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cpufreq: OMAP: scale voltage along with frequency

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Use the regulator framework to get the voltage regulator associated
with the MPU voltage domain and use it to scale voltage along with
frequency.

While here, CONFIG_CPU_FREQ_DEBUG doesn't exist anymore, so move
debug prints to use dev_dbg().

Special thanks to Afzal Mohammed for suggestions on more robust error
checking.

Cc: Afzal Mohammed  <afzal@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
This commit is contained in:
Kevin Hilman 2011-07-15 15:05:04 -07:00
parent b09db45c56
commit 53dfe8a884
1 changed files with 63 additions and 5 deletions
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68
drivers/cpufreq/omap-cpufreq.c
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@ -25,6 +25,7 @@
#include <linux/opp.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <asm/system.h>
#include <asm/smp_plat.h>
@ -52,6 +53,7 @@ static atomic_t freq_table_users = ATOMIC_INIT(0);
static struct clk *mpu_clk;
static char *mpu_clk_name;
static struct device *mpu_dev;
static struct regulator *mpu_reg;
static int omap_verify_speed(struct cpufreq_policy *policy)
{
@ -76,8 +78,10 @@ static int omap_target(struct cpufreq_policy *policy,
unsigned int relation)
{
unsigned int i;
int ret = 0;
int r, ret = 0;
struct cpufreq_freqs freqs;
struct opp *opp;
unsigned long freq, volt = 0, volt_old = 0;
if (!freq_table) {
dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
@ -111,13 +115,49 @@ static int omap_target(struct cpufreq_policy *policy,
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
}
#ifdef CONFIG_CPU_FREQ_DEBUG
pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new);
#endif
freq = freqs.new * 1000;
if (mpu_reg) {
opp = opp_find_freq_ceil(mpu_dev, &freq);
if (IS_ERR(opp)) {
dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
__func__, freqs.new);
return -EINVAL;
}
volt = opp_get_voltage(opp);
volt_old = regulator_get_voltage(mpu_reg);
}
dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
freqs.new / 1000, volt ? volt / 1000 : -1);
/* scaling up? scale voltage before frequency */
if (mpu_reg && (freqs.new > freqs.old)) {
r = regulator_set_voltage(mpu_reg, volt, volt);
if (r < 0) {
dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
__func__);
freqs.new = freqs.old;
goto done;
}
}
ret = clk_set_rate(mpu_clk, freqs.new * 1000);
freqs.new = omap_getspeed(policy->cpu);
/* scaling down? scale voltage after frequency */
if (mpu_reg && (freqs.new < freqs.old)) {
r = regulator_set_voltage(mpu_reg, volt, volt);
if (r < 0) {
dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
__func__);
ret = clk_set_rate(mpu_clk, freqs.old * 1000);
freqs.new = freqs.old;
goto done;
}
}
freqs.new = omap_getspeed(policy->cpu);
#ifdef CONFIG_SMP
/*
* Note that loops_per_jiffy is not updated on SMP systems in
@ -144,6 +184,7 @@ static int omap_target(struct cpufreq_policy *policy,
freqs.new);
#endif
done:
/* notifiers */
for_each_cpu(i, policy->cpus) {
freqs.cpu = i;
@ -260,6 +301,23 @@ static int __init omap_cpufreq_init(void)
return -EINVAL;
}
mpu_reg = regulator_get(mpu_dev, "vcc");
if (IS_ERR(mpu_reg)) {
pr_warning("%s: unable to get MPU regulator\n", __func__);
mpu_reg = NULL;
} else {
/*
* Ensure physical regulator is present.
* (e.g. could be dummy regulator.)
*/
if (regulator_get_voltage(mpu_reg) < 0) {
pr_warn("%s: physical regulator not present for MPU\n",
__func__);
regulator_put(mpu_reg);
mpu_reg = NULL;
}
}
return cpufreq_register_driver(&omap_driver);
}