On 16 August 2012 20:22, Valentin, Eduardo <eduardo.valentin@xxxxxx> wrote: > > Amit, > > Thanks again for keeping this up. > > On Thu, Aug 16, 2012 at 2:41 PM, Amit Daniel Kachhap > <amit.kachhap@xxxxxxxxxx> wrote: > > This patchset introduces a new generic cooling device based on cpufreq > > that can be used on non-ACPI platforms. As a proof of concept, we have > > drivers for the following platforms using this mechanism now: > > > > * Samsung Exynos (Exynos4 and Exynos5) in the current patchset. > > * Freescale i.MX (git://git.linaro.org/people/amitdanielk/linux.git > > imx6q_thermal) > > FYI, the OMAP code is under drivers/staging/omap-thermal/. The file > omap-thermal-common.c is the one which is using your generic cooling > device. But it needs to be updated accordingly to the API change you > mention. > > > > > There is a small change in cpufreq cooling registration APIs, so a minor > > change is needed for Freescale platforms. > > > > Brief Description: > > > > 1) The generic cooling devices code is placed inside driver/thermal/* > > as placing inside acpi folder will need un-necessary enabling of acpi > > code. This code is architecture independent. > > > > 2) This patchset adds generic cpu cooling low level implementation > > through frequency clipping. In future, other cpu related cooling > > devices may be added here. An ACPI version of this already exists > > (drivers/acpi/processor_thermal.c) .But this will be useful for > > platforms like ARM using the generic thermal interface along with the > > generic cpu cooling devices. The cooling device registration API's > > return cooling device pointers which can be easily binded with the > > thermal zone trip points. The important APIs exposed are, > > > > a) struct thermal_cooling_device *cpufreq_cooling_register( > > struct cpumask *clip_cpus) > > b) void cpufreq_cooling_unregister(struct thermal_cooling_device > > *cdev) > > > > 3) Samsung exynos platform thermal implementation is done using the > > generic cpu cooling APIs and the new trip type. The temperature > > sensor > > driver present in the hwmon folder(registered as hwmon driver) is > > moved > > to thermal folder and registered as a thermal driver. > > > > A simple data/control flow diagrams is shown below, > > > > Core Linux thermal <-----> Exynos thermal interface <----- Temperature > > Sensor > > | | > > \|/ | > > Cpufreq cooling device <--------------- > > > > TODO: > > *Will send the DT enablement patches later after the driver is merged. > > > > This patch: > > > > Add 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. > > > > [akpm@xxxxxxxxxxxxxxxxxxxx: fix comment layout] > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx> > > Cc: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> > > Cc: SangWook Ju <sw.ju@xxxxxxxxxxx> > > Cc: Durgadoss <durgadoss.r@xxxxxxxxx> > > Cc: Len Brown <lenb@xxxxxxxxxx> > > Cc: Jean Delvare <khali@xxxxxxxxxxxx> > > Cc: Kyungmin Park <kmpark@xxxxxxxxxxxxx> > > Cc: Kukjin Kim <kgene.kim@xxxxxxxxxxx> > > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx> > > > Reviewed-by: Eduardo Valentin <eduardo.valentin@xxxxxx> Thanks Eduardo . > > > > --- > > Documentation/thermal/cpu-cooling-api.txt | 52 +++ > > drivers/thermal/Kconfig | 11 + > > drivers/thermal/Makefile | 1 + > > drivers/thermal/cpu_cooling.c | 512 > > +++++++++++++++++++++++++++++ > > include/linux/cpu_cooling.h | 79 +++++ > > 5 files changed, 655 insertions(+), 0 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..a1f2a6b > > --- /dev/null > > +++ b/Documentation/thermal/cpu-cooling-api.txt > > @@ -0,0 +1,52 @@ > > +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) 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 cpumask *clip_cpus) > > + > > + This interface function registers the cpufreq cooling device with > > the name > > + "thermal-cpufreq-%x". This api can support multiple instances of > > cpufreq > > + cooling devices. > > + > > + clip_cpus: cpumask of cpus where the frequency constraints will > > happen. > > + > > +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 7dd8c34..996003b 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 > > + bool "generic cpu cooling support" > > + 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 here. > > + > > config SPEAR_THERMAL > > bool "SPEAr thermal sensor driver" > > depends on THERMAL > > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > > index fd9369a..aae59ad 100644 > > --- a/drivers/thermal/Makefile > > +++ b/drivers/thermal/Makefile > > @@ -3,5 +3,6 @@ > > # > > > > obj-$(CONFIG_THERMAL) += thermal_sys.o > > +obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o > > obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o > > obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o > > diff --git a/drivers/thermal/cpu_cooling.c > > b/drivers/thermal/cpu_cooling.c > > new file mode 100644 > > index 0000000..c42e557 > > --- /dev/null > > +++ b/drivers/thermal/cpu_cooling.c > > @@ -0,0 +1,512 @@ > > +/* > > + * 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. > > + * @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. > > + * @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; > > + unsigned int cpufreq_state; > > + unsigned int cpufreq_val; > > + struct cpumask allowed_cpus; > > + struct list_head node; > > +}; > > +static LIST_HEAD(cooling_cpufreq_list); > > +static DEFINE_IDR(cpufreq_idr); > > + > > +static struct mutex cooling_cpufreq_lock; > > + > > +/* notify_table passes value to the CPUFREQ_ADJUST callback function. > > */ > > +#define NOTIFY_INVALID NULL > > +struct cpufreq_cooling_device *notify_device; > > + > > +/* 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 code 