[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_runtime.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/err.h>

#ifdef CONFIG_PM

struct pm_clk_data {
	struct list_head clock_list;
	spinlock_t lock;
};

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;
};

static struct pm_clk_data *__to_pcd(struct device *dev)
{
	return dev ? dev->power.subsys_data : NULL;
}

/**
 * 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_clk_data *pcd = __to_pcd(dev);
	struct pm_clock_entry *ce;

	if (!pcd)
		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;
		}
	}

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

/**
 * __pm_clk_remove - Destroy PM clock entry.
 * @ce: PM clock entry to destroy.
 *
 * This routine must be called under the spinlock protecting the PM list of
 * clocks corresponding the the @ce's device.
 */
static void __pm_clk_remove(struct pm_clock_entry *ce)
{
	if (!ce)
		return;

	list_del(&ce->node);

	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);
	}

	if (ce->con_id)
		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_clk_data *pcd = __to_pcd(dev);
	struct pm_clock_entry *ce;

	if (!pcd)
		return;

	spin_lock_irq(&pcd->lock);

	list_for_each_entry(ce, &pcd->clock_list, node) {
		if (!con_id && !ce->con_id) {
			__pm_clk_remove(ce);
			break;
		} else if (!con_id || !ce->con_id) {
			continue;
		} else if (!strcmp(con_id, ce->con_id)) {
			__pm_clk_remove(ce);
			break;
		}
	}

	spin_unlock_irq(&pcd->lock);
}

/**
 * pm_clk_init - Initialize a device's list of power management clocks.
 * @dev: Device to initialize the list of PM clocks for.
 *
 * Allocate a struct pm_clk_data object, initialize its lock member and
 * make the @dev's power.subsys_data field point to it.
 */
int pm_clk_init(struct device *dev)
{
	struct pm_clk_data *pcd;

	pcd = kzalloc(sizeof(*pcd), GFP_KERNEL);
	if (!pcd) {
		dev_err(dev, "Not enough memory for PM clock data.\n");
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&pcd->clock_list);
	spin_lock_init(&pcd->lock);
	dev->power.subsys_data = pcd;
	return 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_clk_data object pointed to by it before and free
 * that object.
 */
void pm_clk_destroy(struct device *dev)
{
	struct pm_clk_data *pcd = __to_pcd(dev);
	struct pm_clock_entry *ce, *c;

	if (!pcd)
		return;

	dev->power.subsys_data = NULL;

	spin_lock_irq(&pcd->lock);

	list_for_each_entry_safe_reverse(ce, c, &pcd->clock_list, node)
		__pm_clk_remove(ce);

	spin_unlock_irq(&pcd->lock);

	kfree(pcd);
}

#endif /* CONFIG_PM */

#ifdef CONFIG_PM_RUNTIME

/**
 * pm_clk_acquire - Acquire a device clock.
 * @dev: Device whose clock is to be acquired.
 * @con_id: Connection ID of 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_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_clk_data *pcd = __to_pcd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

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

	if (!pcd)
		return 0;

	spin_lock_irqsave(&pcd->lock, flags);

	list_for_each_entry_reverse(ce, &pcd->clock_list, node) {
		if (ce->status == PCE_STATUS_NONE)
			pm_clk_acquire(dev, ce);

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

	spin_unlock_irqrestore(&pcd->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_clk_data *pcd = __to_pcd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

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

	if (!pcd)
		return 0;

	spin_lock_irqsave(&pcd->lock, flags);

	list_for_each_entry(ce, &pcd->clock_list, node) {
		if (ce->status == PCE_STATUS_NONE)
			pm_clk_acquire(dev, ce);

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

	spin_unlock_irqrestore(&pcd->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_init(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_clk_data *pcd = __to_pcd(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 (!pcd || !dev->driver)
		return 0;

	spin_lock_irqsave(&pcd->lock, flags);

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

	spin_unlock_irqrestore(&pcd->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_clk_data *pcd = __to_pcd(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 (!pcd || !dev->driver)
		return 0;

	spin_lock_irqsave(&pcd->lock, flags);

