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authorJohn W. Linville <linville@tuxdriver.com>2011-11-22 14:05:46 -0500
committerJohn W. Linville <linville@tuxdriver.com>2011-11-22 14:05:46 -0500
commit515db09338704a6ad7d27b5f1e33820d3052edd2 (patch)
tree74f915531710303397d34069b325c2be7a5ac93c /drivers/cpufreq/exynos4210-cpufreq.c
parent30be52e44fd4276d768efffb55d424fb682e6505 (diff)
parentcfcfc9eca2bcbd26a8e206baeb005b055dbf8e37 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
Conflicts: drivers/net/wireless/iwlegacy/iwl-debugfs.c drivers/net/wireless/iwlegacy/iwl-rx.c drivers/net/wireless/iwlegacy/iwl-scan.c drivers/net/wireless/iwlegacy/iwl-tx.c include/net/bluetooth/bluetooth.h
Diffstat (limited to 'drivers/cpufreq/exynos4210-cpufreq.c')
-rw-r--r--drivers/cpufreq/exynos4210-cpufreq.c129
1 files changed, 124 insertions, 5 deletions
diff --git a/drivers/cpufreq/exynos4210-cpufreq.c b/drivers/cpufreq/exynos4210-cpufreq.c
index b7c3a84c4cf..ab9741fab92 100644
--- a/drivers/cpufreq/exynos4210-cpufreq.c
+++ b/drivers/cpufreq/exynos4210-cpufreq.c
@@ -17,6 +17,8 @@
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/cpufreq.h>
+#include <linux/notifier.h>
+#include <linux/suspend.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
@@ -36,6 +38,10 @@ static struct regulator *int_regulator;
static struct cpufreq_freqs freqs;
static unsigned int memtype;
+static unsigned int locking_frequency;
+static bool frequency_locked;
+static DEFINE_MUTEX(cpufreq_lock);
+
enum exynos4_memory_type {
DDR2 = 4,
LPDDR2,
@@ -405,22 +411,32 @@ static int exynos4_target(struct cpufreq_policy *policy,
{
unsigned int index, old_index;
unsigned int arm_volt, int_volt;
+ int err = -EINVAL;
freqs.old = exynos4_getspeed(policy->cpu);
+ mutex_lock(&cpufreq_lock);
+
+ if (frequency_locked && target_freq != locking_frequency) {
+ err = -EAGAIN;
+ goto out;
+ }
+
if (cpufreq_frequency_table_target(policy, exynos4_freq_table,
freqs.old, relation, &old_index))
- return -EINVAL;
+ goto out;
if (cpufreq_frequency_table_target(policy, exynos4_freq_table,
target_freq, relation, &index))
- return -EINVAL;
+ goto out;
+
+ err = 0;
freqs.new = exynos4_freq_table[index].frequency;
freqs.cpu = policy->cpu;
if (freqs.new == freqs.old)
- return 0;
+ goto out;
/* get the voltage value */
arm_volt = exynos4_volt_table[index].arm_volt;
@@ -447,10 +463,16 @@ static int exynos4_target(struct cpufreq_policy *policy,
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
- return 0;
+out:
+ mutex_unlock(&cpufreq_lock);
+ return err;
}
#ifdef CONFIG_PM
+/*
+ * These suspend/resume are used as syscore_ops, it is already too
+ * late to set regulator voltages at this stage.
+ */
static int exynos4_cpufreq_suspend(struct cpufreq_policy *policy)
{
return 0;
@@ -462,8 +484,82 @@ static int exynos4_cpufreq_resume(struct cpufreq_policy *policy)
}
#endif
+/**
+ * exynos4_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 exynos4_cpufreq_pm_notifier(struct notifier_block *notifier,
+ unsigned long pm_event, void *v)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
+ static unsigned int saved_frequency;
+ unsigned int temp;
+
+ mutex_lock(&cpufreq_lock);
+ switch (pm_event) {
+ case PM_SUSPEND_PREPARE:
+ if (frequency_locked)
+ goto out;
+ frequency_locked = true;
+
+ if (locking_frequency) {
+ saved_frequency = exynos4_getspeed(0);
+
+ mutex_unlock(&cpufreq_lock);
+ exynos4_target(policy, locking_frequency,
+ CPUFREQ_RELATION_H);
+ mutex_lock(&cpufreq_lock);
+ }
+
+ break;
+ case PM_POST_SUSPEND:
+
+ if (saved_frequency) {
+ /*
+ * While frequency_locked, only locking_frequency
+ * is valid for target(). In order to use
+ * saved_frequency while keeping frequency_locked,
+ * we temporarly overwrite locking_frequency.
+ */
+ temp = locking_frequency;
+ locking_frequency = saved_frequency;
+
+ mutex_unlock(&cpufreq_lock);
+ exynos4_target(policy, locking_frequency,
+ CPUFREQ_RELATION_H);
+ mutex_lock(&cpufreq_lock);
+
+ locking_frequency = temp;
+ }
+
+ frequency_locked = false;
+ break;
+ }
+out:
+ mutex_unlock(&cpufreq_lock);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block exynos4_cpufreq_nb = {
+ .notifier_call = exynos4_cpufreq_pm_notifier,
+};
+
static int exynos4_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
+ int ret;
+
policy->cur = policy->min = policy->max = exynos4_getspeed(policy->cpu);
cpufreq_frequency_table_get_attr(exynos4_freq_table, policy->cpu);
@@ -479,16 +575,35 @@ static int exynos4_cpufreq_cpu_init(struct cpufreq_policy *policy)
*/
cpumask_setall(policy->cpus);
- return cpufreq_frequency_table_cpuinfo(policy, exynos4_freq_table);
+ ret = cpufreq_frequency_table_cpuinfo(policy, exynos4_freq_table);
+ if (ret)
+ return ret;
+
+ cpufreq_frequency_table_get_attr(exynos4_freq_table, policy->cpu);
+
+ return 0;
+}
+
+static int exynos4_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
}
+static struct freq_attr *exynos4_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
static struct cpufreq_driver exynos4_driver = {
.flags = CPUFREQ_STICKY,
.verify = exynos4_verify_speed,
.target = exynos4_target,
.get = exynos4_getspeed,
.init = exynos4_cpufreq_cpu_init,
+ .exit = exynos4_cpufreq_cpu_exit,
.name = "exynos4_cpufreq",
+ .attr = exynos4_cpufreq_attr,
#ifdef CONFIG_PM
.suspend = exynos4_cpufreq_suspend,
.resume = exynos4_cpufreq_resume,
@@ -501,6 +616,8 @@ static int __init exynos4_cpufreq_init(void)
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
+ locking_frequency = exynos4_getspeed(0);
+
moutcore = clk_get(NULL, "moutcore");
if (IS_ERR(moutcore))
goto out;
@@ -540,6 +657,8 @@ static int __init exynos4_cpufreq_init(void)
printk(KERN_DEBUG "%s: memtype= 0x%x\n", __func__, memtype);
}
+ register_pm_notifier(&exynos4_cpufreq_nb);
+
return cpufreq_register_driver(&exynos4_driver);
out: