index 6c2d96be34cb..259dddbda2c7 100644
--- a/drivers/net/wireless/ath/ath11k/thermal.c
+++ b/drivers/net/wireless/ath/ath11k/thermal.c
@@ -6,6 +6,8 @@
 #include <linux/device.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 #include "core.h"
 #include "debug.h"
 
@@ -57,6 +59,70 @@ static struct thermal_cooling_device_ops ath11k_thermal_ops = {
 	.set_cur_state = ath11k_thermal_set_cur_throttle_state,
 };
 
+static ssize_t ath11k_thermal_show_temp(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct ath11k *ar = dev_get_drvdata(dev);
+	int ret, temperature;
+	unsigned long time_left;
+
+	mutex_lock(&ar->conf_mutex);
+
+	/* Can't get temperature when the card is off */
+	if (ar->state != ATH11K_STATE_ON) {
+		ret = -ENETDOWN;
+		goto out;
+	}
+
+	reinit_completion(&ar->thermal.wmi_sync);
+	ret = ath11k_wmi_send_pdev_temperature_cmd(ar);
+	if (ret) {
+		ath11k_warn(ar->ab, "failed to read temperature %d\n", ret);
+		goto out;
+	}
+
+	if (test_bit(ATH11K_FLAG_CRASH_FLUSH, &ar->ab->dev_flags)) {
+		ret = -ESHUTDOWN;
+		goto out;
+	}
+
+	time_left = wait_for_completion_timeout(&ar->thermal.wmi_sync,
+						ATH11K_THERMAL_SYNC_TIMEOUT_HZ);
+	if (!time_left) {
+		ath11k_warn(ar->ab, "failed to synchronize thermal read\n");
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	spin_lock_bh(&ar->data_lock);
+	temperature = ar->thermal.temperature;
+	spin_unlock_bh(&ar->data_lock);
+
+	/* display in millidegree celcius */
+	ret = snprintf(buf, PAGE_SIZE, "%d\n", temperature * 1000);
+out:
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
+}
+
+void ath11k_thermal_event_temperature(struct ath11k *ar, int temperature)
+{
+	spin_lock_bh(&ar->data_lock);
+	ar->thermal.temperature = temperature;
+	spin_unlock_bh(&ar->data_lock);
+	complete(&ar->thermal.wmi_sync);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, 0444, ath11k_thermal_show_temp,
+			  NULL, 0);
+
+static struct attribute *ath11k_hwmon_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ath11k_hwmon);
+
 int ath11k_thermal_set_throttling(struct ath11k *ar, u32 throttle_state)
 {
 	struct ath11k_base *sc = ar->ab;
@@ -91,6 +157,7 @@ int ath11k_thermal_set_throttling(struct ath11k *ar, u32 throttle_state)
 int ath11k_thermal_register(struct ath11k_base *sc)
 {
 	struct thermal_cooling_device *cdev;
+	struct device *hwmon_dev;
 	struct ath11k *ar;
 	struct ath11k_pdev *pdev;
 	int i, ret;
@@ -118,6 +185,18 @@ int ath11k_thermal_register(struct ath11k_base *sc)
 		}
 
 		ar->thermal.cdev = cdev;
+		if (!IS_REACHABLE(CONFIG_HWMON))
+			return 0;
+
+		hwmon_dev = devm_hwmon_device_register_with_groups(&ar->hw->wiphy->dev,
+								   "ath11k_hwmon", ar,
+								   ath11k_hwmon_groups);
+		if (IS_ERR(hwmon_dev)) {
+			ath11k_err(ar->ab, "failed to register hwmon device: %ld\n",
+				   PTR_ERR(hwmon_dev));
+			ret = -EINVAL;
+			goto err_thermal_destroy;
+		}
 	}
 
 	return 0;