diff options
Diffstat (limited to 'drivers/thermal/cpu_cooling.c')
| -rw-r--r-- | drivers/thermal/cpu_cooling.c | 514 |
1 files changed, 0 insertions, 514 deletions
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c deleted file mode 100644 index 82e15dbb3ac7..000000000000 --- a/drivers/thermal/cpu_cooling.c +++ /dev/null @@ -1,514 +0,0 @@ -/* - * 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; -}; -static DEFINE_IDR(cpufreq_idr); -static DEFINE_MUTEX(cooling_cpufreq_lock); - -static unsigned int cpufreq_dev_count; - -/* notify_table passes value to the CPUFREQ_ADJUST callback function. */ -#define NOTIFY_INVALID NULL -static struct cpufreq_cooling_device *notify_device; - -/** - * 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, j; - unsigned long max_level = 0, level = 0; - unsigned int freq = CPUFREQ_ENTRY_INVALID; - int descend = -1; - struct cpufreq_frequency_table *table = - cpufreq_frequency_get_table(cpu); - - if (!output) - return -EINVAL; - - if (!table) - return -EINVAL; - - for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { - /* ignore invalid entries */ - if (table[i].frequency == CPUFREQ_ENTRY_INVALID) - continue; - - /* ignore duplicate entry */ - if (freq == table[i].frequency) - continue; - - /* get the frequency order */ - if (freq != CPUFREQ_ENTRY_INVALID && descend == -1) - descend = !!(freq > table[i].frequency); - - freq = table[i].frequency; - 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 - 1); - - for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { - /* ignore invalid entry */ - if (table[i].frequency == CPUFREQ_ENTRY_INVALID) - continue; - - /* ignore duplicate entry */ - if (freq == table[i].frequency) - continue; - - /* now we have a valid frequency entry */ - freq = table[i].frequency; - - if (property == GET_LEVEL && (unsigned int)input == freq) { - /* get level by frequency */ - *output = descend ? j : (max_level - j - 1); - return 0; - } - if (property == GET_FREQ && level == j) { - /* get frequency by level */ - *output = freq; - return 0; - } - j++; - } - - 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; - notify_device = cpufreq_device; - - for_each_cpu(cpuid, mask) { - if (is_cpufreq_valid(cpuid)) - cpufreq_update_policy(cpuid); - } - - notify_device = NOTIFY_INVALID; - - 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 highjack 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; - - if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID) - return 0; - - if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus)) - max_freq = notify_device->cpufreq_val; - - /* Never exceed user_policy.max */ - if (max_freq > policy->user_policy.max) - max_freq = policy->user_policy.max; - - if (policy->max != max_freq) - cpufreq_verify_within_limits(policy, 0, max_freq); - - 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 - 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) -{ - 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_cooling_device_register(dev_name, cpufreq_dev, - &cpufreq_cooling_ops); - if (!cool_dev) { - release_idr(&cpufreq_idr, cpufreq_dev->id); - kfree(cpufreq_dev); - return ERR_PTR(-EINVAL); - } - 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++; - - mutex_unlock(&cooling_cpufreq_lock); - - return cool_dev; -} -EXPORT_SYMBOL_GPL(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 = cdev->devdata; - - mutex_lock(&cooling_cpufreq_lock); - 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); |