Fixed MTP to work with TWRP

drivers/thermal/cpu_cooling.c

@@ -0,0 +1,569 @@
+/*
+ *  linux/drivers/thermal/cpu_cooling.c
+ *
+ *  Copyright (C) 2012	Samsung Electronics Co., Ltd(http://www.samsung.com)
+ *  Copyright (C) 2012  Amit Daniel <amit.kachhap@linaro.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/thermal.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/cpu_cooling.h>
+
+/**
+ * struct cpufreq_cooling_device - data for cooling device with cpufreq
+ * @id: unique integer value corresponding to each cpufreq_cooling_device
+ *	registered.
+ * @cool_dev: thermal_cooling_device pointer to keep track of the
+ *	registered cooling device.
+ * @cpufreq_state: integer value representing the current state of cpufreq
+ *	cooling	devices.
+ * @cpufreq_val: integer value representing the absolute value of the clipped
+ *	frequency.
+ * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
+ *
+ * This structure is required for keeping information of each
+ * cpufreq_cooling_device registered. In order to prevent corruption of this a
+ * mutex lock cooling_cpufreq_lock is used.
+ */
+struct cpufreq_cooling_device {
+	int id;
+	struct thermal_cooling_device *cool_dev;
+	unsigned int cpufreq_state;
+	unsigned int cpufreq_val;
+	struct cpumask allowed_cpus;
+	struct list_head node;
+};
+static DEFINE_IDR(cpufreq_idr);
+static DEFINE_MUTEX(cooling_cpufreq_lock);
+
+static unsigned int cpufreq_dev_count;
+
+static LIST_HEAD(cpufreq_dev_list);
+
+/**
+ * get_idr - function to get a unique id.
+ * @idr: struct idr * handle used to create a id.
+ * @id: int * value generated by this function.
+ *
+ * This function will populate @id with an unique
+ * id, using the idr API.
+ *
+ * Return: 0 on success, an error code on failure.
+ */
+static int get_idr(struct idr *idr, int *id)
+{
+	int ret;
+
+	mutex_lock(&cooling_cpufreq_lock);
+	ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
+	mutex_unlock(&cooling_cpufreq_lock);
+	if (unlikely(ret < 0))
+		return ret;
+	*id = ret;
+
+	return 0;
+}
+
+/**
+ * release_idr - function to free the unique id.
+ * @idr: struct idr * handle used for creating the id.
+ * @id: int value representing the unique id.
+ */
+static void release_idr(struct idr *idr, int id)
+{
+	mutex_lock(&cooling_cpufreq_lock);
+	idr_remove(idr, id);
+	mutex_unlock(&cooling_cpufreq_lock);
+}
+
+/* Below code defines functions to be used for cpufreq as cooling device */
+
+/**
+ * is_cpufreq_valid - function to check frequency transitioning capability.
+ * @cpu: cpu for which check is needed.
+ *
+ * This function will check the current state of the system if
+ * it is capable of changing the frequency for a given @cpu.
+ *
+ * Return: 0 if the system is not currently capable of changing
+ * the frequency of given cpu. !0 in case the frequency is changeable.
+ */
+static int is_cpufreq_valid(int cpu)
+{
+	struct cpufreq_policy policy;
+
+	return !cpufreq_get_policy(&policy, cpu);
+}
+
+enum cpufreq_cooling_property {
+	GET_LEVEL,
+	GET_FREQ,
+	GET_MAXL,
+};
+
+/**
+ * get_property - fetch a property of interest for a give cpu.
+ * @cpu: cpu for which the property is required
+ * @input: query parameter
+ * @output: query return
+ * @property: type of query (frequency, level, max level)
+ *
+ * This is the common function to
+ * 1. get maximum cpu cooling states
+ * 2. translate frequency to cooling state
+ * 3. translate cooling state to frequency
+ * Note that the code may be not in good shape
+ * but it is written in this way in order to:
+ * a) reduce duplicate code as most of the code can be shared.
+ * b) make sure the logic is consistent when translating between
+ *    cooling states and frequencies.
+ *
+ * Return: 0 on success, -EINVAL when invalid parameters are passed.
