[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/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm.h>
#include <linux/pm_clock.h>
#include <linux/clk.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_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)
{
	ce->clk = clk_get(dev, ce->con_id);
	if (IS_ERR(ce->clk)) {
		ce->status = PCE_STATUS_ERROR;
	} else {
		ce->status = PCE_STATUS_ACQUIRED;
		dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	}
}

/**
 * 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)
{
	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) {
		dev_err(dev, "Not enough memory for clock entry.\n");
		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;
		}
	}

	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_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_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)
{
	int ret = dev_pm_get_subsys_data(dev);
	return ret < 0 ? ret : 0;
}

/**
 * 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);
	}
}

#endif /* CONFIG_PM */

#ifdef CONFIG_PM_RUNTIME

/**
 * 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) {
		if (ce->status < PCE_STATUS_ERROR) {
			clk_enable(ce->clk);
			ce->status = PCE_STATUS_ENABLED;
		}
	}

	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_RUNTIME */

#ifdef CONFIG_PM

/**
 * 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 there is no driver, the clocks are already disabled. */
	if (!psd || !dev->driver)
		return 0;

	spin_lock_irqsave(&psd->lock, flags);

	list_for_each_entry_reverse(ce, &psd->clock_list, node)
		clk_disable(ce->clk);

	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 there is no driver, the clocks should remain disabled. */
	if (!psd || !dev->driver)
		return 0;

	spin_lock_irqsave(&psd->lock, flags);

	list_for_each_entry(ce, &psd->clock_list, node)
		clk_enable(ce->clk);

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

#endif /* 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_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(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_RUNTIME */

