[mirror_ubuntu-bionic-kernel.git] / drivers / usb / gadget / udc-core.c

/**
 * udc.c - Core UDC Framework
 *
 * Copyright (C) 2010 Texas Instruments
 * Author: Felipe Balbi <balbi@ti.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2  of
 * the License as published by the Free Software Foundation.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/dma-mapping.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

/**
 * struct usb_udc - describes one usb device controller
 * @driver - the gadget driver pointer. For use by the class code
 * @dev - the child device to the actual controller
 * @gadget - the gadget. For use by the class code
 * @list - for use by the udc class driver
 *
 * This represents the internal data structure which is used by the UDC-class
 * to hold information about udc driver and gadget together.
 */
struct usb_udc {
	struct usb_gadget_driver	*driver;
	struct usb_gadget		*gadget;
	struct device			dev;
	struct list_head		list;
};

static struct class *udc_class;
static LIST_HEAD(udc_list);
static DEFINE_MUTEX(udc_lock);

/* ------------------------------------------------------------------------- */

int usb_gadget_map_request(struct usb_gadget *gadget,
		struct usb_request *req, int is_in)
{
	if (req->length == 0)
		return 0;

	if (req->num_sgs) {
		int     mapped;

		mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
		if (mapped == 0) {
			dev_err(&gadget->dev, "failed to map SGs\n");
			return -EFAULT;
		}

		req->num_mapped_sgs = mapped;
	} else {
		req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);

		if (dma_mapping_error(&gadget->dev, req->dma)) {
			dev_err(&gadget->dev, "failed to map buffer\n");
			return -EFAULT;
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(usb_gadget_map_request);

void usb_gadget_unmap_request(struct usb_gadget *gadget,
		struct usb_request *req, int is_in)
{
	if (req->length == 0)
		return;

	if (req->num_mapped_sgs) {
		dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);

		req->num_mapped_sgs = 0;
	} else {
		dma_unmap_single(&gadget->dev, req->dma, req->length,
				is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	}
}
EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);

/* ------------------------------------------------------------------------- */

/**
 * usb_gadget_udc_start - tells usb device controller to start up
 * @gadget: The gadget we want to get started
 * @driver: The driver we want to bind to @gadget
 *
 * This call is issued by the UDC Class driver when it's about
 * to register a gadget driver to the device controller, before
 * calling gadget driver's bind() method.
 *
 * It allows the controller to be powered off until strictly
 * necessary to have it powered on.
 *
 * Returns zero on success, else negative errno.
 */
static inline int usb_gadget_udc_start(struct usb_gadget *gadget,
		struct usb_gadget_driver *driver)
{
	return gadget->ops->udc_start(gadget, driver);
}

/**
 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
 * @gadget: The device we want to stop activity
 * @driver: The driver to unbind from @gadget
 *
 * This call is issued by the UDC Class driver after calling
 * gadget driver's unbind() method.
 *
 * The details are implementation specific, but it can go as
 * far as powering off UDC completely and disable its data
 * line pullups.
 */
static inline void usb_gadget_udc_stop(struct usb_gadget *gadget,
		struct usb_gadget_driver *driver)
{
	gadget->ops->udc_stop(gadget, driver);
}

/**
 * usb_udc_release - release the usb_udc struct
 * @dev: the dev member within usb_udc
 *
 * This is called by driver's core in order to free memory once the last
 * reference is released.
 */
static void usb_udc_release(struct device *dev)
{
	struct usb_udc *udc;

	udc = container_of(dev, struct usb_udc, dev);
	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
	kfree(udc);
}

static const struct attribute_group *usb_udc_attr_groups[];
/**
 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
 * @parent: the parent device to this udc. Usually the controller
 * driver's device.
 * @gadget: the gadget to be added to the list
 *
 * Returns zero on success, negative errno otherwise.
 */
int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
{
	struct usb_udc		*udc;
	int			ret = -ENOMEM;