+ */
+static int get_property(unsigned int cpu, unsigned long input,
+			unsigned int *output,
+			enum cpufreq_cooling_property property)
+{
+	int i;
+	unsigned long max_level = 0, level = 0;
+	unsigned int freq = CPUFREQ_ENTRY_INVALID;
+	int descend = -1;
+	struct cpufreq_frequency_table *pos, *table =
+					cpufreq_frequency_get_table(cpu);
+
+	if (!output)
+		return -EINVAL;
+
+	if (!table)
+		return -EINVAL;
+
+	cpufreq_for_each_valid_entry(pos, table) {
+		/* ignore duplicate entry */
+		if (freq == pos->frequency)
+			continue;
+
+		/* get the frequency order */
+		if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)
+			descend = freq > pos->frequency;
+
+		freq = pos->frequency;
+		max_level++;
+	}
+
+	/* No valid cpu frequency entry */
+	if (max_level == 0)
+		return -EINVAL;
+
+	/* max_level is an index, not a counter */
+	max_level--;
+
+	/* get max level */
+	if (property == GET_MAXL) {
+		*output = (unsigned int)max_level;
+		return 0;
+	}
+
+	if (property == GET_FREQ)
+		level = descend ? input : (max_level - input);
+
+	i = 0;
+	cpufreq_for_each_valid_entry(pos, table) {
+		/* ignore duplicate entry */
+		if (freq == pos->frequency)
+			continue;
+
+		/* now we have a valid frequency entry */
+		freq = pos->frequency;
+
+		if (property == GET_LEVEL && (unsigned int)input == freq) {
+			/* get level by frequency */
+			*output = descend ? i : (max_level - i);
+			return 0;
+		}
+		if (property == GET_FREQ && level == i) {
+			/* get frequency by level */
+			*output = freq;
+			return 0;
+		}
+		i++;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
+ * @cpu: cpu for which the level is required
+ * @freq: the frequency of interest
+ *
+ * This function will match the cooling level corresponding to the
+ * requested @freq and return it.
+ *
+ * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
+ * otherwise.
+ */
+unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
+{
+	unsigned int val;
+
+	if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
+		return THERMAL_CSTATE_INVALID;
+
+	return (unsigned long)val;
+}
+EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
+
+/**
+ * get_cpu_frequency - get the absolute value of frequency from level.
+ * @cpu: cpu for which frequency is fetched.
+ * @level: cooling level
+ *
+ * This function matches cooling level with frequency. Based on a cooling level
+ * of frequency, equals cooling state of cpu cooling device, it will return
+ * the corresponding frequency.
+ *	e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
+ *
+ * Return: 0 on error, the corresponding frequency otherwise.
+ */
+static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
+{
+	int ret = 0;
+	unsigned int freq;
+
+	ret = get_property(cpu, level, &freq, GET_FREQ);
+	if (ret)
+		return 0;
+
+	return freq;
+}
+
+/**
+ * cpufreq_apply_cooling - function to apply frequency clipping.
+ * @cpufreq_device: cpufreq_cooling_device pointer containing frequency
+ *	clipping data.
+ * @cooling_state: value of the cooling state.
+ *
+ * Function used to make sure the cpufreq layer is aware of current thermal
+ * limits. The limits are applied by updating the cpufreq policy.
+ *
+ * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
+ * cooling state).
+ */
+static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
+				 unsigned long cooling_state)
+{
+	unsigned int cpuid, clip_freq;
+	struct cpumask *mask = &cpufreq_device->allowed_cpus;
+	unsigned int cpu = cpumask_any(mask);
+
+
+	/* Check if the old cooling action is same as new cooling action */
+	if (cpufreq_device->cpufreq_state == cooling_state)
+		return 0;
+
+	clip_freq = get_cpu_frequency(cpu, cooling_state);
+	if (!clip_freq)
+		return -EINVAL;
+
+	cpufreq_device->cpufreq_state = cooling_state;
+	cpufreq_device->cpufreq_val = clip_freq;
+
+	for_each_cpu(cpuid, mask) {
+		if (is_cpufreq_valid(cpuid))
+			cpufreq_update_policy(cpuid);
+	}
+
+	return 0;
+}
+
+/**
+ * cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
+ * @nb:	struct notifier_block * with callback info.
+ * @event: value showing cpufreq event for which this function invoked.
+ * @data: callback-specific data
+ *
+ * Callback to hijack the notification on cpufreq policy transition.
+ * Every time there is a change in policy, we will intercept and
+ * update the cpufreq policy with thermal constraints.
+ *
+ * Return: 0 (success)
+ */
+static int cpufreq_thermal_notifier(struct notifier_block *nb,
+				    unsigned long event, void *data)
+{
+	struct cpufreq_policy *policy = data;
+	unsigned long max_freq = 0;
+	struct cpufreq_cooling_device *cpufreq_dev;
+
+	if (event != CPUFREQ_ADJUST)
+		return 0;
+
+	mutex_lock(&cooling_cpufreq_lock);
+	list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
+		if (!cpumask_test_cpu(policy->cpu,
+					&cpufreq_dev->allowed_cpus))
+			continue;
+
+		if (!cpufreq_dev->cpufreq_val)
+			cpufreq_dev->cpufreq_val = get_cpu_frequency(
+					cpumask_any(&cpufreq_dev->allowed_cpus),
+					cpufreq_dev->cpufreq_state);
+
+		max_freq = cpufreq_dev->cpufreq_val;
+
+		if (policy->max != max_freq)
+			cpufreq_verify_within_limits(policy, 0, max_freq);
+	}
+	mutex_unlock(&cooling_cpufreq_lock);
+
+	return 0;
+}
+
+/* cpufreq cooling device callback functions are defined below */
+
+/**
+ * cpufreq_get_max_state - callback function to get the max cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: fill this variable with the max cooling state.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * max cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
+	struct cpumask *mask = &cpufreq_device->allowed_cpus;
+	unsigned int cpu;
+	unsigned int count = 0;
+	int ret;
+
+	cpu = cpumask_any(mask);
+
+	ret = get_property(cpu, 0, &count, GET_MAXL);
+
+	if (count > 0)
+		*state = count;
+
+	return ret;
+}
+
+/**
+ * cpufreq_get_cur_state - callback function to get the current cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: fill this variable with the current cooling state.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
+
+	*state = cpufreq_device->cpufreq_state;
+
+	return 0;
+}
+
+/**
+ * cpufreq_set_cur_state - callback function to set the current cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: set this variable to the current cooling state.
