diff options
Diffstat (limited to 'drivers/cpufreq/at32ap-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/at32ap-cpufreq.c | 67 |
1 files changed, 48 insertions, 19 deletions
diff --git a/drivers/cpufreq/at32ap-cpufreq.c b/drivers/cpufreq/at32ap-cpufreq.c index e0c38d9..7439ded 100644 --- a/drivers/cpufreq/at32ap-cpufreq.c +++ b/drivers/cpufreq/at32ap-cpufreq.c @@ -19,18 +19,10 @@ #include <linux/clk.h> #include <linux/err.h> #include <linux/export.h> +#include <linux/slab.h> static struct clk *cpuclk; - -static int at32_verify_speed(struct cpufreq_policy *policy) -{ - if (policy->cpu != 0) - return -EINVAL; - - cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, - policy->cpuinfo.max_freq); - return 0; -} +static struct cpufreq_frequency_table *freq_table; static unsigned int at32_get_speed(unsigned int cpu) { @@ -85,31 +77,68 @@ static int at32_set_target(struct cpufreq_policy *policy, static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy) { + unsigned int frequency, rate, min_freq; + int retval, steps, i; + if (policy->cpu != 0) return -EINVAL; cpuclk = clk_get(NULL, "cpu"); if (IS_ERR(cpuclk)) { pr_debug("cpufreq: could not get CPU clk\n"); - return PTR_ERR(cpuclk); + retval = PTR_ERR(cpuclk); + goto out_err; } - policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; - policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; + min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; + frequency = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; policy->cpuinfo.transition_latency = 0; - policy->cur = at32_get_speed(0); - policy->min = policy->cpuinfo.min_freq; - policy->max = policy->cpuinfo.max_freq; - printk("cpufreq: AT32AP CPU frequency driver\n"); + /* + * AVR32 CPU frequency rate scales in power of two between maximum and + * minimum, also add space for the table end marker. + * + * Further validate that the frequency is usable, and append it to the + * frequency table. + */ + steps = fls(frequency / min_freq) + 1; + freq_table = kzalloc(steps * sizeof(struct cpufreq_frequency_table), + GFP_KERNEL); + if (!freq_table) { + retval = -ENOMEM; + goto out_err_put_clk; + } + + for (i = 0; i < (steps - 1); i++) { + rate = clk_round_rate(cpuclk, frequency * 1000) / 1000; - return 0; + if (rate != frequency) + freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; + else + freq_table[i].frequency = frequency; + + frequency /= 2; + } + + freq_table[steps - 1].frequency = CPUFREQ_TABLE_END; + + retval = cpufreq_table_validate_and_show(policy, freq_table); + if (!retval) { + printk("cpufreq: AT32AP CPU frequency driver\n"); + return 0; + } + + kfree(freq_table); +out_err_put_clk: + clk_put(cpuclk); +out_err: + return retval; } static struct cpufreq_driver at32_driver = { .name = "at32ap", .init = at32_cpufreq_driver_init, - .verify = at32_verify_speed, + .verify = cpufreq_generic_frequency_table_verify, .target = at32_set_target, .get = at32_get_speed, .flags = CPUFREQ_STICKY, |