#include <linux/cpu.h>
#include <linux/cpu_cooling.h>
+/*
+ * Cooling state <-> CPUFreq frequency
+ *
+ * Cooling states are translated to frequencies throughout this driver and this
+ * is the relation between them.
+ *
+ * Highest cooling state corresponds to lowest possible frequency.
+ *
+ * i.e.
+ * level 0 --> 1st Max Freq
+ * level 1 --> 2nd Max Freq
+ * ...
+ */
+
/**
* struct cpufreq_cooling_device - data for cooling device with cpufreq
* @id: unique integer value corresponding to each cpufreq_cooling_device
* frequency.
* @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
*
- * This structure is required for keeping information of each
- * cpufreq_cooling_device registered. In order to prevent corruption of this a
- * mutex lock cooling_cpufreq_lock is used.
+ * This structure is required for keeping information of each registered
+ * cpufreq_cooling_device.
*/
struct cpufreq_cooling_device {
int id;
unsigned int cpufreq_state;
unsigned int cpufreq_val;
struct cpumask allowed_cpus;
+ struct list_head node;
};
static DEFINE_IDR(cpufreq_idr);
static DEFINE_MUTEX(cooling_cpufreq_lock);
static unsigned int cpufreq_dev_count;
-/* notify_table passes value to the CPUFREQ_ADJUST callback function. */
-#define NOTIFY_INVALID NULL
-static struct cpufreq_cooling_device *notify_device;
+static LIST_HEAD(cpufreq_dev_list);
/**
* get_idr - function to get a unique id.
};
/**
- * get_property - fetch a property of interest for a give cpu.
+ * get_property - fetch a property of interest for a given cpu.
* @cpu: cpu for which the property is required
* @input: query parameter
* @output: query return
* 1. get maximum cpu cooling states
* 2. translate frequency to cooling state
* 3. translate cooling state to frequency
+ *
* Note that the code may be not in good shape
* but it is written in this way in order to:
* a) reduce duplicate code as most of the code can be shared.
}
/**
- * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
+ * cpufreq_cooling_get_level - for a given cpu, return the cooling level.
* @cpu: cpu for which the level is required
* @freq: the frequency of interest
*
cpufreq_device->cpufreq_state = cooling_state;
cpufreq_device->cpufreq_val = clip_freq;
- notify_device = cpufreq_device;
for_each_cpu(cpuid, mask) {
if (is_cpufreq_valid(cpuid))
cpufreq_update_policy(cpuid);
}
- notify_device = NOTIFY_INVALID;
-
return 0;
}
{
struct cpufreq_policy *policy = data;
unsigned long max_freq = 0;
+ struct cpufreq_cooling_device *cpufreq_dev;
- if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID)
+ if (event != CPUFREQ_ADJUST)
return 0;
- if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus))
- max_freq = notify_device->cpufreq_val;
- else
- return 0;
+ mutex_lock(&cooling_cpufreq_lock);
+ list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
+ if (!cpumask_test_cpu(policy->cpu,
+ &cpufreq_dev->allowed_cpus))
+ continue;
+
+ if (!cpufreq_dev->cpufreq_val)
+ cpufreq_dev->cpufreq_val = get_cpu_frequency(
+ cpumask_any(&cpufreq_dev->allowed_cpus),
+ cpufreq_dev->cpufreq_state);
- /* Never exceed user_policy.max */
- if (max_freq > policy->user_policy.max)
- max_freq = policy->user_policy.max;
+ max_freq = cpufreq_dev->cpufreq_val;
- if (policy->max != max_freq)
- cpufreq_verify_within_limits(policy, 0, max_freq);
+ if (policy->max != max_freq)
+ cpufreq_verify_within_limits(policy, 0, max_freq);
+ }
+ mutex_unlock(&cooling_cpufreq_lock);
return 0;
}
const struct cpumask *clip_cpus)
{
struct thermal_cooling_device *cool_dev;
- struct cpufreq_cooling_device *cpufreq_dev = NULL;
+ struct cpufreq_cooling_device *cpufreq_dev;
unsigned int min = 0, max = 0;
char dev_name[THERMAL_NAME_LENGTH];
- int ret = 0, i;
+ int ret, i;
struct cpufreq_policy policy;
+ if (!cpufreq_frequency_get_table(cpumask_first(clip_cpus))) {
+ pr_debug("%s: CPUFreq table not found\n", __func__);
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
/* 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 */
return ERR_PTR(-EINVAL);
}
}
- cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
- GFP_KERNEL);
+ cpufreq_dev = kzalloc(sizeof(*cpufreq_dev), GFP_KERNEL);
if (!cpufreq_dev)
return ERR_PTR(-ENOMEM);
ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
if (ret) {
kfree(cpufreq_dev);
- return ERR_PTR(-EINVAL);
+ return ERR_PTR(ret);
}
snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
return cool_dev;
}
cpufreq_dev->cool_dev = cool_dev;
- cpufreq_dev->cpufreq_state = 0;
+
mutex_lock(&cooling_cpufreq_lock);
/* Register the notifier for first cpufreq cooling device */
cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
cpufreq_dev_count++;
+ list_add(&cpufreq_dev->node, &cpufreq_dev_list);
mutex_unlock(&cooling_cpufreq_lock);
cpufreq_dev = cdev->devdata;
mutex_lock(&cooling_cpufreq_lock);
+ list_del(&cpufreq_dev->node);
cpufreq_dev_count--;
/* Unregister the notifier for the last cpufreq cooling device */