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

	spin_unlock_irqrestore(&pcd->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>
	13	#include <linux/pm_runtime.h>
	14	#include <linux/clk.h>
	15	#include <linux/slab.h>
	16	#include <linux/err.h>
	17
b7b95920	18	#ifdef CONFIG_PM
85eb8c8d	19
3d5c3036	20	struct pm_clk_data {
85eb8c8d	21	struct list_head clock_list;
b7ab83ed	22	spinlock_t lock;
85eb8c8d RW	23	};
	24
	25	enum pce_status {
	26	PCE_STATUS_NONE = 0,
	27	PCE_STATUS_ACQUIRED,
	28	PCE_STATUS_ENABLED,
	29	PCE_STATUS_ERROR,
	30	};
	31
	32	struct pm_clock_entry {
	33	struct list_head node;
	34	char *con_id;
	35	struct clk *clk;
	36	enum pce_status status;
	37	};
	38
3d5c3036	39	static struct pm_clk_data __to_pcd(struct device dev)
85eb8c8d RW	40	{
	41	return dev ? dev->power.subsys_data : NULL;
	42	}
	43
	44	/**
3d5c3036 RW	45	* pm_clk_add - Start using a device clock for power management.
3d5c3036 RW	46	* @dev: Device whose clock is going to be used for power management.
85eb8c8d RW	47	* @con_id: Connection ID of the clock.
	48	*
	49	* Add the clock represented by @con_id to the list of clocks used for
3d5c3036	50	* the power management of @dev.
85eb8c8d	51	*/
3d5c3036	52	int pm_clk_add(struct device dev, const char con_id)
85eb8c8d	53	{
3d5c3036	54	struct pm_clk_data *pcd = __to_pcd(dev);
85eb8c8d RW	55	struct pm_clock_entry *ce;
85eb8c8d RW	56
3d5c3036	57	if (!pcd)
85eb8c8d RW	58	return -EINVAL;
	59
	60	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
	61	if (!ce) {
	62	dev_err(dev, "Not enough memory for clock entry.\n");
	63	return -ENOMEM;
	64	}
	65
	66	if (con_id) {
	67	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	68	if (!ce->con_id) {
	69	dev_err(dev,
	70	"Not enough memory for clock connection ID.\n");
	71	kfree(ce);
	72	return -ENOMEM;
	73	}
	74	}
	75
b7ab83ed	76	spin_lock_irq(&pcd->lock);
3d5c3036	77	list_add_tail(&ce->node, &pcd->clock_list);
b7ab83ed	78	spin_unlock_irq(&pcd->lock);
85eb8c8d RW	79	return 0;
	80	}
	81
	82	/**
3d5c3036 RW	83	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	84	* @ce: PM clock entry to destroy.
85eb8c8d	85	*
b7ab83ed RW	86	* This routine must be called under the spinlock protecting the PM list of
b7ab83ed RW	87	* clocks corresponding the the @ce's device.
85eb8c8d	88	*/
3d5c3036	89	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	90	{
	91	if (!ce)
	92	return;
	93
	94	list_del(&ce->node);
	95
	96	if (ce->status < PCE_STATUS_ERROR) {
	97	if (ce->status == PCE_STATUS_ENABLED)
	98	clk_disable(ce->clk);
	99
	100	if (ce->status >= PCE_STATUS_ACQUIRED)
	101	clk_put(ce->clk);
	102	}
	103
	104	if (ce->con_id)
	105	kfree(ce->con_id);
	106
	107	kfree(ce);
	108	}
	109
	110	/**
3d5c3036 RW	111	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	112	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	113	* @con_id: Connection ID of the clock.
	114	*
	115	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	116	* the power management of @dev.
85eb8c8d	117	*/
3d5c3036	118	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	119	{
3d5c3036	120	struct pm_clk_data *pcd = __to_pcd(dev);
85eb8c8d RW	121	struct pm_clock_entry *ce;
85eb8c8d RW	122
3d5c3036	123	if (!pcd)
85eb8c8d RW	124	return;
85eb8c8d RW	125
b7ab83ed	126	spin_lock_irq(&pcd->lock);
85eb8c8d	127
3d5c3036	128	list_for_each_entry(ce, &pcd->clock_list, node) {
85eb8c8d	129	if (!con_id && !ce->con_id) {
3d5c3036	130	__pm_clk_remove(ce);
85eb8c8d RW	131	break;
	132	} else if (!con_id \|\| !ce->con_id) {
	133	continue;
	134	} else if (!strcmp(con_id, ce->con_id)) {
3d5c3036	135	__pm_clk_remove(ce);
85eb8c8d RW	136	break;
	137	}
	138	}
	139
b7ab83ed	140	spin_unlock_irq(&pcd->lock);