/**
 * 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
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/io.h>
	12	#include <linux/pm.h>
b5e8d269	13	#include <linux/pm_clock.h>
85eb8c8d RW	14	#include <linux/clk.h>
	15	#include <linux/slab.h>
	16	#include <linux/err.h>
	17
b7b95920	18	#ifdef CONFIG_PM
85eb8c8d	19
85eb8c8d RW	20	enum pce_status {
	21	PCE_STATUS_NONE = 0,
	22	PCE_STATUS_ACQUIRED,
	23	PCE_STATUS_ENABLED,
	24	PCE_STATUS_ERROR,
	25	};
	26
	27	struct pm_clock_entry {
	28	struct list_head node;
	29	char *con_id;
	30	struct clk *clk;
	31	enum pce_status status;
	32	};
	33
e8b364b8 RW	34	/**
	35	* pm_clk_acquire - Acquire a device clock.
	36	* @dev: Device whose clock is to be acquired.
	37	* @ce: PM clock entry corresponding to the clock.
	38	*/
	39	static void pm_clk_acquire(struct device dev, struct pm_clock_entry ce)
	40	{
	41	ce->clk = clk_get(dev, ce->con_id);
	42	if (IS_ERR(ce->clk)) {
	43	ce->status = PCE_STATUS_ERROR;
	44	} else {
	45	ce->status = PCE_STATUS_ACQUIRED;
	46	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	47	}
	48	}
	49
85eb8c8d	50	/**
3d5c3036 RW	51	* pm_clk_add - Start using a device clock for power management.
3d5c3036 RW	52	* @dev: Device whose clock is going to be used for power management.
85eb8c8d RW	53	* @con_id: Connection ID of the clock.
	54	*
	55	* Add the clock represented by @con_id to the list of clocks used for
3d5c3036	56	* the power management of @dev.
85eb8c8d	57	*/
3d5c3036	58	int pm_clk_add(struct device dev, const char con_id)
85eb8c8d	59	{
5c095a0e	60	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	61	struct pm_clock_entry *ce;
85eb8c8d RW	62
5c095a0e	63	if (!psd)
85eb8c8d RW	64	return -EINVAL;
	65
	66	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
	67	if (!ce) {
	68	dev_err(dev, "Not enough memory for clock entry.\n");
	69	return -ENOMEM;
	70	}
	71
	72	if (con_id) {
	73	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	74	if (!ce->con_id) {
	75	dev_err(dev,
	76	"Not enough memory for clock connection ID.\n");
	77	kfree(ce);
	78	return -ENOMEM;
	79	}
	80	}
	81
e8b364b8 RW	82	pm_clk_acquire(dev, ce);
e8b364b8 RW	83
5c095a0e RW	84	spin_lock_irq(&psd->lock);
	85	list_add_tail(&ce->node, &psd->clock_list);
	86	spin_unlock_irq(&psd->lock);
85eb8c8d RW	87	return 0;
	88	}
	89
	90	/**
3d5c3036 RW	91	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	92	* @ce: PM clock entry to destroy.
85eb8c8d	93	*/
3d5c3036	94	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	95	{
	96	if (!ce)
	97	return;
	98
85eb8c8d RW	99	if (ce->status < PCE_STATUS_ERROR) {
	100	if (ce->status == PCE_STATUS_ENABLED)
	101	clk_disable(ce->clk);
	102
	103	if (ce->status >= PCE_STATUS_ACQUIRED)
	104	clk_put(ce->clk);
	105	}
	106
0ab1e79b	107	kfree(ce->con_id);
85eb8c8d RW	108	kfree(ce);
	109	}
	110
	111	/**
3d5c3036 RW	112	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	113	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	114	* @con_id: Connection ID of the clock.
	115	*
	116	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	117	* the power management of @dev.
85eb8c8d	118	*/
3d5c3036	119	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	120	{
5c095a0e	121	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	122	struct pm_clock_entry *ce;
85eb8c8d RW	123
5c095a0e	124	if (!psd)
85eb8c8d RW	125	return;
85eb8c8d RW	126
5c095a0e	127	spin_lock_irq(&psd->lock);
85eb8c8d	128
5c095a0e	129	list_for_each_entry(ce, &psd->clock_list, node) {
e8b364b8 RW	130	if (!con_id && !ce->con_id)
	131	goto remove;
	132	else if (!con_id \|\| !ce->con_id)
85eb8c8d	133	continue;
e8b364b8 RW	134	else if (!strcmp(con_id, ce->con_id))
e8b364b8 RW	135	goto remove;
85eb8c8d RW	136	}
85eb8c8d RW	137
5c095a0e	138	spin_unlock_irq(&psd->lock);
e8b364b8 RW	139	return;
	140
	141	remove:
	142	list_del(&ce->node);
0d41da2e	143	spin_unlock_irq(&psd->lock);
e8b364b8 RW	144
e8b364b8 RW	145	__pm_clk_remove(ce);
85eb8c8d RW	146	}
	147
	148	/**
3d5c3036 RW	149	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	150	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	151	*
5c095a0e RW	152	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	153	* object.
85eb8c8d	154	*/
5c095a0e	155	void pm_clk_init(struct device *dev)
85eb8c8d	156	{
5c095a0e	157	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	158	if (psd)
ef27bed1 RW	159	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	160	}
	161
	162	/**
	163	* pm_clk_create - Create and initialize a device's list of PM clocks.
	164	* @dev: Device to create and initialize the list of PM clocks for.
	165	*
	166	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	167	* members and make the @dev's power.subsys_data field point to it.
	168	*/
	169	int pm_clk_create(struct device *dev)
	170	{
ef27bed1 RW	171	int ret = dev_pm_get_subsys_data(dev);
ef27bed1 RW	172	return ret < 0 ? ret : 0;
