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From 8726f3a7218b72a1003904a24bb000b3e4f9b4d1 Mon Sep 17 00:00:00 2001
From: Mike Turquette <mturquette@ti.com>
Date: Tue, 17 May 2011 09:35:54 -0500
Subject: [PATCH 1/2] cpufreq: helpers for walking the frequency table
Two new functions for getting the next higher and next lower frequencies
in the cpufreq table, based upon a frequency supplied in kHz.
This is useful for cpufreq governors that do not target frequencies
based upon a percentage or a pre-determined value, but instead access
the cpufreq table directly.
Signed-off-by: Mike Turquette <mturquette@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
---
drivers/cpufreq/freq_table.c | 73 ++++++++++++++++++++++++++++++++++++++++++
include/linux/cpufreq.h | 9 +++++
2 files changed, 82 insertions(+), 0 deletions(-)
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 0543221..11a307b 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
+#include <linux/err.h>
#define dprintk(msg...) \
cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg)
@@ -174,6 +175,78 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
+int cpufreq_frequency_table_next_lowest(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table, int *index)
+{
+ unsigned int cur_freq;
+ unsigned int next_lowest_freq;
+ int optimal_index = -1;
+ int i = 0;
+
+ if (!policy || IS_ERR(policy) || !table || IS_ERR(table) ||
+ !index || IS_ERR(index))
+ return -ENOMEM;
+
+ cur_freq = policy->cur;
+ next_lowest_freq = policy->min;
+
+ /* we're at the lowest frequency in the table already, bail out */
+ if (cur_freq == policy->min)
+ return -EINVAL;
+
+ /* walk the list, find closest freq to cur_freq that is below it */
+ while(table[i].frequency != CPUFREQ_TABLE_END) {
+ if (table[i].frequency < cur_freq &&
+ table[i].frequency >= next_lowest_freq) {
+ next_lowest_freq = table[i].frequency;
+ optimal_index = table[i].index;
+ }
+
+ i++;
+ }
+
+ *index = optimal_index;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_frequency_table_next_lowest);
+
+int cpufreq_frequency_table_next_highest(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table, int *index)
+{
+ unsigned int cur_freq;
+ unsigned int next_higher_freq;
+ int optimal_index = -1;
+ int i = 0;
+
+ if (!policy || IS_ERR(policy) || !table || IS_ERR(table) ||
+ !index || IS_ERR(index))
+ return -ENOMEM;
+
+ cur_freq = policy->cur;
+ next_higher_freq = policy->max;
+
+ /* we're at the highest frequency in the table already, bail out */
+ if (cur_freq == policy->max)
+ return -EINVAL;
+
+ /* walk the list, find closest freq to cur_freq that is above it */
+ while(table[i].frequency != CPUFREQ_TABLE_END) {
+ if (table[i].frequency > cur_freq &&
+ table[i].frequency <= next_higher_freq) {
+ next_higher_freq = table[i].frequency;
+ optimal_index = table[i].index;
+ }
+
+ i++;
+ }
+
+ *index = optimal_index;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_frequency_table_next_highest);
+
static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
/**
* show_available_freqs - show available frequencies for the specified CPU
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 9343dd3..a38fca8 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -396,6 +396,15 @@ void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
void cpufreq_frequency_table_put_attr(unsigned int cpu);
+/* the following are for use in governors, or anywhere else */
+extern int cpufreq_frequency_table_next_lowest(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table,
+ int *index);
+
+extern int cpufreq_frequency_table_next_highest(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table,
+ int *index);
+
/*********************************************************************
* UNIFIED DEBUG HELPERS *
--
1.6.6.1
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