[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/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) {
		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;
		}
	} 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);
	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	}
245bd6f6 GU	97	} else {
	98	if (IS_ERR(ce->clk) \|\| !__clk_get(clk)) {
	99	kfree(ce);
	100	return -ENOENT;
	101	}
	102	ce->clk = clk;
85eb8c8d RW	103	}
85eb8c8d RW	104
e8b364b8 RW	105	pm_clk_acquire(dev, ce);
e8b364b8 RW	106
5c095a0e RW	107	spin_lock_irq(&psd->lock);
	108	list_add_tail(&ce->node, &psd->clock_list);
	109	spin_unlock_irq(&psd->lock);
85eb8c8d RW	110	return 0;
	111	}
	112
245bd6f6 GU	113	/**
	114	* pm_clk_add - Start using a device clock for power management.
	115	* @dev: Device whose clock is going to be used for power management.
	116	* @con_id: Connection ID of the clock.
	117	*
	118	* Add the clock represented by @con_id to the list of clocks used for
	119	* the power management of @dev.
	120	*/
	121	int pm_clk_add(struct device dev, const char con_id)
	122	{
	123	return __pm_clk_add(dev, con_id, NULL);
	124	}
	125
	126	/**
	127	* pm_clk_add_clk - Start using a device clock for power management.
	128	* @dev: Device whose clock is going to be used for power management.
	129	* @clk: Clock pointer
	130	*
	131	* Add the clock to the list of clocks used for the power management of @dev.
	132	* It will increment refcount on clock pointer, use clk_put() on it when done.
	133	*/
	134	int pm_clk_add_clk(struct device dev, struct clk clk)
	135	{
	136	return __pm_clk_add(dev, NULL, clk);
	137	}
	138
85eb8c8d	139	/**
3d5c3036 RW	140	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	141	* @ce: PM clock entry to destroy.
85eb8c8d	142	*/
3d5c3036	143	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	144	{
	145	if (!ce)
	146	return;
	147
85eb8c8d RW	148	if (ce->status < PCE_STATUS_ERROR) {
85eb8c8d RW	149	if (ce->status == PCE_STATUS_ENABLED)
8a6720ec	150	clk_disable(ce->clk);
85eb8c8d	151
8a6720ec BD	152	if (ce->status >= PCE_STATUS_ACQUIRED) {
8a6720ec BD	153	clk_unprepare(ce->clk);
85eb8c8d	154	clk_put(ce->clk);
8a6720ec	155	}
85eb8c8d RW	156	}
85eb8c8d RW	157
0ab1e79b	158	kfree(ce->con_id);
85eb8c8d RW	159	kfree(ce);
	160	}
	161
	162	/**
3d5c3036 RW	163	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	164	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	165	* @con_id: Connection ID of the clock.
	166	*
	167	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	168	* the power management of @dev.
85eb8c8d	169	*/
3d5c3036	170	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	171	{
5c095a0e	172	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	173	struct pm_clock_entry *ce;
85eb8c8d RW	174
5c095a0e	175	if (!psd)
85eb8c8d RW	176	return;
85eb8c8d RW	177
5c095a0e	178	spin_lock_irq(&psd->lock);
85eb8c8d	179
5c095a0e	180	list_for_each_entry(ce, &psd->clock_list, node) {
e8b364b8 RW	181	if (!con_id && !ce->con_id)
	182	goto remove;
	183	else if (!con_id \|\| !ce->con_id)
85eb8c8d	184	continue;
e8b364b8 RW	185	else if (!strcmp(con_id, ce->con_id))
e8b364b8 RW	186	goto remove;
85eb8c8d RW	187	}
85eb8c8d RW	188
5c095a0e	189	spin_unlock_irq(&psd->lock);
e8b364b8 RW	190	return;
	191
	192	remove:
	193	list_del(&ce->node);
0d41da2e	194	spin_unlock_irq(&psd->lock);
e8b364b8 RW	195
e8b364b8 RW	196	__pm_clk_remove(ce);
85eb8c8d RW	197	}
	198
	199	/**
3d5c3036 RW	200	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	201	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	202	*
5c095a0e RW	203	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	204	* object.
85eb8c8d	205	*/
5c095a0e	206	void pm_clk_init(struct device *dev)
85eb8c8d	207	{
5c095a0e	208	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	209	if (psd)
ef27bed1 RW	210	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	211	}
	212
	213	/**
	214	* pm_clk_create - Create and initialize a device's list of PM clocks.
