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 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. (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) > +/** > + * 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); > +{ > + 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