85eb8c8d RW	141	}
	142
	143	/**
3d5c3036 RW	144	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	145	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	146	*
3d5c3036	147	* Allocate a struct pm_clk_data object, initialize its lock member and
85eb8c8d RW	148	* make the @dev's power.subsys_data field point to it.
85eb8c8d RW	149	*/
3d5c3036	150	int pm_clk_init(struct device *dev)
85eb8c8d	151	{
3d5c3036	152	struct pm_clk_data *pcd;
85eb8c8d	153
3d5c3036 RW	154	pcd = kzalloc(sizeof(*pcd), GFP_KERNEL);
	155	if (!pcd) {
	156	dev_err(dev, "Not enough memory for PM clock data.\n");
85eb8c8d RW	157	return -ENOMEM;
	158	}
	159
3d5c3036	160	INIT_LIST_HEAD(&pcd->clock_list);
b7ab83ed	161	spin_lock_init(&pcd->lock);
3d5c3036	162	dev->power.subsys_data = pcd;
85eb8c8d RW	163	return 0;
	164	}
	165
	166	/**
3d5c3036 RW	167	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	168	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	169	*
85eb8c8d RW	170	* Clear the @dev's power.subsys_data field, remove the list of clock entries
3d5c3036	171	* from the struct pm_clk_data object pointed to by it before and free
85eb8c8d RW	172	* that object.
85eb8c8d RW	173	*/
3d5c3036	174	void pm_clk_destroy(struct device *dev)
85eb8c8d	175	{
3d5c3036	176	struct pm_clk_data *pcd = __to_pcd(dev);
85eb8c8d RW	177	struct pm_clock_entry ce, c;
85eb8c8d RW	178
3d5c3036	179	if (!pcd)
85eb8c8d RW	180	return;
	181
	182	dev->power.subsys_data = NULL;
	183
b7ab83ed	184	spin_lock_irq(&pcd->lock);
85eb8c8d	185
3d5c3036 RW	186	list_for_each_entry_safe_reverse(ce, c, &pcd->clock_list, node)
3d5c3036 RW	187	__pm_clk_remove(ce);
85eb8c8d	188
b7ab83ed	189	spin_unlock_irq(&pcd->lock);
85eb8c8d	190
3d5c3036	191	kfree(pcd);
85eb8c8d RW	192	}
85eb8c8d RW	193
b7b95920 RW	194	#endif /* CONFIG_PM */
	195
	196	#ifdef CONFIG_PM_RUNTIME
	197
85eb8c8d	198	/**
3d5c3036	199	* pm_clk_acquire - Acquire a device clock.
85eb8c8d RW	200	* @dev: Device whose clock is to be acquired.
	201	* @con_id: Connection ID of the clock.
	202	*/
3d5c3036	203	static void pm_clk_acquire(struct device *dev,
85eb8c8d RW	204	struct pm_clock_entry *ce)
	205	{
	206	ce->clk = clk_get(dev, ce->con_id);
	207	if (IS_ERR(ce->clk)) {
	208	ce->status = PCE_STATUS_ERROR;
	209	} else {
	210	ce->status = PCE_STATUS_ACQUIRED;
	211	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	212	}
	213	}
	214
	215	/**
3d5c3036	216	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	217	* @dev: Device to disable the clocks for.
85eb8c8d RW	218	*/
3d5c3036	219	int pm_clk_suspend(struct device *dev)
85eb8c8d	220	{
3d5c3036	221	struct pm_clk_data *pcd = __to_pcd(dev);
85eb8c8d	222	struct pm_clock_entry *ce;
b7ab83ed	223	unsigned long flags;
85eb8c8d RW	224
	225	dev_dbg(dev, "%s()\n", __func__);
	226
3d5c3036	227	if (!pcd)
85eb8c8d RW	228	return 0;
85eb8c8d RW	229
b7ab83ed	230	spin_lock_irqsave(&pcd->lock, flags);
85eb8c8d	231
3d5c3036	232	list_for_each_entry_reverse(ce, &pcd->clock_list, node) {
85eb8c8d	233	if (ce->status == PCE_STATUS_NONE)
3d5c3036	234	pm_clk_acquire(dev, ce);
85eb8c8d RW	235
	236	if (ce->status < PCE_STATUS_ERROR) {
	237	clk_disable(ce->clk);
	238	ce->status = PCE_STATUS_ACQUIRED;
	239	}
	240	}
	241
b7ab83ed	242	spin_unlock_irqrestore(&pcd->lock, flags);
85eb8c8d RW	243
	244	return 0;
	245	}
	246
	247	/**
3d5c3036	248	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	249	* @dev: Device to enable the clocks for.
85eb8c8d RW	250	*/
3d5c3036	251	int pm_clk_resume(struct device *dev)
85eb8c8d	252	{
3d5c3036	253	struct pm_clk_data *pcd = __to_pcd(dev);
85eb8c8d	254	struct pm_clock_entry *ce;
b7ab83ed	255	unsigned long flags;
85eb8c8d RW	256
	257	dev_dbg(dev, "%s()\n", __func__);
