[deliverable/linux.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/device.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_enable - Enable a clock, reporting any errors
 * @dev: The device for the given clock
 * @clk: The clock being enabled.
 */
static inline int __pm_clk_enable(struct device *dev, struct clk *clk)
{
	int ret = clk_enable(clk);
	if (ret)
		dev_err(dev, "%s: failed to enable clk %p, error %d\n",
			__func__, 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)
{
	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);
	}
}

/**
 * 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_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);
	}
}

#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;
	int ret;

	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) {
			ret = __pm_clk_enable(dev, ce->clk);
			if (!ret)
				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)
		__pm_clk_enable(dev, 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_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_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>
51990e82	11	#include <linux/device.h>
85eb8c8d RW	12	#include <linux/io.h>
85eb8c8d RW	13	#include <linux/pm.h>
b5e8d269	14	#include <linux/pm_clock.h>
85eb8c8d RW	15	#include <linux/clk.h>
	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
	38	* @clk: The clock being enabled.
	39	*/
	40	static inline int __pm_clk_enable(struct device dev, struct clk clk)
	41	{
	42	int ret = clk_enable(clk);
	43	if (ret)
	44	dev_err(dev, "%s: failed to enable clk %p, error %d\n",
	45	__func__, clk, ret);
	46
	47	return ret;
	48	}
	49
e8b364b8 RW	50	/**
	51	* pm_clk_acquire - Acquire a device clock.
	52	* @dev: Device whose clock is to be acquired.
	53	* @ce: PM clock entry corresponding to the clock.
	54	*/
	55	static void pm_clk_acquire(struct device dev, struct pm_clock_entry ce)
	56	{
	57	ce->clk = clk_get(dev, ce->con_id);
	58	if (IS_ERR(ce->clk)) {
	59	ce->status = PCE_STATUS_ERROR;
	60	} else {
8a6720ec	61	clk_prepare(ce->clk);
e8b364b8 RW	62	ce->status = PCE_STATUS_ACQUIRED;
	63	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	64	}
	65	}
	66
85eb8c8d	67	/**
3d5c3036 RW	68	* pm_clk_add - Start using a device clock for power management.
3d5c3036 RW	69	* @dev: Device whose clock is going to be used for power management.
85eb8c8d RW	70	* @con_id: Connection ID of the clock.
	71	*
	72	* Add the clock represented by @con_id to the list of clocks used for
3d5c3036	73	* the power management of @dev.
85eb8c8d	74	*/
3d5c3036	75	int pm_clk_add(struct device dev, const char con_id)
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);
	84	if (!ce) {
	85	dev_err(dev, "Not enough memory for clock entry.\n");
	86	return -ENOMEM;
	87	}
	88
	89	if (con_id) {
	90	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	91	if (!ce->con_id) {
	92	dev_err(dev,
	93	"Not enough memory for clock connection ID.\n");
	94	kfree(ce);
	95	return -ENOMEM;
	96	}
	97	}
	98
e8b364b8 RW	99	pm_clk_acquire(dev, ce);
e8b364b8 RW	100
5c095a0e RW	101	spin_lock_irq(&psd->lock);
	102	list_add_tail(&ce->node, &psd->clock_list);
	103	spin_unlock_irq(&psd->lock);
85eb8c8d RW	104	return 0;
	105	}
	106
	107	/**
3d5c3036 RW	108	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	109	* @ce: PM clock entry to destroy.
85eb8c8d	110	*/
3d5c3036	111	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	112	{
	113	if (!ce)
	114	return;
	115
85eb8c8d RW	116	if (ce->status < PCE_STATUS_ERROR) {
85eb8c8d RW	117	if (ce->status == PCE_STATUS_ENABLED)
8a6720ec	118	clk_disable(ce->clk);
85eb8c8d	119
8a6720ec BD	120	if (ce->status >= PCE_STATUS_ACQUIRED) {
8a6720ec BD	121	clk_unprepare(ce->clk);
85eb8c8d	122	clk_put(ce->clk);
8a6720ec	123	}
85eb8c8d RW	124	}
85eb8c8d RW	125
0ab1e79b	126	kfree(ce->con_id);
85eb8c8d RW	127	kfree(ce);
	128	}
	129
	130	/**
3d5c3036 RW	131	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	132	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	133	* @con_id: Connection ID of the clock.
