diff options
Diffstat (limited to 'Documentation/cpu-freq/cpu-drivers.txt')
| -rw-r--r-- | Documentation/cpu-freq/cpu-drivers.txt | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index 40282e61791..8b1a4451422 100644 --- a/Documentation/cpu-freq/cpu-drivers.txt +++ b/Documentation/cpu-freq/cpu-drivers.txt @@ -23,8 +23,8 @@ Contents: 1.1 Initialization 1.2 Per-CPU Initialization 1.3 verify -1.4 target or setpolicy? -1.5 target +1.4 target/target_index or setpolicy? +1.5 target/target_index 1.6 setpolicy 2. Frequency Table Helpers @@ -56,7 +56,8 @@ cpufreq_driver.init - A pointer to the per-CPU initialization cpufreq_driver.verify - A pointer to a "verification" function. cpufreq_driver.setpolicy _or_ -cpufreq_driver.target - See below on the differences. +cpufreq_driver.target/ +target_index - See below on the differences. And optionally @@ -66,7 +67,7 @@ cpufreq_driver.resume - A pointer to a per-CPU resume function which is called with interrupts disabled and _before_ the pre-suspend frequency and/or policy is restored by a call to - ->target or ->setpolicy. + ->target/target_index or ->setpolicy. cpufreq_driver.attr - A pointer to a NULL-terminated list of "struct freq_attr" which allow to @@ -103,8 +104,8 @@ policy->governor must contain the "default policy" for this CPU. A few moments later, cpufreq_driver.verify and either cpufreq_driver.setpolicy or - cpufreq_driver.target is called with - these values. + cpufreq_driver.target/target_index is called + with these values. For setting some of these values (cpuinfo.min[max]_freq, policy->min[max]), the frequency table helpers might be helpful. See the section 2 for more information @@ -133,20 +134,28 @@ range) is within policy->min and policy->max. If necessary, increase policy->max first, and only if this is no solution, decrease policy->min. -1.4 target or setpolicy? +1.4 target/target_index or setpolicy? ---------------------------- Most cpufreq drivers or even most cpu frequency scaling algorithms only allow the CPU to be set to one frequency. For these, you use the -->target call. +->target/target_index call. Some cpufreq-capable processors switch the frequency between certain limits on their own. These shall use the ->setpolicy call -1.4. target +1.4. target/target_index ------------- +The target_index call has two arguments: struct cpufreq_policy *policy, +and unsigned int index (into the exposed frequency table). + +The CPUfreq driver must set the new frequency when called here. The +actual frequency must be determined by freq_table[index].frequency. + +Deprecated: +---------- The target call has three arguments: struct cpufreq_policy *policy, unsigned int target_frequency, unsigned int relation. |