	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
	if (!udc)
		goto err1;

	dev_set_name(&gadget->dev, "gadget");

	ret = device_register(&gadget->dev);
	if (ret)
		goto err2;

	device_initialize(&udc->dev);
	udc->dev.release = usb_udc_release;
	udc->dev.class = udc_class;
	udc->dev.groups = usb_udc_attr_groups;
	udc->dev.parent = parent;
	ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
	if (ret)
		goto err3;

	udc->gadget = gadget;

	mutex_lock(&udc_lock);
	list_add_tail(&udc->list, &udc_list);

	ret = device_add(&udc->dev);
	if (ret)
		goto err4;

	mutex_unlock(&udc_lock);

	return 0;

err4:
	list_del(&udc->list);
	mutex_unlock(&udc_lock);

err3:
	put_device(&udc->dev);

err2:
	put_device(&gadget->dev);

err1:
	return ret;
}
EXPORT_SYMBOL_GPL(usb_add_gadget_udc);

static void usb_gadget_remove_driver(struct usb_udc *udc)
{
	dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
			udc->gadget->name);

	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);

	usb_gadget_disconnect(udc->gadget);
	udc->driver->disconnect(udc->gadget);
	udc->driver->unbind(udc->gadget);
	usb_gadget_udc_stop(udc->gadget, udc->driver);

	udc->driver = NULL;
	udc->dev.driver = NULL;
}

/**
 * usb_del_gadget_udc - deletes @udc from udc_list
 * @gadget: the gadget to be removed.
 *
 * This, will call usb_gadget_unregister_driver() if
 * the @udc is still busy.
 */
void usb_del_gadget_udc(struct usb_gadget *gadget)
{
	struct usb_udc		*udc = NULL;

	mutex_lock(&udc_lock);
	list_for_each_entry(udc, &udc_list, list)
		if (udc->gadget == gadget)
			goto found;

	dev_err(gadget->dev.parent, "gadget not registered.\n");
	mutex_unlock(&udc_lock);

	return;

found:
	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");

	list_del(&udc->list);
	mutex_unlock(&udc_lock);

	if (udc->driver)
		usb_gadget_remove_driver(udc);

	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
	device_unregister(&udc->dev);
	device_unregister(&gadget->dev);
}
EXPORT_SYMBOL_GPL(usb_del_gadget_udc);

/* ------------------------------------------------------------------------- */

static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
{
	int ret;

	dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
			driver->function);

	udc->driver = driver;
	udc->dev.driver = &driver->driver;

	ret = driver->bind(udc->gadget, driver);
	if (ret)
		goto err1;
	ret = usb_gadget_udc_start(udc->gadget, driver);
	if (ret) {
		driver->unbind(udc->gadget);
		goto err1;
	}
	usb_gadget_connect(udc->gadget);

	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
	return 0;
err1:
	dev_err(&udc->dev, "failed to start %s: %d\n",
			udc->driver->function, ret);
	udc->driver = NULL;
	udc->dev.driver = NULL;
	return ret;
}

int udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
{
	struct usb_udc *udc = NULL;
	int ret = -ENODEV;

	mutex_lock(&udc_lock);
	list_for_each_entry(udc, &udc_list, list) {
		ret = strcmp(name, dev_name(&udc->dev));
		if (!ret)
			break;
	}
	if (ret) {
		ret = -ENODEV;
		goto out;
	}
	if (udc->driver) {
		ret = -EBUSY;
		goto out;
	}
	ret = udc_bind_to_driver(udc, driver);
out:
	mutex_unlock(&udc_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(udc_attach_driver);

int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
{
	struct usb_udc		*udc = NULL;
	int			ret;

	if (!driver || !driver->bind || !driver->setup)
		return -EINVAL;

	mutex_lock(&udc_lock);
	list_for_each_entry(udc, &udc_list, list) {
		/* For now we take the first one */
		if (!udc->driver)
			goto found;
	}

	pr_debug("couldn't find an available UDC\n");
	mutex_unlock(&udc_lock);
	return -ENODEV;
found:
	ret = udc_bind_to_driver(udc, driver);
	mutex_unlock(&udc_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);

int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
	struct usb_udc		*udc = NULL;
	int			ret = -ENODEV;

	if (!driver || !driver->unbind)
		return -EINVAL;

	mutex_lock(&udc_lock);
	list_for_each_entry(udc, &udc_list, list)
		if (udc->driver == driver) {
			usb_gadget_remove_driver(udc);
			ret = 0;
			break;
		}

	mutex_unlock(&udc_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);

