From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com>
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 <e...@linux.vnet.ibm.com>
---
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 0ecd163..183bbc4 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
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
