[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / dca / dca-core.c

/*
 * Copyright(c) 2007 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called COPYING.
 */

/*
 * This driver supports an interface for DCA clients and providers to meet.
 */

#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/dca.h>

#define DCA_VERSION "1.8"

MODULE_VERSION(DCA_VERSION);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");

static DEFINE_SPINLOCK(dca_lock);

static LIST_HEAD(dca_providers);

static struct dca_provider *dca_find_provider_by_dev(struct device *dev)
{
	struct dca_provider *dca, *ret = NULL;

	list_for_each_entry(dca, &dca_providers, node) {
		if ((!dev) || (dca->ops->dev_managed(dca, dev))) {
			ret = dca;
			break;
		}
	}

	return ret;
}

/**
 * dca_add_requester - add a dca client to the list
 * @dev - the device that wants dca service
 */
int dca_add_requester(struct device *dev)
{
	struct dca_provider *dca;
	int err, slot = -ENODEV;
	unsigned long flags;

	if (!dev)
		return -EFAULT;

	spin_lock_irqsave(&dca_lock, flags);

	/* check if the requester has not been added already */
	dca = dca_find_provider_by_dev(dev);
	if (dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -EEXIST;
	}

	list_for_each_entry(dca, &dca_providers, node) {
		slot = dca->ops->add_requester(dca, dev);
		if (slot >= 0)
			break;
	}

	spin_unlock_irqrestore(&dca_lock, flags);

	if (slot < 0)
		return slot;

	err = dca_sysfs_add_req(dca, dev, slot);
	if (err) {
		spin_lock_irqsave(&dca_lock, flags);
		if (dca == dca_find_provider_by_dev(dev))
			dca->ops->remove_requester(dca, dev);
		spin_unlock_irqrestore(&dca_lock, flags);
		return err;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(dca_add_requester);

/**
 * dca_remove_requester - remove a dca client from the list
 * @dev - the device that wants dca service
 */
int dca_remove_requester(struct device *dev)
{
	struct dca_provider *dca;
	int slot;
	unsigned long flags;

	if (!dev)
		return -EFAULT;

	spin_lock_irqsave(&dca_lock, flags);
	dca = dca_find_provider_by_dev(dev);
	if (!dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	slot = dca->ops->remove_requester(dca, dev);
	spin_unlock_irqrestore(&dca_lock, flags);

	if (slot < 0)
		return slot;

	dca_sysfs_remove_req(dca, slot);

	return 0;
}
EXPORT_SYMBOL_GPL(dca_remove_requester);

/**
 * dca_common_get_tag - return the dca tag (serves both new and old api)
 * @dev - the device that wants dca service
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca_common_get_tag(struct device *dev, int cpu)
{
	struct dca_provider *dca;
	u8 tag;
	unsigned long flags;

	spin_lock_irqsave(&dca_lock, flags);

	dca = dca_find_provider_by_dev(dev);
	if (!dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	tag = dca->ops->get_tag(dca, dev, cpu);

	spin_unlock_irqrestore(&dca_lock, flags);
	return tag;
}

/**
 * dca3_get_tag - return the dca tag to the requester device
 *                for the given cpu (new api)
 * @dev - the device that wants dca service
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca3_get_tag(struct device *dev, int cpu)
{
	if (!dev)
		return -EFAULT;

	return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca3_get_tag);

/**
 * dca_get_tag - return the dca tag for the given cpu (old api)
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca_get_tag(int cpu)
{
	struct device *dev = NULL;

	return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca_get_tag);

/**
 * alloc_dca_provider - get data struct for describing a dca provider
 * @ops - pointer to struct of dca operation function pointers
 * @priv_size - size of extra mem to be added for provider's needs
 */
struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size)
{
	struct dca_provider *dca;
	int alloc_size;

	alloc_size = (sizeof(*dca) + priv_size);
	dca = kzalloc(alloc_size, GFP_KERNEL);
	if (!dca)
		return NULL;
	dca->ops = ops;

	return dca;
}
EXPORT_SYMBOL_GPL(alloc_dca_provider);

