Multiple platforms need to set CPU to a particular frequency before suspending
system. And so they need a common infrastructure which is provided by this
patch. Those platforms just need to initialize their ->suspend() pointers with
the generic routine.

Tested-by: Stephen Warren <swar...@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 25 +++++++++++++++++++++++++
 include/linux/cpufreq.h   |  3 +++
 2 files changed, 28 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 443c053..ae4923e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1530,6 +1530,31 @@ 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;
+}
+
 /**
  * cpufreq_suspend() - Suspend CPUFreq governors
  *
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index b26bfab..ce6f06f 100644
--- 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;
@@ -285,6 +287,7 @@ 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) {}
-- 
1.7.12.rc2.18.g61b472e

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