On 16 August 2012 20:22, Valentin, Eduardo <eduardo.valen...@ti.com> wrote:
>
> Amit,
>
> Thanks again for keeping this up.
>
> On Thu, Aug 16, 2012 at 2:41 PM, Amit Daniel Kachhap
> <amit.kach...@linaro.org> 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.
> >
> > [a...@linux-foundation.org: fix comment layout]
> > Signed-off-by: Amit Daniel Kachhap <amit.kach...@linaro.org>
> > Cc: Guenter Roeck <guenter.ro...@ericsson.com>
> > Cc: SangWook Ju <sw...@samsung.com>
> > Cc: Durgadoss <durgados...@intel.com>
> > Cc: Len Brown <l...@kernel.org>
> > Cc: Jean Delvare <kh...@linux-fr.org>
> > Cc: Kyungmin Park <kmp...@infradead.org>
> > Cc: Kukjin Kim <kgene....@samsung.com>
> > Signed-off-by: Andrew Morton <a...@linux-foundation.org>
> > Signed-off-by: Amit Daniel Kachhap <amit.dan...@samsung.com>
>
>
> Reviewed-by: Eduardo Valentin <eduardo.valen...@ti.com>

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.kach...@linaro.org>
> > +
> > +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.kach...@linaro.org>
> > + *
> > + *
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > + *  This program is free software; you can redistribute it and/or
> > modify
> > + *  it under the terms of the GNU General Public License as published
> > by
> > + *  the Free Software Foundation; version 2 of the License.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + *  General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > along
> > + *  with this program; if not, write to the Free Software Foundation,
> > Inc.,
> > + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> > + *
> > + *
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > + */
> > +#include <linux/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, &notify_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.kach...@linaro.org>
> > + *
> > + *
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > + *  This program is free software; you can redistribute it and/or
> > modify
> > + *  it under the terms of the GNU General Public License as published
> > by
> > + *  the Free Software Foundation; version 2 of the License.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + *  General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > along
> > + *  with this program; if not, write to the Free Software Foundation,
> > Inc.,
> > + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> > + *
> > + *
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > + */
> > +
> > +#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
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to