	134	*
	135	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	136	* the power management of @dev.
85eb8c8d	137	*/
3d5c3036	138	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	139	{
5c095a0e	140	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	141	struct pm_clock_entry *ce;
85eb8c8d RW	142
5c095a0e	143	if (!psd)
85eb8c8d RW	144	return;
85eb8c8d RW	145
5c095a0e	146	spin_lock_irq(&psd->lock);
85eb8c8d	147
5c095a0e	148	list_for_each_entry(ce, &psd->clock_list, node) {
e8b364b8 RW	149	if (!con_id && !ce->con_id)
	150	goto remove;
	151	else if (!con_id \|\| !ce->con_id)
85eb8c8d	152	continue;
e8b364b8 RW	153	else if (!strcmp(con_id, ce->con_id))
e8b364b8 RW	154	goto remove;
85eb8c8d RW	155	}
85eb8c8d RW	156
5c095a0e	157	spin_unlock_irq(&psd->lock);
e8b364b8 RW	158	return;
	159
	160	remove:
	161	list_del(&ce->node);
0d41da2e	162	spin_unlock_irq(&psd->lock);
e8b364b8 RW	163
e8b364b8 RW	164	__pm_clk_remove(ce);
85eb8c8d RW	165	}
	166
	167	/**
3d5c3036 RW	168	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	169	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	170	*
5c095a0e RW	171	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	172	* object.
85eb8c8d	173	*/
5c095a0e	174	void pm_clk_init(struct device *dev)
85eb8c8d	175	{
5c095a0e	176	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	177	if (psd)
ef27bed1 RW	178	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	179	}
	180
	181	/**
	182	* pm_clk_create - Create and initialize a device's list of PM clocks.
	183	* @dev: Device to create and initialize the list of PM clocks for.
	184	*
	185	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	186	* members and make the @dev's power.subsys_data field point to it.
	187	*/
	188	int pm_clk_create(struct device *dev)
	189	{
77254950	190	return dev_pm_get_subsys_data(dev);
85eb8c8d RW	191	}
	192
	193	/**
3d5c3036 RW	194	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	195	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	196	*
85eb8c8d RW	197	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	198	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	199	* that object.
85eb8c8d RW	200	*/
3d5c3036	201	void pm_clk_destroy(struct device *dev)
85eb8c8d	202	{
5c095a0e	203	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	204	struct pm_clock_entry ce, c;
e8b364b8	205	struct list_head list;
85eb8c8d	206
5c095a0e	207	if (!psd)
85eb8c8d RW	208	return;
85eb8c8d RW	209
e8b364b8	210	INIT_LIST_HEAD(&list);
85eb8c8d	211
5c095a0e	212	spin_lock_irq(&psd->lock);
85eb8c8d	213
5c095a0e	214	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
e8b364b8	215	list_move(&ce->node, &list);
85eb8c8d	216
5c095a0e	217	spin_unlock_irq(&psd->lock);
85eb8c8d	218
ef27bed1	219	dev_pm_put_subsys_data(dev);
e8b364b8 RW	220
	221	list_for_each_entry_safe_reverse(ce, c, &list, node) {
	222	list_del(&ce->node);
	223	__pm_clk_remove(ce);
	224	}
85eb8c8d RW	225	}
85eb8c8d RW	226
b7b95920 RW	227	#endif /* CONFIG_PM */
	228
	229	#ifdef CONFIG_PM_RUNTIME
	230
85eb8c8d	231	/**
3d5c3036	232	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	233	* @dev: Device to disable the clocks for.
85eb8c8d RW	234	*/
3d5c3036	235	int pm_clk_suspend(struct device *dev)
85eb8c8d	236	{
5c095a0e	237	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	238	struct pm_clock_entry *ce;
b7ab83ed	239	unsigned long flags;
85eb8c8d RW	240
	241	dev_dbg(dev, "%s()\n", __func__);
	242
5c095a0e	243	if (!psd)
85eb8c8d RW	244	return 0;
85eb8c8d RW	245
5c095a0e	246	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	247
5c095a0e	248	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	249	if (ce->status < PCE_STATUS_ERROR) {
24050956 MD	250	if (ce->status == PCE_STATUS_ENABLED)
24050956 MD	251	clk_disable(ce->clk);
85eb8c8d RW	252	ce->status = PCE_STATUS_ACQUIRED;
	253	}
	254	}
	255
5c095a0e	256	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	257
	258	return 0;
	259	}
	260
	261	/**
3d5c3036	262	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	263	* @dev: Device to enable the clocks for.
