[linux-block.git] / drivers / base / power / clock_ops.c

/*
 * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
 *
 * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
 *
 * This file is released under the GPLv2.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/pm.h>
#include <linux/pm_clock.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/slab.h>
#include <linux/err.h>

#ifdef CONFIG_PM

enum pce_status {
	PCE_STATUS_NONE = 0,
	PCE_STATUS_ACQUIRED,
	PCE_STATUS_ENABLED,
	PCE_STATUS_ERROR,
};

struct pm_clock_entry {
	struct list_head node;
	char *con_id;
	struct clk *clk;
	enum pce_status status;
};

/**
 * pm_clk_enable - Enable a clock, reporting any errors
 * @dev: The device for the given clock
 * @ce: PM clock entry corresponding to the clock.
 */
static inline int __pm_clk_enable(struct device *dev, struct pm_clock_entry *ce)
{
	int ret;

	if (ce->status < PCE_STATUS_ERROR) {
		ret = clk_enable(ce->clk);
		if (!ret)
			ce->status = PCE_STATUS_ENABLED;
		else
			dev_err(dev, "%s: failed to enable clk %p, error %d\n",
				__func__, ce->clk, ret);
	}

	return ret;
}

/**
 * pm_clk_acquire - Acquire a device clock.
 * @dev: Device whose clock is to be acquired.
 * @ce: PM clock entry corresponding to the clock.
 */
static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
{
	if (!ce->clk)
		ce->clk = clk_get(dev, ce->con_id);
	if (IS_ERR(ce->clk)) {
		ce->status = PCE_STATUS_ERROR;
	} else {
		clk_prepare(ce->clk);
		ce->status = PCE_STATUS_ACQUIRED;
		dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	}
}

static int __pm_clk_add(struct device *dev, const char *con_id,
			struct clk *clk)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;

	if (!psd)
		return -EINVAL;

	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
	if (!ce)
		return -ENOMEM;

	if (con_id) {
		ce->con_id = kstrdup(con_id, GFP_KERNEL);
		if (!ce->con_id) {
			dev_err(dev,
				"Not enough memory for clock connection ID.\n");
			kfree(ce);
			return -ENOMEM;
		}
	} else {
		if (IS_ERR(ce->clk) || !__clk_get(clk)) {
			kfree(ce);
			return -ENOENT;
		}
		ce->clk = clk;
	}

	pm_clk_acquire(dev, ce);

	spin_lock_irq(&psd->lock);
	list_add_tail(&ce->node, &psd->clock_list);
	spin_unlock_irq(&psd->lock);
	return 0;
}

/**
 * pm_clk_add - Start using a device clock for power management.
 * @dev: Device whose clock is going to be used for power management.
 * @con_id: Connection ID of the clock.
 *
 * Add the clock represented by @con_id to the list of clocks used for
 * the power management of @dev.
 */
int pm_clk_add(struct device *dev, const char *con_id)
{
	return __pm_clk_add(dev, con_id, NULL);
}

/**
 * pm_clk_add_clk - Start using a device clock for power management.
 * @dev: Device whose clock is going to be used for power management.
 * @clk: Clock pointer
 *
 * Add the clock to the list of clocks used for the power management of @dev.
 * It will increment refcount on clock pointer, use clk_put() on it when done.
 */
int pm_clk_add_clk(struct device *dev, struct clk *clk)
{
	return __pm_clk_add(dev, NULL, clk);
}