	258
3d5c3036	259	if (!pcd)
85eb8c8d RW	260	return 0;
85eb8c8d RW	261
b7ab83ed	262	spin_lock_irqsave(&pcd->lock, flags);
85eb8c8d	263
3d5c3036	264	list_for_each_entry(ce, &pcd->clock_list, node) {
85eb8c8d	265	if (ce->status == PCE_STATUS_NONE)
3d5c3036	266	pm_clk_acquire(dev, ce);
85eb8c8d RW	267
	268	if (ce->status < PCE_STATUS_ERROR) {
	269	clk_enable(ce->clk);
	270	ce->status = PCE_STATUS_ENABLED;
	271	}
	272	}
	273
b7ab83ed	274	spin_unlock_irqrestore(&pcd->lock, flags);
85eb8c8d RW	275
	276	return 0;
	277	}
	278
	279	/**
3d5c3036	280	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	281	* @nb: Notifier block object this function is a member of.
	282	* @action: Operation being carried out by the caller.
	283	* @data: Device the routine is being run for.
	284	*
	285	* For this function to work, @nb must be a member of an object of type
	286	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	287	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	288	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	289	* of PM clocks, depending on @action.
85eb8c8d	290	*
564b905a	291	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	292	* from the one stored in the struct pm_clk_notifier_block object, the function
	293	* does nothing.
	294	*/
3d5c3036	295	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	296	unsigned long action, void *data)
	297	{
	298	struct pm_clk_notifier_block *clknb;
	299	struct device *dev = data;
3b3eca31	300	char **con_id;
85eb8c8d RW	301	int error;
	302
	303	dev_dbg(dev, "%s() %ld\n", __func__, action);
	304
	305	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	306
	307	switch (action) {
	308	case BUS_NOTIFY_ADD_DEVICE:
564b905a	309	if (dev->pm_domain)
85eb8c8d RW	310	break;
85eb8c8d RW	311
3d5c3036	312	error = pm_clk_init(dev);
85eb8c8d RW	313	if (error)
	314	break;
	315
564b905a	316	dev->pm_domain = clknb->pm_domain;
85eb8c8d	317	if (clknb->con_ids[0]) {
3b3eca31	318	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	319	pm_clk_add(dev, *con_id);
85eb8c8d	320	} else {
3d5c3036	321	pm_clk_add(dev, NULL);
85eb8c8d RW	322	}
	323
	324	break;
	325	case BUS_NOTIFY_DEL_DEVICE:
564b905a	326	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	327	break;
85eb8c8d RW	328
564b905a	329	dev->pm_domain = NULL;
3d5c3036	330	pm_clk_destroy(dev);
85eb8c8d RW	331	break;
	332	}
	333
	334	return 0;
	335	}
	336
	337	#else /* !CONFIG_PM_RUNTIME */
	338
b7b95920 RW	339	#ifdef CONFIG_PM
	340
	341	/**
3d5c3036	342	* pm_clk_suspend - Disable clocks in a device's PM clock list.
b7b95920 RW	343	* @dev: Device to disable the clocks for.
b7b95920 RW	344	*/
3d5c3036	345	int pm_clk_suspend(struct device *dev)
b7b95920	346	{
3d5c3036	347	struct pm_clk_data *pcd = __to_pcd(dev);
b7b95920	348	struct pm_clock_entry *ce;
b7ab83ed	349	unsigned long flags;
b7b95920 RW	350
	351	dev_dbg(dev, "%s()\n", __func__);
	352
	353	/* If there is no driver, the clocks are already disabled. */
3d5c3036	354	if (!pcd \|\| !dev->driver)
b7b95920 RW	355	return 0;
b7b95920 RW	356
b7ab83ed	357	spin_lock_irqsave(&pcd->lock, flags);
b7b95920	358
3d5c3036	359	list_for_each_entry_reverse(ce, &pcd->clock_list, node)
b7b95920 RW	360	clk_disable(ce->clk);
b7b95920 RW	361
b7ab83ed	362	spin_unlock_irqrestore(&pcd->lock, flags);
b7b95920 RW	363
	364	return 0;
	365	}
	366
	367	/**
3d5c3036	368	* pm_clk_resume - Enable clocks in a device's PM clock list.
b7b95920 RW	369	* @dev: Device to enable the clocks for.
b7b95920 RW	370	*/
3d5c3036	371	int pm_clk_resume(struct device *dev)
b7b95920	372	{
3d5c3036	373	struct pm_clk_data *pcd = __to_pcd(dev);
b7b95920	374	struct pm_clock_entry *ce;
b7ab83ed	375	unsigned long flags;
