[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_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 = clk_enable(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)
		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_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
e8b364b8 RW	35	/**
	36	* pm_clk_acquire - Acquire a device clock.
	37	* @dev: Device whose clock is to be acquired.
	38	* @ce: PM clock entry corresponding to the clock.
	39	*/
	40	static void pm_clk_acquire(struct device dev, struct pm_clock_entry ce)
	41	{
	42	ce->clk = clk_get(dev, ce->con_id);
	43	if (IS_ERR(ce->clk)) {
	44	ce->status = PCE_STATUS_ERROR;
	45	} else {
8a6720ec	46	clk_prepare(ce->clk);
e8b364b8 RW	47	ce->status = PCE_STATUS_ACQUIRED;
	48	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	49	}
	50	}
	51
85eb8c8d	52	/**
3d5c3036 RW	53	* pm_clk_add - Start using a device clock for power management.
3d5c3036 RW	54	* @dev: Device whose clock is going to be used for power management.
85eb8c8d RW	55	* @con_id: Connection ID of the clock.
	56	*
	57	* Add the clock represented by @con_id to the list of clocks used for
3d5c3036	58	* the power management of @dev.
85eb8c8d	59	*/
3d5c3036	60	int pm_clk_add(struct device dev, const char con_id)
85eb8c8d	61	{
5c095a0e	62	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	63	struct pm_clock_entry *ce;
85eb8c8d RW	64
5c095a0e	65	if (!psd)
85eb8c8d RW	66	return -EINVAL;
	67
	68	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
	69	if (!ce) {
	70	dev_err(dev, "Not enough memory for clock entry.\n");
	71	return -ENOMEM;
	72	}
	73
	74	if (con_id) {
	75	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	76	if (!ce->con_id) {
	77	dev_err(dev,
	78	"Not enough memory for clock connection ID.\n");
	79	kfree(ce);
	80	return -ENOMEM;
	81	}
	82	}
	83
e8b364b8 RW	84	pm_clk_acquire(dev, ce);
e8b364b8 RW	85
5c095a0e RW	86	spin_lock_irq(&psd->lock);
	87	list_add_tail(&ce->node, &psd->clock_list);
	88	spin_unlock_irq(&psd->lock);
85eb8c8d RW	89	return 0;
	90	}
	91
	92	/**
3d5c3036 RW	93	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	94	* @ce: PM clock entry to destroy.
85eb8c8d	95	*/
3d5c3036	96	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	97	{
	98	if (!ce)
	99	return;
	100
85eb8c8d RW	101	if (ce->status < PCE_STATUS_ERROR) {
85eb8c8d RW	102	if (ce->status == PCE_STATUS_ENABLED)
8a6720ec	103	clk_disable(ce->clk);
85eb8c8d	104
8a6720ec BD	105	if (ce->status >= PCE_STATUS_ACQUIRED) {
8a6720ec BD	106	clk_unprepare(ce->clk);
85eb8c8d	107	clk_put(ce->clk);
8a6720ec	108	}
85eb8c8d RW	109	}
85eb8c8d RW	110
0ab1e79b	111	kfree(ce->con_id);
85eb8c8d RW	112	kfree(ce);
	113	}
	114
	115	/**
3d5c3036 RW	116	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	117	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	118	* @con_id: Connection ID of the clock.
	119	*
	120	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	121	* the power management of @dev.
85eb8c8d	122	*/
3d5c3036	123	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	124	{
5c095a0e	125	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	126	struct pm_clock_entry *ce;
85eb8c8d RW	127
5c095a0e	128	if (!psd)
85eb8c8d RW	129	return;
85eb8c8d RW	130
5c095a0e	131	spin_lock_irq(&psd->lock);
85eb8c8d	132
5c095a0e	133	list_for_each_entry(ce, &psd->clock_list, node) {
e8b364b8 RW	134	if (!con_id && !ce->con_id)
	135	goto remove;
	136	else if (!con_id \|\| !ce->con_id)
85eb8c8d	137	continue;
e8b364b8 RW	138	else if (!strcmp(con_id, ce->con_id))
e8b364b8 RW	139	goto remove;
85eb8c8d RW	140	}
85eb8c8d RW	141
5c095a0e	142	spin_unlock_irq(&psd->lock);
e8b364b8 RW	143	return;
	144
	145	remove:
	146	list_del(&ce->node);
0d41da2e	147	spin_unlock_irq(&psd->lock);
e8b364b8 RW	148
e8b364b8 RW	149	__pm_clk_remove(ce);
85eb8c8d RW	150	}
	151
	152	/**
3d5c3036 RW	153	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	154	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	155	*
5c095a0e RW	156	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	157	* object.