/**
 * __pm_clk_remove - Destroy PM clock entry.
 * @ce: PM clock entry to destroy.
 */
static void __pm_clk_remove(struct pm_clock_entry *ce)
{
	if (!ce)
		return;

	if (ce->status < PCE_STATUS_ERROR) {
		if (ce->status == PCE_STATUS_ENABLED)
			clk_disable(ce->clk);

		if (ce->status >= PCE_STATUS_ACQUIRED) {
			clk_unprepare(ce->clk);
			clk_put(ce->clk);
		}
	}

	kfree(ce->con_id);
	kfree(ce);
}

/**
 * pm_clk_remove - Stop using a device clock for power management.
 * @dev: Device whose clock should not be used for PM any more.
 * @con_id: Connection ID of the clock.
 *
 * Remove the clock represented by @con_id from the list of clocks used for
 * the power management of @dev.
 */
void pm_clk_remove(struct device *dev, const char *con_id)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;

	if (!psd)
		return;

	spin_lock_irq(&psd->lock);

	list_for_each_entry(ce, &psd->clock_list, node) {
		if (!con_id && !ce->con_id)
			goto remove;
		else if (!con_id || !ce->con_id)
			continue;
		else if (!strcmp(con_id, ce->con_id))
			goto remove;
	}

	spin_unlock_irq(&psd->lock);
	return;

 remove:
	list_del(&ce->node);
	spin_unlock_irq(&psd->lock);

	__pm_clk_remove(ce);
}

/**
 * pm_clk_init - Initialize a device's list of power management clocks.
 * @dev: Device to initialize the list of PM clocks for.
 *
 * Initialize the lock and clock_list members of the device's pm_subsys_data
 * object.
 */
void pm_clk_init(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	if (psd)
		INIT_LIST_HEAD(&psd->clock_list);
}

/**
 * pm_clk_create - Create and initialize a device's list of PM clocks.
 * @dev: Device to create and initialize the list of PM clocks for.
 *
 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
 * members and make the @dev's power.subsys_data field point to it.
 */
int pm_clk_create(struct device *dev)
{
	return dev_pm_get_subsys_data(dev);
}

/**
 * pm_clk_destroy - Destroy a device's list of power management clocks.
 * @dev: Device to destroy the list of PM clocks for.
 *
 * Clear the @dev's power.subsys_data field, remove the list of clock entries
 * from the struct pm_subsys_data object pointed to by it before and free
 * that object.
 */
void pm_clk_destroy(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce, *c;
	struct list_head list;

	if (!psd)
		return;

	INIT_LIST_HEAD(&list);

	spin_lock_irq(&psd->lock);

	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
		list_move(&ce->node, &list);

	spin_unlock_irq(&psd->lock);

	dev_pm_put_subsys_data(dev);

	list_for_each_entry_safe_reverse(ce, c, &list, node) {
		list_del(&ce->node);
		__pm_clk_remove(ce);
	}
}

/**
 * pm_clk_suspend - Disable clocks in a device's PM clock list.
 * @dev: Device to disable the clocks for.
 */
int pm_clk_suspend(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

	dev_dbg(dev, "%s()\n", __func__);

	if (!psd)
		return 0;

	spin_lock_irqsave(&psd->lock, flags);

	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
		if (ce->status < PCE_STATUS_ERROR) {
			if (ce->status == PCE_STATUS_ENABLED)
				clk_disable(ce->clk);
			ce->status = PCE_STATUS_ACQUIRED;
		}
	}

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

/**
 * pm_clk_resume - Enable clocks in a device's PM clock list.
 * @dev: Device to enable the clocks for.
 */
int pm_clk_resume(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

	dev_dbg(dev, "%s()\n", __func__);

	if (!psd)
		return 0;

	spin_lock_irqsave(&psd->lock, flags);

	list_for_each_entry(ce, &psd->clock_list, node)
		__pm_clk_enable(dev, ce);

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

/**
 * pm_clk_notify - Notify routine for device addition and removal.
 * @nb: Notifier block object this function is a member of.
 * @action: Operation being carried out by the caller.
 * @data: Device the routine is being run for.
 *
 * For this function to work, @nb must be a member of an object of type
 * struct pm_clk_notifier_block containing all of the requisite data.
 * Specifically, the pm_domain member of that object is copied to the device's
 * pm_domain field and its con_ids member is used to populate the device's list
 * of PM clocks, depending on @action.
 *
 * If the device's pm_domain field is already populated with a value different
 * from the one stored in the struct pm_clk_notifier_block object, the function
 * does nothing.
 */
static int pm_clk_notify(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct pm_clk_notifier_block *clknb;
	struct device *dev = data;
	char **con_id;
	int error;

