[linux-block.git] / drivers / base / power / clock_ops.c

/*
 * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
 *
 * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
 *
 * This file is released under the GPLv2.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm.h>
#include <linux/pm_clock.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/err.h>

#ifdef CONFIG_PM

enum pce_status {
	PCE_STATUS_NONE = 0,
	PCE_STATUS_ACQUIRED,
	PCE_STATUS_ENABLED,
	PCE_STATUS_ERROR,
};

struct pm_clock_entry {
	struct list_head node;
	char *con_id;
	struct clk *clk;
	enum pce_status status;
};

/**
 * pm_clk_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;
		}
	}

	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.
 *
 * 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_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) {
			__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(&psd->lock);
}

/**
 * pm_clk_init - Initialize a device's list of power management clocks.
 * @dev: Device to initialize the list of PM clocks for.
 *
 * Initialize the lock and clock_list members of the device's pm_subsys_data
 * object.
 */
void pm_clk_init(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	if (psd)
		INIT_LIST_HEAD(&psd->clock_list);
}

/**
 * pm_clk_create - Create and initialize a device's list of PM clocks.
 * @dev: Device to create and initialize the list of PM clocks for.
 *
 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
 * members and make the @dev's power.subsys_data field point to it.
 */
int pm_clk_create(struct device *dev)
{
	int ret = dev_pm_get_subsys_data(dev);
	return ret < 0 ? ret : 0;
}

/**
 * pm_clk_destroy - Destroy a device's list of power management clocks.
 * @dev: Device to destroy the list of PM clocks for.
 *
 * Clear the @dev's power.subsys_data field, remove the list of clock entries
 * from the struct pm_subsys_data object pointed to by it before and free
 * that object.
 */
void pm_clk_destroy(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce, *c;

	if (!psd)
		return;

	spin_lock_irq(&psd->lock);

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

	spin_unlock_irq(&psd->lock);

	dev_pm_put_subsys_data(dev);
}

#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_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_NONE)
			pm_clk_acquire(dev, ce);

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

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

/**
 * pm_clk_resume - Enable clocks in a device's PM clock list.
 * @dev: Device to enable the clocks for.
 */
int pm_clk_resume(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

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

	if (!psd)
		return 0;

	spin_lock_irqsave(&psd->lock, flags);

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

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

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

/**
 * pm_clk_notify - Notify routine for device addition and removal.
 * @nb: Notifier block object this function is a member of.
 * @action: Operation being carried out by the caller.
 * @data: Device the routine is being run for.
 *
 * For this function to work, @nb must be a member of an object of type
 * struct pm_clk_notifier_block containing all of the requisite data.
 * Specifically, the pm_domain member of that object is copied to the device's
 * pm_domain field and its con_ids member is used to populate the device's list
 * of PM clocks, depending on @action.
 *
 * If the device's pm_domain field is already populated with a value different
 * from the one stored in the struct pm_clk_notifier_block object, the function
 * does nothing.
 */
static int pm_clk_notify(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct pm_clk_notifier_block *clknb;
	struct device *dev = data;
	char **con_id;
	int error;

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

	clknb = container_of(nb, struct pm_clk_notifier_block, nb);

	switch (action) {
	case BUS_NOTIFY_ADD_DEVICE:
		if (dev->pm_domain)
			break;

		error = pm_clk_create(dev);
		if (error)
			break;

		dev->pm_domain = clknb->pm_domain;
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				pm_clk_add(dev, *con_id);
		} else {
			pm_clk_add(dev, NULL);
		}

		break;
	case BUS_NOTIFY_DEL_DEVICE:
		if (dev->pm_domain != clknb->pm_domain)
			break;

		dev->pm_domain = NULL;
		pm_clk_destroy(dev);
		break;
	}

	return 0;
}

#else /* !CONFIG_PM_RUNTIME */

#ifdef CONFIG_PM

/**
 * pm_clk_suspend - Disable clocks in a device's PM clock list.
 * @dev: Device to disable the clocks for.
 */
int pm_clk_suspend(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