85eb8c8d	158	*/
5c095a0e	159	void pm_clk_init(struct device *dev)
85eb8c8d	160	{
5c095a0e	161	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	162	if (psd)
ef27bed1 RW	163	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	164	}
	165
	166	/**
	167	* pm_clk_create - Create and initialize a device's list of PM clocks.
	168	* @dev: Device to create and initialize the list of PM clocks for.
	169	*
	170	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	171	* members and make the @dev's power.subsys_data field point to it.
	172	*/
	173	int pm_clk_create(struct device *dev)
	174	{
77254950	175	return dev_pm_get_subsys_data(dev);
85eb8c8d RW	176	}
	177
	178	/**
3d5c3036 RW	179	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	180	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	181	*
85eb8c8d RW	182	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	183	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	184	* that object.
85eb8c8d RW	185	*/
3d5c3036	186	void pm_clk_destroy(struct device *dev)
85eb8c8d	187	{
5c095a0e	188	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	189	struct pm_clock_entry ce, c;
e8b364b8	190	struct list_head list;
85eb8c8d	191
5c095a0e	192	if (!psd)
85eb8c8d RW	193	return;
85eb8c8d RW	194
e8b364b8	195	INIT_LIST_HEAD(&list);
85eb8c8d	196
5c095a0e	197	spin_lock_irq(&psd->lock);
85eb8c8d	198
5c095a0e	199	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
e8b364b8	200	list_move(&ce->node, &list);
85eb8c8d	201
5c095a0e	202	spin_unlock_irq(&psd->lock);
85eb8c8d	203
ef27bed1	204	dev_pm_put_subsys_data(dev);
e8b364b8 RW	205
	206	list_for_each_entry_safe_reverse(ce, c, &list, node) {
	207	list_del(&ce->node);
	208	__pm_clk_remove(ce);
	209	}
85eb8c8d RW	210	}
85eb8c8d RW	211
b7b95920 RW	212	#endif /* CONFIG_PM */
	213
	214	#ifdef CONFIG_PM_RUNTIME
	215
85eb8c8d	216	/**
3d5c3036	217	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	218	* @dev: Device to disable the clocks for.
85eb8c8d RW	219	*/
3d5c3036	220	int pm_clk_suspend(struct device *dev)
85eb8c8d	221	{
5c095a0e	222	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	223	struct pm_clock_entry *ce;
b7ab83ed	224	unsigned long flags;
85eb8c8d RW	225
	226	dev_dbg(dev, "%s()\n", __func__);
	227
5c095a0e	228	if (!psd)
85eb8c8d RW	229	return 0;
85eb8c8d RW	230
5c095a0e	231	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	232
5c095a0e	233	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	234	if (ce->status < PCE_STATUS_ERROR) {
24050956 MD	235	if (ce->status == PCE_STATUS_ENABLED)
24050956 MD	236	clk_disable(ce->clk);
85eb8c8d RW	237	ce->status = PCE_STATUS_ACQUIRED;
	238	}
	239	}
	240
5c095a0e	241	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	242
	243	return 0;
	244	}
	245
	246	/**
3d5c3036	247	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	248	* @dev: Device to enable the clocks for.
