1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
40  * pm_clk_list_lock - ensure exclusive access for modifying the PM clock
53 	__acquires(&psd->lock)  in pm_clk_list_lock()
55 	mutex_lock(&psd->clock_mutex);  in pm_clk_list_lock()
56 	spin_lock_irq(&psd->lock);  in pm_clk_list_lock()
60  * pm_clk_list_unlock - counterpart to pm_clk_list_lock().
65 	__releases(&psd->lock)  in pm_clk_list_unlock()
67 	spin_unlock_irq(&psd->lock);  in pm_clk_list_unlock()
68 	mutex_unlock(&psd->clock_mutex);  in pm_clk_list_unlock()
72  * pm_clk_op_lock - ensure exclusive access for performing clock operations.
84  * Returns -EINVAL if called in atomic context when clock ops might sleep.
93 	spin_lock_irqsave(&psd->lock, *flags);  in pm_clk_op_lock()
94 	if (!psd->clock_op_might_sleep) {  in pm_clk_op_lock()
96 		__release(&psd->lock);  in pm_clk_op_lock()
103 		       fn, psd->clock_op_might_sleep);  in pm_clk_op_lock()
104 		spin_unlock_irqrestore(&psd->lock, *flags);  in pm_clk_op_lock()
106 		return -EPERM;  in pm_clk_op_lock()
110 	spin_unlock_irqrestore(&psd->lock, *flags);  in pm_clk_op_lock()
111 	mutex_lock(&psd->clock_mutex);  in pm_clk_op_lock()
114 	 * There was a possibility for psd->clock_op_might_sleep  in pm_clk_op_lock()
117 	if (likely(psd->clock_op_might_sleep))  in pm_clk_op_lock()
120 	mutex_unlock(&psd->clock_mutex);  in pm_clk_op_lock()
125  * pm_clk_op_unlock - counterpart to pm_clk_op_lock().
133 	if (psd->clock_op_might_sleep) {  in pm_clk_op_unlock()
134 		mutex_unlock(&psd->clock_mutex);  in pm_clk_op_unlock()
137 		__acquire(&psd->lock);  in pm_clk_op_unlock()
138 		spin_unlock_irqrestore(&psd->lock, *flags);  in pm_clk_op_unlock()
143  * __pm_clk_enable - Enable a clock, reporting any errors
151 	switch (ce->status) {  in __pm_clk_enable()
153 		ret = clk_prepare_enable(ce->clk);  in __pm_clk_enable()
156 		ret = clk_enable(ce->clk);  in __pm_clk_enable()
162 		ce->status = PCE_STATUS_ENABLED;  in __pm_clk_enable()
165 			__func__, ce->clk, ret);  in __pm_clk_enable()
169  * pm_clk_acquire - Acquire a device clock.
175 	if (!ce->clk)  in pm_clk_acquire()
176 		ce->clk = clk_get(dev, ce->con_id);  in pm_clk_acquire()
177 	if (IS_ERR(ce->clk)) {  in pm_clk_acquire()
178 		ce->status = PCE_STATUS_ERROR;  in pm_clk_acquire()
180 	} else if (clk_is_enabled_when_prepared(ce->clk)) {  in pm_clk_acquire()
182 		ce->status = PCE_STATUS_ACQUIRED;  in pm_clk_acquire()
183 		ce->enabled_when_prepared = true;  in pm_clk_acquire()
184 	} else if (clk_prepare(ce->clk)) {  in pm_clk_acquire()
185 		ce->status = PCE_STATUS_ERROR;  in pm_clk_acquire()
189 		ce->status = PCE_STATUS_PREPARED;  in pm_clk_acquire()
192 		ce->clk, ce->con_id);  in pm_clk_acquire()
202 		return -EINVAL;  in __pm_clk_add()
206 		return -ENOMEM;  in __pm_clk_add()
209 		ce->con_id = kstrdup(con_id, GFP_KERNEL);  in __pm_clk_add()
210 		if (!ce->con_id) {  in __pm_clk_add()
212 			return -ENOMEM;  in __pm_clk_add()
217 			return -ENOENT;  in __pm_clk_add()
219 		ce->clk = clk;  in __pm_clk_add()
225 	list_add_tail(&ce->node, &psd->clock_list);  in __pm_clk_add()
226 	if (ce->enabled_when_prepared)  in __pm_clk_add()
227 		psd->clock_op_might_sleep++;  in __pm_clk_add()
233  * pm_clk_add - Start using a device clock for power management.
234  * @dev: Device whose clock is going to be used for power management.
238  * the power management of @dev.
247  * pm_clk_add_clk - Start using a device clock for power management.
248  * @dev: Device whose clock is going to be used for power management.
251  * Add the clock to the list of clocks used for the power management of @dev.
252  * The power-management code will take control of the clock reference, so
264  * of_pm_clk_add_clk - Start using a device clock for power management.
265  * @dev: Device whose clock is going to be used for power management.
266  * @name: Name of clock that is going to be used for power management.
268  * Add the clock described in the 'clocks' device-tree node that matches
269  * with the 'name' provided, to the list of clocks used for the power
270  * management of @dev. On success, returns 0. Returns a negative error
278 	if (!dev || !dev->of_node || !name)  in of_pm_clk_add_clk()
279 		return -EINVAL;  in of_pm_clk_add_clk()
281 	clk = of_clk_get_by_name(dev->of_node, name);  in of_pm_clk_add_clk()
296  * of_pm_clk_add_clks - Start using device clock(s) for power management.
