diff options
Diffstat (limited to 'drivers/thermal/cpu_cooling.c')
-rw-r--r-- | drivers/thermal/cpu_cooling.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c new file mode 100644 index 00000000000..cdd148c0036 --- /dev/null +++ b/drivers/thermal/cpu_cooling.c @@ -0,0 +1,302 @@ +/* + * linux/drivers/thermal/cpu_cooling.c + * + * Copyright (C) 2011 Samsung Electronics Co., Ltd(http://www.samsung.com) + * Copyright (C) 2011 Amit Daniel <amit.kachhap@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> + +#ifdef CONFIG_CPU_FREQ +struct cpufreq_cooling_device { + struct thermal_cooling_device *cool_dev; + struct freq_pctg_table *tab_ptr; + unsigned int tab_size; + unsigned int cpufreq_state; + const struct cpumask *allowed_cpus; +}; + +static struct cpufreq_cooling_device *cpufreq_device; + +/*Below codes defines functions to be used for cpufreq as cooling device*/ +static bool is_cpufreq_valid(int cpu) +{ + struct cpufreq_policy policy; + if (!cpufreq_get_policy(&policy, cpu)) + return true; + return false; +} + +static int cpufreq_apply_cooling(int cooling_state) +{ + int cpuid, this_cpu = smp_processor_id(); + + if (!is_cpufreq_valid(this_cpu)) + return 0; + + if (cooling_state > cpufreq_device->tab_size) + return -EINVAL; + + /*Check if last cooling level is same as current cooling level*/ + if (cpufreq_device->cpufreq_state == cooling_state) + return 0; + + cpufreq_device->cpufreq_state = cooling_state; + + for_each_cpu(cpuid, cpufreq_device->allowed_cpus) { + if (is_cpufreq_valid(cpuid)) + cpufreq_update_policy(cpuid); + } + + return 0; +} + +static int thermal_cpufreq_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct cpufreq_policy *policy = data; + struct freq_pctg_table *th_table; + unsigned long max_freq = 0; + unsigned int cpu = policy->cpu, th_pctg = 0, level; + + if (event != CPUFREQ_ADJUST) + return 0; + + level = cpufreq_device->cpufreq_state; + + if (level > 0) { + th_table = + &(cpufreq_device->tab_ptr[level - 1]); + th_pctg = th_table->freq_clip_pctg[cpu]; + } + + max_freq = + (policy->cpuinfo.max_freq * (100 - th_pctg)) / 100; + + cpufreq_verify_within_limits(policy, 0, max_freq); + + return 0; +} + +/* + * cpufreq cooling device callback functions + */ +static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + *state = cpufreq_device->tab_size; + return 0; +} + +static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + *state = cpufreq_device->cpufreq_state; + return 0; +} + +/*This cooling may be as PASSIVE/STATE_ACTIVE type*/ +static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + cpufreq_apply_cooling(state); + return 0; +} + +/* bind cpufreq callbacks to cpufreq cooling device */ +static struct thermal_cooling_device_ops cpufreq_cooling_ops = { + .get_max_state = cpufreq_get_max_state, + .get_cur_state = cpufreq_get_cur_state, + .set_cur_state = cpufreq_set_cur_state, +}; + +static struct notifier_block thermal_cpufreq_notifier_block = { + .notifier_call = thermal_cpufreq_notifier, +}; + +struct thermal_cooling_device *cpufreq_cooling_register( + struct freq_pctg_table *tab_ptr, unsigned int tab_size, + const struct cpumask *mask_val) +{ + struct thermal_cooling_device *cool_dev; + + if (tab_ptr == NULL || tab_size == 0) + return ERR_PTR(-EINVAL); + + cpufreq_device = + kzalloc(sizeof(struct cpufreq_cooling_device), GFP_KERNEL); + + if (!cpufreq_device) + return ERR_PTR(-ENOMEM); + + cool_dev = thermal_cooling_device_register("thermal-cpufreq", NULL, + &cpufreq_cooling_ops); + if (!cool_dev) { + kfree(cpufreq_device); + return ERR_PTR(-EINVAL); + } + + cpufreq_device->tab_ptr = tab_ptr; + cpufreq_device->tab_size = tab_size; + cpufreq_device->cool_dev = cool_dev; + cpufreq_device->allowed_cpus = mask_val; + + cpufreq_register_notifier(&thermal_cpufreq_notifier_block, + CPUFREQ_POLICY_NOTIFIER); + return cool_dev; +} +EXPORT_SYMBOL(cpufreq_cooling_register); + +void cpufreq_cooling_unregister(void) +{ + cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, + CPUFREQ_POLICY_NOTIFIER); + thermal_cooling_device_unregister(cpufreq_device->cool_dev); + kfree(cpufreq_device); +} +EXPORT_SYMBOL(cpufreq_cooling_unregister); +#else /*!CONFIG_CPU_FREQ*/ +struct thermal_cooling_device *cpufreq_cooling_register( + struct freq_pctg_table *tab_ptr, unsigned int tab_size) +{ + return NULL; +} +EXPORT_SYMBOL(cpufreq_cooling_register); +void cpufreq_cooling_unregister(void) +{ + return; +} +EXPORT_SYMBOL(cpufreq_cooling_unregister); +#endif /*CONFIG_CPU_FREQ*/ + +#ifdef CONFIG_HOTPLUG_CPU + +struct hotplug_cooling_device { + struct thermal_cooling_device *cool_dev; + unsigned int hotplug_state; + const struct cpumask *allowed_cpus; +}; +static struct hotplug_cooling_device *hotplug_device; + +/* + * cpu hotplug cooling device callback functions + */ +static int cpuhotplug_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + *state = 1; + return 0; +} + +static int cpuhotplug_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + /*This cooling device may be of type ACTIVE, so state field + can be 0 or 1*/ + *state = hotplug_device->hotplug_state; + return 0; +} + +/*This cooling may be as PASSIVE/STATE_ACTIVE type*/ +static int cpuhotplug_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + int cpuid, this_cpu = smp_processor_id(); + + if (hotplug_device->hotplug_state == state) + return 0; + + /*This cooling device may be of type ACTIVE, so state field + can be 0 or 1*/ + if (state == 1) { + for_each_cpu(cpuid, hotplug_device->allowed_cpus) { + if (cpu_online(cpuid) && (cpuid != this_cpu)) + cpu_down(cpuid); + } + } else if (state == 0) { + for_each_cpu(cpuid, hotplug_device->allowed_cpus) { + if (!cpu_online(cpuid) && (cpuid != this_cpu)) + cpu_up(cpuid); + } + } else + return -EINVAL; + + hotplug_device->hotplug_state = state; + + return 0; +} +/* bind hotplug callbacks to cpu hotplug cooling device */ +static struct thermal_cooling_device_ops cpuhotplug_cooling_ops = { + .get_max_state = cpuhotplug_get_max_state, + .get_cur_state = cpuhotplug_get_cur_state, + .set_cur_state = cpuhotplug_set_cur_state, +}; + +struct thermal_cooling_device *cpuhotplug_cooling_register( + const struct cpumask *mask_val) +{ + struct thermal_cooling_device *cool_dev; + + hotplug_device = + kzalloc(sizeof(struct hotplug_cooling_device), GFP_KERNEL); + + if (!hotplug_device) + return ERR_PTR(-ENOMEM); + + cool_dev = thermal_cooling_device_register("thermal-cpuhotplug", NULL, + &cpuhotplug_cooling_ops); + if (!cool_dev) { + kfree(hotplug_device); + return ERR_PTR(-EINVAL); + } + + hotplug_device->cool_dev = cool_dev; + hotplug_device->hotplug_state = 0; + hotplug_device->allowed_cpus = mask_val; + + return cool_dev; +} +EXPORT_SYMBOL(cpuhotplug_cooling_register); + +void cpuhotplug_cooling_unregister(void) +{ + thermal_cooling_device_unregister(hotplug_device->cool_dev); + kfree(hotplug_device); +} +EXPORT_SYMBOL(cpuhotplug_cooling_unregister); +#else /*!CONFIG_HOTPLUG_CPU*/ +struct thermal_cooling_device *cpuhotplug_cooling_register( + const struct cpumask *mask_val) +{ + return NULL; +} +EXPORT_SYMBOL(cpuhotplug_cooling_register); +void cpuhotplug_cooling_unregister(void) +{ + return; +} +EXPORT_SYMBOL(cpuhotplug_cooling_unregister); +#endif /*CONFIG_HOTPLUG_CPU*/ |