Hi Rob/Eduardo, As these patches have still not made into mainline. I will rebase the whole set along with your suggestion and send them shortly. Sorry for late reply. Thanks, Amit Daniel On Tue, Jun 26, 2012 at 1:12 PM, Valentin, Eduardo <eduardo.valentin@xxxxxx> wrote: > 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 > -- > 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
