cpufreq: exynos: Use cpufreq_generic_suspend()

The cpufreq core now supports suspending and resuming of cpufreq
drivers and governors during systems suspend and resume, so use
the common infrastructure instead of defining special PM notifiers
for the same thing.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/exynos-cpufreq.c

@@ -16,7 +16,6 @@
 #include <linux/slab.h>
 #include <linux/regulator/consumer.h>
 #include <linux/cpufreq.h>
-#include <linux/suspend.h>
 #include <linux/platform_device.h>
 
 #include <plat/cpu.h>
@@ -24,12 +23,8 @@
 #include "exynos-cpufreq.h"
 
 static struct exynos_dvfs_info *exynos_info;
-
 static struct regulator *arm_regulator;
-
 static unsigned int locking_frequency;
-static bool frequency_locked;
-static DEFINE_MUTEX(cpufreq_lock);
 
 static int exynos_cpufreq_get_index(unsigned int freq)
 {
@@ -134,83 +129,13 @@ static int exynos_cpufreq_scale(unsigned int target_freq)
 
 static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
 {
-	struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
-	int ret = 0;
-
-	mutex_lock(&cpufreq_lock);
-
-	if (frequency_locked)
-		goto out;
-
-	ret = exynos_cpufreq_scale(freq_table[index].frequency);
-
-out:
-	mutex_unlock(&cpufreq_lock);
-
-	return ret;
-}
-
-#ifdef CONFIG_PM
-static int exynos_cpufreq_suspend(struct cpufreq_policy *policy)
-{
-	return 0;
-}
-
-static int exynos_cpufreq_resume(struct cpufreq_policy *policy)
-{
-	return 0;
-}
-#endif
-
-/**
- * exynos_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume
- *			context
- * @notifier
- * @pm_event
- * @v
- *
- * While frequency_locked == true, target() ignores every frequency but
- * locking_frequency. The locking_frequency value is the initial frequency,
- * which is set by the bootloader. In order to eliminate possible
- * inconsistency in clock values, we save and restore frequencies during
- * suspend and resume and block CPUFREQ activities. Note that the standard
- * suspend/resume cannot be used as they are too deep (syscore_ops) for
- * regulator actions.
- */
-static int exynos_cpufreq_pm_notifier(struct notifier_block *notifier,
-				       unsigned long pm_event, void *v)
-{
-	int ret;
-
-	switch (pm_event) {
-	case PM_SUSPEND_PREPARE:
-		mutex_lock(&cpufreq_lock);
-		frequency_locked = true;
-		mutex_unlock(&cpufreq_lock);
-
-		ret = exynos_cpufreq_scale(locking_frequency);
-		if (ret < 0)
-			return NOTIFY_BAD;
-
-		break;
-
-	case PM_POST_SUSPEND:
-		mutex_lock(&cpufreq_lock);
-		frequency_locked = false;
-		mutex_unlock(&cpufreq_lock);
-		break;
-	}
-
-	return NOTIFY_OK;
+	return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
 }
 
-static struct notifier_block exynos_cpufreq_nb = {
-	.notifier_call = exynos_cpufreq_pm_notifier,
-};
-
 static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	policy->clk = exynos_info->cpu_clk;
+	policy->suspend_freq = locking_frequency;
 	return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
 }
 
@@ -227,8 +152,7 @@ static struct cpufreq_driver exynos_driver = {
 	.boost_supported = true,
 #endif
 #ifdef CONFIG_PM
-	.suspend	= exynos_cpufreq_suspend,
-	.resume		= exynos_cpufreq_resume,
+	.suspend	= cpufreq_generic_suspend,
 #endif
 };
 
@@ -263,19 +187,13 @@ static int exynos_cpufreq_probe(struct platform_device *pdev)
 		goto err_vdd_arm;
 	}
 
+	/* Done here as we want to capture boot frequency */
 	locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;
 
-	register_pm_notifier(&exynos_cpufreq_nb);
-
-	if (cpufreq_register_driver(&exynos_driver)) {
-		pr_err("%s: failed to register cpufreq driver\n", __func__);
-		goto err_cpufreq;
-	}
-
+	if (!cpufreq_register_driver(&exynos_driver))
 		return 0;
-err_cpufreq:
-	unregister_pm_notifier(&exynos_cpufreq_nb);
 
+	pr_err("%s: failed to register cpufreq driver\n", __func__);
 	regulator_put(arm_regulator);
 err_vdd_arm:
 	kfree(exynos_info);