1 // SPDX-License-Identifier: GPL-2.0-only
26  * struct clock_cooling_device - data for cooling device with clock
30  *       clock frequencies.
33  * @clk_rate_change_nb: reference to notifier block used to receive clock
35  * @freq_table: frequency table used to keep track of available frequencies.
36  * @clock_state: integer value representing the current state of clock
39  *	frequency.
40  * @clk: struct clk reference used to enforce clock limits.
62 /* Below code defines functions to be used for clock as cooling device */
71  * clock_cooling_get_property - fetch a property of interest for a give cpu.
72  * @ccdev: clock cooling device reference
75  * @property: type of query (frequency, level, max level)
78  * 1. get maximum clock cooling states
79  * 2. translate frequency to cooling state
80  * 3. translate cooling state to frequency
87  * Return: 0 on success, -EINVAL when invalid parameters are passed.
97 	int descend = -1;  in clock_cooling_get_property()
98 	struct cpufreq_frequency_table *pos, *table = ccdev->freq_table;  in clock_cooling_get_property()
101 		return -EINVAL;  in clock_cooling_get_property()
104 		return -EINVAL;  in clock_cooling_get_property()
108 		if (freq == pos->frequency)  in clock_cooling_get_property()
111 		/* get the frequency order */  in clock_cooling_get_property()
112 		if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)  in clock_cooling_get_property()
113 			descend = freq > pos->frequency;  in clock_cooling_get_property()
115 		freq = pos->frequency;  in clock_cooling_get_property()
119 	/* No valid cpu frequency entry */  in clock_cooling_get_property()
121 		return -EINVAL;  in clock_cooling_get_property()
124 	max_level--;  in clock_cooling_get_property()
133 		level = descend ? input : (max_level - input);  in clock_cooling_get_property()
138 		if (freq == pos->frequency)  in clock_cooling_get_property()
141 		/* now we have a valid frequency entry */  in clock_cooling_get_property()
142 		freq = pos->frequency;  in clock_cooling_get_property()
145 			/* get level by frequency */  in clock_cooling_get_property()
146 			*output = descend ? i : (max_level - i);  in clock_cooling_get_property()
150 			/* get frequency by level */  in clock_cooling_get_property()
157 	return -EINVAL;  in clock_cooling_get_property()
161  * clock_cooling_get_level - return the cooling level of given clock cooling.
162  * @cdev: reference of a thermal cooling device of used as clock cooling device
163  * @freq: the frequency of interest
174 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_level()
186  * clock_cooling_get_frequency - get the absolute value of frequency from level.
187  * @ccdev: clock cooling device reference
190  * This function matches cooling level with frequency. Based on a cooling level
191  * of frequency, equals cooling state of cpu cooling device, it will return
192  * the corresponding frequency.
193  *	e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
195  * Return: 0 on error, the corresponding frequency otherwise.
212  * clock_cooling_apply - function to apply frequency clipping.
213  * @ccdev: clock_cooling_device pointer containing frequency clipping data.
216  * Function used to make sure the clock layer is aware of current thermal
217  * limits. The limits are applied by updating the clock rate in case it is
218  * higher than the corresponding frequency based on the requested cooling_state.
220  * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
231 	if (ccdev->clock_state == cooling_state)  in clock_cooling_apply()
236 		return -EINVAL;  in clock_cooling_apply()
238 	cur_freq = clk_get_rate(ccdev->clk);  in clock_cooling_apply()
240 	mutex_lock(&ccdev->lock);  in clock_cooling_apply()
241 	ccdev->clock_state = cooling_state;  in clock_cooling_apply()
242 	ccdev->clock_val = clip_freq;  in clock_cooling_apply()
243 	/* enforce clock level */  in clock_cooling_apply()
245 		ret = clk_set_rate(ccdev->clk, clip_freq);  in clock_cooling_apply()
246 	mutex_unlock(&ccdev->lock);  in clock_cooling_apply()
252  * clock_cooling_clock_notifier - notifier callback on clock rate changes.
