Hey Rob and Amit, On Tue, Jun 26, 2012 at 6:12 AM, Rob Lee <rob.lee@xxxxxxxxxx> wrote: > Hey Amit, > > I was just re-organizing the imx thermal driver that uses this cpu > cooling interface and noticed a couple of small issues here. If While rewriting the OMAP BG driver on top of this series I noticed similar issues. Apart from those pointed by Rob, I have another minor fix. > these suggestions are agreed upon and if it's too late for these > issues be changed with this patchset, I can submit them separately > unless you'd prefer to. > > On Sat, May 12, 2012 at 4:40 AM, Amit Daniel Kachhap > <amit.kachhap@xxxxxxxxxx> wrote: >> This patch adds support for generic cpu thermal cooling low level >> implementations using frequency scaling up/down based on the registration >> parameters. Different cpu related cooling devices can be registered by the >> user and the binding of these cooling devices to the corresponding >> trip points can be easily done as the registration APIs return the >> cooling device pointer. The user of these APIs are responsible for >> passing clipping frequency . The drivers can also register to recieve >> notification about any cooling action called. >> >> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> >> --- >> Documentation/thermal/cpu-cooling-api.txt | 60 ++++ >> drivers/thermal/Kconfig | 11 + >> drivers/thermal/Makefile | 3 +- >> drivers/thermal/cpu_cooling.c | 483 +++++++++++++++++++++++++++++ >> include/linux/cpu_cooling.h | 99 ++++++ >> 5 files changed, 655 insertions(+), 1 deletions(-) >> create mode 100644 Documentation/thermal/cpu-cooling-api.txt >> create mode 100644 drivers/thermal/cpu_cooling.c >> create mode 100644 include/linux/cpu_cooling.h >> >> diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt >> new file mode 100644 >> index 0000000..557adb8 >> --- /dev/null >> +++ b/Documentation/thermal/cpu-cooling-api.txt >> @@ -0,0 +1,60 @@ >> +CPU cooling APIs How To >> +=================================== >> + >> +Written by Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> >> + >> +Updated: 12 May 2012 >> + >> +Copyright (c) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + >> +0. Introduction >> + >> +The generic cpu cooling(freq clipping, cpuhotplug etc) provides >> +registration/unregistration APIs to the caller. The binding of the cooling >> +devices to the trip point is left for the user. The registration APIs returns >> +the cooling device pointer. >> + >> +1. cpu cooling APIs >> + >> +1.1 cpufreq registration/unregistration APIs >> +1.1.1 struct thermal_cooling_device *cpufreq_cooling_register( >> + struct freq_clip_table *tab_ptr, unsigned int tab_size) >> + >> + This interface function registers the cpufreq cooling device with the name >> + "thermal-cpufreq-%x". This api can support multiple instances of cpufreq >> + cooling devices. >> + >> + tab_ptr: The table containing the maximum value of frequency to be clipped >> + for each cooling state. >> + .freq_clip_max: Value of frequency to be clipped for each allowed >> + cpus. >> + .temp_level: Temperature level at which the frequency clamping will >> + happen. >> + .mask_val: cpumask of the allowed cpu's >> + tab_size: the total number of cpufreq cooling states. >> + >> +1.1.2 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) >> + >> + This interface function unregisters the "thermal-cpufreq-%x" cooling device. >> + >> + cdev: Cooling device pointer which has to be unregistered. >> + >> + >> +1.2 CPU cooling action notifier register/unregister interface >> +1.2.1 int cputherm_register_notifier(struct notifier_block *nb, >> + unsigned int list) >> + >> + This interface registers a driver with cpu cooling layer. The driver will >> + be notified when any cpu cooling action is called. >> + >> + nb: notifier function to register >> + list: CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP >> + >> +1.2.2 