+ *
+ * Callback for the thermal cooling device to change the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long state)
+{
+	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
+
+	return cpufreq_apply_cooling(cpufreq_device, state);
+}
+
+/* Bind cpufreq callbacks to thermal cooling device ops */
+static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
+	.get_max_state = cpufreq_get_max_state,
+	.get_cur_state = cpufreq_get_cur_state,
+	.set_cur_state = cpufreq_set_cur_state,
+};
+
+/* Notifier for cpufreq policy change */
+static struct notifier_block thermal_cpufreq_notifier_block = {
+	.notifier_call = cpufreq_thermal_notifier,
+};
+
+/**
+ * __cpufreq_cooling_register - helper function to create cpufreq cooling device
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. It also gives the opportunity to link the cooling device
+ * with a device tree node, in order to bind it via the thermal DT code.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+static struct thermal_cooling_device *
+__cpufreq_cooling_register(struct device_node *np,
+			   const struct cpumask *clip_cpus)
+{
+	struct thermal_cooling_device *cool_dev;
+	struct cpufreq_cooling_device *cpufreq_dev = NULL;
+	unsigned int min = 0, max = 0;
+	char dev_name[THERMAL_NAME_LENGTH];
+	int ret = 0, i;
+	struct cpufreq_policy policy;
+
+	/* Verify that all the clip cpus have same freq_min, freq_max limit */
+	for_each_cpu(i, clip_cpus) {
+		/* continue if cpufreq policy not found and not return error */
+		if (!cpufreq_get_policy(&policy, i))
+			continue;
+		if (min == 0 && max == 0) {
+			min = policy.cpuinfo.min_freq;
+			max = policy.cpuinfo.max_freq;
+		} else {
+			if (min != policy.cpuinfo.min_freq ||
+			    max != policy.cpuinfo.max_freq)
+				return ERR_PTR(-EINVAL);
+		}
+	}
+	cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
+			      GFP_KERNEL);
+	if (!cpufreq_dev)
+		return ERR_PTR(-ENOMEM);
+
+	cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
+
+	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
+	if (ret) {
+		kfree(cpufreq_dev);
+		return ERR_PTR(-EINVAL);
+	}
+
+	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
+		 cpufreq_dev->id);
+
+	cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
+						      &cpufreq_cooling_ops);
+	if (IS_ERR(cool_dev)) {
+		release_idr(&cpufreq_idr, cpufreq_dev->id);
+		kfree(cpufreq_dev);
+		return cool_dev;
+	}
+	cpufreq_dev->cool_dev = cool_dev;
+	cpufreq_dev->cpufreq_state = 0;
+	mutex_lock(&cooling_cpufreq_lock);
+
+	/* Register the notifier for first cpufreq cooling device */
+	if (cpufreq_dev_count == 0)
+		cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
+					  CPUFREQ_POLICY_NOTIFIER);
+	cpufreq_dev_count++;
+	list_add(&cpufreq_dev->node, &cpufreq_dev_list);
+
+	mutex_unlock(&cooling_cpufreq_lock);
+
+	return cool_dev;
+}
+
+/**
+ * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+cpufreq_cooling_register(const struct cpumask *clip_cpus)
+{
+	return __cpufreq_cooling_register(NULL, clip_cpus);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
+
+/**
+ * of_cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. Using this API, the cpufreq cooling device will be
+ * linked to the device tree node provided.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	if (!np)
+		return ERR_PTR(-EINVAL);
+
+	return __cpufreq_cooling_register(np, clip_cpus);
+}
+EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
+
+/**
+ * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
+ * @cdev: thermal cooling device pointer.
+ *
+ * This interface function unregisters the "thermal-cpufreq-%x" cooling device.
+ */
+void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
+{
+	struct cpufreq_cooling_device *cpufreq_dev;
+
+	if (!cdev)
+		return;
+
+	cpufreq_dev = cdev->devdata;
+	mutex_lock(&cooling_cpufreq_lock);
+	list_del(&cpufreq_dev->node);
+	cpufreq_dev_count--;
+
+	/* Unregister the notifier for the last cpufreq cooling device */
+	if (cpufreq_dev_count == 0)
+		cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
+					    CPUFREQ_POLICY_NOTIFIER);
+	mutex_unlock(&cooling_cpufreq_lock);
+
+	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
+	release_idr(&cpufreq_idr, cpufreq_dev->id);
+	kfree(cpufreq_dev);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);