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

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

	spin_lock_irqsave(&psd->lock, flags);

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

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

/**
 * pm_clk_resume - Enable clocks in a device's PM clock list.
 * @dev: Device to enable the clocks for.
 */
int pm_clk_resume(struct device *dev)
{
	struct pm_subsys_data *psd = dev_to_psd(dev);
	struct pm_clock_entry *ce;
	unsigned long flags;

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

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

	spin_lock_irqsave(&psd->lock, flags);

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

	spin_unlock_irqrestore(&psd->lock, flags);

	return 0;
}

#endif /* CONFIG_PM */

/**
 * enable_clock - Enable a device clock.
 * @dev: Device whose clock is to be enabled.
 * @con_id: Connection ID of the clock.
 */
static void enable_clock(struct device *dev, const char *con_id)
{
	struct clk *clk;

	clk = clk_get(dev, con_id);
	if (!IS_ERR(clk)) {
		clk_enable(clk);
		clk_put(clk);
		dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	}
}

/**
 * disable_clock - Disable a device clock.
 * @dev: Device whose clock is to be disabled.
 * @con_id: Connection ID of the clock.
 */
static void disable_clock(struct device *dev, const char *con_id)
{
	struct clk *clk;

	clk = clk_get(dev, con_id);
	if (!IS_ERR(clk)) {
		clk_disable(clk);
		clk_put(clk);
		dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	}
}

/**
 * pm_clk_notify - Notify routine for device addition and removal.
 * @nb: Notifier block object this function is a member of.
 * @action: Operation being carried out by the caller.
 * @data: Device the routine is being run for.
 *
 * For this function to work, @nb must be a member of an object of type
 * struct pm_clk_notifier_block containing all of the requisite data.
 * Specifically, the con_ids member of that object is used to enable or disable
 * the device's clocks, depending on @action.
 */
static int pm_clk_notify(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct pm_clk_notifier_block *clknb;
	struct device *dev = data;
	char **con_id;

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

	clknb = container_of(nb, struct pm_clk_notifier_block, nb);

	switch (action) {
	case BUS_NOTIFY_BIND_DRIVER:
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				enable_clock(dev, *con_id);
		} else {
			enable_clock(dev, NULL);
		}
		break;
	case BUS_NOTIFY_UNBOUND_DRIVER:
		if (clknb->con_ids[0]) {
			for (con_id = clknb->con_ids; *con_id; con_id++)
				disable_clock(dev, *con_id);
		} else {
			disable_clock(dev, NULL);
		}
		break;
	}

	return 0;
}

#endif /* !CONFIG_PM_RUNTIME */

/**
 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
 * @bus: Bus type to add the notifier to.
 * @clknb: Notifier to be added to the given bus type.
 *
 * The nb member of @clknb is not expected to be initialized and its
 * notifier_call member will be replaced with pm_clk_notify().  However,
 * the remaining members of @clknb should be populated prior to calling this
 * routine.
 */
void pm_clk_add_notifier(struct bus_type *bus,
				 struct pm_clk_notifier_block *clknb)
{
	if (!bus || !clknb)
		return;

