cpufreq: Implement cpufreq_generic_suspend()

Multiple platforms need to set CPUs to a particular frequency before suspending the system, so provide a common infrastructure for them. Those platforms only need to point their ->suspend callback pointers to the generic routine. Tested-by: Stephen Warren <[email protected]> Signed-off-by: Viresh Kumar <[email protected]> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <[email protected]>
djekels-zz · Mar 6, 2014 · e28867e · e28867e
1 parent 2f0aea9
commit e28867e
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diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
@@ -1567,6 +1567,32 @@ static struct subsys_interface cpufreq_interface = {
 	.remove_dev	= cpufreq_remove_dev,
 };
 
+/*
+ * In case platform wants some specific frequency to be configured
+ * during suspend..
+ */
+int cpufreq_generic_suspend(struct cpufreq_policy *policy)
+{
+	int ret;
+
+	if (!policy->suspend_freq) {
+		pr_err("%s: suspend_freq can't be zero\n", __func__);
+		return -EINVAL;
+	}
+
+	pr_debug("%s: Setting suspend-freq: %u\n", __func__,
+			policy->suspend_freq);
+
+	ret = __cpufreq_driver_target(policy, policy->suspend_freq,
+			CPUFREQ_RELATION_H);
+	if (ret)
+		pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
+				__func__, policy->suspend_freq, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(cpufreq_generic_suspend);
+
 /**
  * cpufreq_suspend() - Suspend CPUFreq governors
  *

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
@@ -74,6 +74,8 @@ struct cpufreq_policy {
 	unsigned int		max;    /* in kHz */
 	unsigned int		cur;    /* in kHz, only needed if cpufreq
 					 * governors are used */
+	unsigned int		suspend_freq; /* freq to set during suspend */
+
 	unsigned int		policy; /* see above */
 	struct cpufreq_governor	*governor; /* see below */
 	void			*governor_data;
@@ -299,6 +301,7 @@ cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 #ifdef CONFIG_CPU_FREQ
 void cpufreq_suspend(void);
 void cpufreq_resume(void);
+int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 #else
 static inline void cpufreq_suspend(void) {}
 static inline void cpufreq_resume(void) {}