297  * @dev: Device whose clock(s) is going to be used for power management.
299  * Add a series of clocks described in the 'clocks' device-tree node for
300  * a device to the list of clocks used for the power management of @dev.
311 	if (!dev || !dev->of_node)  in of_pm_clk_add_clks()
312 		return -EINVAL;  in of_pm_clk_add_clks()
314 	count = of_clk_get_parent_count(dev->of_node);  in of_pm_clk_add_clks()
316 		return -ENODEV;  in of_pm_clk_add_clks()
320 		return -ENOMEM;  in of_pm_clk_add_clks()
323 		clks[i] = of_clk_get(dev->of_node, i);  in of_pm_clk_add_clks()
341 	while (i--)  in of_pm_clk_add_clks()
351  * __pm_clk_remove - Destroy PM clock entry.
359 	switch (ce->status) {  in __pm_clk_remove()
361 		clk_disable(ce->clk);  in __pm_clk_remove()
364 		clk_unprepare(ce->clk);  in __pm_clk_remove()
368 		if (!IS_ERR(ce->clk))  in __pm_clk_remove()
369 			clk_put(ce->clk);  in __pm_clk_remove()
375 	kfree(ce->con_id);  in __pm_clk_remove()
380  * pm_clk_remove - Stop using a device clock for power management.
385  * the power management of @dev.
397 	list_for_each_entry(ce, &psd->clock_list, node) {  in pm_clk_remove()
398 		if (!con_id && !ce->con_id)  in pm_clk_remove()
400 		else if (!con_id || !ce->con_id)  in pm_clk_remove()
402 		else if (!strcmp(con_id, ce->con_id))  in pm_clk_remove()
410 	list_del(&ce->node);  in pm_clk_remove()
411 	if (ce->enabled_when_prepared)  in pm_clk_remove()
412 		psd->clock_op_might_sleep--;  in pm_clk_remove()
420  * pm_clk_remove_clk - Stop using a device clock for power management.
425  * the power management of @dev.
437 	list_for_each_entry(ce, &psd->clock_list, node) {  in pm_clk_remove_clk()
438 		if (clk == ce->clk)  in pm_clk_remove_clk()
446 	list_del(&ce->node);  in pm_clk_remove_clk()
447 	if (ce->enabled_when_prepared)  in pm_clk_remove_clk()
448 		psd->clock_op_might_sleep--;  in pm_clk_remove_clk()
456  * pm_clk_init - Initialize a device's list of power management clocks.
466 		INIT_LIST_HEAD(&psd->clock_list);  in pm_clk_init()
467 		mutex_init(&psd->clock_mutex);  in pm_clk_init()
468 		psd->clock_op_might_sleep = 0;  in pm_clk_init()
474  * pm_clk_create - Create and initialize a device's list of PM clocks.
478  * members and make the @dev's power.subsys_data field point to it.
487  * pm_clk_destroy - Destroy a device's list of power management clocks.
490  * Clear the @dev's power.subsys_data field, remove the list of clock entries
507 	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)  in pm_clk_destroy()
508 		list_move(&ce->node, &list);  in pm_clk_destroy()
509 	psd->clock_op_might_sleep = 0;  in pm_clk_destroy()
516 		list_del(&ce->node);  in pm_clk_destroy()
540  * pm_clk_suspend - Disable clocks in a device's PM clock list.
559 	list_for_each_entry_reverse(ce, &psd->clock_list, node) {  in pm_clk_suspend()
560 		if (ce->status == PCE_STATUS_ENABLED) {  in pm_clk_suspend()
561 			if (ce->enabled_when_prepared) {  in pm_clk_suspend()
562 				clk_disable_unprepare(ce->clk);  in pm_clk_suspend()
563 				ce->status = PCE_STATUS_ACQUIRED;  in pm_clk_suspend()
565 				clk_disable(ce->clk);  in pm_clk_suspend()
566 				ce->status = PCE_STATUS_PREPARED;  in pm_clk_suspend()
578  * pm_clk_resume - Enable clocks in a device's PM clock list.
597 	list_for_each_entry(ce, &psd->clock_list, node)  in pm_clk_resume()
607  * pm_clk_notify - Notify routine for device addition and removal.
636 		if (dev->pm_domain)  in pm_clk_notify()
643 		dev_pm_domain_set(dev, clknb->pm_domain);  in pm_clk_notify()
644 		if (clknb->con_ids[0]) {  in pm_clk_notify()
645 			for (con_id = clknb->con_ids; *con_id; con_id++)  in pm_clk_notify()
653 		if (dev->pm_domain != clknb->pm_domain)  in pm_clk_notify()
706  * enable_clock - Enable a device clock.
723  * disable_clock - Disable a device clock.
740  * pm_clk_notify - Notify routine for device addition and removal.
763 		if (clknb->con_ids[0]) {  in pm_clk_notify()
764 			for (con_id = clknb->con_ids; *con_id; con_id++)  in pm_clk_notify()
772 		if (clknb->con_ids[0]) {  in pm_clk_notify()
773 			for (con_id = clknb->con_ids; *con_id; con_id++)  in pm_clk_notify()
787  * pm_clk_add_notifier - Add bus type notifier for power management clocks.
802 	clknb->nb.notifier_call = pm_clk_notify;  in pm_clk_add_notifier()
803 	bus_register_notifier(bus, &clknb->nb);  in pm_clk_add_notifier()