b7b95920 RW	376
	377	dev_dbg(dev, "%s()\n", __func__);
	378
	379	/* If there is no driver, the clocks should remain disabled. */
3d5c3036	380	if (!pcd \|\| !dev->driver)
b7b95920 RW	381	return 0;
b7b95920 RW	382
b7ab83ed	383	spin_lock_irqsave(&pcd->lock, flags);
b7b95920	384
3d5c3036	385	list_for_each_entry(ce, &pcd->clock_list, node)
b7b95920 RW	386	clk_enable(ce->clk);
b7b95920 RW	387
b7ab83ed	388	spin_unlock_irqrestore(&pcd->lock, flags);
b7b95920 RW	389
	390	return 0;
	391	}
	392
	393	#endif /* CONFIG_PM */
	394
85eb8c8d RW	395	/**
	396	* enable_clock - Enable a device clock.
	397	* @dev: Device whose clock is to be enabled.
	398	* @con_id: Connection ID of the clock.
	399	*/
	400	static void enable_clock(struct device dev, const char con_id)
	401	{
	402	struct clk *clk;
	403
	404	clk = clk_get(dev, con_id);
	405	if (!IS_ERR(clk)) {
	406	clk_enable(clk);
	407	clk_put(clk);
	408	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	409	}
	410	}
	411
	412	/**
	413	* disable_clock - Disable a device clock.
	414	* @dev: Device whose clock is to be disabled.
	415	* @con_id: Connection ID of the clock.
	416	*/
	417	static void disable_clock(struct device dev, const char con_id)
	418	{
	419	struct clk *clk;
	420
	421	clk = clk_get(dev, con_id);
	422	if (!IS_ERR(clk)) {
	423	clk_disable(clk);
	424	clk_put(clk);
	425	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	426	}
	427	}
	428
	429	/**
3d5c3036	430	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	431	* @nb: Notifier block object this function is a member of.
	432	* @action: Operation being carried out by the caller.
	433	* @data: Device the routine is being run for.
	434	*
	435	* For this function to work, @nb must be a member of an object of type
	436	* struct pm_clk_notifier_block containing all of the requisite data.
	437	* Specifically, the con_ids member of that object is used to enable or disable
	438	* the device's clocks, depending on @action.
	439	*/
3d5c3036	440	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	441	unsigned long action, void *data)
	442	{
	443	struct pm_clk_notifier_block *clknb;
	444	struct device *dev = data;
3b3eca31	445	char **con_id;
85eb8c8d RW	446
	447	dev_dbg(dev, "%s() %ld\n", __func__, action);
	448
	449	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	450
	451	switch (action) {
4d1518f5	452	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	453	if (clknb->con_ids[0]) {
3b3eca31 RW	454	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	455	enable_clock(dev, *con_id);
85eb8c8d RW	456	} else {
	457	enable_clock(dev, NULL);
	458	}
	459	break;
4d1518f5	460	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	461	if (clknb->con_ids[0]) {
3b3eca31 RW	462	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	463	disable_clock(dev, *con_id);
85eb8c8d RW	464	} else {
	465	disable_clock(dev, NULL);
	466	}
	467	break;
	468	}
	469
	470	return 0;
	471	}
	472
	473	#endif /* !CONFIG_PM_RUNTIME */
	474
	475	/**
3d5c3036	476	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	477	* @bus: Bus type to add the notifier to.
	478	* @clknb: Notifier to be added to the given bus type.
	479	*
	480	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	481	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	482	* the remaining members of @clknb should be populated prior to calling this
	483	* routine.
	484	*/
3d5c3036	485	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	486	struct pm_clk_notifier_block *clknb)
	487	{
	488	if (!bus \|\| !clknb)
	489	return;
	490
3d5c3036	491	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	492	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	493	}