1 files changed, 574 insertions, 0 deletions

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
new file mode 100644
index 000000000..dfab49a67
--- /dev/null
+++ b/drivers/thermal/devfreq_cooling.c
@@ -0,0 +1,574 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * devfreq_cooling: Thermal cooling device implementation for devices using
+ *                  devfreq
+ *
+ * Copyright (C) 2014-2015 ARM Limited
+ *
+ * TODO:
+ *    - If OPPs are added or removed after devfreq cooling has
+ *      registered, the devfreq cooling won't react to it.
+ */
+
+#include <linux/devfreq.h>
+#include <linux/devfreq_cooling.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_qos.h>
+#include <linux/thermal.h>
+
+#include <trace/events/thermal.h>
+
+#define HZ_PER_KHZ		1000
+#define SCALE_ERROR_MITIGATION	100
+
+static DEFINE_IDA(devfreq_ida);
+
+/**
+ * struct devfreq_cooling_device - Devfreq cooling device
+ * @id:		unique integer value corresponding to each
+ *		devfreq_cooling_device registered.
+ * @cdev:	Pointer to associated thermal cooling device.
+ * @devfreq:	Pointer to associated devfreq device.
+ * @cooling_state:	Current cooling state.
+ * @power_table:	Pointer to table with maximum power draw for each
+ *			cooling state. State is the index into the table, and
+ *			the power is in mW.
+ * @freq_table:	Pointer to a table with the frequencies sorted in descending
+ *		order.  You can index the table by cooling device state
+ * @freq_table_size:	Size of the @freq_table and @power_table
+ * @power_ops:	Pointer to devfreq_cooling_power, used to generate the
+ *		@power_table.
+ * @res_util:	Resource utilization scaling factor for the power.
+ *		It is multiplied by 100 to minimize the error. It is used
+ *		for estimation of the power budget instead of using
+ *		'utilization' (which is	'busy_time / 'total_time').
+ *		The 'res_util' range is from 100 to (power_table[state] * 100)
+ *		for the corresponding 'state'.
+ * @capped_state:	index to cooling state with in dynamic power budget
+ * @req_max_freq:	PM QoS request for limiting the maximum frequency
+ *			of the devfreq device.
+ */
+struct devfreq_cooling_device {
+	int id;
+	struct thermal_cooling_device *cdev;
+	struct devfreq *devfreq;
+	unsigned long cooling_state;
+	u32 *power_table;
+	u32 *freq_table;
+	size_t freq_table_size;
+	struct devfreq_cooling_power *power_ops;
+	u32 res_util;
+	int capped_state;
+	struct dev_pm_qos_request req_max_freq;
+};
+
+static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev,
+					 unsigned long *state)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+
+	*state = dfc->freq_table_size - 1;
+
+	return 0;
+}
+
+static int devfreq_cooling_get_cur_state(struct thermal_cooling_device *cdev,
+					 unsigned long *state)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+
+	*state = dfc->cooling_state;
+
+	return 0;
+}
+
+static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev,
+					 unsigned long state)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+	struct devfreq *df = dfc->devfreq;
+	struct device *dev = df->dev.parent;
+	unsigned long freq;
+
+	if (state == dfc->cooling_state)
+		return 0;
+
+	dev_dbg(dev, "Setting cooling state %lu\n", state);
+
+	if (state >= dfc->freq_table_size)
+		return -EINVAL;
+
+	freq = dfc->freq_table[state];
+
+	dev_pm_qos_update_request(&dfc->req_max_freq,
+				  DIV_ROUND_UP(freq, HZ_PER_KHZ));
+
+	dfc->cooling_state = state;
+
+	return 0;
+}
+
+/**
+ * freq_get_state() - get the cooling state corresponding to a frequency
+ * @dfc:	Pointer to devfreq cooling device
+ * @freq:	frequency in Hz
+ *
+ * Return: the cooling state associated with the @freq, or
+ * THERMAL_CSTATE_INVALID if it wasn't found.