	215	* @dev: Device to create and initialize the list of PM clocks for.
	216	*
	217	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	218	* members and make the @dev's power.subsys_data field point to it.
	219	*/
	220	int pm_clk_create(struct device *dev)
	221	{
77254950	222	return dev_pm_get_subsys_data(dev);
85eb8c8d RW	223	}
	224
	225	/**
3d5c3036 RW	226	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	227	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	228	*
85eb8c8d RW	229	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	230	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	231	* that object.
85eb8c8d RW	232	*/
3d5c3036	233	void pm_clk_destroy(struct device *dev)
85eb8c8d	234	{
5c095a0e	235	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	236	struct pm_clock_entry ce, c;
e8b364b8	237	struct list_head list;
85eb8c8d	238
5c095a0e	239	if (!psd)
85eb8c8d RW	240	return;
85eb8c8d RW	241
e8b364b8	242	INIT_LIST_HEAD(&list);
85eb8c8d	243
5c095a0e	244	spin_lock_irq(&psd->lock);
85eb8c8d	245
5c095a0e	246	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
e8b364b8	247	list_move(&ce->node, &list);
85eb8c8d	248
5c095a0e	249	spin_unlock_irq(&psd->lock);
85eb8c8d	250
ef27bed1	251	dev_pm_put_subsys_data(dev);
e8b364b8 RW	252
	253	list_for_each_entry_safe_reverse(ce, c, &list, node) {
	254	list_del(&ce->node);
	255	__pm_clk_remove(ce);
	256	}
85eb8c8d RW	257	}
85eb8c8d RW	258
85eb8c8d	259	/**
3d5c3036	260	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	261	* @dev: Device to disable the clocks for.
85eb8c8d RW	262	*/
3d5c3036	263	int pm_clk_suspend(struct device *dev)
85eb8c8d	264	{
5c095a0e	265	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	266	struct pm_clock_entry *ce;
b7ab83ed	267	unsigned long flags;
85eb8c8d RW	268
	269	dev_dbg(dev, "%s()\n", __func__);
	270
5c095a0e	271	if (!psd)
85eb8c8d RW	272	return 0;
85eb8c8d RW	273
5c095a0e	274	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	275
5c095a0e	276	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	277	if (ce->status < PCE_STATUS_ERROR) {
24050956 MD	278	if (ce->status == PCE_STATUS_ENABLED)
24050956 MD	279	clk_disable(ce->clk);
85eb8c8d RW	280	ce->status = PCE_STATUS_ACQUIRED;
	281	}
	282	}
	283
5c095a0e	284	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	285
	286	return 0;
	287	}
	288
	289	/**
3d5c3036	290	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	291	* @dev: Device to enable the clocks for.
85eb8c8d RW	292	*/
3d5c3036	293	int pm_clk_resume(struct device *dev)
85eb8c8d	294	{
5c095a0e	295	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	296	struct pm_clock_entry *ce;
b7ab83ed	297	unsigned long flags;
85eb8c8d RW	298
	299	dev_dbg(dev, "%s()\n", __func__);
	300
5c095a0e	301	if (!psd)
85eb8c8d RW	302	return 0;
85eb8c8d RW	303
5c095a0e	304	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	305
471f7707 SG	306	list_for_each_entry(ce, &psd->clock_list, node)
471f7707 SG	307	__pm_clk_enable(dev, ce);
85eb8c8d	308
5c095a0e	309	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	310
	311	return 0;
	312	}
	313
	314	/**
3d5c3036	315	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	316	* @nb: Notifier block object this function is a member of.
	317	* @action: Operation being carried out by the caller.
	318	* @data: Device the routine is being run for.
	319	*
	320	* For this function to work, @nb must be a member of an object of type
	321	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	322	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	323	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	324	* of PM clocks, depending on @action.
85eb8c8d	325	*
564b905a	326	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	327	* from the one stored in the struct pm_clk_notifier_block object, the function
	328	* does nothing.