	dev_dbg(dev, "%s() %ld\n", __func__, action);

	clknb = container_of(nb, struct pm_clk_notifier_block, nb);

	switch (action) {
	case BUS_NOTIFY_ADD_DEVICE:
		if (dev->pm_domain)
			break;

		error = pm_clk_create(dev);
		if (error)
			break;

		dev->pm_domain = clknb->pm_domain;
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				pm_clk_add(dev, *con_id);
		} else {
			pm_clk_add(dev, NULL);
		}

		break;
	case BUS_NOTIFY_DEL_DEVICE:
		if (dev->pm_domain != clknb->pm_domain)
			break;

		dev->pm_domain = NULL;
		pm_clk_destroy(dev);
		break;
	}

	return 0;
}

#else /* !CONFIG_PM */

/**
 * enable_clock - Enable a device clock.
 * @dev: Device whose clock is to be enabled.
 * @con_id: Connection ID of the clock.
 */
static void enable_clock(struct device *dev, const char *con_id)
{
	struct clk *clk;

	clk = clk_get(dev, con_id);
	if (!IS_ERR(clk)) {
		clk_prepare_enable(clk);
		clk_put(clk);
		dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	}
}

/**
 * disable_clock - Disable a device clock.
 * @dev: Device whose clock is to be disabled.
 * @con_id: Connection ID of the clock.
 */
static void disable_clock(struct device *dev, const char *con_id)
{
	struct clk *clk;

	clk = clk_get(dev, con_id);
	if (!IS_ERR(clk)) {
		clk_disable_unprepare(clk);
		clk_put(clk);
		dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	}
}

/**
 * pm_clk_notify - Notify routine for device addition and removal.
 * @nb: Notifier block object this function is a member of.
 * @action: Operation being carried out by the caller.
 * @data: Device the routine is being run for.
 *
 * For this function to work, @nb must be a member of an object of type
 * struct pm_clk_notifier_block containing all of the requisite data.
 * Specifically, the con_ids member of that object is used to enable or disable
 * the device's clocks, depending on @action.
 */
static int pm_clk_notify(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct pm_clk_notifier_block *clknb;
	struct device *dev = data;
	char **con_id;

	dev_dbg(dev, "%s() %ld\n", __func__, action);

	clknb = container_of(nb, struct pm_clk_notifier_block, nb);

	switch (action) {
	case BUS_NOTIFY_BIND_DRIVER:
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				enable_clock(dev, *con_id);
		} else {
			enable_clock(dev, NULL);
		}
		break;
	case BUS_NOTIFY_UNBOUND_DRIVER:
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				disable_clock(dev, *con_id);
		} else {
			disable_clock(dev, NULL);
		}
		break;
	}

	return 0;
}

#endif /* !CONFIG_PM */

/**
 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
 * @bus: Bus type to add the notifier to.
 * @clknb: Notifier to be added to the given bus type.
 *
 * The nb member of @clknb is not expected to be initialized and its
 * notifier_call member will be replaced with pm_clk_notify().  However,
 * the remaining members of @clknb should be populated prior to calling this
 * routine.
 */
void pm_clk_add_notifier(struct bus_type *bus,
				 struct pm_clk_notifier_block *clknb)
{
	if (!bus || !clknb)
		return;