	clknb->nb.notifier_call = pm_clk_notify;
	bus_register_notifier(bus, &clknb->nb);
}
Commit	Line	Data
85eb8c8d RW	1	/*
	2	* drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
	3	*
	4	* Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
	5	*
	6	* This file is released under the GPLv2.
	7	*/
	8
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/io.h>
	12	#include <linux/pm.h>
b5e8d269	13	#include <linux/pm_clock.h>
85eb8c8d RW	14	#include <linux/clk.h>
	15	#include <linux/slab.h>
	16	#include <linux/err.h>
	17
b7b95920	18	#ifdef CONFIG_PM
85eb8c8d	19
85eb8c8d RW	20	enum pce_status {
	21	PCE_STATUS_NONE = 0,
	22	PCE_STATUS_ACQUIRED,
	23	PCE_STATUS_ENABLED,
	24	PCE_STATUS_ERROR,
	25	};
	26
	27	struct pm_clock_entry {
	28	struct list_head node;
	29	char *con_id;
	30	struct clk *clk;
	31	enum pce_status status;
	32	};
	33
85eb8c8d	34	/**
3d5c3036 RW	35	* pm_clk_add - Start using a device clock for power management.
3d5c3036 RW	36	* @dev: Device whose clock is going to be used for power management.
85eb8c8d RW	37	* @con_id: Connection ID of the clock.
	38	*
	39	* Add the clock represented by @con_id to the list of clocks used for
3d5c3036	40	* the power management of @dev.
85eb8c8d	41	*/
3d5c3036	42	int pm_clk_add(struct device dev, const char con_id)
85eb8c8d	43	{
5c095a0e	44	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	45	struct pm_clock_entry *ce;
85eb8c8d RW	46
5c095a0e	47	if (!psd)
85eb8c8d RW	48	return -EINVAL;
	49
	50	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
	51	if (!ce) {
	52	dev_err(dev, "Not enough memory for clock entry.\n");
	53	return -ENOMEM;
	54	}
	55
	56	if (con_id) {
	57	ce->con_id = kstrdup(con_id, GFP_KERNEL);
	58	if (!ce->con_id) {
	59	dev_err(dev,
	60	"Not enough memory for clock connection ID.\n");
	61	kfree(ce);
	62	return -ENOMEM;
	63	}
	64	}
	65
5c095a0e RW	66	spin_lock_irq(&psd->lock);
	67	list_add_tail(&ce->node, &psd->clock_list);
	68	spin_unlock_irq(&psd->lock);
85eb8c8d RW	69	return 0;
	70	}
	71
	72	/**
3d5c3036 RW	73	* __pm_clk_remove - Destroy PM clock entry.
3d5c3036 RW	74	* @ce: PM clock entry to destroy.
85eb8c8d	75	*
b7ab83ed RW	76	* This routine must be called under the spinlock protecting the PM list of
b7ab83ed RW	77	* clocks corresponding the the @ce's device.
85eb8c8d	78	*/
3d5c3036	79	static void __pm_clk_remove(struct pm_clock_entry *ce)
85eb8c8d RW	80	{
	81	if (!ce)
	82	return;
	83
	84	list_del(&ce->node);
	85
	86	if (ce->status < PCE_STATUS_ERROR) {
	87	if (ce->status == PCE_STATUS_ENABLED)
	88	clk_disable(ce->clk);
	89
	90	if (ce->status >= PCE_STATUS_ACQUIRED)
	91	clk_put(ce->clk);
	92	}
	93
	94	if (ce->con_id)
	95	kfree(ce->con_id);
	96
	97	kfree(ce);
	98	}
	99
	100	/**
3d5c3036 RW	101	* pm_clk_remove - Stop using a device clock for power management.
3d5c3036 RW	102	* @dev: Device whose clock should not be used for PM any more.
85eb8c8d RW	103	* @con_id: Connection ID of the clock.
	104	*
	105	* Remove the clock represented by @con_id from the list of clocks used for
3d5c3036	106	* the power management of @dev.
85eb8c8d	107	*/
