* @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
+ * cpufreq_cooling_device registered. In order to prevent corruption of this a
* mutex lock cooling_cpufreq_lock is used.
*/
struct cpufreq_cooling_device {
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 DEFINE_MUTEX(cooling_cpufreq_lock);
* get_idr - function to get a unique id.
* @idr: struct idr * handle used to create a id.
* @id: int * value generated by this function.
+ *
+ * This function will populate @id with an unique
+ * id, using the idr API.
+ *
+ * Return: 0 on success, an error code on failure.
*/
static int get_idr(struct idr *idr, int *id)
{
if (unlikely(ret < 0))
return ret;
*id = ret;
+
return 0;
}
static int is_cpufreq_valid(int cpu)
{
struct cpufreq_policy policy;
+
return !cpufreq_get_policy(&policy, cpu);
}
* Return: 0 on success, -EINVAL when invalid parameters are passed.
*/
static int get_property(unsigned int cpu, unsigned long input,
- unsigned int* output, enum cpufreq_cooling_property property)
+ unsigned int *output,
+ enum cpufreq_cooling_property property)
{
int i, j;
unsigned long max_level = 0, level = 0;
int descend = -1;
struct cpufreq_frequency_table *table =
cpufreq_frequency_get_table(cpu);
-
+
if (!output)
return -EINVAL;
if (!table)
return -EINVAL;
-
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
/* ignore invalid entries */
if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
}
if (property == GET_FREQ)
- level = descend ? input : (max_level - input -1);
-
+ level = descend ? input : (max_level - input - 1);
for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
/* ignore invalid entry */
}
j++;
}
+
return -EINVAL;
}
+/**
+ * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
+ * @cpu: cpu for which the level is required
+ * @freq: the frequency of interest
+ *
+ * This function will match the cooling level corresponding to the
+ * requested @freq and return it.
+ *
+ * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
+ * otherwise.
+ */
unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
{
unsigned int val;
if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
return THERMAL_CSTATE_INVALID;
+
return (unsigned long)val;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
/**
* get_cpu_frequency - get the absolute value of frequency from level.
* @cpu: cpu for which frequency is fetched.
- * @level: level of frequency, equals cooling state of cpu cooling device
+ * @level: cooling level
+ *
+ * This function matches cooling level with frequency. Based on a cooling level
+ * of frequency, equals cooling state of cpu cooling device, it will return
+ * the corresponding frequency.
* e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
+ *
+ * Return: 0 on error, the corresponding frequency otherwise.
*/
static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
{
ret = get_property(cpu, level, &freq, GET_FREQ);
if (ret)
return 0;
+
return freq;
}
* @cpufreq_device: cpufreq_cooling_device pointer containing frequency
* clipping data.
* @cooling_state: value of the cooling state.
+ *
+ * Function used to make sure the cpufreq layer is aware of current thermal
+ * limits. The limits are applied by updating the cpufreq policy.
+ *
+ * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
+ * cooling state).
*/
static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
- unsigned long cooling_state)
+ unsigned long cooling_state)
{
unsigned int cpuid, clip_freq;
struct cpumask *mask = &cpufreq_device->allowed_cpus;
* @nb: struct notifier_block * with callback info.
* @event: value showing cpufreq event for which this function invoked.
* @data: callback-specific data
+ *
+ * Callback to highjack the notification on cpufreq policy transition.
+ * Every time there is a change in policy, we will intercept and
+ * update the cpufreq policy with thermal constraints.
+ *
+ * Return: 0 (success)
*/
static int cpufreq_thermal_notifier(struct notifier_block *nb,
- unsigned long event, void *data)
+ unsigned long event, void *data)
{
struct cpufreq_policy *policy = data;
unsigned long max_freq = 0;
if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus))
max_freq = notify_device->cpufreq_val;
- /* Never exceed user_policy.max*/
+ /* Never exceed user_policy.max */
if (max_freq > policy->user_policy.max)
max_freq = policy->user_policy.max;
return 0;
}
-/*
- * cpufreq cooling device callback functions are defined below
- */
+/* 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.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * max cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
*/
static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
* 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.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
*/
static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)
struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
*state = cpufreq_device->cpufreq_state;
+
return 0;
}
* 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.
+ *
+ * Callback for the thermal cooling device to change the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
*/
static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
/**
* cpufreq_cooling_register - function to create cpufreq cooling device.
* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
*/
-struct thermal_cooling_device *cpufreq_cooling_register(
- const struct cpumask *clip_cpus)
+struct thermal_cooling_device *
+cpufreq_cooling_register(const struct cpumask *clip_cpus)
{
struct thermal_cooling_device *cool_dev;
struct cpufreq_cooling_device *cpufreq_dev = NULL;
int ret = 0, i;
struct cpufreq_policy policy;
- /*Verify that all the clip cpus have same freq_min, freq_max limit*/
+ /* 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*/
+ /* continue if cpufreq policy not found and not return error */
if (!cpufreq_get_policy(&policy, i))
continue;
if (min == 0 && max == 0) {
max = policy.cpuinfo.max_freq;
} else {
if (min != policy.cpuinfo.min_freq ||
- max != policy.cpuinfo.max_freq)
+ max != policy.cpuinfo.max_freq)
return ERR_PTR(-EINVAL);
}
}
cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
- GFP_KERNEL);
+ GFP_KERNEL);
if (!cpufreq_dev)
return ERR_PTR(-ENOMEM);
return ERR_PTR(-EINVAL);
}
- sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id);
+ snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
+ cpufreq_dev->id);
cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
- &cpufreq_cooling_ops);
+ &cpufreq_cooling_ops);
if (!cool_dev) {
release_idr(&cpufreq_idr, cpufreq_dev->id);
kfree(cpufreq_dev);
/* Register the notifier for first cpufreq cooling device */
if (cpufreq_dev_count == 0)
cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
- CPUFREQ_POLICY_NOTIFIER);
+ CPUFREQ_POLICY_NOTIFIER);
cpufreq_dev_count++;
mutex_unlock(&cooling_cpufreq_lock);
+
return cool_dev;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
/**
* cpufreq_cooling_unregister - function to remove cpufreq cooling device.
* @cdev: thermal cooling device pointer.
+ *
+ * This interface function unregisters the "thermal-cpufreq-%x" cooling device.
*/
void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
{
cpufreq_dev_count--;
/* Unregister the notifier for the last cpufreq cooling device */
- if (cpufreq_dev_count == 0) {
+ if (cpufreq_dev_count == 0)
cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
- CPUFREQ_POLICY_NOTIFIER);
- }
+ CPUFREQ_POLICY_NOTIFIER);
mutex_unlock(&cooling_cpufreq_lock);
thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
projects / cascardo / linux.git / blobdiff