@@ -2,6 +2,7 @@ menu "CPU Frequency scaling"
config CPU_FREQ
bool "CPU Frequency scaling"
+ select CPU_FREQ_TABLE
help
CPU Frequency scaling allows you to change the clock speed of
CPUs on the fly. This is a nice method to save power, because
@@ -183,6 +183,37 @@ u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time);
+/*
+ * This is a generic cpufreq init() routine which can be used by cpufreq
+ * drivers of SMP systems. It will do following:
+ * - validate & show freq table passed
+ * - set policies transition latency
+ * - policy->cpus with all possible CPUs
+ */
+int cpufreq_generic_init(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table,
+ unsigned int transition_latency)
+{
+ int ret;
+
+ ret = cpufreq_table_validate_and_show(policy, table);
+ if (ret) {
+ pr_err("%s: invalid frequency table: %d\n", __func__, ret);
+ return ret;
+ }
+
+ policy->cpuinfo.transition_latency = transition_latency;
+
+ /*
+ * The driver only supports the SMP configuartion where all processors
+ * share the clock and voltage and clock.
+ */
+ cpumask_setall(policy->cpus);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_generic_init);
+
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
{
struct cpufreq_policy *policy = NULL;
@@ -438,6 +438,9 @@ void cpufreq_frequency_table_put_attr(unsigned int cpu);
int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table);
+int cpufreq_generic_init(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table,
+ unsigned int transition_latency);
static inline int cpufreq_generic_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
Many CPUFreq drivers for SMP system (where all cores share same clock lines), do similar stuff in their ->init() part. This patch creates a generic routine in cpufreq core which can be used by these so that we can remove some redundant code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/Kconfig | 1 + drivers/cpufreq/cpufreq.c | 31 +++++++++++++++++++++++++++++++ include/linux/cpufreq.h | 3 +++ 3 files changed, 35 insertions(+)