/* ------------------------------------------------------------------------- */

static ssize_t usb_udc_srp_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);

	if (sysfs_streq(buf, "1"))
		usb_gadget_wakeup(udc->gadget);

	return n;
}
static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);

static ssize_t usb_udc_softconn_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);

	if (sysfs_streq(buf, "connect")) {
		usb_gadget_udc_start(udc->gadget, udc->driver);
		usb_gadget_connect(udc->gadget);
	} else if (sysfs_streq(buf, "disconnect")) {
		usb_gadget_disconnect(udc->gadget);
		usb_gadget_udc_stop(udc->gadget, udc->driver);
	} else {
		dev_err(dev, "unsupported command '%s'\n", buf);
		return -EINVAL;
	}

	return n;
}
static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store);

#define USB_UDC_SPEED_ATTR(name, param)					\
ssize_t usb_udc_##param##_show(struct device *dev,			\
		struct device_attribute *attr, char *buf)		\
{									\
	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);	\
	return snprintf(buf, PAGE_SIZE, "%s\n",				\
			usb_speed_string(udc->gadget->param));		\
}									\
static DEVICE_ATTR(name, S_IRUSR, usb_udc_##param##_show, NULL)

static USB_UDC_SPEED_ATTR(current_speed, speed);
static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);

#define USB_UDC_ATTR(name)					\
ssize_t usb_udc_##name##_show(struct device *dev,		\
		struct device_attribute *attr, char *buf)	\
{								\
	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev); \
	struct usb_gadget	*gadget = udc->gadget;		\
								\
	return snprintf(buf, PAGE_SIZE, "%d\n", gadget->name);	\
}								\
static DEVICE_ATTR(name, S_IRUGO, usb_udc_##name##_show, NULL)

static USB_UDC_ATTR(is_otg);
static USB_UDC_ATTR(is_a_peripheral);
static USB_UDC_ATTR(b_hnp_enable);
static USB_UDC_ATTR(a_hnp_support);
static USB_UDC_ATTR(a_alt_hnp_support);

static struct attribute *usb_udc_attrs[] = {
	&dev_attr_srp.attr,
	&dev_attr_soft_connect.attr,
	&dev_attr_current_speed.attr,
	&dev_attr_maximum_speed.attr,

	&dev_attr_is_otg.attr,
	&dev_attr_is_a_peripheral.attr,
	&dev_attr_b_hnp_enable.attr,
	&dev_attr_a_hnp_support.attr,
	&dev_attr_a_alt_hnp_support.attr,
	NULL,
};

static const struct attribute_group usb_udc_attr_group = {
	.attrs = usb_udc_attrs,
};

static const struct attribute_group *usb_udc_attr_groups[] = {
	&usb_udc_attr_group,
	NULL,
};

static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
	int			ret;

	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
	if (ret) {
		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
		return ret;
	}

	if (udc->driver) {
		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
				udc->driver->function);
		if (ret) {
			dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
			return ret;
		}
	}

	return 0;
}

static int __init usb_udc_init(void)
{
	udc_class = class_create(THIS_MODULE, "udc");
	if (IS_ERR(udc_class)) {
		pr_err("failed to create udc class --> %ld\n",
				PTR_ERR(udc_class));
		return PTR_ERR(udc_class);
	}

	udc_class->dev_uevent = usb_udc_uevent;
	return 0;
}
subsys_initcall(usb_udc_init);

static void __exit usb_udc_exit(void)
{
	class_destroy(udc_class);
}
module_exit(usb_udc_exit);