+ */
+static unsigned long
+freq_get_state(struct devfreq_cooling_device *dfc, unsigned long freq)
+{
+	int i;
+
+	for (i = 0; i < dfc->freq_table_size; i++) {
+		if (dfc->freq_table[i] == freq)
+			return i;
+	}
+
+	return THERMAL_CSTATE_INVALID;
+}
+
+static unsigned long get_voltage(struct devfreq *df, unsigned long freq)
+{
+	struct device *dev = df->dev.parent;
+	unsigned long voltage;
+	struct dev_pm_opp *opp;
+
+	opp = dev_pm_opp_find_freq_exact(dev, freq, true);
+	if (PTR_ERR(opp) == -ERANGE)
+		opp = dev_pm_opp_find_freq_exact(dev, freq, false);
+
+	if (IS_ERR(opp)) {
+		dev_err_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n",
+				    freq, PTR_ERR(opp));
+		return 0;
+	}
+
+	voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
+	dev_pm_opp_put(opp);
+
+	if (voltage == 0) {
+		dev_err_ratelimited(dev,
+				    "Failed to get voltage for frequency %lu\n",
+				    freq);
+	}
+
+	return voltage;
+}
+
+/**
+ * get_static_power() - calculate the static power
+ * @dfc:	Pointer to devfreq cooling device
+ * @freq:	Frequency in Hz
+ *
+ * Calculate the static power in milliwatts using the supplied
+ * get_static_power().  The current voltage is calculated using the
+ * OPP library.  If no get_static_power() was supplied, assume the
+ * static power is negligible.
+ */
+static unsigned long
+get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
+{
+	struct devfreq *df = dfc->devfreq;
+	unsigned long voltage;
+
+	if (!dfc->power_ops->get_static_power)
+		return 0;
+
+	voltage = get_voltage(df, freq);
+
+	if (voltage == 0)
+		return 0;
+
+	return dfc->power_ops->get_static_power(df, voltage);
+}
+
+/**
+ * get_dynamic_power - calculate the dynamic power
+ * @dfc:	Pointer to devfreq cooling device
+ * @freq:	Frequency in Hz
+ * @voltage:	Voltage in millivolts
+ *
+ * Calculate the dynamic power in milliwatts consumed by the device at
+ * frequency @freq and voltage @voltage.  If the get_dynamic_power()
+ * was supplied as part of the devfreq_cooling_power struct, then that
+ * function is used.  Otherwise, a simple power model (Pdyn = Coeff *
+ * Voltage^2 * Frequency) is used.
+ */
+static unsigned long
+get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq,
+		  unsigned long voltage)
+{
+	u64 power;
+	u32 freq_mhz;
+	struct devfreq_cooling_power *dfc_power = dfc->power_ops;
+
+	if (dfc_power->get_dynamic_power)
+		return dfc_power->get_dynamic_power(dfc->devfreq, freq,
+						    voltage);
+
+	freq_mhz = freq / 1000000;
+	power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage;
+	do_div(power, 1000000000);
+
+	return power;
+}
+
+
+static inline unsigned long get_total_power(struct devfreq_cooling_device *dfc,
+					    unsigned long freq,
+					    unsigned long voltage)
+{
+	return get_static_power(dfc, freq) + get_dynamic_power(dfc, freq,
+							       voltage);
+}
+
+
+static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev,
+					       u32 *power)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+	struct devfreq *df = dfc->devfreq;
+	struct devfreq_dev_status *status = &df->last_status;
+	unsigned long state;
+	unsigned long freq = status->current_frequency;
+	unsigned long voltage;
+	u32 dyn_power = 0;
+	u32 static_power = 0;
+	int res;
+
+	state = freq_get_state(dfc, freq);
+	if (state == THERMAL_CSTATE_INVALID) {
+		res = -EAGAIN;
+		goto fail;
+	}
+
+	if (dfc->power_ops->get_real_power) {
+		voltage = get_voltage(df, freq);
+		if (voltage == 0) {
+			res = -EINVAL;
+			goto fail;
+		}
+
+		res = dfc->power_ops->get_real_power(df, power, freq, voltage);
+		if (!res) {
+			state = dfc->capped_state;
+			dfc->res_util = dfc->power_table[state];
+			dfc->res_util *= SCALE_ERROR_MITIGATION;
+
+			if (*power > 1)
+				dfc->res_util /= *power;
+		} else {
+			goto fail;
+		}
+	} else {
+		dyn_power = dfc->power_table[state];
+
+		/* Scale dynamic power for utilization */
+		dyn_power *= status->busy_time;
+		dyn_power /= status->total_time;
+		/* Get static power */
+		static_power = get_static_power(dfc, freq);
+
+		*power = dyn_power + static_power;
+	}
+
+	trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power,
+					      static_power, *power);
+
+	return 0;
+fail:
+	/* It is safe to set max in this case */