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); > > +} > > + > > +/** > > + * get_cpu_frequency - get the absolute value of frequency from level. > > + * @cpu: cpu for which frequency is fetched. > > + * @level: level of frequency of the CPU > > + * e.g level=1 --> 1st MAX FREQ, LEVEL=2 ---> 2nd MAX FREQ, .... > > etc > > + */ > > +static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long > > level) > > > I like this. With previous implemention I had to write a similar > function, but with output of the required freq clip table. Now that > you have the freq walk here it simplifies the zone setup code. > > > > +{ > > + int ret = 0, i = 0; > > + unsigned long level_index; > > + bool descend = false; > > + struct cpufreq_frequency_table *table = > > + > > cpufreq_frequency_get_table(cpu); > > + if (!table) > > + return ret; > > + > > + while (table[i].frequency != CPUFREQ_TABLE_END) { > > + if (table[i].frequency == CPUFREQ_ENTRY_INVALID) > > + continue; > > + > > + /*check if table in ascending or descending order*/ > > + if ((table[i + 1].frequency != CPUFREQ_TABLE_END) && > > + (table[i + 1].frequency < table[i].frequency) > > + && !descend) { > > + descend = true; > > + } > > + > > + /*return if level matched and table in descending > > order*/ > > + if (descend && i == level) > > + return table[i].frequency; > > + i++; > > + } > > + i--; > > + > > + if (level > i || descend) > > + return ret; > > + level_index = i - level; > > + > > + /*Scan the table in reverse order and match the level*/ > > + while (i >= 0) { > > + if (table[i].frequency == CPUFREQ_ENTRY_INVALID) > > + continue; > > + /*return if level matched*/ > > + if (i == level_index) > > + return table[i].frequency; > > + i--; > > + } > > + return ret; > > +} > > + > > +/** > > + * 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, clip_freq; > > + struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; > > + unsigned int cpu = cpumask_any(maskPtr); > > + > > + > > + /* 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; > > + > > + if (cooling_state != 0) > > + event = CPUFREQ_COOLING_START; > > + else > > + event = CPUFREQ_COOLING_STOP; > > + > > + blocking_notifier_call_chain(&cputherm_state_notifier_list, > > + event, &clip_freq); > > + > > + for_each_cpu(cpuid, maskPtr) { > > + 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 > > + */ > > +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. > > + */ > > +static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, > > + unsigned long *state) > > +{ > > + int ret = -EINVAL, i = 0; > > + struct cpufreq_cooling_device *cpufreq_device; > > + struct cpumask *maskPtr; > > + unsigned int cpu; > > + struct cpufreq_frequency_table *table; > > + > > + mutex_lock(&cooling_cpufreq_lock); > > + list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) > > { > > + if (cpufreq_device && cpufreq_device->cool_dev == cdev) > > + break; > > + } > > + if (cpufreq_device == NULL) > > + goto return_get_max_state; > > + > > + maskPtr = &cpufreq_device->allowed_cpus; > > + cpu = cpumask_any(maskPtr); > > + table = cpufreq_frequency_get_table(cpu); > > + if (!table) { > > + *state = 0; > > + ret = 0; > > + goto return_get_max_state; > > + } > > + > > + while (table[i].frequency != CPUFREQ_TABLE_END) { > > + if (table[i].frequency == CPUFREQ_ENTRY_INVALID) > > + continue; > > + i++; > > + } > > + if (i > 0) { > > + *state = --i; > > + ret = 0; > > + } > > + > > +return_get_max_state: > > + 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. > > + * @clip_cpus: cpumask of cpus where the frequency constraints will > > happen. > > + */ > > +struct thermal_cooling_device *cpufreq_cooling_register( > > + struct cpumask *clip_cpus) > > +{ > > + struct thermal_cooling_device *cool_dev; > > + struct cpufreq_cooling_device *cpufreq_dev = NULL; > > + unsigned int cpufreq_dev_count = 0, min = 0, max = 0; > > + char dev_name[THERMAL_NAME_LENGTH]; > > + int ret = 0, id = 0, i; > > + struct cpufreq_policy policy; > > + > > + list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) > > + cpufreq_dev_count++; > > + > > + /*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); > > + > > + if (cpufreq_dev_count == 0) > > + mutex_init(&cooling_cpufreq_lock); > > + > > + 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; > > + cpufreq_dev->cpufreq_state = 0; > > + 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); > > + if (cpufreq_dev_count == 1) > > + mutex_destroy(&cooling_cpufreq_lock); > > + 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..555b917 > > --- /dev/null > > +++ b/include/linux/cpu_cooling.h > > @@ -0,0 +1,79 @@ > > +/* > > + * 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 > > + > > +/** > > + * 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); > > + > > +/** > > + * 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 and 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); > > + > > +#ifdef CONFIG_CPU_THERMAL > > +/** > > + * cpufreq_cooling_register - function to create cpufreq cooling > > device. > > + * @clip_cpus: cpumask of cpus where the frequency constraints will > > happen > > + */ > > +struct thermal_cooling_device *cpufreq_cooling_register( > > + struct cpumask *clip_cpus); > > + > > +/** > > + * 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_THERMAL */ > > +static inline struct thermal_cooling_device *cpufreq_cooling_register( > > + struct cpumask *clip_cpus) > > +{ > > + return NULL; > > +} > > +static inline void cpufreq_cooling_unregister( > > + struct thermal_cooling_device *cdev) > > +{ > > + return; > > +} > > +#endif /* CONFIG_CPU_THERMAL */ > > + > > +#endif /* __CPU_COOLING_H__ */ > > -- > > 1.7.1 > > > > > > -- > > Eduardo Valentin
