34  * struct clock_cooling_device - data for cooling device with clock
38  *       clock frequencies.
41  * @clk_rate_change_nb: reference to notifier block used to receive clock
43  * @freq_table: frequency table used to keep track of available frequencies.
44  * @clock_state: integer value representing the current state of clock
47  *	frequency.
48  * @clk: struct clk reference used to enforce clock limits.
70 /* Below code defines functions to be used for clock as cooling device */
79  * clock_cooling_get_property - fetch a property of interest for a give cpu.
80  * @ccdev: clock cooling device reference
83  * @property: type of query (frequency, level, max level)
86  * 1. get maximum clock cooling states
87  * 2. translate frequency to cooling state
88  * 3. translate cooling state to frequency
95  * Return: 0 on success, -EINVAL when invalid parameters are passed.
105 	int descend = -1;  in clock_cooling_get_property()
106 	struct cpufreq_frequency_table *pos, *table = ccdev->freq_table;  in clock_cooling_get_property()
109 		return -EINVAL;  in clock_cooling_get_property()
112 		return -EINVAL;  in clock_cooling_get_property()
116 		if (freq == pos->frequency)  in clock_cooling_get_property()
119 		/* get the frequency order */  in clock_cooling_get_property()
120 		if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)  in clock_cooling_get_property()
121 			descend = freq > pos->frequency;  in clock_cooling_get_property()
123 		freq = pos->frequency;  in clock_cooling_get_property()
127 	/* No valid cpu frequency entry */  in clock_cooling_get_property()
129 		return -EINVAL;  in clock_cooling_get_property()
132 	max_level--;  in clock_cooling_get_property()
141 		level = descend ? input : (max_level - input);  in clock_cooling_get_property()
146 		if (freq == pos->frequency)  in clock_cooling_get_property()
149 		/* now we have a valid frequency entry */  in clock_cooling_get_property()
150 		freq = pos->frequency;  in clock_cooling_get_property()
153 			/* get level by frequency */  in clock_cooling_get_property()
154 			*output = descend ? i : (max_level - i);  in clock_cooling_get_property()
158 			/* get frequency by level */  in clock_cooling_get_property()
165 	return -EINVAL;  in clock_cooling_get_property()
169  * clock_cooling_get_level - return the cooling level of given clock cooling.
170  * @cdev: reference of a thermal cooling device of used as clock cooling device
171  * @freq: the frequency of interest
182 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_level()
194  * clock_cooling_get_frequency - get the absolute value of frequency from level.
195  * @ccdev: clock cooling device reference
198  * This function matches cooling level with frequency. Based on a cooling level
199  * of frequency, equals cooling state of cpu cooling device, it will return
200  * the corresponding frequency.
201  *	e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
203  * Return: 0 on error, the corresponding frequency otherwise.
220  * clock_cooling_apply - function to apply frequency clipping.
221  * @ccdev: clock_cooling_device pointer containing frequency clipping data.
224  * Function used to make sure the clock layer is aware of current thermal
225  * limits. The limits are applied by updating the clock rate in case it is
226  * higher than the corresponding frequency based on the requested cooling_state.
228  * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
239 	if (ccdev->clock_state == cooling_state)  in clock_cooling_apply()
244 		return -EINVAL;  in clock_cooling_apply()
246 	cur_freq = clk_get_rate(ccdev->clk);  in clock_cooling_apply()
248 	mutex_lock(&ccdev->lock);  in clock_cooling_apply()
249 	ccdev->clock_state = cooling_state;  in clock_cooling_apply()
250 	ccdev->clock_val = clip_freq;  in clock_cooling_apply()
251 	/* enforce clock level */  in clock_cooling_apply()
253 		ret = clk_set_rate(ccdev->clk, clip_freq);  in clock_cooling_apply()
254 	mutex_unlock(&ccdev->lock);  in clock_cooling_apply()
260  * clock_cooling_clock_notifier - notifier callback on clock rate changes.
262  * @event: value showing clock event for which this function invoked.
263  * @data: callback-specific data
265  * Callback to hijack the notification on clock transition.
266  * Every time there is a clock change, we intercept all pre change events
283 		 * layer is also hijacking clock pre notifications.  in clock_cooling_clock_notifier()
285 		if (ndata->new_rate > ccdev->clock_val)  in clock_cooling_clock_notifier()
295 /* clock cooling device thermal callback functions are defined below */
298  * clock_cooling_get_max_state - callback function to get the max cooling state.
302  * Callback for the thermal cooling device to return the clock
310 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_max_state()
322  * clock_cooling_get_cur_state - function to get the current cooling state.
326  * Callback for the thermal cooling device to return the clock
334 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_cur_state()
336 	*state = ccdev->clock_state;  in clock_cooling_get_cur_state()
342  * clock_cooling_set_cur_state - function to set the current cooling state.
346  * Callback for the thermal cooling device to change the clock cooling
354 	struct clock_cooling_device *clock_device = cdev->devdata;  in clock_cooling_set_cur_state()
359 /* Bind clock callbacks to thermal cooling device ops */
367  * clock_cooling_register - function to create clock cooling device.
368  * @dev: struct device pointer to the device used as clock cooling device.
369  * @clock_name: string containing the clock used as cooling mechanism.
371  * This interface function registers the clock cooling device with the name
372  * "thermal-clock-%x". The cooling device is based on clock frequencies.
375  * the referred device. The ordered frequency table is used to control
376  * the clock cooling device cooling states and to limit clock transitions
392 		return ERR_PTR(-ENOMEM);  in clock_cooling_register()
394 	mutex_init(&ccdev->lock);  in clock_cooling_register()
395 	ccdev->dev = dev;  in clock_cooling_register()
396 	ccdev->clk = devm_clk_get(dev, clock_name);  in clock_cooling_register()
397 	if (IS_ERR(ccdev->clk))  in clock_cooling_register()
398 		return ERR_CAST(ccdev->clk);  in clock_cooling_register()
403 	ccdev->id = ret;  in clock_cooling_register()
405 	snprintf(dev_name, sizeof(dev_name), "thermal-clock-%d", ccdev->id);  in clock_cooling_register()
410 		ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_register()
411 		return ERR_PTR(-EINVAL);  in clock_cooling_register()
413 	ccdev->cdev = cdev;  in clock_cooling_register()
414 	ccdev->clk_rate_change_nb.notifier_call = clock_cooling_clock_notifier;  in clock_cooling_register()
417 	ret = dev_pm_opp_init_cpufreq_table(dev, &ccdev->freq_table);  in clock_cooling_register()
419 		ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_register()
422 	ccdev->clock_state = 0;  in clock_cooling_register()
423 	ccdev->clock_val = clock_cooling_get_frequency(ccdev, 0);  in clock_cooling_register()
425 	clk_notifier_register(ccdev->clk, &ccdev->clk_rate_change_nb);  in clock_cooling_register()
432  * clock_cooling_unregister - function to remove clock cooling device.
435  * This interface function unregisters the "thermal-clock-%x" cooling device.
444 	ccdev = cdev->devdata;  in clock_cooling_unregister()
446 	clk_notifier_unregister(ccdev->clk, &ccdev->clk_rate_change_nb);  in clock_cooling_unregister()
447 	dev_pm_opp_free_cpufreq_table(ccdev->dev, &ccdev->freq_table);  in clock_cooling_unregister()
449 	thermal_cooling_device_unregister(ccdev->cdev);  in clock_cooling_unregister()
450 	ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_unregister()