3d5c3036	108	void pm_clk_remove(struct device dev, const char con_id)
85eb8c8d	109	{
5c095a0e	110	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	111	struct pm_clock_entry *ce;
85eb8c8d RW	112
5c095a0e	113	if (!psd)
85eb8c8d RW	114	return;
85eb8c8d RW	115
5c095a0e	116	spin_lock_irq(&psd->lock);
85eb8c8d	117
5c095a0e	118	list_for_each_entry(ce, &psd->clock_list, node) {
85eb8c8d	119	if (!con_id && !ce->con_id) {
3d5c3036	120	__pm_clk_remove(ce);
85eb8c8d RW	121	break;
	122	} else if (!con_id \|\| !ce->con_id) {
	123	continue;
	124	} else if (!strcmp(con_id, ce->con_id)) {
3d5c3036	125	__pm_clk_remove(ce);
85eb8c8d RW	126	break;
	127	}
	128	}
	129
5c095a0e	130	spin_unlock_irq(&psd->lock);
85eb8c8d RW	131	}
	132
	133	/**
3d5c3036 RW	134	* pm_clk_init - Initialize a device's list of power management clocks.
3d5c3036 RW	135	* @dev: Device to initialize the list of PM clocks for.
85eb8c8d	136	*
5c095a0e RW	137	* Initialize the lock and clock_list members of the device's pm_subsys_data
5c095a0e RW	138	* object.
85eb8c8d	139	*/
5c095a0e	140	void pm_clk_init(struct device *dev)
85eb8c8d	141	{
5c095a0e	142	struct pm_subsys_data *psd = dev_to_psd(dev);
ef27bed1 RW	143	if (psd)
ef27bed1 RW	144	INIT_LIST_HEAD(&psd->clock_list);
5c095a0e RW	145	}
	146
	147	/**
	148	* pm_clk_create - Create and initialize a device's list of PM clocks.
	149	* @dev: Device to create and initialize the list of PM clocks for.
	150	*
	151	* Allocate a struct pm_subsys_data object, initialize its lock and clock_list
	152	* members and make the @dev's power.subsys_data field point to it.
	153	*/
	154	int pm_clk_create(struct device *dev)
	155	{
ef27bed1 RW	156	int ret = dev_pm_get_subsys_data(dev);
ef27bed1 RW	157	return ret < 0 ? ret : 0;
85eb8c8d RW	158	}
	159
	160	/**
3d5c3036 RW	161	* pm_clk_destroy - Destroy a device's list of power management clocks.
3d5c3036 RW	162	* @dev: Device to destroy the list of PM clocks for.
85eb8c8d RW	163	*
85eb8c8d RW	164	* Clear the @dev's power.subsys_data field, remove the list of clock entries
5c095a0e	165	* from the struct pm_subsys_data object pointed to by it before and free
85eb8c8d RW	166	* that object.
85eb8c8d RW	167	*/
3d5c3036	168	void pm_clk_destroy(struct device *dev)
85eb8c8d	169	{
5c095a0e	170	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d RW	171	struct pm_clock_entry ce, c;
85eb8c8d RW	172
5c095a0e	173	if (!psd)
85eb8c8d RW	174	return;
85eb8c8d RW	175
5c095a0e	176	spin_lock_irq(&psd->lock);
85eb8c8d	177
5c095a0e	178	list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
3d5c3036	179	__pm_clk_remove(ce);
85eb8c8d	180
5c095a0e	181	spin_unlock_irq(&psd->lock);
85eb8c8d	182
ef27bed1	183	dev_pm_put_subsys_data(dev);
85eb8c8d RW	184	}
85eb8c8d RW	185
b7b95920 RW	186	#endif /* CONFIG_PM */
	187
	188	#ifdef CONFIG_PM_RUNTIME
	189
85eb8c8d	190	/**
3d5c3036	191	* pm_clk_acquire - Acquire a device clock.
85eb8c8d RW	192	* @dev: Device whose clock is to be acquired.
	193	* @con_id: Connection ID of the clock.
	194	*/
3d5c3036	195	static void pm_clk_acquire(struct device *dev,
85eb8c8d RW	196	struct pm_clock_entry *ce)