/**
 * free_dca_provider - release the dca provider data struct
 * @ops - pointer to struct of dca operation function pointers
 * @priv_size - size of extra mem to be added for provider's needs
 */
void free_dca_provider(struct dca_provider *dca)
{
	kfree(dca);
}
EXPORT_SYMBOL_GPL(free_dca_provider);

static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);

/**
 * register_dca_provider - register a dca provider
 * @dca - struct created by alloc_dca_provider()
 * @dev - device providing dca services
 */
int register_dca_provider(struct dca_provider *dca, struct device *dev)
{
	int err;
	unsigned long flags;

	err = dca_sysfs_add_provider(dca, dev);
	if (err)
		return err;

	spin_lock_irqsave(&dca_lock, flags);
	list_add(&dca->node, &dca_providers);
	spin_unlock_irqrestore(&dca_lock, flags);

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_ADD, NULL);
	return 0;
}
EXPORT_SYMBOL_GPL(register_dca_provider);

/**
 * unregister_dca_provider - remove a dca provider
 * @dca - struct created by alloc_dca_provider()
 */
void unregister_dca_provider(struct dca_provider *dca)
{
	unsigned long flags;

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_REMOVE, NULL);

	spin_lock_irqsave(&dca_lock, flags);
	list_del(&dca->node);
	spin_unlock_irqrestore(&dca_lock, flags);

	dca_sysfs_remove_provider(dca);
}
EXPORT_SYMBOL_GPL(unregister_dca_provider);

/**
 * dca_register_notify - register a client's notifier callback
 */
void dca_register_notify(struct notifier_block *nb)
{
	blocking_notifier_chain_register(&dca_provider_chain, nb);
}
EXPORT_SYMBOL_GPL(dca_register_notify);

/**
 * dca_unregister_notify - remove a client's notifier callback
 */
void dca_unregister_notify(struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&dca_provider_chain, nb);
}
EXPORT_SYMBOL_GPL(dca_unregister_notify);

static int __init dca_init(void)
{
	printk(KERN_ERR "dca service started, version %s\n", DCA_VERSION);
	return dca_sysfs_init();
}

