Thread (40 messages) 40 messages, 6 authors, 2014-03-22

Re: [PATCH v3 4/5] powernv:cpufreq: Export nominal frequency via sysfs.

From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2014-03-21 08:47:29
Also in: linux-pm

On Thu, Mar 20, 2014 at 5:40 PM, Gautham R. Shenoy
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
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);
return sprintf(buf, "%u\n",
pstate_id_to_freq(powernv_pstate_info.pstate_nominal_id));

??
+}
+
+
remove extra blank line.
+struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq = {
+       .attr = { .name = "cpuinfo_nominal_freq",
+                 .mode = 0444,
+               },
Align {}
+       .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,
 };
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