[CPUFREQ] S5PV210: Add pm_notifier to prevent system unstable
Minimum 800MHz is needed to enter/exit suspend mode due to voltage mismatch.
Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 9a5b284..79b1b4ec 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -17,6 +17,7 @@
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/regulator/consumer.h>
+#include <linux/suspend.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
@@ -30,6 +31,9 @@
#define APLL_VAL_1000 ((1 << 31) | (125 << 16) | (3 << 8) | 1)
#define APLL_VAL_800 ((1 << 31) | (100 << 16) | (3 << 8) | 1)
+/* Use 800MHz when entering sleep mode */
+#define SLEEP_FREQ (800 * 1000)
+
/*
* relation has an additional symantics other than the standard of cpufreq
* DISALBE_FURTHER_CPUFREQ: disable further access to target
@@ -552,6 +556,30 @@
return ret;
}
+static int s5pv210_cpufreq_notifier_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ int ret;
+
+ switch (event) {
+ case PM_SUSPEND_PREPARE:
+ ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
+ DISABLE_FURTHER_CPUFREQ);
+ if (ret < 0)
+ return NOTIFY_BAD;
+
+ return NOTIFY_OK;
+ case PM_POST_RESTORE:
+ case PM_POST_SUSPEND:
+ cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
+ ENABLE_FURTHER_CPUFREQ);
+
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
static struct cpufreq_driver s5pv210_driver = {
.flags = CPUFREQ_STICKY,
.verify = s5pv210_verify_speed,
@@ -565,6 +593,10 @@
#endif
};
+static struct notifier_block s5pv210_cpufreq_notifier = {
+ .notifier_call = s5pv210_cpufreq_notifier_event,
+};
+
static int __init s5pv210_cpufreq_init(void)
{
arm_regulator = regulator_get(NULL, "vddarm");
@@ -580,6 +612,8 @@
return PTR_ERR(int_regulator);
}
+ register_pm_notifier(&s5pv210_cpufreq_notifier);
+
return cpufreq_register_driver(&s5pv210_driver);
}