int cputherm_unregister_notifier(struct notifier_block *nb, >> + unsigned int list) >> + >> + This interface registers a driver with cpu cooling layer. The driver will >> + be notified when any cpu cooling action is called. >> + >> + nb: notifier function to register >> + list: CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP >> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig >> index 514a691..d9c529f 100644 >> --- a/drivers/thermal/Kconfig >> +++ b/drivers/thermal/Kconfig >> @@ -19,6 +19,17 @@ config THERMAL_HWMON >> depends on HWMON=y || HWMON=THERMAL >> default y >> >> +config CPU_THERMAL > > Perhaps the name CPU_COOLING or CPUFREQ_COOLING would more accurately > describe this functionality? I like the latter since now this > mechanism only supports cooling by using cpufreq. > >> + bool "generic cpu cooling support" > > If we use CPUFREQ_COOLING, then perhaps this could say: > > bool "cpu cooling through cpufreq frequency limiting" > >> + depends on THERMAL && CPU_FREQ >> + help >> + This implements the generic cpu cooling mechanism through frequency >> + reduction, cpu hotplug and any other ways of reducing temperature. An >> + ACPI version of this already exists(drivers/acpi/processor_thermal.c). >> + This will be useful for platforms using the generic thermal interface >> + and not the ACPI interface. >> + If you want this support, you should say Y or M here. >> + > > Currently, only the "frequency reduction" method exists so perhaps > it's best to remove mention of "cpu hotplug and any other ways of > reducing temperature"? Here'as a version for cpufreq only: > > config CPUFREQ_COOLING > bool "cpu cooling through cpufreq frequency limiting" > depends on THERMAL && CPU_FREQ > help > This implements a generic cpu cooling mechanism through cpufreq > frequency limiting. An ACPI version of this already exists > (drivers/acpi/processor_thermal.c). This will be useful for > platforms using the generic thermal interface and not the ACPI > interface. > If you want this support, you should say Y or M here. > >> config SPEAR_THERMAL >> bool "SPEAr thermal sensor driver" >> depends on THERMAL >> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile >> index a9fff0b..30c456c 100644 >> --- a/drivers/thermal/Makefile >> +++ b/drivers/thermal/Makefile >> @@ -3,4 +3,5 @@ >> # >> >> obj-$(CONFIG_THERMAL) += thermal_sys.o >> -obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o >> \ No newline at end of file >> +obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o >> +obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o >> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c >> new file mode 100644 >> index 0000000..c40d9a0 >> --- /dev/null >> +++ b/drivers/thermal/cpu_cooling.c >> @@ -0,0 +1,483 @@ >> +/* >> + * linux/drivers/thermal/cpu_cooling.c >> + * >> + * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + * Copyright (C) 2012 Amit Daniel <amit.kachhap@xxxxxxxxxx> >> + * >> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> + * 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/kernel.h> >> +#include <linux/module.h> >> +#include <linux/thermal.h> >> +#include <linux/platform_device.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 >> + * @id: unique integer value corresponding to each cpufreq_cooling_device >> + * registered. >> + * @cool_dev: thermal_cooling_device pointer to keep track of the the >> + * egistered cooling device. >> + * @tab_ptr: freq_clip_table table containing the maximum value of frequency to >> + * be set for different cooling state. >> + * @tab_size: integer value representing a count of the above table. >> + * @cpufreq_state: integer value representing the current state of cpufreq >> + * cooling devices. >> + * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device. >> + * @node: list_head to link all cpufreq_cooling_device together. >> + * >> + * This