cpufreq: Introduce ->ready() callback for cpufreq drivers

Currently there is no callback for cpufreq drivers which is called once the
policy is ready to be used. There are some requirements where such a callback is
required.

One of them is registering a cooling device with the help of
of_cpufreq_cooling_register(). This routine tries to get 'struct cpufreq_policy'
for CPUs which isn't yet initialed at the time ->init() is called and so we face
issues while registering the cooling device.

Because we can't register cooling device from ->init(), we need a callback that
is called after the policy is ready to be used and hence we introduce ->ready()
callback.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Eduardo Valentin <edubezval@gmail.com>
Tested-by: Eduardo Valentin <edubezval@gmail.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index de2c3e198b62edf19a8a42225cbfc355b09a6517..a09a29c312a9cbeef8cb43a2862c07f13c78a24e 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1285,8 +1285,13 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
        up_write(&policy->rwsem);
 
        kobject_uevent(&policy->kobj, KOBJ_ADD);
+
        up_read(&cpufreq_rwsem);
 
+       /* Callback for handling stuff after policy is ready */
+       if (cpufreq_driver->ready)
+               cpufreq_driver->ready(policy);
+
        pr_debug("initialization complete\n");
 
        return 0;

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index db3c1308567126cbd0fbd070b9d3091765b7f630..4d078cebafd2dd5f059c65bd75a683a81b80e15f 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -267,6 +267,10 @@ struct cpufreq_driver {
        void            (*stop_cpu)(struct cpufreq_policy *policy);
        int             (*suspend)(struct cpufreq_policy *policy);
        int             (*resume)(struct cpufreq_policy *policy);
+
+       /* Will be called after the driver is fully initialized */
+       void            (*ready)(struct cpufreq_policy *policy);
+
        struct freq_attr **attr;
 
        /* platform specific boost support code */