85eb8c8d RW	173	}
	174
	175	/**
3d5c3036 RW	176	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	177	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	178	*
85eb8c8d RW	179	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	180	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	181	* that object.
85eb8c8d RW	182	*/
3d5c3036	183	void pm_clk_destroy(struct device *dev)
85eb8c8d	184	{
5c095a0e	185	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	186	struct pm_clock_entry ce, c;
e8b364b8	187	struct list_head list;
85eb8c8d	188
5c095a0e	189	if (!psd)
85eb8c8d RW	190	return;
85eb8c8d RW	191
e8b364b8	192	INIT_LIST_HEAD(&list);
85eb8c8d	193
5c095a0e	194	spin_lock_irq(&psd->lock);
85eb8c8d	195
5c095a0e	196	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
e8b364b8	197	list_move(&ce->node, &list);
85eb8c8d	198
5c095a0e	199	spin_unlock_irq(&psd->lock);
85eb8c8d	200
ef27bed1	201	dev_pm_put_subsys_data(dev);
e8b364b8 RW	202
	203	list_for_each_entry_safe_reverse(ce, c, &list, node) {
	204	list_del(&ce->node);
	205	__pm_clk_remove(ce);
	206	}
85eb8c8d RW	207	}
85eb8c8d RW	208
b7b95920 RW	209	#endif /* CONFIG_PM */
	210
	211	#ifdef CONFIG_PM_RUNTIME
	212
85eb8c8d	213	/**
3d5c3036	214	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	215	* @dev: Device to disable the clocks for.
85eb8c8d RW	216	*/
3d5c3036	217	int pm_clk_suspend(struct device *dev)
85eb8c8d	218	{
5c095a0e	219	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	220	struct pm_clock_entry *ce;
b7ab83ed	221	unsigned long flags;
85eb8c8d RW	222
	223	dev_dbg(dev, "%s()\n", __func__);
	224
5c095a0e	225	if (!psd)
85eb8c8d RW	226	return 0;
85eb8c8d RW	227
5c095a0e	228	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	229
5c095a0e	230	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	231	if (ce->status < PCE_STATUS_ERROR) {
24050956 MD	232	if (ce->status == PCE_STATUS_ENABLED)
24050956 MD	233	clk_disable(ce->clk);
85eb8c8d RW	234	ce->status = PCE_STATUS_ACQUIRED;
	235	}
	236	}
	237
5c095a0e	238	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	239
	240	return 0;
	241	}
	242
	243	/**
3d5c3036	244	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	245	* @dev: Device to enable the clocks for.
85eb8c8d RW	246	*/
3d5c3036	247	int pm_clk_resume(struct device *dev)
85eb8c8d	248	{
5c095a0e	249	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	250	struct pm_clock_entry *ce;
b7ab83ed	251	unsigned long flags;
85eb8c8d RW	252
	253	dev_dbg(dev, "%s()\n", __func__);
	254
5c095a0e	255	if (!psd)
85eb8c8d RW	256	return 0;
85eb8c8d RW	257
5c095a0e	258	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	259
5c095a0e	260	list_for_each_entry(ce, &psd->clock_list, node) {
85eb8c8d RW	261	if (ce->status < PCE_STATUS_ERROR) {
	262	clk_enable(ce->clk);
	263	ce->status = PCE_STATUS_ENABLED;
	264	}
	265	}
	266
5c095a0e	267	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	268
	269	return 0;
	270	}
	271
	272	/**
3d5c3036	273	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	274	* @nb: Notifier block object this function is a member of.
	275	* @action: Operation being carried out by the caller.
	276	* @data: Device the routine is being run for.
	277	*
	278	* For this function to work, @nb must be a member of an object of type
	279	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	280	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	281	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	282	* of PM clocks, depending on @action.
85eb8c8d	283	*
564b905a	284	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	285	* from the one stored in the struct pm_clk_notifier_block object, the function
	286	* does nothing.
	287	*/
3d5c3036	288	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	289	unsigned long action, void *data)
	290	{
	291	struct pm_clk_notifier_block *clknb;
	292	struct device *dev = data;
3b3eca31	293	char **con_id;
85eb8c8d RW	294	int error;
	295
	296	dev_dbg(dev, "%s() %ld\n", __func__, action);
	297
	298	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	299
	300	switch (action) {
	301	case BUS_NOTIFY_ADD_DEVICE:
564b905a	302	if (dev->pm_domain)
85eb8c8d RW	303	break;
85eb8c8d RW	304
5c095a0e	305	error = pm_clk_create(dev);
85eb8c8d RW	306	if (error)
	307	break;
	308
564b905a	309	dev->pm_domain = clknb->pm_domain;
85eb8c8d	310	if (clknb->con_ids[0]) {
3b3eca31	311	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	312	pm_clk_add(dev, *con_id);
85eb8c8d	313	} else {
3d5c3036	314	pm_clk_add(dev, NULL);
85eb8c8d RW	315	}
	316
	317	break;
	318	case BUS_NOTIFY_DEL_DEVICE:
564b905a	319	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	320	break;
85eb8c8d RW	321
564b905a	322	dev->pm_domain = NULL;
3d5c3036	323	pm_clk_destroy(dev);
85eb8c8d RW	324	break;
	325	}
	326
	327	return 0;
	328	}
	329
	330	#else /* !CONFIG_PM_RUNTIME */
	331
b7b95920 RW	332	#ifdef CONFIG_PM
	333
	334	/**
