ath10k: 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 using hw MAC quiet time setting. Period, duration and offset
from TBTT can be set up to quiet the MAC transmits for the required duty
cycle (% of quiet duration). The thermal device allows user to configure
duty cycle.

The quiet params are derived as follows.
	period = max(25TU, beacon interval / number of bss)
	duration = period * duty cycle / 100

Quiet mode 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: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 155 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath10k/thermal.c b/drivers/net/wireless/ath/ath10k/thermal.c
new file mode 100644
index 000000000000..e98ce8ce27e2
--- /dev/null
+++ b/drivers/net/wireless/ath/ath10k/thermal.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2014 Qualcomm Atheros, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+#include "core.h"
+#include "debug.h"
+#include "wmi-ops.h"
+
+static int ath10k_thermal_get_active_vifs(struct ath10k *ar,
+					  enum wmi_vdev_type type)
+{
+	struct ath10k_vif *arvif;
+	int count = 0;
+
+	lockdep_assert_held(&ar->conf_mutex);
+
+	list_for_each_entry(arvif, &ar->arvifs, list) {
+		if (!arvif->is_started)
+			continue;
+
+		if (!arvif->is_up)
+			continue;
+
+		if (arvif->vdev_type != type)
+			continue;
+
+		count++;
+	}
+	return count;
+}
+
+static int ath10k_thermal_get_max_dutycycle(struct thermal_cooling_device *cdev,
+					    unsigned long *state)
+{
+	*state = ATH10K_QUIET_DUTY_CYCLE_MAX;
+
+	return 0;
+}
+
+static int ath10k_thermal_get_cur_dutycycle(struct thermal_cooling_device *cdev,
+					    unsigned long *state)
+{
+	struct ath10k *ar = cdev->devdata;
+
+	mutex_lock(&ar->conf_mutex);
+	*state = ar->thermal.duty_cycle;
+	mutex_unlock(&ar->conf_mutex);
+
+	return 0;
+}
+
+static int ath10k_thermal_set_cur_dutycycle(struct thermal_cooling_device *cdev,
+					    unsigned long duty_cycle)
+{
+	struct ath10k *ar = cdev->devdata;
+	u32 period, duration, enabled;
+	int num_bss, ret = 0;
+
+	mutex_lock(&ar->conf_mutex);
+	if (ar->state != ATH10K_STATE_ON) {
+		ret = -ENETDOWN;
+		goto out;
+	}
+
+	if (duty_cycle > ATH10K_QUIET_DUTY_CYCLE_MAX) {
+		ath10k_warn(ar, "duty cycle %ld is exceeding the limit %d\n",
+			    duty_cycle, ATH10K_QUIET_DUTY_CYCLE_MAX);
+		ret = -EINVAL;
+		goto out;
+	}
+	/* TODO: Right now, thermal mitigation is handled only for single/multi
+	 * vif AP mode. Since quiet param is not validated in STA mode, it needs
+	 * to be investigated further to handle multi STA and multi-vif (AP+STA)
+	 * mode properly.
+	 */
+	num_bss = ath10k_thermal_get_active_vifs(ar, WMI_VDEV_TYPE_AP);
+	if (!num_bss) {
+		ath10k_warn(ar, "no active AP interfaces\n");
+		ret = -ENETDOWN;
+		goto out;
+	}
+	period = max(ATH10K_QUIET_PERIOD_MIN,
+		     (ATH10K_QUIET_PERIOD_DEFAULT / num_bss));
+	duration = period * (duty_cycle / 100);
+	enabled = duration ? 1 : 0;
+
+	ret = ath10k_wmi_pdev_set_quiet_mode(ar, period, duration,
+					     ATH10K_QUIET_START_OFFSET,
+					     enabled);
+	if (ret) {
+		ath10k_warn(ar, "failed to set quiet mode period %u duarion %u enabled %u ret %d\n",
+			    period, duration, enabled, ret);
+		goto out;
+	}
+	ar->thermal.duty_cycle = duty_cycle;
+out:
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
+}
+
+static struct thermal_cooling_device_ops ath10k_thermal_ops = {
+	.get_max_state = ath10k_thermal_get_max_dutycycle,
+	.get_cur_state = ath10k_thermal_get_cur_dutycycle,
+	.set_cur_state = ath10k_thermal_set_cur_dutycycle,
+};
+
+int ath10k_thermal_register(struct ath10k *ar)
+{
+	struct thermal_cooling_device *cdev;
+	int ret;
+
+	cdev = thermal_cooling_device_register("ath10k_thermal", ar,
+					       &ath10k_thermal_ops);
+
+	if (IS_ERR(cdev)) {
+		ath10k_err(ar, "failed to setup thermal device result: %ld\n",
+			   PTR_ERR(cdev));
+		return -EINVAL;
+	}
+
+	ret = sysfs_create_link(&ar->dev->kobj, &cdev->device.kobj,
+				"cooling_device");
+	if (ret) {
+		ath10k_err(ar, "failed to create thermal symlink\n");
+		goto err_cooling_destroy;
+	}
+
+	ar->thermal.cdev = cdev;
+	return 0;
+
+err_cooling_destroy:
+	thermal_cooling_device_unregister(cdev);
+	return ret;
+}
+
+void ath10k_thermal_unregister(struct ath10k *ar)
+{
+	thermal_cooling_device_unregister(ar->thermal.cdev);
+	sysfs_remove_link(&ar->dev->kobj, "cooling_device");
+}