+	dfc->res_util = SCALE_ERROR_MITIGATION;
+	return res;
+}
+
+static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev,
+				       unsigned long state,
+				       u32 *power)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+	unsigned long freq;
+	u32 static_power;
+
+	if (state >= dfc->freq_table_size)
+		return -EINVAL;
+
+	freq = dfc->freq_table[state];
+	static_power = get_static_power(dfc, freq);
+
+	*power = dfc->power_table[state] + static_power;
+	return 0;
+}
+
+static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
+				       u32 power, unsigned long *state)
+{
+	struct devfreq_cooling_device *dfc = cdev->devdata;
+	struct devfreq *df = dfc->devfreq;
+	struct devfreq_dev_status *status = &df->last_status;
+	unsigned long freq = status->current_frequency;
+	unsigned long busy_time;
+	s32 dyn_power;
+	u32 static_power;
+	s32 est_power;
+	int i;
+
+	if (dfc->power_ops->get_real_power) {
+		/* Scale for resource utilization */
+		est_power = power * dfc->res_util;
+		est_power /= SCALE_ERROR_MITIGATION;
+	} else {
+		static_power = get_static_power(dfc, freq);
+
+		dyn_power = power - static_power;
+		dyn_power = dyn_power > 0 ? dyn_power : 0;
+
+		/* Scale dynamic power for utilization */
+		busy_time = status->busy_time ?: 1;
+		est_power = (dyn_power * status->total_time) / busy_time;
+	}
+
+	/*
+	 * Find the first cooling state that is within the power
+	 * budget for dynamic power.
+	 */
+	for (i = 0; i < dfc->freq_table_size - 1; i++)
+		if (est_power >= dfc->power_table[i])
+			break;
+
+	*state = i;
+	dfc->capped_state = i;
+	trace_thermal_power_devfreq_limit(cdev, freq, *state, power);
+	return 0;
+}
+
+static struct thermal_cooling_device_ops devfreq_cooling_ops = {
+	.get_max_state = devfreq_cooling_get_max_state,
+	.get_cur_state = devfreq_cooling_get_cur_state,
+	.set_cur_state = devfreq_cooling_set_cur_state,
+};
+
+/**
+ * devfreq_cooling_gen_tables() - Generate power and freq tables.
+ * @dfc: Pointer to devfreq cooling device.
+ *
+ * Generate power and frequency tables: the power table hold the
+ * device's maximum power usage at each cooling state (OPP).  The
+ * static and dynamic power using the appropriate voltage and
+ * frequency for the state, is acquired from the struct
+ * devfreq_cooling_power, and summed to make the maximum power draw.
+ *
+ * The frequency table holds the frequencies in descending order.
+ * That way its indexed by cooling device state.
+ *
+ * The tables are malloced, and pointers put in dfc.  They must be
+ * freed when unregistering the devfreq cooling device.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc)
+{
+	struct devfreq *df = dfc->devfreq;
+	struct device *dev = df->dev.parent;
+	int ret, num_opps;
+	unsigned long freq;
+	u32 *power_table = NULL;
+	u32 *freq_table;
+	int i;
+
+	num_opps = dev_pm_opp_get_opp_count(dev);
+
+	if (dfc->power_ops) {
+		power_table = kcalloc(num_opps, sizeof(*power_table),
+				      GFP_KERNEL);
+		if (!power_table)
+			return -ENOMEM;
+	}
+
+	freq_table = kcalloc(num_opps, sizeof(*freq_table),
+			     GFP_KERNEL);
+	if (!freq_table) {
+		ret = -ENOMEM;
+		goto free_power_table;
+	}
+
+	for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) {
+		unsigned long power, voltage;
+		struct dev_pm_opp *opp;
+
+		opp = dev_pm_opp_find_freq_floor(dev, &freq);
+		if (IS_ERR(opp)) {
+			ret = PTR_ERR(opp);
+			goto free_tables;
+		}
+
+		voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
+		dev_pm_opp_put(opp);
+
+		if (dfc->power_ops) {
+			if (dfc->power_ops->get_real_power)
+				power = get_total_power(dfc, freq, voltage);
+			else
+				power = get_dynamic_power(dfc, freq, voltage);
+
+			dev_dbg(dev, "Power table: %lu MHz @ %lu mV: %lu = %lu mW\n",
+				freq / 1000000, voltage, power, power);
+
+			power_table[i] = power;
+		}
+
+		freq_table[i] = freq;
+	}
+
+	if (dfc->power_ops)
+		dfc->power_table = power_table;
+
+	dfc->freq_table = freq_table;
+	dfc->freq_table_size = num_opps;
+
+	return 0;
+
+free_tables:
+	kfree(freq_table);
+free_power_table:
+	kfree(power_table);
+
+	return ret;
+}
+
+/**
+ * of_devfreq_cooling_register_power() - Register devfreq cooling device,
+ *                                      with OF and power information.
