ath11k: add thermal cooling device support

Thermal cooling device support is added to control the temperature by
throttling the data transmission for the given duration. Throttling is
done by suspending all data tx queues by given percentage of time. The
thermal device allows user to configure duty cycle.

Throttling can be disabled by setting the duty cycle to 0. The cooling
device can be found under /sys/class/thermal/cooling_deviceX/.
Corresponding soft link to this device can be found under phy folder.

/sys/class/ieee80211/phy*/device/cooling_device.

To set duty cycle as 40%,

echo 40 >/sys/class/ieee80211/phy*/device/cooling_device/cur_state

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

1 files changed, 145 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath11k/thermal.c b/drivers/net/wireless/ath/ath11k/thermal.c
new file mode 100644
index 000000000000..6c2d96be34cb
--- /dev/null
+++ b/drivers/net/wireless/ath/ath11k/thermal.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+/*
+ * Copyright (c) 2020 The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+#include "core.h"
+#include "debug.h"
+
+static int
+ath11k_thermal_get_max_throttle_state(struct thermal_cooling_device *cdev,
+				      unsigned long *state)
+{
+	*state = ATH11K_THERMAL_THROTTLE_MAX;
+
+	return 0;
+}
+
+static int
+ath11k_thermal_get_cur_throttle_state(struct thermal_cooling_device *cdev,
+				      unsigned long *state)
+{
+	struct ath11k *ar = cdev->devdata;
+
+	mutex_lock(&ar->conf_mutex);
+	*state = ar->thermal.throttle_state;
+	mutex_unlock(&ar->conf_mutex);
+
+	return 0;
+}
+
+static int
+ath11k_thermal_set_cur_throttle_state(struct thermal_cooling_device *cdev,
+				      unsigned long throttle_state)
+{
+	struct ath11k *ar = cdev->devdata;
+	int ret;
+
+	if (throttle_state > ATH11K_THERMAL_THROTTLE_MAX) {
+		ath11k_warn(ar->ab, "throttle state %ld is exceeding the limit %d\n",
+			    throttle_state, ATH11K_THERMAL_THROTTLE_MAX);
+		return -EINVAL;
+	}
+	mutex_lock(&ar->conf_mutex);
+	ret = ath11k_thermal_set_throttling(ar, throttle_state);
+	if (ret == 0)
+		ar->thermal.throttle_state = throttle_state;
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
+}
+
+static struct thermal_cooling_device_ops ath11k_thermal_ops = {
+	.get_max_state = ath11k_thermal_get_max_throttle_state,
+	.get_cur_state = ath11k_thermal_get_cur_throttle_state,
+	.set_cur_state = ath11k_thermal_set_cur_throttle_state,
+};
+
+int ath11k_thermal_set_throttling(struct ath11k *ar, u32 throttle_state)
+{
+	struct ath11k_base *sc = ar->ab;
+	struct thermal_mitigation_params param;
+	int ret = 0;
+
+	lockdep_assert_held(&ar->conf_mutex);
+
+	if (ar->state != ATH11K_STATE_ON)
+		return 0;
+
+	memset(&param, 0, sizeof(param));
+	param.pdev_id = ar->pdev->pdev_id;
+	param.enable = throttle_state ? 1 : 0;
+	param.dc = ATH11K_THERMAL_DEFAULT_DUTY_CYCLE;
+	param.dc_per_event = 0xFFFFFFFF;
+
+	param.levelconf[0].tmplwm = ATH11K_THERMAL_TEMP_LOW_MARK;
+	param.levelconf[0].tmphwm = ATH11K_THERMAL_TEMP_HIGH_MARK;
+	param.levelconf[0].dcoffpercent = throttle_state;
+	param.levelconf[0].priority = 0; /* disable all data tx queues */
+
+	ret = ath11k_wmi_send_thermal_mitigation_param_cmd(ar, &param);
+	if (ret) {
+		ath11k_warn(sc, "failed to send thermal mitigation duty cycle %u ret %d\n",
+			    throttle_state, ret);
+	}
+
+	return ret;
+}
+
+int ath11k_thermal_register(struct ath11k_base *sc)
+{
+	struct thermal_cooling_device *cdev;
+	struct ath11k *ar;
+	struct ath11k_pdev *pdev;
+	int i, ret;
+
+	for (i = 0; i < sc->num_radios; i++) {
+		pdev = &sc->pdevs[i];
+		ar = pdev->ar;
+		if (!ar)
+			continue;
+
+		cdev = thermal_cooling_device_register("ath11k_thermal", ar,
+						       &ath11k_thermal_ops);
+
+		if (IS_ERR(cdev)) {
+			ath11k_err(sc, "failed to setup thermal device result: %ld\n",
+				   PTR_ERR(cdev));
+			return -EINVAL;
+		}
+
+		ret = sysfs_create_link(&ar->hw->wiphy->dev.kobj, &cdev->device.kobj,
+					"cooling_device");
+		if (ret) {
+			ath11k_err(sc, "failed to create cooling device symlink\n");
+			goto err_thermal_destroy;
+		}
+
+		ar->thermal.cdev = cdev;
+	}
+
+	return 0;
+
+err_thermal_destroy:
+	ath11k_thermal_unregister(sc);
+	return ret;
+}
+
+void ath11k_thermal_unregister(struct ath11k_base *sc)
+{
+	struct ath11k *ar;
+	struct ath11k_pdev *pdev;
+	int i;
+
+	for (i = 0; i < sc->num_radios; i++) {
+		pdev = &sc->pdevs[i];
+		ar = pdev->ar;
+		if (!ar)
+			continue;
+
+		sysfs_remove_link(&ar->hw->wiphy->dev.kobj, "cooling_device");
+		thermal_cooling_device_unregister(ar->thermal.cdev);
+	}
+}