	clknb->nb.notifier_call = pm_clk_notify;
	bus_register_notifier(bus, &clknb->nb);
}
Commit	Line	Data
85eb8c8d RW	1	/*
	2	* drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
	3	*
	4	* Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
	5	*
	6	* This file is released under the GPLv2.
	7	*/
	8
85eb8c8d	9	#include <linux/kernel.h>
51990e82	10	#include <linux/device.h>
85eb8c8d RW	11	#include <linux/io.h>
85eb8c8d RW	12	#include <linux/pm.h>
b5e8d269	13	#include <linux/pm_clock.h>
85eb8c8d	14	#include <linux/clk.h>
245bd6f6	15	#include <linux/clkdev.h>
85eb8c8d RW	16	#include <linux/slab.h>
	17	#include <linux/err.h>
	18
b7b95920	19	#ifdef CONFIG_PM
85eb8c8d	20
85eb8c8d RW	21	enum pce_status {
	22	PCE_STATUS_NONE = 0,
	23	PCE_STATUS_ACQUIRED,
	24	PCE_STATUS_ENABLED,
	25	PCE_STATUS_ERROR,
	26	};
	27
	28	struct pm_clock_entry {
	29	struct list_head node;
	30	char *con_id;
	31	struct clk *clk;
	32	enum pce_status status;
	33	};
	34
5cda3fbb BD	35	/**
	36	* pm_clk_enable - Enable a clock, reporting any errors
	37	* @dev: The device for the given clock
471f7707	38	* @ce: PM clock entry corresponding to the clock.
5cda3fbb	39	*/
471f7707	40	static inline int __pm_clk_enable(struct device dev, struct pm_clock_entry ce)
5cda3fbb	41	{
471f7707 SG	42	int ret;
	43
	44	if (ce->status < PCE_STATUS_ERROR) {
	45	ret = clk_enable(ce->clk);
	46	if (!ret)
	47	ce->status = PCE_STATUS_ENABLED;
	48	else
	49	dev_err(dev, "%s: failed to enable clk %p, error %d\n",
	50	__func__, ce->clk, ret);
	51	}
5cda3fbb BD	52
	53	return ret;
	54	}
	55
e8b364b8 RW	56	/**
	57	* pm_clk_acquire - Acquire a device clock.
	58	* @dev: Device whose clock is to be acquired.
	59	* @ce: PM clock entry corresponding to the clock.
	60	*/
	61	static void pm_clk_acquire(struct device dev, struct pm_clock_entry ce)
	62	{
245bd6f6 GU	63	if (!ce->clk)
245bd6f6 GU	64	ce->clk = clk_get(dev, ce->con_id);
e8b364b8 RW	65	if (IS_ERR(ce->clk)) {
	66	ce->status = PCE_STATUS_ERROR;
	67	} else {
8a6720ec	68	clk_prepare(ce->clk);
e8b364b8 RW	69	ce->status = PCE_STATUS_ACQUIRED;
	70	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	71	}
	72	}
	73
245bd6f6 GU	74	static int __pm_clk_add(struct device dev, const char con_id,
245bd6f6 GU	75	struct clk *clk)
85eb8c8d	76	{
5c095a0e	77	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	78	struct pm_clock_entry *ce;
85eb8c8d RW	79
5c095a0e	80	if (!psd)
85eb8c8d RW	81	return -EINVAL;
	82
	83	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
59d84ca8	84	if (!ce)
85eb8c8d	85	return -ENOMEM;
85eb8c8d RW	86
	87	if (con_id) {
	88	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	89	if (!ce->con_id) {
	90	dev_err(dev,
	91	"Not enough memory for clock connection ID.\n");
	92	kfree(ce);
	93	return -ENOMEM;
	94	}
245bd6f6 GU	95	} else {
	96	if (IS_ERR(ce->clk) \|\| !__clk_get(clk)) {
	97	kfree(ce);
	98	return -ENOENT;
	99	}
	100	ce->clk = clk;
85eb8c8d RW	101	}
85eb8c8d RW	102
e8b364b8 RW	103	pm_clk_acquire(dev, ce);
e8b364b8 RW	104
5c095a0e RW	105	spin_lock_irq(&psd->lock);
	106	list_add_tail(&ce->node, &psd->clock_list);
	107	spin_unlock_irq(&psd->lock);
85eb8c8d RW	108	return 0;
	109	}
	110
245bd6f6 GU	111	/**
	112	* pm_clk_add - Start using a device clock for power management.
	113	* @dev: Device whose clock is going to be used for power management.
	114	* @con_id: Connection ID of the clock.
	115	*
	116	* Add the clock represented by @con_id to the list of clocks used for
	117	* the power management of @dev.
	118	*/
	119	int pm_clk_add(struct device dev, const char con_id)
	120	{
	121	return __pm_clk_add(dev, con_id, NULL);
	122	}
	123
	124	/**
	125	* pm_clk_add_clk - Start using a device clock for power management.
