cpufreq: Add boost frequency support in core

This commit adds boost frequency support in cpufreq core (Hardware &
Software). Some SoCs (like Exynos4 - e.g. 4x12) allow setting frequency
above its normal operation limits. Such mode shall be only used for a
short time.

Overclocking (boost) support is essentially provided by platform
dependent cpufreq driver.

This commit unifies support for SW and HW (Intel) overclocking solutions
in the core cpufreq driver. Previously the "boost" sysfs attribute was
defined in the ACPI processor driver code. By default boost is disabled.
One global attribute is available at: /sys/devices/system/cpu/cpufreq/boost.

It only shows up when cpufreq driver supports overclocking.
Under the hood frequencies dedicated for boosting are marked with a
special flag (CPUFREQ_BOOST_FREQ) at driver's frequency table.
It is the user's concern to enable/disable overclocking with a proper call
to sysfs.

The cpufreq_boost_trigger_state() function is defined non static on purpose.
It is used later with thermal subsystem to provide automatic enable/disable
of the BOOST feature.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 422f10561e0b..4d89e0e6f9cc 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -227,6 +227,11 @@ struct cpufreq_driver {
 	int	(*suspend)	(struct cpufreq_policy *policy);
 	int	(*resume)	(struct cpufreq_policy *policy);
 	struct freq_attr	**attr;
+
+	/* platform specific boost support code */
+	bool                    boost_supported;
+	bool                    boost_enabled;
+	int     (*set_boost)    (int state);
 };
 
 /* flags */
@@ -435,6 +440,7 @@ extern struct cpufreq_governor cpufreq_gov_conservative;
 
 #define CPUFREQ_ENTRY_INVALID ~0
 #define CPUFREQ_TABLE_END     ~1
+#define CPUFREQ_BOOST_FREQ    ~2
 
 struct cpufreq_frequency_table {
 	unsigned int	driver_data; /* driver specific data, not used by core */
@@ -460,6 +466,24 @@ int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 
+#ifdef CONFIG_CPU_FREQ
+int cpufreq_boost_trigger_state(int state);
+int cpufreq_boost_supported(void);
+int cpufreq_boost_enabled(void);
+#else
+static inline int cpufreq_boost_trigger_state(int state)
+{
+	return 0;
+}
+static inline int cpufreq_boost_supported(void)
+{
+	return 0;
+}
+static inline int cpufreq_boost_enabled(void)
+{
+	return 0;
+}
+#endif
 /* the following funtion is for cpufreq core use only */
 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);