85eb8c8d RW	264	*/
3d5c3036	265	int pm_clk_resume(struct device *dev)
85eb8c8d	266	{
5c095a0e	267	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	268	struct pm_clock_entry *ce;
b7ab83ed	269	unsigned long flags;
afdd3ab3	270	int ret;
85eb8c8d RW	271
	272	dev_dbg(dev, "%s()\n", __func__);
	273
5c095a0e	274	if (!psd)
85eb8c8d RW	275	return 0;
85eb8c8d RW	276
5c095a0e	277	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	278
5c095a0e	279	list_for_each_entry(ce, &psd->clock_list, node) {
85eb8c8d	280	if (ce->status < PCE_STATUS_ERROR) {
5cda3fbb	281	ret = __pm_clk_enable(dev, ce->clk);
afdd3ab3 BD	282	if (!ret)
afdd3ab3 BD	283	ce->status = PCE_STATUS_ENABLED;
85eb8c8d RW	284	}
	285	}
	286
5c095a0e	287	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	288
	289	return 0;
	290	}
	291
	292	/**
3d5c3036	293	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	294	* @nb: Notifier block object this function is a member of.
	295	* @action: Operation being carried out by the caller.
	296	* @data: Device the routine is being run for.
	297	*
	298	* For this function to work, @nb must be a member of an object of type
	299	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	300	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	301	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	302	* of PM clocks, depending on @action.
85eb8c8d	303	*
564b905a	304	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	305	* from the one stored in the struct pm_clk_notifier_block object, the function
	306	* does nothing.
	307	*/
3d5c3036	308	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	309	unsigned long action, void *data)
	310	{
	311	struct pm_clk_notifier_block *clknb;
	312	struct device *dev = data;
3b3eca31	313	char **con_id;
85eb8c8d RW	314	int error;
	315
	316	dev_dbg(dev, "%s() %ld\n", __func__, action);
	317
	318	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	319
	320	switch (action) {
	321	case BUS_NOTIFY_ADD_DEVICE:
564b905a	322	if (dev->pm_domain)
85eb8c8d RW	323	break;
85eb8c8d RW	324
5c095a0e	325	error = pm_clk_create(dev);
85eb8c8d RW	326	if (error)
	327	break;
	328
564b905a	329	dev->pm_domain = clknb->pm_domain;
85eb8c8d	330	if (clknb->con_ids[0]) {
3b3eca31	331	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	332	pm_clk_add(dev, *con_id);
85eb8c8d	333	} else {
3d5c3036	334	pm_clk_add(dev, NULL);
85eb8c8d RW	335	}
	336
	337	break;
	338	case BUS_NOTIFY_DEL_DEVICE:
564b905a	339	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	340	break;
85eb8c8d RW	341
564b905a	342	dev->pm_domain = NULL;
3d5c3036	343	pm_clk_destroy(dev);
85eb8c8d RW	344	break;
	345	}
	346
	347	return 0;
	348	}
	349
	350	#else /* !CONFIG_PM_RUNTIME */
	351
b7b95920 RW	352	#ifdef CONFIG_PM
	353
	354	/**
3d5c3036	355	* pm_clk_suspend - Disable clocks in a device's PM clock list.
b7b95920 RW	356	* @dev: Device to disable the clocks for.
b7b95920 RW	357	*/
3d5c3036	358	int pm_clk_suspend(struct device *dev)
b7b95920	359	{
5c095a0e	360	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	361	struct pm_clock_entry *ce;
b7ab83ed	362	unsigned long flags;
b7b95920 RW	363
	364	dev_dbg(dev, "%s()\n", __func__);
	365
	366	/* If there is no driver, the clocks are already disabled. */
5c095a0e	367	if (!psd \|\| !dev->driver)
b7b95920 RW	368	return 0;
b7b95920 RW	369
5c095a0e	370	spin_lock_irqsave(&psd->lock, flags);
b7b95920	371
5c095a0e	372	list_for_each_entry_reverse(ce, &psd->clock_list, node)
b7b95920 RW	373	clk_disable(ce->clk);
b7b95920 RW	374
5c095a0e	375	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	376
	377	return 0;
	378	}
	379
	380	/**
3d5c3036	381	* pm_clk_resume - Enable clocks in a device's PM clock list.
