cpufreq: OMAP: AM33XX: Use PM notifiers to scale voltage in suspend

Use the PM notifiers to scale down the frequency and voltage in the
suspend path and then block any further transitions till the system
resumes.

NOTE: THIS PATCH HAS CHECKPATCH ERRORS WHICH VIM IS NOT WILLING
TO REMOVE RIGHT NOW :(

Signed-off-by: Vaibhav Bedia <vaibhav.bedia@ti.com>

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 39d8d36ff958e9d2797de8c05ee32e2dc6c11c6f..0d1d0705507036eda9e20b25cbe8ff39a7fd0215 100644 (file)
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -45,6 +45,10 @@
 #define MPU_TOLERANCE  4
 #define PER_ROUND_VAL  100
 
+/* Use 275MHz when entering suspend */
+#define SLEEP_FREQ     (275 * 1000)
+
+
 #ifdef CONFIG_SMP
 struct lpj_info {
        unsigned long   ref;
@@ -237,14 +241,33 @@ static inline void freq_table_free(void)
 }
 
 static int omap_pm_notify(struct notifier_block *nb, unsigned long event,
-       void *dummy)
+                                void *dummy)
 {
+       struct cpufreq_policy *policy = cpufreq_cpu_get(0);
+       static unsigned int saved_frequency;
+
        mutex_lock(&omap_cpu_lock);
-       if (event == PM_SUSPEND_PREPARE) {
+       switch (event) {
+       case PM_SUSPEND_PREPARE:
+               if (is_suspended)
+                       goto out;
+
+                saved_frequency = omap_getspeed(0);
+
+                mutex_unlock(&omap_cpu_lock);
+               omap_target(policy, SLEEP_FREQ, CPUFREQ_RELATION_H);
+               mutex_lock(&omap_cpu_lock);
                is_suspended = true;
-       } else if (event == PM_POST_SUSPEND) {
-               is_suspended = false;
+                break;
+
+        case PM_POST_SUSPEND:
+                is_suspended = false;
+                mutex_unlock(&omap_cpu_lock);
+               omap_target(policy, saved_frequency, CPUFREQ_RELATION_H);
+               mutex_lock(&omap_cpu_lock);
+                break;
        }
+out:
        mutex_unlock(&omap_cpu_lock);
 
        return NOTIFY_OK;