structure is required for keeping information of each >> + * cpufreq_cooling_device registered as a list whose head is represented by >> + * cooling_cpufreq_list. In order to prevent corruption of this list a >> + * mutex lock cooling_cpufreq_lock is used. >> + */ >> +struct cpufreq_cooling_device { >> + int id; >> + struct thermal_cooling_device *cool_dev; >> + struct freq_clip_table *tab_ptr; >> + unsigned int tab_size; >> + unsigned int cpufreq_state; >> + struct cpumask allowed_cpus; >> + struct list_head node; >> +}; >> +static LIST_HEAD(cooling_cpufreq_list); >> +static DEFINE_MUTEX(cooling_cpufreq_lock); >> +static DEFINE_IDR(cpufreq_idr); >> + >> +/*per cpu variable to store the previous max frequency allowed*/ >> +static DEFINE_PER_CPU(unsigned int, max_policy_freq); >> + >> +/*notify_table passes value to the CPUFREQ_ADJUST callback function.*/ >> +#define NOTIFY_INVALID NULL >> +static struct freq_clip_table *notify_table; >> + >> +/*Head of the blocking notifier chain to inform about frequency clamping*/ >> +static BLOCKING_NOTIFIER_HEAD(cputherm_state_notifier_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. >> + */ >> +static int get_idr(struct idr *idr, int *id) >> +{ >> + int err; >> +again: >> + if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0)) >> + return -ENOMEM; >> + >> + mutex_lock(&cooling_cpufreq_lock); >> + err = idr_get_new(idr, NULL, id); >> + mutex_unlock(&cooling_cpufreq_lock); >> + >> + if (unlikely(err == -EAGAIN)) >> + goto again; >> + else if (unlikely(err)) >> + return err; >> + >> + *id = *id & MAX_ID_MASK; >> + 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); >> +} >> + >> +/** >> + * cputherm_register_notifier - Register a notifier with cpu cooling interface. >> + * @nb: struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. possible values are >> + * CPUFREQ_COOLING_START and CPUFREQ_COOLING_STOP. >> + * >> + * This exported function registers a driver with cpu cooling layer. The driver >> + * will be notified when any cpu cooling action is called. >> + */ >> +int cputherm_register_notifier(struct notifier_block *nb, unsigned int list) >> +{ >> + int ret = 0; >> + >> + switch (list) { >> + case CPUFREQ_COOLING_START: >> + case CPUFREQ_COOLING_STOP: >> + ret = blocking_notifier_chain_register( >> + &cputherm_state_notifier_list, nb); >> + break; >> + default: >> + ret = -EINVAL; >> + } >> + return ret; >> +} >> +EXPORT_SYMBOL(cputherm_register_notifier); >> + >> +/** >> + * cputherm_unregister_notifier - Un-register a notifier. >> + * @nb: struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. values possible are >> + * CPUFREQ_COOLING_START or CPUFREQ_COOLING_STOP. >> + * >> + * This exported function un-registers a driver with cpu cooling layer. >> + */ >> +int cputherm_unregister_notifier(struct notifier_block *nb, unsigned int list) >> +{ >> + int ret = 0; >> + >> + switch (list) { >> + case CPUFREQ_COOLING_START: >> + case CPUFREQ_COOLING_STOP: >> + ret = blocking_notifier_chain_unregister( >> + &cputherm_state_notifier_list, nb); >> + break; >> + default: >> + ret = -EINVAL; >> + } >> + return ret; >> +} >> +EXPORT_SYMBOL(cputherm_unregister_notifier); >> + >> +/*Below codes defines functions to be used for cpufreq as cooling device*/ >> + >> +/** >> + * is_cpufreq_valid - function to check if a cpu has frequency transition policy. >> + * @cpu: cpu for which check is needed. >> + */ >> +static int is_cpufreq_valid(int cpu) >> +{ >> + struct cpufreq_policy policy; >> + return !cpufreq_get_policy(&policy, cpu); >> +} >> + >> +/** >> + * 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. >> + */ >> +static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, >> + unsigned long cooling_state) >> +{ >> + unsigned int event, cpuid, state; >> + struct freq_clip_table *th_table, *table_ptr; >> + const struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; >> + struct cpufreq_cooling_device *cpufreq_ptr; >> + >> + if (cooling_state > cpufreq_device->tab_size) >> + return -EINVAL; >> + >> + /*Check if the old cooling action is same as new cooling action*/ >> + if (cpufreq_device->cpufreq_state == cooling_state) >> + return 0; >> + >> + /*pass cooling table info to the cpufreq_thermal_notifier callback*/ >> + notify_table = NOTIFY_INVALID; >> + >> + if (cooling_state > 0) { >> + th_table = &(cpufreq_device->tab_ptr[cooling_state - 1]); >> + notify_table = th_table; >> + } >> + >> + /*check if any lower clip frequency active in other cpufreq_device's*/ >> + list_for_each_entry(cpufreq_ptr, &cooling_cpufreq_list, node) { >> + >> + state = cpufreq_ptr->cpufreq_state; >> + if (state == 0 || cpufreq_ptr == cpufreq_device) >> + continue; >> + >> + if (!cpumask_equal(&cpufreq_ptr->allowed_cpus, >> + &cpufreq_device->allowed_cpus)) >> + continue; >> + >> + table_ptr = &(cpufreq_ptr->tab_ptr[state - 1]); >> + if (notify_table == NULL || >> + (table_ptr->freq_clip_max < >> + notify_table->freq_clip_max)) >> + notify_table = table_ptr; >> + } >> + >> + cpufreq_device->cpufreq_state = cooling_state; >> + >> + if (notify_table != NOTIFY_INVALID) { >> + event = CPUFREQ_COOLING_START; >> + maskPtr = notify_table->mask_val; >> + } else { >> + event = CPUFREQ_COOLING_STOP; >> + } >> + >> + blocking_notifier_call_chain(&cputherm_state_notifier_list, >> + event, notify_table); >> + >> + for_each_cpu(cpuid, maskPtr) { >> + if (is_cpufreq_valid(cpuid)) >> + cpufreq_update_policy(cpuid); >> + } >> + >> + notify_table = 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 >> + */ >> +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) >> + return 0; >> + >> + if (notify_table != NOTIFY_INVALID) { >> + max_freq = notify_table->freq_clip_max; >> + >> + if (!per_cpu(max_policy_freq, policy->cpu)) >> + per_cpu(max_policy_freq, policy->cpu) = policy->max; >> + } else { >> + if (per_cpu(max_policy_freq, policy->cpu)) { >> + max_freq = per_cpu(max_policy_freq, policy->cpu); >> + per_cpu(max_policy_freq, policy->cpu) = 0; >> + } else { >> + max_freq = policy->max; >> + } >> + } >> + >> + /* 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. >> + */ >> +static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, >> + unsigned long *state) >> +{ >> + int ret = -EINVAL; >> + struct cpufreq_cooling_device *cpufreq_device; >> + >> + mutex_lock(&cooling_cpufreq_lock); >> + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { >> + *state = cpufreq_device->tab_size; >> + ret = 0; >> + break; >> + } >> + } >> + mutex_unlock(&cooling_cpufreq_lock); >> + 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. >> + */ >> +static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, >> + unsigned long *state) >> +{ >> + int ret = -EINVAL; >> + struct cpufreq_cooling_device *cpufreq_device; >> + >> + mutex_lock(&cooling_cpufreq_lock); >> + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { >> + *state = cpufreq_device->cpufreq_state; >> + ret = 0; >> + break; >> + } >> + } >> + mutex_unlock(&cooling_cpufreq_lock); >> + return ret; >> +} >> + >> +/** >> + * 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. >> + */ >> +static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, >> + unsigned long state) >> +{ >> + int ret = -EINVAL; >> + struct cpufreq_cooling_device *cpufreq_device; >> + >> + mutex_lock(&cooling_cpufreq_lock); >> + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> + if (cpufreq_device && cpufreq_device->cool_dev == cdev) { >> + ret = 0; >> + break; >> + } >> + } >> + if (!ret) >> + ret = cpufreq_apply_cooling(cpufreq_device, state); >> + >> + mutex_unlock(&cooling_cpufreq_lock); >> + >> + return ret; >> +} >> + >> +/*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. >> + * @tab_ptr: table ptr containing the maximum value of frequency to be