	329	*/
3d5c3036	330	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	331	unsigned long action, void *data)
	332	{
	333	struct pm_clk_notifier_block *clknb;
	334	struct device *dev = data;
3b3eca31	335	char **con_id;
85eb8c8d RW	336	int error;
	337
	338	dev_dbg(dev, "%s() %ld\n", __func__, action);
	339
	340	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	341
	342	switch (action) {
	343	case BUS_NOTIFY_ADD_DEVICE:
564b905a	344	if (dev->pm_domain)
85eb8c8d RW	345	break;
85eb8c8d RW	346
5c095a0e	347	error = pm_clk_create(dev);
85eb8c8d RW	348	if (error)
	349	break;
	350
564b905a	351	dev->pm_domain = clknb->pm_domain;
85eb8c8d	352	if (clknb->con_ids[0]) {
3b3eca31	353	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	354	pm_clk_add(dev, *con_id);
85eb8c8d	355	} else {
3d5c3036	356	pm_clk_add(dev, NULL);
85eb8c8d RW	357	}
	358
	359	break;
	360	case BUS_NOTIFY_DEL_DEVICE:
564b905a	361	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	362	break;
85eb8c8d RW	363
564b905a	364	dev->pm_domain = NULL;
3d5c3036	365	pm_clk_destroy(dev);
85eb8c8d RW	366	break;
	367	}
	368
	369	return 0;
	370	}
	371
d30d819d	372	#else /* !CONFIG_PM */
b7b95920	373
85eb8c8d RW	374	/**
	375	* enable_clock - Enable a device clock.
	376	* @dev: Device whose clock is to be enabled.
	377	* @con_id: Connection ID of the clock.
	378	*/
	379	static void enable_clock(struct device dev, const char con_id)
	380	{
	381	struct clk *clk;
	382
	383	clk = clk_get(dev, con_id);
	384	if (!IS_ERR(clk)) {
c122f27e	385	clk_prepare_enable(clk);
85eb8c8d RW	386	clk_put(clk);
	387	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	388	}
	389	}
	390
	391	/**
	392	* disable_clock - Disable a device clock.
	393	* @dev: Device whose clock is to be disabled.
	394	* @con_id: Connection ID of the clock.
	395	*/
	396	static void disable_clock(struct device dev, const char con_id)
	397	{
	398	struct clk *clk;
	399
	400	clk = clk_get(dev, con_id);
	401	if (!IS_ERR(clk)) {
c122f27e	402	clk_disable_unprepare(clk);
85eb8c8d RW	403	clk_put(clk);
	404	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	405	}
	406	}
	407
	408	/**
3d5c3036	409	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	410	* @nb: Notifier block object this function is a member of.
	411	* @action: Operation being carried out by the caller.
	412	* @data: Device the routine is being run for.
	413	*
	414	* For this function to work, @nb must be a member of an object of type
	415	* struct pm_clk_notifier_block containing all of the requisite data.
	416	* Specifically, the con_ids member of that object is used to enable or disable
	417	* the device's clocks, depending on @action.
	418	*/
3d5c3036	419	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	420	unsigned long action, void *data)
	421	{
	422	struct pm_clk_notifier_block *clknb;
	423	struct device *dev = data;
3b3eca31	424	char **con_id;
85eb8c8d RW	425
	426	dev_dbg(dev, "%s() %ld\n", __func__, action);
	427
	428	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	429
	430	switch (action) {
4d1518f5	431	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	432	if (clknb->con_ids[0]) {
3b3eca31 RW	433	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	434	enable_clock(dev, *con_id);
85eb8c8d RW	435	} else {
	436	enable_clock(dev, NULL);
	437	}
	438	break;
4d1518f5	439	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	440	if (clknb->con_ids[0]) {
3b3eca31 RW	441	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	442	disable_clock(dev, *con_id);
85eb8c8d RW	443	} else {
	444	disable_clock(dev, NULL);
	445	}
	446	break;
	447	}
	448
	449	return 0;
	450	}
	451
d30d819d	452	#endif /* !CONFIG_PM */
85eb8c8d RW	453
85eb8c8d RW	454	/**
3d5c3036	455	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	456	* @bus: Bus type to add the notifier to.
	457	* @clknb: Notifier to be added to the given bus type.
	458	*
	459	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	460	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	461	* the remaining members of @clknb should be populated prior to calling this
	462	* routine.
	463	*/
3d5c3036	464	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	465	struct pm_clk_notifier_block *clknb)
	466	{
	467	if (!bus \|\| !clknb)
	468	return;
	469
3d5c3036	470	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	471	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	472	}