[pkg-fso-commits] [SCM] linux-2.6-openmoko, the Linux 2.6 kernel tree from Openmoko branch, andy-tracking, updated. upstream/20090303.gitb9de904e-140-g23b564c
Andy Green
agreen at octopus.localdomain
Mon Jun 8 17:29:30 UTC 2009
The following commit has been merged in the andy-tracking branch:
commit 5cdd4f17f1375a228c4b33e57912ccc057395f68
Author: Mark Brown <broonie at opensource.wolfsonmicro.com>
Date: Mon Mar 9 21:02:13 2009 +0000
S3C64XX: Add DVFS support to the S3C64XX cpufreq driver
Use the regulator framework to provide optional support for DVFS in
the S3C64XX cpufreq driver. When a software controllable regulator
is configured the driver will use it to lower the supply voltage when
running at a lower frequency, giving improved power saving.
When regulator support is disabled or no regulator can be obtained
for VDDARM the driver will fall back to scaling only the frequency.
Signed-off-by: Mark Brown <broonie at opensource.wolfsonmicro.com>
diff --git a/arch/arm/plat-s3c64xx/cpufreq.c b/arch/arm/plat-s3c64xx/cpufreq.c
index 4179cab..97617e5 100644
--- a/arch/arm/plat-s3c64xx/cpufreq.c
+++ b/arch/arm/plat-s3c64xx/cpufreq.c
@@ -15,26 +15,42 @@
#include <linux/cpufreq.h>
#include <linux/clk.h>
#include <linux/err.h>
+#include <linux/regulator/consumer.h>
#include <mach/cpu.h>
static struct clk *armclk;
+static struct regulator *vddarm;
+
+struct s3c64xx_dvfs {
+ unsigned int vddarm_min;
+ unsigned int vddarm_max;
+};
+
+static struct s3c64xx_dvfs s3c6410_dvfs_table[] = {
+ [0] = { 1000000, 1000000 },
+ [1] = { 1000000, 1050000 },
+ [2] = { 1050000, 1100000 },
+ [3] = { 1050000, 1150000 },
+ [4] = { 1250000, 1350000 },
+};
static struct cpufreq_frequency_table s3c6410_freq_table[] = {
{ 0, 66000 },
- { 1, 133000 },
- { 2, 222000 },
- { 3, 266000 },
- { 4, 333000 },
- { 5, 400000 },
- { 6, 532000 },
- { 7, 533000 },
- { 8, 667000 },
+ { 0, 133000 },
+ { 1, 222000 },
+ { 1, 266000 },
+ { 2, 333000 },
+ { 2, 400000 },
+ { 3, 532000 },
+ { 3, 533000 },
+ { 4, 667000 },
{ 0, CPUFREQ_TABLE_END },
};
/* Data tables for current CPU and maximum index into it */
static struct cpufreq_frequency_table *s3c64xx_freq_table;
+static struct s3c64xx_dvfs *s3c64xx_dvfs_table;
static int s3c64xx_cpufreq_verify_speed(struct cpufreq_policy *policy)
{
@@ -56,19 +72,21 @@ static int s3c64xx_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
- int ret;
- unsigned int index;
+ int ret = 0;
+ unsigned int i;
struct cpufreq_freqs freqs;
+ struct s3c64xx_dvfs *dvfs;
ret = cpufreq_frequency_table_target(policy, s3c64xx_freq_table,
- target_freq, relation, &index);
+ target_freq, relation, &i);
if (ret != 0)
return ret;
freqs.cpu = 0;
freqs.old = clk_get_rate(armclk) / 1000;
- freqs.new = s3c64xx_freq_table[index].frequency;
+ freqs.new = s3c64xx_freq_table[i].frequency;
freqs.flags = 0;
+ dvfs = &s3c64xx_dvfs_table[s3c64xx_freq_table[i].index];
if (freqs.old == freqs.new)
return 0;
@@ -77,31 +95,68 @@ static int s3c64xx_cpufreq_set_target(struct cpufreq_policy *policy,
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- ret = clk_set_rate(armclk, freqs.new * 1000);
-
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+#ifdef CONFIG_REGULATOR
+ if (vddarm && freqs.new > freqs.old) {
+ ret = regulator_set_voltage(vddarm,
+ dvfs->vddarm_min,
+ dvfs->vddarm_max);
+ if (ret != 0) {
+ pr_err("cpufreq: Failed to set VDDARM for %dkHz: %d\n",
+ freqs.new, ret);
+ goto err;
+ }
+ }
+#endif
+ ret = clk_set_rate(armclk, freqs.new * 1000);
if (ret < 0) {
pr_err("cpufreq: Failed to set rate %dkHz: %d\n",
freqs.new, ret);
- return ret;
+ goto err;
+ }
+
+#ifdef CONFIG_REGULATOR
+ if (vddarm && freqs.new < freqs.old) {
+ ret = regulator_set_voltage(vddarm,
+ dvfs->vddarm_min,
+ dvfs->vddarm_max);
+ if (ret != 0) {
+ pr_err("cpufreq: Failed to set VDDARM for %dkHz: %d\n",
+ freqs.new, ret);
+ goto err_clk;
+ }
}
+#endif
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
pr_debug("cpufreq: Set actual frequency %lukHz\n",
clk_get_rate(armclk) / 1000);
return 0;
+
+err_clk:
+ if (clk_set_rate(armclk, freqs.old * 1000) < 0)
+ pr_err("Failed to restore original clock rate\n");
+err:
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+ return ret;
}
+
static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
{
+ int ret;
struct cpufreq_frequency_table *freq;;
if (policy->cpu != 0)
return -EINVAL;
- if (cpu_is_s3c6410())
+ if (cpu_is_s3c6410()) {
s3c64xx_freq_table = s3c6410_freq_table;
+ s3c64xx_dvfs_table = s3c6410_dvfs_table;
+ }
if (s3c64xx_freq_table == NULL) {
pr_err("cpufreq: No frequency information for this CPU\n");
@@ -115,6 +170,16 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
return PTR_ERR(armclk);
}
+#ifdef CONFIG_REGULATOR
+ vddarm = regulator_get(NULL, "vddarm");
+ if (IS_ERR(vddarm)) {
+ ret = PTR_ERR(vddarm);
+ pr_err("cpufreq: Failed to obtain VDDARM: %d\n", ret);
+ pr_err("cpufreq: Only frequency scaling available\n");
+ vddarm = NULL;
+ }
+#endif
+
/* Check for frequencies we can generate */
freq = s3c64xx_freq_table;
while (freq->frequency != CPUFREQ_TABLE_END) {
@@ -132,7 +197,15 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
policy->cur = clk_get_rate(armclk) / 1000;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- return cpufreq_frequency_table_cpuinfo(policy, s3c64xx_freq_table);
+ ret = cpufreq_frequency_table_cpuinfo(policy, s3c64xx_freq_table);
+ if (ret == 0)
+ return ret;
+
+ pr_err("cpufreq: Failed to configure frequency table: %d\n", ret);
+
+ regulator_put(vddarm);
+ clk_put(armclk);
+ return ret;
}
static struct cpufreq_driver s3c64xx_cpufreq_driver = {
--
linux-2.6-openmoko, the Linux 2.6 kernel tree from Openmoko
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