+ * @np:	Pointer to OF device_node.
+ * @df:	Pointer to devfreq device.
+ * @dfc_power:	Pointer to devfreq_cooling_power.
+ *
+ * Register a devfreq cooling device.  The available OPPs must be
+ * registered on the device.
+ *
+ * If @dfc_power is provided, the cooling device is registered with the
+ * power extensions.  For the power extensions to work correctly,
+ * devfreq should use the simple_ondemand governor, other governors
+ * are not currently supported.
+ */
+struct thermal_cooling_device *
+of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
+				  struct devfreq_cooling_power *dfc_power)
+{
+	struct thermal_cooling_device *cdev;
+	struct devfreq_cooling_device *dfc;
+	char dev_name[THERMAL_NAME_LENGTH];
+	int err;
+
+	dfc = kzalloc(sizeof(*dfc), GFP_KERNEL);
+	if (!dfc)
+		return ERR_PTR(-ENOMEM);
+
+	dfc->devfreq = df;
+
+	if (dfc_power) {
+		dfc->power_ops = dfc_power;
+
+		devfreq_cooling_ops.get_requested_power =
+			devfreq_cooling_get_requested_power;
+		devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
+		devfreq_cooling_ops.power2state = devfreq_cooling_power2state;
+	}
+
+	err = devfreq_cooling_gen_tables(dfc);
+	if (err)
+		goto free_dfc;
+
+	err = dev_pm_qos_add_request(df->dev.parent, &dfc->req_max_freq,
+				     DEV_PM_QOS_MAX_FREQUENCY,
+				     PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
+	if (err < 0)
+		goto free_tables;
+
+	err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL);
+	if (err < 0)
+		goto remove_qos_req;
+	dfc->id = err;
+
+	snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id);
+
+	cdev = thermal_of_cooling_device_register(np, dev_name, dfc,
+						  &devfreq_cooling_ops);
+	if (IS_ERR(cdev)) {
+		err = PTR_ERR(cdev);
+		dev_err(df->dev.parent,
+			"Failed to register devfreq cooling device (%d)\n",
+			err);
+		goto release_ida;
+	}
+
+	dfc->cdev = cdev;
+
+	return cdev;
+
+release_ida:
+	ida_simple_remove(&devfreq_ida, dfc->id);
+
+remove_qos_req:
+	dev_pm_qos_remove_request(&dfc->req_max_freq);
+
+free_tables:
+	kfree(dfc->power_table);
+	kfree(dfc->freq_table);
+free_dfc:
+	kfree(dfc);
+
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(of_devfreq_cooling_register_power);
+
+/**
+ * of_devfreq_cooling_register() - Register devfreq cooling device,
+ *                                with OF information.
+ * @np: Pointer to OF device_node.
+ * @df: Pointer to devfreq device.
+ */
+struct thermal_cooling_device *
+of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
+{
+	return of_devfreq_cooling_register_power(np, df, NULL);
+}
+EXPORT_SYMBOL_GPL(of_devfreq_cooling_register);
+
+/**
+ * devfreq_cooling_register() - Register devfreq cooling device.
+ * @df: Pointer to devfreq device.
+ */
+struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
+{
+	return of_devfreq_cooling_register(NULL, df);
+}
+EXPORT_SYMBOL_GPL(devfreq_cooling_register);
+
+/**
+ * devfreq_cooling_unregister() - Unregister devfreq cooling device.
+ * @cdev: Pointer to devfreq cooling device to unregister.
+ */
+void devfreq_cooling_unregister(struct thermal_cooling_device *cdev)
+{
+	struct devfreq_cooling_device *dfc;
+
+	if (!cdev)
+		return;
+
+	dfc = cdev->devdata;
+
+	thermal_cooling_device_unregister(dfc->cdev);
+	ida_simple_remove(&devfreq_ida, dfc->id);
+	dev_pm_qos_remove_request(&dfc->req_max_freq);
+	kfree(dfc->power_table);
+	kfree(dfc->freq_table);
+
+	kfree(dfc);
+}
+EXPORT_SYMBOL_GPL(devfreq_cooling_unregister);