On 13 August 2013 00:40, Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx> wrote:
> This patch adds a dynamically calculated frequency table to the at32ap driver.
> In short the architecture can scale in power of two between a maximum and
> minimum frequency. Min, max, and the steps in between are added to the table.
>
> Signed-off-by: Hans-Christian Egtvedt <egtvedt@xxxxxxxxxxxx>
> ---
> drivers/cpufreq/at32ap-cpufreq.c | 47 +++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/at32ap-cpufreq.c b/drivers/cpufreq/at32ap-cpufreq.c
> index 6544887..dbf3f3d 100644
> --- a/drivers/cpufreq/at32ap-cpufreq.c
> +++ b/drivers/cpufreq/at32ap-cpufreq.c
> @@ -19,8 +19,10 @@
> #include <linux/clk.h>
> #include <linux/err.h>
> #include <linux/export.h>
> +#include <linux/slab.h>
>
> static struct clk *cpuclk;
> +static struct cpufreq_frequency_table *freq_table;
>
> static int at32_verify_speed(struct cpufreq_policy *policy)
> {
> @@ -85,13 +87,19 @@ static int at32_set_target(struct cpufreq_policy *policy,
>
> static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
> {
> + unsigned int frequency;
> + int retval;
> + int steps;
> + int 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;
> @@ -101,9 +109,46 @@ static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
> policy->min = policy->cpuinfo.min_freq;
> policy->max = policy->cpuinfo.max_freq;
>
> + /*
> + * 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(policy->cpuinfo.max_freq / policy->cpuinfo.min_freq) + 1;
> + freq_table = kzalloc(steps * sizeof(struct cpufreq_frequency_table),
> + GFP_KERNEL);
> + if (!freq_table) {
> + retval = -ENOMEM;
> + goto out_err_put_clk;
> + }
> +
> + frequency = policy->cpuinfo.max_freq;
> + for (i = 0; i < (steps - 1); i++) {
> + unsigned int rate = clk_round_rate(cpuclk, frequency * 1000);
> + rate /= 1000;
> + 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_frequency_table_cpuinfo(policy, freq_table);
> + if (retval)
> + goto out_err_kfree;
> +
> printk("cpufreq: AT32AP CPU frequency driver\n");
>
> return 0;
> +out_err_kfree:
> + kfree(freq_table);
> +out_err_put_clk:
> + clk_put(cpuclk);
> +out_err:
> + return retval;
> }
>
> static struct cpufreq_driver at32_driver = {
Thanks for your patch, I have folded below patch with your patch while
applying..
diff --git a/drivers/cpufreq/at32ap-cpufreq.c b/drivers/cpufreq/at32ap-cpufreq.c
index eaac7cb..c586d3e 100644
--- a/drivers/cpufreq/at32ap-cpufreq.c
+++ b/drivers/cpufreq/at32ap-cpufreq.c
@@ -87,10 +87,8 @@ static int at32_set_target(struct cpufreq_policy *policy,
static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy)
{
- unsigned int frequency;
- int retval;
- int steps;
- int i;
+ unsigned int frequency, rate;
+ int retval, steps, i;
if (policy->cpu != 0)
return -EINVAL;
@@ -126,20 +124,23 @@ static int __init
at32_cpufreq_driver_init(struct cpufreq_policy *policy)
frequency = policy->cpuinfo.max_freq;
for (i = 0; i < (steps - 1); i++) {
- unsigned int rate = clk_round_rate(cpuclk, frequency * 1000);
- rate /= 1000;
+ rate = clk_round_rate(cpuclk, frequency * 1000) / 1000;
+
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_frequency_table_cpuinfo(policy, freq_table);
if (retval)
goto out_err_kfree;
+ cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
printk("cpufreq: AT32AP CPU frequency driver\n");
return 0;
--
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