MODULE_DESCRIPTION("UDC Framework");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2ccea03a FB	1	/**
	2	* udc.c - Core UDC Framework
	3	*
	4	* Copyright (C) 2010 Texas Instruments
	5	* Author: Felipe Balbi <balbi@ti.com>
	6	*
	7	* This program is free software: you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 of
	9	* the License as published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <linux/kernel.h>
	21	#include <linux/module.h>
	22	#include <linux/device.h>
	23	#include <linux/list.h>
	24	#include <linux/err.h>
a698908d	25	#include <linux/dma-mapping.h>
2ccea03a FB	26
	27	#include <linux/usb/ch9.h>
	28	#include <linux/usb/gadget.h>
	29
	30	/**
	31	* struct usb_udc - describes one usb device controller
	32	* @driver - the gadget driver pointer. For use by the class code
	33	* @dev - the child device to the actual controller
	34	* @gadget - the gadget. For use by the class code
	35	* @list - for use by the udc class driver
	36	*
	37	* This represents the internal data structure which is used by the UDC-class
	38	* to hold information about udc driver and gadget together.
	39	*/
	40	struct usb_udc {
	41	struct usb_gadget_driver *driver;
	42	struct usb_gadget *gadget;
	43	struct device dev;
	44	struct list_head list;
	45	};
	46
	47	static struct class *udc_class;
2ccea03a FB	48	static LIST_HEAD(udc_list);
	49	static DEFINE_MUTEX(udc_lock);
	50
	51	/* ------------------------------------------------------------------------- */
	52
a698908d FB	53	int usb_gadget_map_request(struct usb_gadget *gadget,
	54	struct usb_request *req, int is_in)
	55	{
	56	if (req->length == 0)
	57	return 0;
	58
	59	if (req->num_sgs) {
	60	int mapped;
	61
	62	mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
	63	is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	64	if (mapped == 0) {
	65	dev_err(&gadget->dev, "failed to map SGs\n");
	66	return -EFAULT;
	67	}
	68
	69	req->num_mapped_sgs = mapped;
	70	} else {
	71	req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
	72	is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	73
	74	if (dma_mapping_error(&gadget->dev, req->dma)) {
	75	dev_err(&gadget->dev, "failed to map buffer\n");
	76	return -EFAULT;
	77	}
	78	}
	79
	80	return 0;
	81	}
	82	EXPORT_SYMBOL_GPL(usb_gadget_map_request);
	83
	84	void usb_gadget_unmap_request(struct usb_gadget *gadget,
	85	struct usb_request *req, int is_in)
	86	{
	87	if (req->length == 0)
	88	return;
	89
	90	if (req->num_mapped_sgs) {
	91	dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
	92	is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	93
	94	req->num_mapped_sgs = 0;
	95	} else {
	96	dma_unmap_single(&gadget->dev, req->dma, req->length,
	97	is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	98	}
	99	}
	100	EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
	101
	102	/* ------------------------------------------------------------------------- */
	103
352c2dc8 SAS	104	/**
	105	* usb_gadget_udc_start - tells usb device controller to start up
	106	* @gadget: The gadget we want to get started
	107	* @driver: The driver we want to bind to @gadget
	108	*
	109	* This call is issued by the UDC Class driver when it's about
	110	* to register a gadget driver to the device controller, before
	111	* calling gadget driver's bind() method.
	112	*
	113	* It allows the controller to be powered off until strictly
	114	* necessary to have it powered on.
	115	*
	116	* Returns zero on success, else negative errno.
	117	*/
	118	static inline int usb_gadget_udc_start(struct usb_gadget *gadget,
	119	struct usb_gadget_driver *driver)
	120	{
	121	return gadget->ops->udc_start(gadget, driver);
	122	}
	123
352c2dc8 SAS	124	/**
	125	* usb_gadget_udc_stop - tells usb device controller we don't need it anymore
	126	* @gadget: The device we want to stop activity
	127	* @driver: The driver to unbind from @gadget
	128	*
	129	* This call is issued by the UDC Class driver after calling
	130	* gadget driver's unbind() method.
	131	*
	132	* The details are implementation specific, but it can go as
	133	* far as powering off UDC completely and disable its data
	134	* line pullups.
	135	*/
	136	static inline void usb_gadget_udc_stop(struct usb_gadget *gadget,