85eb8c8d RW	249	*/
3d5c3036	250	int pm_clk_resume(struct device *dev)
85eb8c8d	251	{
5c095a0e	252	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	253	struct pm_clock_entry *ce;
b7ab83ed	254	unsigned long flags;
afdd3ab3	255	int ret;
85eb8c8d RW	256
	257	dev_dbg(dev, "%s()\n", __func__);
	258
5c095a0e	259	if (!psd)
85eb8c8d RW	260	return 0;
85eb8c8d RW	261
5c095a0e	262	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	263
5c095a0e	264	list_for_each_entry(ce, &psd->clock_list, node) {
85eb8c8d	265	if (ce->status < PCE_STATUS_ERROR) {
afdd3ab3 BD	266	ret = clk_enable(ce->clk);
	267	if (!ret)
	268	ce->status = PCE_STATUS_ENABLED;
85eb8c8d RW	269	}
	270	}
	271
5c095a0e	272	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	273
	274	return 0;
	275	}
	276
	277	/**
3d5c3036	278	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	279	* @nb: Notifier block object this function is a member of.
	280	* @action: Operation being carried out by the caller.
	281	* @data: Device the routine is being run for.
	282	*
	283	* For this function to work, @nb must be a member of an object of type
	284	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	285	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	286	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	287	* of PM clocks, depending on @action.
85eb8c8d	288	*
564b905a	289	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	290	* from the one stored in the struct pm_clk_notifier_block object, the function
	291	* does nothing.
	292	*/
3d5c3036	293	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	294	unsigned long action, void *data)
	295	{
	296	struct pm_clk_notifier_block *clknb;
	297	struct device *dev = data;
3b3eca31	298	char **con_id;
85eb8c8d RW	299	int error;
	300
	301	dev_dbg(dev, "%s() %ld\n", __func__, action);
	302
	303	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	304
	305	switch (action) {
	306	case BUS_NOTIFY_ADD_DEVICE:
564b905a	307	if (dev->pm_domain)
85eb8c8d RW	308	break;
85eb8c8d RW	309
5c095a0e	310	error = pm_clk_create(dev);
85eb8c8d RW	311	if (error)
	312	break;
	313
564b905a	314	dev->pm_domain = clknb->pm_domain;
85eb8c8d	315	if (clknb->con_ids[0]) {
3b3eca31	316	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	317	pm_clk_add(dev, *con_id);
85eb8c8d	318	} else {
3d5c3036	319	pm_clk_add(dev, NULL);
85eb8c8d RW	320	}
	321
	322	break;
	323	case BUS_NOTIFY_DEL_DEVICE:
564b905a	324	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	325	break;
85eb8c8d RW	326
564b905a	327	dev->pm_domain = NULL;
3d5c3036	328	pm_clk_destroy(dev);
85eb8c8d RW	329	break;
	330	}
	331
	332	return 0;
	333	}
	334
	335	#else /* !CONFIG_PM_RUNTIME */
	336
b7b95920 RW	337	#ifdef CONFIG_PM
	338
	339	/**
3d5c3036	340	* pm_clk_suspend - Disable clocks in a device's PM clock list.
b7b95920 RW	341	* @dev: Device to disable the clocks for.
b7b95920 RW	342	*/
3d5c3036	343	int pm_clk_suspend(struct device *dev)
b7b95920	344	{
5c095a0e	345	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	346	struct pm_clock_entry *ce;
b7ab83ed	347	unsigned long flags;
b7b95920 RW	348
	349	dev_dbg(dev, "%s()\n", __func__);
	350
	351	/* If there is no driver, the clocks are already disabled. */
5c095a0e	352	if (!psd \|\| !dev->driver)
b7b95920 RW	353	return 0;
b7b95920 RW	354
5c095a0e	355	spin_lock_irqsave(&psd->lock, flags);
b7b95920	356
5c095a0e	357	list_for_each_entry_reverse(ce, &psd->clock_list, node)
b7b95920 RW	358	clk_disable(ce->clk);
b7b95920 RW	359
5c095a0e	360	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	361
	362	return 0;
	363	}
	364
	365	/**
3d5c3036	366	* pm_clk_resume - Enable clocks in a device's PM clock list.
b7b95920 RW	367	* @dev: Device to enable the clocks for.
b7b95920 RW	368	*/
3d5c3036	369	int pm_clk_resume(struct device *dev)
b7b95920	370	{
5c095a0e	371	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	372	struct pm_clock_entry *ce;
b7ab83ed	373	unsigned long flags;
b7b95920 RW	374
	375	dev_dbg(dev, "%s()\n", __func__);
	376
	377	/* If there is no driver, the clocks should remain disabled. */
5c095a0e	378	if (!psd \|\| !dev->driver)
b7b95920 RW	379	return 0;
b7b95920 RW	380
5c095a0e	381	spin_lock_irqsave(&psd->lock, flags);
b7b95920	382
5c095a0e	383	list_for_each_entry(ce, &psd->clock_list, node)
b7b95920 RW	384	clk_enable(ce->clk);
b7b95920 RW	385
5c095a0e	386	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	387
	388	return 0;
	389	}
	390
	391	#endif /* CONFIG_PM */
	392
85eb8c8d RW	393	/**
	394	* enable_clock - Enable a device clock.
	395	* @dev: Device whose clock is to be enabled.
	396	* @con_id: Connection ID of the clock.
	397	*/
	398	static void enable_clock(struct device dev, const char con_id)
	399	{
	400	struct clk *clk;
	401
	402	clk = clk_get(dev, con_id);
	403	if (!IS_ERR(clk)) {
c122f27e	404	clk_prepare_enable(clk);
85eb8c8d RW	405	clk_put(clk);
	406	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	407	}
	408	}
	409
	410	/**
	411	* disable_clock - Disable a device clock.
	412	* @dev: Device whose clock is to be disabled.
	413	* @con_id: Connection ID of the clock.
	414	*/
	415	static void disable_clock(struct device dev, const char con_id)
	416	{
	417	struct clk *clk;
	418
	419	clk = clk_get(dev, con_id);
	420	if (!IS_ERR(clk)) {
c122f27e	421	clk_disable_unprepare(clk);
85eb8c8d RW	422	clk_put(clk);
	423	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	424	}
	425	}
	426
	427	/**
3d5c3036	428	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	429	* @nb: Notifier block object this function is a member of.
	430	* @action: Operation being carried out by the caller.
	431	* @data: Device the routine is being run for.
	432	*
	433	* For this function to work, @nb must be a member of an object of type
	434	* struct pm_clk_notifier_block containing all of the requisite data.
	435	* Specifically, the con_ids member of that object is used to enable or disable
	436	* the device's clocks, depending on @action.
	437	*/
3d5c3036	438	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	439	unsigned long action, void *data)
	440	{
	441	struct pm_clk_notifier_block *clknb;
	442	struct device *dev = data;
3b3eca31	443	char **con_id;
85eb8c8d RW	444
	445	dev_dbg(dev, "%s() %ld\n", __func__, action);
	446
	447	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	448
	449	switch (action) {
4d1518f5	450	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	451	if (clknb->con_ids[0]) {
3b3eca31 RW	452	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	453	enable_clock(dev, *con_id);
85eb8c8d RW	454	} else {
	455	enable_clock(dev, NULL);
	456	}
	457	break;
4d1518f5	458	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	459	if (clknb->con_ids[0]) {
3b3eca31 RW	460	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	461	disable_clock(dev, *con_id);
85eb8c8d RW	462	} else {
	463	disable_clock(dev, NULL);
	464	}
	465	break;
	466	}
	467
	468	return 0;
	469	}
	470
	471	#endif /* !CONFIG_PM_RUNTIME */
	472
	473	/**
3d5c3036	474	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	475	* @bus: Bus type to add the notifier to.
	476	* @clknb: Notifier to be added to the given bus type.
	477	*
	478	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	479	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	480	* the remaining members of @clknb should be populated prior to calling this
	481	* routine.
	482	*/
3d5c3036	483	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	484	struct pm_clk_notifier_block *clknb)
	485	{
	486	if (!bus \|\| !clknb)
	487	return;
	488
3d5c3036	489	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	490	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	491	}