static void __exit dca_exit(void)
{
	dca_sysfs_exit();
}

arch_initcall(dca_init);
module_exit(dca_exit);
Commit	Line	Data
7589670f SN	1	/*
	2	* Copyright(c) 2007 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the Free
	6	* Software Foundation; either version 2 of the License, or (at your option)
	7	* any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc., 59
	16	* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* The full GNU General Public License is included in this distribution in the
	19	* file called COPYING.
	20	*/
	21
	22	/*
	23	* This driver supports an interface for DCA clients and providers to meet.
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/notifier.h>
	28	#include <linux/device.h>
	29	#include <linux/dca.h>
	30
eb4400e3	31	#define DCA_VERSION "1.8"
7589670f	32
7f1b358a MS	33	MODULE_VERSION(DCA_VERSION);
	34	MODULE_LICENSE("GPL");
	35	MODULE_AUTHOR("Intel Corporation");
7589670f SN	36
	37	static DEFINE_SPINLOCK(dca_lock);
	38
7f1b358a MS	39	static LIST_HEAD(dca_providers);
	40
	41	static struct dca_provider dca_find_provider_by_dev(struct device dev)
	42	{
	43	struct dca_provider dca, ret = NULL;
	44
	45	list_for_each_entry(dca, &dca_providers, node) {
	46	if ((!dev) \|\| (dca->ops->dev_managed(dca, dev))) {
	47	ret = dca;
	48	break;
	49	}
	50	}
	51
	52	return ret;
	53	}
7589670f SN	54
	55	/**
	56	* dca_add_requester - add a dca client to the list
	57	* @dev - the device that wants dca service
	58	*/
	59	int dca_add_requester(struct device *dev)
	60	{
7f1b358a MS	61	struct dca_provider *dca;
7f1b358a MS	62	int err, slot = -ENODEV;
eb4400e3	63	unsigned long flags;
7589670f	64
7f1b358a MS	65	if (!dev)
7f1b358a MS	66	return -EFAULT;
7589670f	67
eb4400e3	68	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	69
	70	/* check if the requester has not been added already */
	71	dca = dca_find_provider_by_dev(dev);
	72	if (dca) {
eb4400e3	73	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	74	return -EEXIST;
	75	}
	76
	77	list_for_each_entry(dca, &dca_providers, node) {
	78	slot = dca->ops->add_requester(dca, dev);
	79	if (slot >= 0)
	80	break;
	81	}
eb4400e3 MS	82
	83	spin_unlock_irqrestore(&dca_lock, flags);
	84
	85	if (slot < 0)
7589670f SN	86	return slot;
7589670f SN	87
7f1b358a	88	err = dca_sysfs_add_req(dca, dev, slot);
7589670f	89	if (err) {
eb4400e3 MS	90	spin_lock_irqsave(&dca_lock, flags);
	91	if (dca == dca_find_provider_by_dev(dev))
	92	dca->ops->remove_requester(dca, dev);
	93	spin_unlock_irqrestore(&dca_lock, flags);
7589670f SN	94	return err;
	95	}
	96
	97	return 0;
	98	}
	99	EXPORT_SYMBOL_GPL(dca_add_requester);
	100
	101	/**
	102	* dca_remove_requester - remove a dca client from the list
	103	* @dev - the device that wants dca service
	104	*/
	105	int dca_remove_requester(struct device *dev)
	106	{
7f1b358a	107	struct dca_provider *dca;
7589670f	108	int slot;
eb4400e3	109	unsigned long flags;
7f1b358a MS	110
	111	if (!dev)
	112	return -EFAULT;
7589670f	113
eb4400e3	114	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	115	dca = dca_find_provider_by_dev(dev);
7f1b358a MS	116	if (!dca) {
eb4400e3	117	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	118	return -ENODEV;
	119	}
	120	slot = dca->ops->remove_requester(dca, dev);
eb4400e3 MS	121	spin_unlock_irqrestore(&dca_lock, flags);
	122
	123	if (slot < 0)
7589670f SN	124	return slot;
7589670f SN	125
7f1b358a MS	126	dca_sysfs_remove_req(dca, slot);
7f1b358a MS	127
7589670f SN	128	return 0;
	129	}
	130	EXPORT_SYMBOL_GPL(dca_remove_requester);
	131
	132	/**
7f1b358a MS	133	* dca_common_get_tag - return the dca tag (serves both new and old api)
7f1b358a MS	134	* @dev - the device that wants dca service
7589670f SN	135	* @cpu - the cpuid as returned by get_cpu()
7589670f SN	136	*/
7f1b358a	137	u8 dca_common_get_tag(struct device *dev, int cpu)
7589670f	138	{
7f1b358a MS	139	struct dca_provider *dca;
7f1b358a MS	140	u8 tag;
eb4400e3	141	unsigned long flags;
7f1b358a	142
eb4400e3	143	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	144
	145	dca = dca_find_provider_by_dev(dev);
	146	if (!dca) {
eb4400e3	147	spin_unlock_irqrestore(&dca_lock, flags);
7589670f	148	return -ENODEV;
7f1b358a MS	149	}