	126	* @dev: Device whose clock is going to be used for power management.
	127	* @clk: Clock pointer
	128	*
	129	* Add the clock to the list of clocks used for the power management of @dev.
	130	* It will increment refcount on clock pointer, use clk_put() on it when done.
	131	*/
	132	int pm_clk_add_clk(struct device dev, struct clk clk)
	133	{
	134	return __pm_clk_add(dev, NULL, clk);
	135	}
	136
85eb8c8d	137	/**
3d5c3036 RW	138	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	139	* @ce: PM clock entry to destroy.
85eb8c8d	140	*/
3d5c3036	141	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	142	{
	143	if (!ce)
	144	return;
	145
85eb8c8d RW	146	if (ce->status < PCE_STATUS_ERROR) {
85eb8c8d RW	147	if (ce->status == PCE_STATUS_ENABLED)
8a6720ec	148	clk_disable(ce->clk);
85eb8c8d	149
8a6720ec BD	150	if (ce->status >= PCE_STATUS_ACQUIRED) {
8a6720ec BD	151	clk_unprepare(ce->clk);
85eb8c8d	152	clk_put(ce->clk);
8a6720ec	153	}
85eb8c8d RW	154	}
85eb8c8d RW	155
0ab1e79b	156	kfree(ce->con_id);
85eb8c8d RW	157	kfree(ce);
	158	}
	159
	160	/**
3d5c3036 RW	161	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	162	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	163	* @con_id: Connection ID of the clock.
	164	*
	165	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	166	* the power management of @dev.
85eb8c8d	167	*/
3d5c3036	168	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	169	{
5c095a0e	170	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	171	struct pm_clock_entry *ce;
85eb8c8d RW	172
5c095a0e	173	if (!psd)
85eb8c8d RW	174	return;
85eb8c8d RW	175
5c095a0e	176	spin_lock_irq(&psd->lock);
85eb8c8d	177
5c095a0e	178	list_for_each_entry(ce, &psd->clock_list, node) {
e8b364b8 RW	179	if (!con_id && !ce->con_id)
	180	goto remove;
	181	else if (!con_id \|\| !ce->con_id)
85eb8c8d	182	continue;
e8b364b8 RW	183	else if (!strcmp(con_id, ce->con_id))
e8b364b8 RW	184	goto remove;
85eb8c8d RW	185	}
85eb8c8d RW	186
5c095a0e	187	spin_unlock_irq(&psd->lock);
e8b364b8 RW	188	return;
	189
	190	remove:
	191	list_del(&ce->node);
0d41da2e	192	spin_unlock_irq(&psd->lock);
e8b364b8 RW	193
e8b364b8 RW	194	__pm_clk_remove(ce);
85eb8c8d RW	195	}
	196
	197	/**
3d5c3036 RW	198	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	199	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	200	*
5c095a0e RW	201	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	202	* object.
85eb8c8d	203	*/
5c095a0e	204	void pm_clk_init(struct device *dev)
85eb8c8d	205	{
5c095a0e	206	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	207	if (psd)
ef27bed1 RW	208	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	209	}
	210
	211	/**
	212	* pm_clk_create - Create and initialize a device's list of PM clocks.
	213	* @dev: Device to create and initialize the list of PM clocks for.
	214	*
	215	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	216	* members and make the @dev's power.subsys_data field point to it.
	217	*/
	218	int pm_clk_create(struct device *dev)
	219	{
77254950	220	return dev_pm_get_subsys_data(dev);
85eb8c8d RW	221	}
	222
	223	/**
3d5c3036 RW	224	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	225	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	226	*
85eb8c8d RW	227	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	228	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	229	* that object.
85eb8c8d RW	230	*/
3d5c3036	231	void pm_clk_destroy(struct device *dev)
85eb8c8d	232	{
5c095a0e	233	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	234	struct pm_clock_entry ce, c;
e8b364b8	235	struct list_head list;
85eb8c8d	236
5c095a0e	237	if (!psd)
