Documentation/cpu-freq/cpu-drivers.rst

24    2.   Frequency Table Helpers
61  .resolve_freq - Returns the most appropriate frequency for a target
62  frequency. Doesn't change the frequency though.
65  frequency while changing CPU frequency.
67  .get - Returns current frequency of the CPU.
69  .bios_limit - Returns HW/BIOS max frequency limitations for the CPU.
112 |policy->cpuinfo.max_freq	    | the minimum and maximum frequency	   |
121 |policy->cur			    | The current operating frequency of   |
141 frequency table helpers might be helpful. See the section 2 for more information
153 See section 2 for details on frequency table helpers.
155 You need to make sure that at least one valid frequency (or operating
163 Most cpufreq drivers or even most cpu frequency scaling algorithms
164 only allow the CPU frequency to be set to predefined fixed values. For
168 Some cpufreq capable processors switch the frequency between certain
176 and ``unsigned int`` index (into the exposed frequency table).
178 The CPUfreq driver must set the new frequency when called here. The
179 actual frequency must be determined by freq_table[index].frequency.
181 It should always restore to earlier frequency (i.e. policy->restore_freq) in
182 case of errors, even if we switched to intermediate frequency earlier.
189 The CPUfreq driver must set the new frequency when called here. The
190 actual frequency must be determined using the following rules:
199 Here again the frequency table helper might assist you - see section 2
205 This function is used for frequency switching from scheduler's context.
219 in-chipset dynamic frequency switching to policy->min, the upper limit
230 get_intermediate should return a stable intermediate frequency platform wants to
231 switch to, and target_intermediate() should set CPU to that frequency, before
232 jumping to the frequency corresponding to 'index'. Core will take care of
237 to intermediate frequency for some target frequency. In that case core will
244 2. Frequency Table Helpers
248 frequencies, a "frequency table" with some functions might assist in
249 some work of the processor driver. Such a "frequency table" consists of
251 values in "driver_data", the corresponding frequency in "frequency" and
253 cpufreq_frequency_table entry with frequency set to CPUFREQ_TABLE_END.
254 And if you want to skip one entry in the table, set the frequency to
263 frequency is within policy->min and policy->max, and all other criteria
266 cpufreq_frequency_table_target() is the corresponding frequency table
268 and this function returns the of the frequency table entry which
269 contains the frequency the CPU shall be set to.
273 cpufreq_for_each_entry(pos, table) - iterates over all entries of frequency
287 		pos->frequency = ...