	150	tag = dca->ops->get_tag(dca, dev, cpu);
	151
eb4400e3	152	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	153	return tag;
	154	}
	155
	156	/**
	157	* dca3_get_tag - return the dca tag to the requester device
	158	* for the given cpu (new api)
	159	* @dev - the device that wants dca service
	160	* @cpu - the cpuid as returned by get_cpu()
	161	*/
	162	u8 dca3_get_tag(struct device *dev, int cpu)
	163	{
	164	if (!dev)
	165	return -EFAULT;
	166
	167	return dca_common_get_tag(dev, cpu);
	168	}
	169	EXPORT_SYMBOL_GPL(dca3_get_tag);
	170
	171	/**
	172	* dca_get_tag - return the dca tag for the given cpu (old api)
	173	* @cpu - the cpuid as returned by get_cpu()
	174	*/
	175	u8 dca_get_tag(int cpu)
	176	{
	177	struct device *dev = NULL;
	178
	179	return dca_common_get_tag(dev, cpu);
7589670f SN	180	}
	181	EXPORT_SYMBOL_GPL(dca_get_tag);
	182
	183	/**
	184	* alloc_dca_provider - get data struct for describing a dca provider
	185	* @ops - pointer to struct of dca operation function pointers
	186	* @priv_size - size of extra mem to be added for provider's needs
	187	*/
	188	struct dca_provider alloc_dca_provider(struct dca_ops ops, int priv_size)
	189	{
	190	struct dca_provider *dca;
	191	int alloc_size;
	192
	193	alloc_size = (sizeof(*dca) + priv_size);
	194	dca = kzalloc(alloc_size, GFP_KERNEL);
	195	if (!dca)
	196	return NULL;
	197	dca->ops = ops;
	198
	199	return dca;
	200	}
	201	EXPORT_SYMBOL_GPL(alloc_dca_provider);
	202
	203	/**
	204	* free_dca_provider - release the dca provider data struct
	205	* @ops - pointer to struct of dca operation function pointers
	206	* @priv_size - size of extra mem to be added for provider's needs
	207	*/
	208	void free_dca_provider(struct dca_provider *dca)
	209	{
	210	kfree(dca);
	211	}
	212	EXPORT_SYMBOL_GPL(free_dca_provider);
	213
	214	static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);
	215
	216	/**
	217	* register_dca_provider - register a dca provider
	218	* @dca - struct created by alloc_dca_provider()
	219	* @dev - device providing dca services
	220	*/
	221	int register_dca_provider(struct dca_provider dca, struct device dev)
	222	{
	223	int err;
eb4400e3	224	unsigned long flags;
7589670f	225
7589670f SN	226	err = dca_sysfs_add_provider(dca, dev);
	227	if (err)
	228	return err;
eb4400e3 MS	229
eb4400e3 MS	230	spin_lock_irqsave(&dca_lock, flags);
7f1b358a	231	list_add(&dca->node, &dca_providers);
eb4400e3 MS	232	spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	233
7589670f SN	234	blocking_notifier_call_chain(&dca_provider_chain,
	235	DCA_PROVIDER_ADD, NULL);
	236	return 0;
	237	}
	238	EXPORT_SYMBOL_GPL(register_dca_provider);
	239
	240	/**
	241	* unregister_dca_provider - remove a dca provider
	242	* @dca - struct created by alloc_dca_provider()
	243	*/
	244	void unregister_dca_provider(struct dca_provider *dca)
	245	{
eb4400e3 MS	246	unsigned long flags;
eb4400e3 MS	247
7589670f SN	248	blocking_notifier_call_chain(&dca_provider_chain,
7589670f SN	249	DCA_PROVIDER_REMOVE, NULL);
eb4400e3 MS	250
eb4400e3 MS	251	spin_lock_irqsave(&dca_lock, flags);
7f1b358a	252	list_del(&dca->node);
eb4400e3 MS	253	spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	254
7589670f SN	255	dca_sysfs_remove_provider(dca);
	256	}
	257	EXPORT_SYMBOL_GPL(unregister_dca_provider);
	258
	259	/**
	260	* dca_register_notify - register a client's notifier callback
	261	*/
	262	void dca_register_notify(struct notifier_block *nb)
	263	{
	264	blocking_notifier_chain_register(&dca_provider_chain, nb);
	265	}
	266	EXPORT_SYMBOL_GPL(dca_register_notify);
	267
	268	/**
	269	* dca_unregister_notify - remove a client's notifier callback
	270	*/
	271	void dca_unregister_notify(struct notifier_block *nb)
	272	{
	273	blocking_notifier_chain_unregister(&dca_provider_chain, nb);
	274	}
	275	EXPORT_SYMBOL_GPL(dca_unregister_notify);
	276
	277	static int __init dca_init(void)
	278	{
7f1b358a	279	printk(KERN_ERR "dca service started, version %s\n", DCA_VERSION);
7589670f SN	280	return dca_sysfs_init();
	281	}
	282
	283	static void __exit dca_exit(void)
	284	{
	285	dca_sysfs_exit();
	286	}
	287
652afc27	288	arch_initcall(dca_init);
7589670f SN	289	module_exit(dca_exit);
7589670f SN	290