254  * @event: value showing clock event for which this function invoked.
255  * @data: callback-specific data
257  * Callback to hijack the notification on clock transition.
258  * Every time there is a clock change, we intercept all pre change events
275 		 * layer is also hijacking clock pre notifications.  in clock_cooling_clock_notifier()
277 		if (ndata->new_rate > ccdev->clock_val)  in clock_cooling_clock_notifier()
287 /* clock cooling device thermal callback functions are defined below */
290  * clock_cooling_get_max_state - callback function to get the max cooling state.
294  * Callback for the thermal cooling device to return the clock
302 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_max_state()
314  * clock_cooling_get_cur_state - function to get the current cooling state.
318  * Callback for the thermal cooling device to return the clock
326 	struct clock_cooling_device *ccdev = cdev->devdata;  in clock_cooling_get_cur_state()
328 	*state = ccdev->clock_state;  in clock_cooling_get_cur_state()
334  * clock_cooling_set_cur_state - function to set the current cooling state.
338  * Callback for the thermal cooling device to change the clock cooling
346 	struct clock_cooling_device *clock_device = cdev->devdata;  in clock_cooling_set_cur_state()
351 /* Bind clock callbacks to thermal cooling device ops */
359  * clock_cooling_register - function to create clock cooling device.
360  * @dev: struct device pointer to the device used as clock cooling device.
361  * @clock_name: string containing the clock used as cooling mechanism.
363  * This interface function registers the clock cooling device with the name
364  * "thermal-clock-%x". The cooling device is based on clock frequencies.
367  * the referred device. The ordered frequency table is used to control
368  * the clock cooling device cooling states and to limit clock transitions
384 		return ERR_PTR(-ENOMEM);  in clock_cooling_register()
386 	mutex_init(&ccdev->lock);  in clock_cooling_register()
387 	ccdev->dev = dev;  in clock_cooling_register()
388 	ccdev->clk = devm_clk_get(dev, clock_name);  in clock_cooling_register()
389 	if (IS_ERR(ccdev->clk))  in clock_cooling_register()
390 		return ERR_CAST(ccdev->clk);  in clock_cooling_register()
395 	ccdev->id = ret;  in clock_cooling_register()
397 	snprintf(dev_name, sizeof(dev_name), "thermal-clock-%d", ccdev->id);  in clock_cooling_register()
402 		ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_register()
403 		return ERR_PTR(-EINVAL);  in clock_cooling_register()
405 	ccdev->cdev = cdev;  in clock_cooling_register()
406 	ccdev->clk_rate_change_nb.notifier_call = clock_cooling_clock_notifier;  in clock_cooling_register()
409 	ret = dev_pm_opp_init_cpufreq_table(dev, &ccdev->freq_table);  in clock_cooling_register()
411 		ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_register()
414 	ccdev->clock_state = 0;  in clock_cooling_register()
415 	ccdev->clock_val = clock_cooling_get_frequency(ccdev, 0);  in clock_cooling_register()
417 	clk_notifier_register(ccdev->clk, &ccdev->clk_rate_change_nb);  in clock_cooling_register()
424  * clock_cooling_unregister - function to remove clock cooling device.
427  * This interface function unregisters the "thermal-clock-%x" cooling device.
436 	ccdev = cdev->devdata;  in clock_cooling_unregister()
438 	clk_notifier_unregister(ccdev->clk, &ccdev->clk_rate_change_nb);  in clock_cooling_unregister()
439 	dev_pm_opp_free_cpufreq_table(ccdev->dev, &ccdev->freq_table);  in clock_cooling_unregister()
441 	thermal_cooling_device_unregister(ccdev->cdev);  in clock_cooling_unregister()
442 	ida_simple_remove(&clock_ida, ccdev->id);  in clock_cooling_unregister()