	197	{
	198	ce->clk = clk_get(dev, ce->con_id);
	199	if (IS_ERR(ce->clk)) {
	200	ce->status = PCE_STATUS_ERROR;
	201	} else {
	202	ce->status = PCE_STATUS_ACQUIRED;
	203	dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
	204	}
	205	}
	206
	207	/**
3d5c3036	208	* pm_clk_suspend - Disable clocks in a device's PM clock list.
85eb8c8d RW	209	* @dev: Device to disable the clocks for.
85eb8c8d RW	210	*/
3d5c3036	211	int pm_clk_suspend(struct device *dev)
85eb8c8d	212	{
5c095a0e	213	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	214	struct pm_clock_entry *ce;
b7ab83ed	215	unsigned long flags;
85eb8c8d RW	216
	217	dev_dbg(dev, "%s()\n", __func__);
	218
5c095a0e	219	if (!psd)
85eb8c8d RW	220	return 0;
85eb8c8d RW	221
5c095a0e	222	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	223
5c095a0e	224	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
85eb8c8d	225	if (ce->status == PCE_STATUS_NONE)
3d5c3036	226	pm_clk_acquire(dev, ce);
85eb8c8d RW	227
	228	if (ce->status < PCE_STATUS_ERROR) {
	229	clk_disable(ce->clk);
	230	ce->status = PCE_STATUS_ACQUIRED;
	231	}
	232	}
	233
5c095a0e	234	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	235
	236	return 0;
	237	}
	238
	239	/**
3d5c3036	240	* pm_clk_resume - Enable clocks in a device's PM clock list.
85eb8c8d RW	241	* @dev: Device to enable the clocks for.
85eb8c8d RW	242	*/
3d5c3036	243	int pm_clk_resume(struct device *dev)
85eb8c8d	244	{
5c095a0e	245	struct pm_subsys_data *psd = dev_to_psd(dev);
85eb8c8d	246	struct pm_clock_entry *ce;
b7ab83ed	247	unsigned long flags;
85eb8c8d RW	248
	249	dev_dbg(dev, "%s()\n", __func__);
	250
5c095a0e	251	if (!psd)
85eb8c8d RW	252	return 0;
85eb8c8d RW	253
5c095a0e	254	spin_lock_irqsave(&psd->lock, flags);
85eb8c8d	255
5c095a0e	256	list_for_each_entry(ce, &psd->clock_list, node) {
85eb8c8d	257	if (ce->status == PCE_STATUS_NONE)
3d5c3036	258	pm_clk_acquire(dev, ce);
85eb8c8d RW	259
	260	if (ce->status < PCE_STATUS_ERROR) {
	261	clk_enable(ce->clk);
	262	ce->status = PCE_STATUS_ENABLED;
	263	}
	264	}
	265
5c095a0e	266	spin_unlock_irqrestore(&psd->lock, flags);
85eb8c8d RW	267
	268	return 0;
	269	}
	270
	271	/**
3d5c3036	272	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	273	* @nb: Notifier block object this function is a member of.
	274	* @action: Operation being carried out by the caller.
	275	* @data: Device the routine is being run for.
	276	*
	277	* For this function to work, @nb must be a member of an object of type
	278	* struct pm_clk_notifier_block containing all of the requisite data.
564b905a RW	279	* Specifically, the pm_domain member of that object is copied to the device's
564b905a RW	280	* pm_domain field and its con_ids member is used to populate the device's list
3d5c3036	281	* of PM clocks, depending on @action.
85eb8c8d	282	*
564b905a	283	* If the device's pm_domain field is already populated with a value different
85eb8c8d RW	284	* from the one stored in the struct pm_clk_notifier_block object, the function
	285	* does nothing.
	286	*/