b7b95920 RW	382	* @dev: Device to enable the clocks for.
b7b95920 RW	383	*/
3d5c3036	384	int pm_clk_resume(struct device *dev)
b7b95920	385	{
5c095a0e	386	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	387	struct pm_clock_entry *ce;
b7ab83ed	388	unsigned long flags;
b7b95920 RW	389
	390	dev_dbg(dev, "%s()\n", __func__);
	391
	392	/* If there is no driver, the clocks should remain disabled. */
5c095a0e	393	if (!psd \|\| !dev->driver)
b7b95920 RW	394	return 0;
b7b95920 RW	395
5c095a0e	396	spin_lock_irqsave(&psd->lock, flags);
b7b95920	397
5c095a0e	398	list_for_each_entry(ce, &psd->clock_list, node)
5cda3fbb	399	__pm_clk_enable(dev, ce->clk);
b7b95920	400
5c095a0e	401	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	402
	403	return 0;
	404	}
	405
	406	#endif /* CONFIG_PM */
	407
85eb8c8d RW	408	/**
	409	* enable_clock - Enable a device clock.
	410	* @dev: Device whose clock is to be enabled.
	411	* @con_id: Connection ID of the clock.
	412	*/
	413	static void enable_clock(struct device dev, const char con_id)
	414	{
	415	struct clk *clk;
	416
	417	clk = clk_get(dev, con_id);
	418	if (!IS_ERR(clk)) {
c122f27e	419	clk_prepare_enable(clk);
85eb8c8d RW	420	clk_put(clk);
	421	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	422	}
	423	}
	424
	425	/**
	426	* disable_clock - Disable a device clock.
	427	* @dev: Device whose clock is to be disabled.
	428	* @con_id: Connection ID of the clock.
	429	*/
	430	static void disable_clock(struct device dev, const char con_id)
	431	{
	432	struct clk *clk;
	433
	434	clk = clk_get(dev, con_id);
	435	if (!IS_ERR(clk)) {
c122f27e	436	clk_disable_unprepare(clk);
85eb8c8d RW	437	clk_put(clk);
	438	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	439	}
	440	}
	441
	442	/**
3d5c3036	443	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	444	* @nb: Notifier block object this function is a member of.
	445	* @action: Operation being carried out by the caller.
	446	* @data: Device the routine is being run for.
	447	*
	448	* For this function to work, @nb must be a member of an object of type
	449	* struct pm_clk_notifier_block containing all of the requisite data.
	450	* Specifically, the con_ids member of that object is used to enable or disable
	451	* the device's clocks, depending on @action.
	452	*/
3d5c3036	453	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	454	unsigned long action, void *data)
	455	{
	456	struct pm_clk_notifier_block *clknb;
	457	struct device *dev = data;
3b3eca31	458	char **con_id;
85eb8c8d RW	459
	460	dev_dbg(dev, "%s() %ld\n", __func__, action);
	461
	462	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	463
	464	switch (action) {
4d1518f5	465	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	466	if (clknb->con_ids[0]) {
3b3eca31 RW	467	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	468	enable_clock(dev, *con_id);
85eb8c8d RW	469	} else {
	470	enable_clock(dev, NULL);
	471	}
	472	break;
4d1518f5	473	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	474	if (clknb->con_ids[0]) {
3b3eca31 RW	475	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	476	disable_clock(dev, *con_id);
85eb8c8d RW	477	} else {
	478	disable_clock(dev, NULL);
	479	}
	480	break;
	481	}
	482
	483	return 0;
	484	}
	485
	486	#endif /* !CONFIG_PM_RUNTIME */
	487
	488	/**
3d5c3036	489	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	490	* @bus: Bus type to add the notifier to.
	491	* @clknb: Notifier to be added to the given bus type.
	492	*
	493	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	494	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	495	* the remaining members of @clknb should be populated prior to calling this
	496	* routine.
	497	*/
3d5c3036	498	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	499	struct pm_clk_notifier_block *clknb)
	500	{
	501	if (!bus \|\| !clknb)
	502	return;
	503
3d5c3036	504	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	505	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	506	}