85eb8c8d RW	238	return;
85eb8c8d RW	239
e8b364b8	240	INIT_LIST_HEAD(&list);
85eb8c8d	241
5c095a0e	242	spin_lock_irq(&psd->lock);
85eb8c8d	243
5c095a0e	244	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
e8b364b8	245	list_move(&ce->node, &list);
85eb8c8d	246
5c095a0e	247	spin_unlock_irq(&psd->lock);
85eb8c8d	248
ef27bed1	249	dev_pm_put_subsys_data(dev);
e8b364b8 RW	250
	251	list_for_each_entry_safe_reverse(ce, c, &list, node) {
	252	list_del(&ce->node);
	253	__pm_clk_remove(ce);
	254	}
85eb8c8d RW	255	}
85eb8c8d RW	256
85eb8c8d	257	/**
3d5c3036	258	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	259	* @dev: Device to disable the clocks for.
85eb8c8d RW	260	*/
3d5c3036	261	int pm_clk_suspend(struct device *dev)
85eb8c8d	262	{
5c095a0e	263	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	264	struct pm_clock_entry *ce;
b7ab83ed	265	unsigned long flags;
85eb8c8d RW	266
	267	dev_dbg(dev, "%s()\n", __func__);
	268
5c095a0e	269	if (!psd)
85eb8c8d RW	270	return 0;
85eb8c8d RW	271
5c095a0e	272	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	273
5c095a0e	274	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	275	if (ce->status < PCE_STATUS_ERROR) {
24050956 MD	276	if (ce->status == PCE_STATUS_ENABLED)
24050956 MD	277	clk_disable(ce->clk);
85eb8c8d RW	278	ce->status = PCE_STATUS_ACQUIRED;
	279	}
	280	}
	281
5c095a0e	282	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	283
	284	return 0;
	285	}
	286
	287	/**
3d5c3036	288	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	289	* @dev: Device to enable the clocks for.
85eb8c8d RW	290	*/
3d5c3036	291	int pm_clk_resume(struct device *dev)
85eb8c8d	292	{
5c095a0e	293	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	294	struct pm_clock_entry *ce;
b7ab83ed	295	unsigned long flags;
85eb8c8d RW	296
	297	dev_dbg(dev, "%s()\n", __func__);
	298
5c095a0e	299	if (!psd)
85eb8c8d RW	300	return 0;
85eb8c8d RW	301
5c095a0e	302	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	303
471f7707 SG	304	list_for_each_entry(ce, &psd->clock_list, node)
471f7707 SG	305	__pm_clk_enable(dev, ce);
85eb8c8d	306
5c095a0e	307	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	308
	309	return 0;
	310	}
	311
	312	/**
3d5c3036	313	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	314	* @nb: Notifier block object this function is a member of.
	315	* @action: Operation being carried out by the caller.
	316	* @data: Device the routine is being run for.
	317	*
	318	* For this function to work, @nb must be a member of an object of type
	319	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	320	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	321	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	322	* of PM clocks, depending on @action.
85eb8c8d	323	*
564b905a	324	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	325	* from the one stored in the struct pm_clk_notifier_block object, the function
	326	* does nothing.
	327	*/
3d5c3036	328	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	329	unsigned long action, void *data)
	330	{
	331	struct pm_clk_notifier_block *clknb;
	332	struct device *dev = data;
3b3eca31	333	char **con_id;
85eb8c8d RW	334	int error;
	335
	336	dev_dbg(dev, "%s() %ld\n", __func__, action);
	337
	338	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	339
	340	switch (action) {
	341	case BUS_NOTIFY_ADD_DEVICE:
564b905a	342	if (dev->pm_domain)
85eb8c8d RW	343	break;
85eb8c8d RW	344
5c095a0e	345	error = pm_clk_create(dev);
85eb8c8d RW	346	if (error)
	347	break;
	348
564b905a	349	dev->pm_domain = clknb->pm_domain;
85eb8c8d	350	if (clknb->con_ids[0]) {
3b3eca31	351	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	352	pm_clk_add(dev, *con_id);