clipped >> + * for each cooling state. >> + * @tab_size: count of entries in the above table. >> + * happen. >> + */ >> +struct thermal_cooling_device *cpufreq_cooling_register( >> + struct freq_clip_table *tab_ptr, unsigned int tab_size) >> +{ >> + struct thermal_cooling_device *cool_dev; >> + struct cpufreq_cooling_device *cpufreq_dev = NULL; >> + struct freq_clip_table *clip_tab; >> + unsigned int cpufreq_dev_count = 0; >> + char dev_name[THERMAL_NAME_LENGTH]; >> + int ret = 0, id = 0, i; >> + >> + if (tab_ptr == NULL || tab_size == 0) >> + return ERR_PTR(-EINVAL); >> + >> + list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) >> + cpufreq_dev_count++; >> + >> + cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), >> + GFP_KERNEL); >> + if (!cpufreq_dev) >> + return ERR_PTR(-ENOMEM); >> + >> + /*Verify that all the entries of freq_clip_table are present*/ >> + for (i = 0; i < tab_size; i++) { >> + clip_tab = ((struct freq_clip_table *)&tab_ptr[i]); >> + if (!clip_tab->freq_clip_max || !clip_tab->mask_val >> + || !clip_tab->temp_level) { >> + kfree(cpufreq_dev); >> + return ERR_PTR(-EINVAL); >> + } >> + /* >> + *Consolidate all the cpumask for all the individual entries >> + *of the trip table. This is useful in resetting all the >> + *clipped frequencies to the normal level for each cpufreq >> + *cooling device. >> + */ >> + cpumask_or(&cpufreq_dev->allowed_cpus, >> + &cpufreq_dev->allowed_cpus, clip_tab->mask_val); >> + } >> + >> + cpufreq_dev->tab_ptr = tab_ptr; >> + cpufreq_dev->tab_size = tab_size; >> + >> + ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); >> + if (ret) { >> + kfree(cpufreq_dev); >> + return ERR_PTR(-EINVAL); >> + } >> + >> + sprintf(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->id = id; >> + cpufreq_dev->cool_dev = cool_dev; >> + mutex_lock(&cooling_cpufreq_lock); >> + list_add_tail(&cpufreq_dev->node, &cooling_cpufreq_list); >> + >> + /*Register the notifier for first cpufreq cooling device*/ >> + if (cpufreq_dev_count == 0) >> + cpufreq_register_notifier(&thermal_cpufreq_notifier_block, >> + CPUFREQ_POLICY_NOTIFIER); >> + >> + mutex_unlock(&cooling_cpufreq_lock); >> + return cool_dev; >> +} >> +EXPORT_SYMBOL(cpufreq_cooling_register); >> + >> +/** >> + * cpufreq_cooling_unregister - function to remove cpufreq cooling device. >> + * @cdev: thermal cooling device pointer. >> + */ >> +void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) >> +{ >> + struct cpufreq_cooling_device *cpufreq_dev = NULL; >> + unsigned int cpufreq_dev_count = 0; >> + >> + mutex_lock(&cooling_cpufreq_lock); >> + list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) { >> + if (cpufreq_dev && cpufreq_dev->cool_dev == cdev) >> + break; >> + cpufreq_dev_count++; >> + } >> + >> + if (!cpufreq_dev || cpufreq_dev->cool_dev != cdev) { >> + mutex_unlock(&cooling_cpufreq_lock); >> + return; >> + } >> + >> + list_del(&cpufreq_dev->node); >> + >> + /*Unregister the notifier for the last cpufreq cooling device*/ >> + if (cpufreq_dev_count == 1) { >> + 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(cpufreq_cooling_unregister); >> diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h >> new file mode 100644 >> index 0000000..ed6c096 >> --- /dev/null >> +++ b/include/linux/cpu_cooling.h >> @@ -0,0 +1,99 @@ >> +/* >> + * linux/include/linux/cpu_cooling.h >> + * >> + * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) >> + * Copyright (C) 2012 Amit Daniel <amit.kachhap@xxxxxxxxxx> >> + * >> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> + * 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. >> + * >> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> + */ >> + >> +#ifndef __CPU_COOLING_H__ >> +#define __CPU_COOLING_H__ >> + >> +#include <linux/thermal.h> >> + >> +#define CPUFREQ_COOLING_START 0 >> +#define CPUFREQ_COOLING_STOP 1 >> + >> +/** >> + * struct freq_clip_table >> + * @freq_clip_max: maximum frequency allowed for this cooling state. >> + * @temp_level: Temperature level at which the temperature clipping will >> + * happen. >> + * @mask_val: cpumask of the allowed cpu's where the clipping will take place. >> + * >> + * This structure is required to be filled and passed to the >> + * cpufreq_cooling_unregister function. >> + */ >> +struct freq_clip_table { >> + unsigned int freq_clip_max; >> + unsigned int temp_level; >> + const struct cpumask *mask_val; >> +}; >> + >> +/** >> + * cputherm_register_notifier - Register a notifier with cpu cooling interface. >> + * @nb: struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. possible values are >> + * CPUFREQ_COOLING_TYPE and CPUHOTPLUG_COOLING_TYPE. > > CPUFREQ_COOLING_TYPE and CPUHOTPLUG_COOLING_TYPE should be changed to > CPUFREQ_COOLING_START CPUFREQ_COOLING_STOP, right? > >> + * >> + * This exported function registers a driver with cpu cooling layer. The driver >> + * will be notified when any cpu cooling action is called. >> + */ >> +int cputherm_register_notifier(struct notifier_block *nb, unsigned int list); >> + >> +/** >> + * cputherm_unregister_notifier - Un-register a notifier. >> + * @nb: struct notifier_block * with callback info. >> + * @list: integer value for which notification is needed. values possible are >> + * CPUFREQ_COOLING_TYPE. > > Should be changed to CPUFREQ_COOLING_START, CPUFREQ_COOLING_STOP, right? > >> + * >> + * This exported function un-registers a driver with cpu cooling layer. >> + */ >> +int cputherm_unregister_notifier(struct notifier_block *nb, unsigned int list); >> + >> +#ifdef CONFIG_CPU_FREQ > > Consider changing this to "#ifdef CPU_THERMAL" A platform thermal > driver may want to always call this function as its cpu cooling > mechanism but it should still function without the cpu_cooling being > enabled. In this case, the platform thermal driver would only provide > temperature readings and critical trip point handling. But if the > platform happened may have CONFIG_CPU_FREQ enabled, a build error > would occur in the current implementation. I agree here. It makes more sense to have the check against CPU_THERMAL > > (the CONFIG_CPU_FREQ requirement will be met by CPU_THERMAL being > enabled since it also implies CONFIG_CPU_FREQ being enabled per the > Kconfig dependency) True. > >> +/** >> + * cpufreq_cooling_register - function to create cpufreq cooling device. >> + * @tab_ptr: table ptr containing the maximum value of frequency to be clipped >> + * for each cooling state. >> + * @tab_size: count of entries in the above table. >> + * @mask_val: cpumask containing the allowed cpu's where frequency clipping can >> + * happen. >> + */ >> +struct thermal_cooling_device *cpufreq_cooling_register( >> + struct freq_clip_table *tab_ptr, unsigned int tab_size); >> + >> +/** >> + * cpufreq_cooling_unregister - function to remove cpufreq cooling device. >> + * @cdev: thermal cooling device pointer. >> + */ >> +void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev); >> +#else /*!CONFIG_CPU_FREQ*/ > > Modify comment if above suggestion is taken. > >> +static inline struct thermal_cooling_device *cpufreq_cooling_register( >> + struct freq_clip_table *tab_ptr, unsigned int tab_size); The above semicollon will cause a build error in case this path of the ifdef is taken. >> +{ >> + return NULL; >> +} >> +static inline void cpufreq_cooling_unregister( >> + struct thermal_cooling_device *cdev) >> +{ >> + return; >> +} >> +#endif /*CONFIG_CPU_FREQ*/ > > Modify comment if above suggestion is taken. > >> + >> +#endif /* __CPU_COOLING_H__ */ >> -- >> 1.7.1 >> >> >> _______________________________________________ >> linaro-dev mailing list >> linaro-dev@xxxxxxxxxxxxxxxx >> http://lists.linaro.org/mailman/listinfo/linaro-dev > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Eduardo Valentin
