diff options
Diffstat (limited to 'drivers/cpufreq/omap-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/omap-cpufreq.c | 72 |
1 files changed, 67 insertions, 5 deletions
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c index 5d04c57aae3..67bbb06d046 100644 --- a/drivers/cpufreq/omap-cpufreq.c +++ b/drivers/cpufreq/omap-cpufreq.c @@ -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> @@ -37,6 +38,9 @@ #include <mach/hardware.h> +/* OPP tolerance in percentage */ +#define OPP_TOLERANCE 4 + #ifdef CONFIG_SMP struct lpj_info { unsigned long ref; @@ -52,6 +56,7 @@ 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 +81,10 @@ 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, tol = 0; if (!freq_table) { dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__, @@ -111,13 +118,50 @@ 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); + tol = volt * OPP_TOLERANCE / 100; + 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 - tol, volt + tol); + 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 - tol, volt + tol); + 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 +188,7 @@ static int omap_target(struct cpufreq_policy *policy, freqs.new); #endif +done: /* notifiers */ for_each_cpu(i, policy->cpus) { freqs.cpu = i; @@ -260,6 +305,23 @@ 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); } |