85eb8c8d	353	} else {
3d5c3036	354	pm_clk_add(dev, NULL);
85eb8c8d RW	355	}
	356
	357	break;
	358	case BUS_NOTIFY_DEL_DEVICE:
564b905a	359	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	360	break;
85eb8c8d RW	361
564b905a	362	dev->pm_domain = NULL;
3d5c3036	363	pm_clk_destroy(dev);
85eb8c8d RW	364	break;
	365	}
	366
	367	return 0;
	368	}
	369
d30d819d	370	#else /* !CONFIG_PM */
b7b95920	371
85eb8c8d RW	372	/**
	373	* enable_clock - Enable a device clock.
	374	* @dev: Device whose clock is to be enabled.
	375	* @con_id: Connection ID of the clock.
	376	*/
	377	static void enable_clock(struct device dev, const char con_id)
	378	{
	379	struct clk *clk;
	380
	381	clk = clk_get(dev, con_id);
	382	if (!IS_ERR(clk)) {
c122f27e	383	clk_prepare_enable(clk);
85eb8c8d RW	384	clk_put(clk);
	385	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	386	}
	387	}
	388
	389	/**
	390	* disable_clock - Disable a device clock.
	391	* @dev: Device whose clock is to be disabled.
	392	* @con_id: Connection ID of the clock.
	393	*/
	394	static void disable_clock(struct device dev, const char con_id)
	395	{
	396	struct clk *clk;
	397
	398	clk = clk_get(dev, con_id);
	399	if (!IS_ERR(clk)) {
c122f27e	400	clk_disable_unprepare(clk);
85eb8c8d RW	401	clk_put(clk);
	402	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	403	}
	404	}
	405
	406	/**
3d5c3036	407	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	408	* @nb: Notifier block object this function is a member of.
	409	* @action: Operation being carried out by the caller.
	410	* @data: Device the routine is being run for.
	411	*
	412	* For this function to work, @nb must be a member of an object of type
	413	* struct pm_clk_notifier_block containing all of the requisite data.
	414	* Specifically, the con_ids member of that object is used to enable or disable
	415	* the device's clocks, depending on @action.
	416	*/
3d5c3036	417	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	418	unsigned long action, void *data)
	419	{
	420	struct pm_clk_notifier_block *clknb;
	421	struct device *dev = data;
3b3eca31	422	char **con_id;
85eb8c8d RW	423
	424	dev_dbg(dev, "%s() %ld\n", __func__, action);
	425
	426	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	427
	428	switch (action) {
4d1518f5	429	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	430	if (clknb->con_ids[0]) {
3b3eca31 RW	431	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	432	enable_clock(dev, *con_id);
85eb8c8d RW	433	} else {
	434	enable_clock(dev, NULL);
	435	}
	436	break;
4d1518f5	437	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	438	if (clknb->con_ids[0]) {
3b3eca31 RW	439	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	440	disable_clock(dev, *con_id);
85eb8c8d RW	441	} else {
	442	disable_clock(dev, NULL);
	443	}
	444	break;
	445	}
	446
	447	return 0;
	448	}
	449
d30d819d	450	#endif /* !CONFIG_PM */
85eb8c8d RW	451
85eb8c8d RW	452	/**
3d5c3036	453	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	454	* @bus: Bus type to add the notifier to.
	455	* @clknb: Notifier to be added to the given bus type.
	456	*
	457	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	458	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	459	* the remaining members of @clknb should be populated prior to calling this
	460	* routine.
	461	*/
3d5c3036	462	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	463	struct pm_clk_notifier_block *clknb)
	464	{
	465	if (!bus \|\| !clknb)
	466	return;
	467
3d5c3036	468	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	469	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	470	}