diff options
Diffstat (limited to 'arch/arm/plat-s3c64xx/cpufreq.c')
| -rw-r--r-- | arch/arm/plat-s3c64xx/cpufreq.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/arch/arm/plat-s3c64xx/cpufreq.c b/arch/arm/plat-s3c64xx/cpufreq.c index e6e0843215d..74c0e8347de 100644 --- a/arch/arm/plat-s3c64xx/cpufreq.c +++ b/arch/arm/plat-s3c64xx/cpufreq.c @@ -19,6 +19,7 @@ static struct clk *armclk; static struct regulator *vddarm; +static unsigned long regulator_latency; #ifdef CONFIG_CPU_S3C6410 struct s3c64xx_dvfs { @@ -27,11 +28,10 @@ struct s3c64xx_dvfs { }; static struct s3c64xx_dvfs s3c64xx_dvfs_table[] = { - [0] = { 1000000, 1000000 }, - [1] = { 1000000, 1050000 }, - [2] = { 1050000, 1100000 }, - [3] = { 1050000, 1150000 }, - [4] = { 1250000, 1350000 }, + [0] = { 1000000, 1150000 }, + [1] = { 1050000, 1150000 }, + [2] = { 1100000, 1150000 }, + [3] = { 1200000, 1350000 }, }; static struct cpufreq_frequency_table s3c64xx_freq_table[] = { @@ -41,9 +41,9 @@ static struct cpufreq_frequency_table s3c64xx_freq_table[] = { { 1, 266000 }, { 2, 333000 }, { 2, 400000 }, - { 3, 532000 }, - { 3, 533000 }, - { 4, 667000 }, + { 2, 532000 }, + { 2, 533000 }, + { 3, 667000 }, { 0, CPUFREQ_TABLE_END }, }; #endif @@ -141,7 +141,7 @@ err: } #ifdef CONFIG_REGULATOR -static void __init s3c64xx_cpufreq_constrain_voltages(void) +static void __init s3c64xx_cpufreq_config_regulator(void) { int count, v, i, found; struct cpufreq_frequency_table *freq; @@ -150,11 +150,10 @@ static void __init s3c64xx_cpufreq_constrain_voltages(void) count = regulator_count_voltages(vddarm); if (count < 0) { pr_err("cpufreq: Unable to check supported voltages\n"); - return; } freq = s3c64xx_freq_table; - while (freq->frequency != CPUFREQ_TABLE_END) { + while (count > 0 && freq->frequency != CPUFREQ_TABLE_END) { if (freq->frequency == CPUFREQ_ENTRY_INVALID) continue; @@ -175,6 +174,10 @@ static void __init s3c64xx_cpufreq_constrain_voltages(void) freq++; } + + /* Guess based on having to do an I2C/SPI write; in future we + * will be able to query the regulator performance here. */ + regulator_latency = 1 * 1000 * 1000; } #endif @@ -206,7 +209,7 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy) pr_err("cpufreq: Only frequency scaling available\n"); vddarm = NULL; } else { - s3c64xx_cpufreq_constrain_voltages(); + s3c64xx_cpufreq_config_regulator(); } #endif @@ -217,8 +220,11 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy) /* Check for frequencies we can generate */ r = clk_round_rate(armclk, freq->frequency * 1000); r /= 1000; - if (r != freq->frequency) + if (r != freq->frequency) { + pr_debug("cpufreq: %dkHz unsupported by clock\n", + freq->frequency); freq->frequency = CPUFREQ_ENTRY_INVALID; + } /* If we have no regulator then assume startup * frequency is the maximum we can support. */ @@ -230,9 +236,11 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy) policy->cur = clk_get_rate(armclk) / 1000; - /* Pick a conservative guess in ns: we'll need ~1 I2C/SPI - * write plus clock reprogramming. */ - policy->cpuinfo.transition_latency = 2 * 1000 * 1000; + /* Datasheet says PLL stabalisation time (if we were to use + * the PLLs, which we don't currently) is ~300us worst case, + * but add some fudge. + */ + policy->cpuinfo.transition_latency = (500 * 1000) + regulator_latency; ret = cpufreq_frequency_table_cpuinfo(policy, s3c64xx_freq_table); if (ret != 0) { |