3d5c3036	287	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	288	unsigned long action, void *data)
	289	{
	290	struct pm_clk_notifier_block *clknb;
	291	struct device *dev = data;
3b3eca31	292	char **con_id;
85eb8c8d RW	293	int error;
	294
	295	dev_dbg(dev, "%s() %ld\n", __func__, action);
	296
	297	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	298
	299	switch (action) {
	300	case BUS_NOTIFY_ADD_DEVICE:
564b905a	301	if (dev->pm_domain)
85eb8c8d RW	302	break;
85eb8c8d RW	303
5c095a0e	304	error = pm_clk_create(dev);
85eb8c8d RW	305	if (error)
	306	break;
	307
564b905a	308	dev->pm_domain = clknb->pm_domain;
85eb8c8d	309	if (clknb->con_ids[0]) {
3b3eca31	310	for (con_id = clknb->con_ids; *con_id; con_id++)
3d5c3036	311	pm_clk_add(dev, *con_id);
85eb8c8d	312	} else {
3d5c3036	313	pm_clk_add(dev, NULL);
85eb8c8d RW	314	}
	315
	316	break;
	317	case BUS_NOTIFY_DEL_DEVICE:
564b905a	318	if (dev->pm_domain != clknb->pm_domain)
85eb8c8d RW	319	break;
85eb8c8d RW	320
564b905a	321	dev->pm_domain = NULL;
3d5c3036	322	pm_clk_destroy(dev);
85eb8c8d RW	323	break;
	324	}
	325
	326	return 0;
	327	}
	328
	329	#else /* !CONFIG_PM_RUNTIME */
	330
b7b95920 RW	331	#ifdef CONFIG_PM
	332
	333	/**
3d5c3036	334	* pm_clk_suspend - Disable clocks in a device's PM clock list.
b7b95920 RW	335	* @dev: Device to disable the clocks for.
b7b95920 RW	336	*/
3d5c3036	337	int pm_clk_suspend(struct device *dev)
b7b95920	338	{
5c095a0e	339	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	340	struct pm_clock_entry *ce;
b7ab83ed	341	unsigned long flags;
b7b95920 RW	342
	343	dev_dbg(dev, "%s()\n", __func__);
	344
	345	/* If there is no driver, the clocks are already disabled. */
5c095a0e	346	if (!psd \|\| !dev->driver)
b7b95920 RW	347	return 0;
b7b95920 RW	348
5c095a0e	349	spin_lock_irqsave(&psd->lock, flags);
b7b95920	350
5c095a0e	351	list_for_each_entry_reverse(ce, &psd->clock_list, node)
b7b95920 RW	352	clk_disable(ce->clk);
b7b95920 RW	353
5c095a0e	354	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	355
	356	return 0;
	357	}
	358
	359	/**
3d5c3036	360	* pm_clk_resume - Enable clocks in a device's PM clock list.
b7b95920 RW	361	* @dev: Device to enable the clocks for.
b7b95920 RW	362	*/
3d5c3036	363	int pm_clk_resume(struct device *dev)
b7b95920	364	{
5c095a0e	365	struct pm_subsys_data *psd = dev_to_psd(dev);
b7b95920	366	struct pm_clock_entry *ce;
b7ab83ed	367	unsigned long flags;
b7b95920 RW	368
	369	dev_dbg(dev, "%s()\n", __func__);
	370
	371	/* If there is no driver, the clocks should remain disabled. */
5c095a0e	372	if (!psd \|\| !dev->driver)
b7b95920 RW	373	return 0;
b7b95920 RW	374
5c095a0e	375	spin_lock_irqsave(&psd->lock, flags);
b7b95920	376
5c095a0e	377	list_for_each_entry(ce, &psd->clock_list, node)
b7b95920 RW	378	clk_enable(ce->clk);
b7b95920 RW	379
5c095a0e	380	spin_unlock_irqrestore(&psd->lock, flags);
b7b95920 RW	381
	382	return 0;
	383	}
	384
	385	#endif /* CONFIG_PM */
	386
85eb8c8d RW	387	/**
	388	* enable_clock - Enable a device clock.
	389	* @dev: Device whose clock is to be enabled.
	390	* @con_id: Connection ID of the clock.
	391	*/
