[PATCH v3 4/5] powernv:cpufreq: Export nominal frequency via sysfs.
From: Gautham R. Shenoy <hidden>
Date: 2014-03-20 12:11:16
Also in:
linux-pm
Subsystem:
cpu frequency scaling framework, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Linus Torvalds
From: "Gautham R. Shenoy" <redacted> Create a driver attribute named cpuinfo_nominal_freq which creates a sysfs read-only file named cpuinfo_nominal_freq. Export the frequency corresponding to the nominal_pstate through this interface. Nominal frequency is the highest non-turbo frequency for the platform. This is generally used for setting governor policies from user space for optimal energy efficiency. Signed-off-by: Gautham R. Shenoy <redacted> --- drivers/cpufreq/powernv-cpufreq.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index e7b0292..46bee8a 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c@@ -142,8 +142,30 @@ static unsigned int pstate_id_to_freq(int pstate_id) return powernv_freqs[i].frequency; } +/** + * show_cpuinfo_nominal_freq - Show the nominal CPU frequency as indicated by + * the firmware + */ +static ssize_t show_cpuinfo_nominal_freq(struct cpufreq_policy *policy, + char *buf) +{ + int nominal_freq; + nominal_freq = pstate_id_to_freq(powernv_pstate_info.pstate_nominal_id); + return sprintf(buf, "%u\n", nominal_freq); +} + + +struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq = { + .attr = { .name = "cpuinfo_nominal_freq", + .mode = 0444, + }, + .show = show_cpuinfo_nominal_freq, +}; + + static struct freq_attr *powernv_cpu_freq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, + &cpufreq_freq_attr_cpuinfo_nominal_freq, NULL, };
--
1.8.3.1