3d5c3036	335	* pm_clk_suspend - Disable clocks in a device's PM clock list.
b7b95920 RW	336	* @dev: Device to disable the clocks for.
b7b95920 RW	337	*/
3d5c3036	338	int pm_clk_suspend(struct device *dev)
b7b95920	339	{
5c095a0e	340	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	341	struct pm_clock_entry *ce;
b7ab83ed	342	unsigned long flags;
b7b95920 RW	343
	344	dev_dbg(dev, "%s()\n", __func__);
	345
	346	/* If there is no driver, the clocks are already disabled. */
5c095a0e	347	if (!psd \|\| !dev->driver)
b7b95920 RW	348	return 0;
b7b95920 RW	349
5c095a0e	350	spin_lock_irqsave(&psd->lock, flags);
b7b95920	351
5c095a0e	352	list_for_each_entry_reverse(ce, &psd->clock_list, node)
b7b95920 RW	353	clk_disable(ce->clk);
b7b95920 RW	354
5c095a0e	355	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	356
	357	return 0;
	358	}
	359
	360	/**
3d5c3036	361	* pm_clk_resume - Enable clocks in a device's PM clock list.
b7b95920 RW	362	* @dev: Device to enable the clocks for.
b7b95920 RW	363	*/
3d5c3036	364	int pm_clk_resume(struct device *dev)
b7b95920	365	{
5c095a0e	366	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	367	struct pm_clock_entry *ce;
b7ab83ed	368	unsigned long flags;
b7b95920 RW	369
	370	dev_dbg(dev, "%s()\n", __func__);
	371
	372	/* If there is no driver, the clocks should remain disabled. */
5c095a0e	373	if (!psd \|\| !dev->driver)
b7b95920 RW	374	return 0;
b7b95920 RW	375
5c095a0e	376	spin_lock_irqsave(&psd->lock, flags);
b7b95920	377
5c095a0e	378	list_for_each_entry(ce, &psd->clock_list, node)
b7b95920 RW	379	clk_enable(ce->clk);
b7b95920 RW	380
5c095a0e	381	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	382
	383	return 0;
	384	}
	385
	386	#endif /* CONFIG_PM */
	387
85eb8c8d RW	388	/**
	389	* enable_clock - Enable a device clock.
	390	* @dev: Device whose clock is to be enabled.
	391	* @con_id: Connection ID of the clock.
	392	*/
	393	static void enable_clock(struct device dev, const char con_id)
	394	{
	395	struct clk *clk;
	396
	397	clk = clk_get(dev, con_id);
	398	if (!IS_ERR(clk)) {
	399	clk_enable(clk);
	400	clk_put(clk);
	401	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	402	}
	403	}
	404
	405	/**
	406	* disable_clock - Disable a device clock.
	407	* @dev: Device whose clock is to be disabled.
	408	* @con_id: Connection ID of the clock.
	409	*/
	410	static void disable_clock(struct device dev, const char con_id)
	411	{
	412	struct clk *clk;
	413
	414	clk = clk_get(dev, con_id);
	415	if (!IS_ERR(clk)) {
	416	clk_disable(clk);
	417	clk_put(clk);
	418	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	419	}
	420	}
	421
	422	/**
3d5c3036	423	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	424	* @nb: Notifier block object this function is a member of.
	425	* @action: Operation being carried out by the caller.
	426	* @data: Device the routine is being run for.
	427	*
	428	* For this function to work, @nb must be a member of an object of type
	429	* struct pm_clk_notifier_block containing all of the requisite data.
	430	* Specifically, the con_ids member of that object is used to enable or disable
	431	* the device's clocks, depending on @action.
	432	*/
3d5c3036	433	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	434	unsigned long action, void *data)
	435	{
	436	struct pm_clk_notifier_block *clknb;
	437	struct device *dev = data;
3b3eca31	438	char **con_id;
85eb8c8d RW	439
	440	dev_dbg(dev, "%s() %ld\n", __func__, action);
	441
	442	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	443
	444	switch (action) {
4d1518f5	445	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	446	if (clknb->con_ids[0]) {
3b3eca31 RW	447	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	448	enable_clock(dev, *con_id);
85eb8c8d RW	449	} else {
	450	enable_clock(dev, NULL);
	451	}
	452	break;
4d1518f5	453	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	454	if (clknb->con_ids[0]) {
3b3eca31 RW	455	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	456	disable_clock(dev, *con_id);
85eb8c8d RW	457	} else {
	458	disable_clock(dev, NULL);
	459	}
	460	break;
	461	}
	462
	463	return 0;
	464	}
	465
	466	#endif /* !CONFIG_PM_RUNTIME */
	467
	468	/**
3d5c3036	469	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	470	* @bus: Bus type to add the notifier to.
	471	* @clknb: Notifier to be added to the given bus type.
	472	*
	473	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	474	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	475	* the remaining members of @clknb should be populated prior to calling this
	476	* routine.
	477	*/
3d5c3036	478	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	479	struct pm_clk_notifier_block *clknb)
	480	{
	481	if (!bus \|\| !clknb)
	482	return;
	483
3d5c3036	484	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	485	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	486	}