	392	static void enable_clock(struct device dev, const char con_id)
	393	{
	394	struct clk *clk;
	395
	396	clk = clk_get(dev, con_id);
	397	if (!IS_ERR(clk)) {
	398	clk_enable(clk);
	399	clk_put(clk);
	400	dev_info(dev, "Runtime PM disabled, clock forced on.\n");
	401	}
	402	}
	403
	404	/**
	405	* disable_clock - Disable a device clock.
	406	* @dev: Device whose clock is to be disabled.
	407	* @con_id: Connection ID of the clock.
	408	*/
	409	static void disable_clock(struct device dev, const char con_id)
	410	{
	411	struct clk *clk;
	412
	413	clk = clk_get(dev, con_id);
	414	if (!IS_ERR(clk)) {
	415	clk_disable(clk);
	416	clk_put(clk);
	417	dev_info(dev, "Runtime PM disabled, clock forced off.\n");
	418	}
	419	}
	420
	421	/**
3d5c3036	422	* pm_clk_notify - Notify routine for device addition and removal.
85eb8c8d RW	423	* @nb: Notifier block object this function is a member of.
	424	* @action: Operation being carried out by the caller.
	425	* @data: Device the routine is being run for.
	426	*
	427	* For this function to work, @nb must be a member of an object of type
	428	* struct pm_clk_notifier_block containing all of the requisite data.
	429	* Specifically, the con_ids member of that object is used to enable or disable
	430	* the device's clocks, depending on @action.
	431	*/
3d5c3036	432	static int pm_clk_notify(struct notifier_block *nb,
85eb8c8d RW	433	unsigned long action, void *data)
	434	{
	435	struct pm_clk_notifier_block *clknb;
	436	struct device *dev = data;
3b3eca31	437	char **con_id;
85eb8c8d RW	438
	439	dev_dbg(dev, "%s() %ld\n", __func__, action);
	440
	441	clknb = container_of(nb, struct pm_clk_notifier_block, nb);
	442
	443	switch (action) {
4d1518f5	444	case BUS_NOTIFY_BIND_DRIVER:
85eb8c8d	445	if (clknb->con_ids[0]) {
3b3eca31 RW	446	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	447	enable_clock(dev, *con_id);
85eb8c8d RW	448	} else {
	449	enable_clock(dev, NULL);
	450	}
	451	break;
4d1518f5	452	case BUS_NOTIFY_UNBOUND_DRIVER:
85eb8c8d	453	if (clknb->con_ids[0]) {
3b3eca31 RW	454	for (con_id = clknb->con_ids; *con_id; con_id++)
3b3eca31 RW	455	disable_clock(dev, *con_id);
85eb8c8d RW	456	} else {
	457	disable_clock(dev, NULL);
	458	}
	459	break;
	460	}
	461
	462	return 0;
	463	}
	464
	465	#endif /* !CONFIG_PM_RUNTIME */
	466
	467	/**
3d5c3036	468	* pm_clk_add_notifier - Add bus type notifier for power management clocks.
85eb8c8d RW	469	* @bus: Bus type to add the notifier to.
	470	* @clknb: Notifier to be added to the given bus type.
	471	*
	472	* The nb member of @clknb is not expected to be initialized and its
3d5c3036	473	* notifier_call member will be replaced with pm_clk_notify(). However,
85eb8c8d RW	474	* the remaining members of @clknb should be populated prior to calling this
	475	* routine.
	476	*/
3d5c3036	477	void pm_clk_add_notifier(struct bus_type *bus,
85eb8c8d RW	478	struct pm_clk_notifier_block *clknb)
	479	{
	480	if (!bus \|\| !clknb)
	481	return;
	482
3d5c3036	483	clknb->nb.notifier_call = pm_clk_notify;
85eb8c8d RW	484	bus_register_notifier(bus, &clknb->nb);
85eb8c8d RW	485	}