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authorRichard Zhao <richard.zhao@linaro.org>2011-12-12 00:13:38 +0800
committerEric Miao <eric.miao@linaro.org>2012-01-12 10:16:00 +0800
commitf26e2f273488817d50b29e644e742b73e75cca8f (patch)
tree605b8426f495b0cb599445ed596c21e986222d2c
parent6155aface4a5048b6398fe2b5bc33687db9fb26b (diff)
downloadlinux-linaro-f26e2f273488817d50b29e644e742b73e75cca8f.tar.gz
arm/imx: cpufreq: add multi-core support
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
-rw-r--r--arch/arm/plat-mxc/cpufreq.c99
1 files changed, 66 insertions, 33 deletions
diff --git a/arch/arm/plat-mxc/cpufreq.c b/arch/arm/plat-mxc/cpufreq.c
index 73db34bf588..71e0d095996 100644
--- a/arch/arm/plat-mxc/cpufreq.c
+++ b/arch/arm/plat-mxc/cpufreq.c
@@ -22,6 +22,7 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <asm/cpu.h>
#include <mach/hardware.h>
#include <mach/clock.h>
@@ -34,6 +35,7 @@ static int cpu_freq_khz_min;
static int cpu_freq_khz_max;
static struct clk *cpu_clk;
+static DEFINE_MUTEX(cpu_lock);
static struct cpufreq_frequency_table *imx_freq_table;
static int cpu_op_nr;
@@ -59,17 +61,11 @@ static int set_cpu_freq(int freq)
static int mxc_verify_speed(struct cpufreq_policy *policy)
{
- if (policy->cpu != 0)
- return -EINVAL;
-
return cpufreq_frequency_table_verify(policy, imx_freq_table);
}
static unsigned int mxc_get_speed(unsigned int cpu)
{
- if (cpu)
- return 0;
-
return clk_get_rate(cpu_clk) / 1000;
}
@@ -77,23 +73,49 @@ static int mxc_set_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
struct cpufreq_freqs freqs;
- int freq_Hz;
+ int freq_Hz, cpu;
int ret = 0;
unsigned int index;
+ mutex_lock(&cpu_lock);
+
cpufreq_frequency_table_target(policy, imx_freq_table,
target_freq, relation, &index);
freq_Hz = imx_freq_table[index].frequency * 1000;
freqs.old = clk_get_rate(cpu_clk) / 1000;
- freqs.new = freq_Hz / 1000;
- freqs.cpu = 0;
+ freqs.new = clk_round_rate(cpu_clk, freq_Hz);
+ freqs.new = (freqs.new ? freqs.new : freq_Hz) / 1000;
freqs.flags = 0;
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ if (freqs.old == freqs.new) {
+ mutex_unlock(&cpu_lock);
+ return 0;
+ }
+
+ for_each_possible_cpu(cpu) {
+ freqs.cpu = cpu;
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ }
ret = set_cpu_freq(freq_Hz);
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+#ifdef CONFIG_SMP
+ /* loops_per_jiffy is not updated by the cpufreq core for SMP systems.
+ * So update it for all CPUs.
+ */
+ for_each_possible_cpu(cpu)
+ per_cpu(cpu_data, cpu).loops_per_jiffy =
+ cpufreq_scale(per_cpu(cpu_data, cpu).loops_per_jiffy,
+ freqs.old, freqs.new);
+#endif
+
+ for_each_possible_cpu(cpu) {
+ freqs.cpu = cpu;
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ }
+
+ mutex_unlock(&cpu_lock);
return ret;
}
@@ -105,7 +127,7 @@ static int mxc_cpufreq_init(struct cpufreq_policy *policy)
printk(KERN_INFO "i.MXC CPU frequency driver\n");
- if (policy->cpu != 0)
+ if (policy->cpu >= num_possible_cpus())
return -EINVAL;
if (!get_cpu_op)
@@ -117,37 +139,45 @@ static int mxc_cpufreq_init(struct cpufreq_policy *policy)
return PTR_ERR(cpu_clk);
}
- cpu_op_tbl = get_cpu_op(&cpu_op_nr);
+ mutex_lock(&cpu_lock);
+ if (!imx_freq_table) {
+ cpu_op_tbl = get_cpu_op(&cpu_op_nr);
- cpu_freq_khz_min = cpu_op_tbl[0].cpu_rate / 1000;
- cpu_freq_khz_max = cpu_op_tbl[0].cpu_rate / 1000;
+ cpu_freq_khz_min = cpu_op_tbl[0].cpu_rate / 1000;
+ cpu_freq_khz_max = cpu_op_tbl[0].cpu_rate / 1000;
- imx_freq_table = kmalloc(
- sizeof(struct cpufreq_frequency_table) * (cpu_op_nr + 1),
- GFP_KERNEL);
- if (!imx_freq_table) {
- ret = -ENOMEM;
- goto err1;
- }
+ imx_freq_table = kmalloc(sizeof(struct cpufreq_frequency_table)
+ * (cpu_op_nr + 1), GFP_KERNEL);
+ if (!imx_freq_table) {
+ ret = -ENOMEM;
+ mutex_unlock(&cpu_lock);
+ goto err1;
+ }
- for (i = 0; i < cpu_op_nr; i++) {
- imx_freq_table[i].index = i;
- imx_freq_table[i].frequency = cpu_op_tbl[i].cpu_rate / 1000;
+ for (i = 0; i < cpu_op_nr; i++) {
+ imx_freq_table[i].index = i;
+ imx_freq_table[i].frequency =
+ cpu_op_tbl[i].cpu_rate / 1000;
- if ((cpu_op_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min)
- cpu_freq_khz_min = cpu_op_tbl[i].cpu_rate / 1000;
+ if ((cpu_op_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min)
+ cpu_freq_khz_min =
+ cpu_op_tbl[i].cpu_rate / 1000;
- if ((cpu_op_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max)
- cpu_freq_khz_max = cpu_op_tbl[i].cpu_rate / 1000;
- }
+ if ((cpu_op_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max)
+ cpu_freq_khz_max =
+ cpu_op_tbl[i].cpu_rate / 1000;
+ }
- imx_freq_table[i].index = i;
- imx_freq_table[i].frequency = CPUFREQ_TABLE_END;
+ imx_freq_table[i].index = i;
+ imx_freq_table[i].frequency = CPUFREQ_TABLE_END;
+ }
+ mutex_unlock(&cpu_lock);
policy->cur = clk_get_rate(cpu_clk) / 1000;
policy->min = policy->cpuinfo.min_freq = cpu_freq_khz_min;
policy->max = policy->cpuinfo.max_freq = cpu_freq_khz_max;
-
+ policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
+ cpumask_setall(policy->cpus);
/* Manual states, that PLL stabilizes in two CLK32 periods */
policy->cpuinfo.transition_latency = 2 * NANOSECOND / CLK32_FREQ;
@@ -174,7 +204,10 @@ static int mxc_cpufreq_exit(struct cpufreq_policy *policy)
set_cpu_freq(cpu_freq_khz_max * 1000);
clk_put(cpu_clk);
+ mutex_lock(&cpu_lock);
kfree(imx_freq_table);
+ imx_freq_table = NULL;
+ mutex_unlock(&cpu_lock);
return 0;
}