	137	struct usb_gadget_driver *driver)
	138	{
	139	gadget->ops->udc_stop(gadget, driver);
	140	}
	141
2ccea03a FB	142	/**
	143	* usb_udc_release - release the usb_udc struct
	144	* @dev: the dev member within usb_udc
	145	*
	146	* This is called by driver's core in order to free memory once the last
	147	* reference is released.
	148	*/
	149	static void usb_udc_release(struct device *dev)
	150	{
	151	struct usb_udc *udc;
	152
	153	udc = container_of(dev, struct usb_udc, dev);
	154	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
	155	kfree(udc);
	156	}
	157
019f976e	158	static const struct attribute_group *usb_udc_attr_groups[];
2ccea03a FB	159	/**
	160	* usb_add_gadget_udc - adds a new gadget to the udc class driver list
	161	* @parent: the parent device to this udc. Usually the controller
	162	* driver's device.
	163	* @gadget: the gadget to be added to the list
	164	*
	165	* Returns zero on success, negative errno otherwise.
	166	*/
	167	int usb_add_gadget_udc(struct device parent, struct usb_gadget gadget)
	168	{
	169	struct usb_udc *udc;
	170	int ret = -ENOMEM;
	171
	172	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
	173	if (!udc)
	174	goto err1;
	175
7bce401c	176	dev_set_name(&gadget->dev, "gadget");
f07bd56b	177
7bce401c FB	178	ret = device_register(&gadget->dev);
	179	if (ret)
	180	goto err2;
f07bd56b	181
2ccea03a FB	182	device_initialize(&udc->dev);
	183	udc->dev.release = usb_udc_release;
	184	udc->dev.class = udc_class;
019f976e	185	udc->dev.groups = usb_udc_attr_groups;
2ccea03a FB	186	udc->dev.parent = parent;
	187	ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
	188	if (ret)
f07bd56b	189	goto err3;
2ccea03a FB	190
	191	udc->gadget = gadget;
	192
	193	mutex_lock(&udc_lock);
	194	list_add_tail(&udc->list, &udc_list);
	195
	196	ret = device_add(&udc->dev);
	197	if (ret)
f07bd56b	198	goto err4;
2ccea03a FB	199
	200	mutex_unlock(&udc_lock);
	201
	202	return 0;
f07bd56b FB	203
f07bd56b FB	204	err4:
2ccea03a FB	205	list_del(&udc->list);
	206	mutex_unlock(&udc_lock);
	207
f07bd56b	208	err3:
2ccea03a FB	209	put_device(&udc->dev);
2ccea03a FB	210
f07bd56b	211	err2:
7bce401c FB	212	put_device(&gadget->dev);
7bce401c FB	213
2ccea03a FB	214	err1:
	215	return ret;
	216	}
	217	EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
	218
	219	static void usb_gadget_remove_driver(struct usb_udc *udc)
	220	{
	221	dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
	222	udc->gadget->name);
	223
	224	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
	225
2d7ebbb0 FB	226	usb_gadget_disconnect(udc->gadget);
	227	udc->driver->disconnect(udc->gadget);
	228	udc->driver->unbind(udc->gadget);
	229	usb_gadget_udc_stop(udc->gadget, udc->driver);
2ccea03a FB	230
	231	udc->driver = NULL;
	232	udc->dev.driver = NULL;
	233	}
	234
	235	/**
	236	* usb_del_gadget_udc - deletes @udc from udc_list
	237	* @gadget: the gadget to be removed.
	238	*
	239	* This, will call usb_gadget_unregister_driver() if
	240	* the @udc is still busy.
	241	*/
	242	void usb_del_gadget_udc(struct usb_gadget *gadget)
	243	{
	244	struct usb_udc *udc = NULL;
	245
	246	mutex_lock(&udc_lock);
	247	list_for_each_entry(udc, &udc_list, list)
	248	if (udc->gadget == gadget)
	249	goto found;
	250
	251	dev_err(gadget->dev.parent, "gadget not registered.\n");
	252	mutex_unlock(&udc_lock);
	253
	254	return;
	255
	256	found:
	257	dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
	258
	259	list_del(&udc->list);
	260	mutex_unlock(&udc_lock);
	261
	262	if (udc->driver)
	263	usb_gadget_remove_driver(udc);
	264
	265	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
	266	device_unregister(&udc->dev);
7bce401c	267	device_unregister(&gadget->dev);
2ccea03a FB	268	}
	269	EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
	270
	271	/* ------------------------------------------------------------------------- */
	272
4c49a5f0	273	static int udc_bind_to_driver(struct usb_udc udc, struct usb_gadget_driver driver)
2ccea03a	274	{
4c49a5f0	275	int ret;
2ccea03a	276
2ccea03a FB	277	dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
	278	driver->function);
	279
	280	udc->driver = driver;
	281	udc->dev.driver = &driver->driver;
	282
2d7ebbb0 FB	283	ret = driver->bind(udc->gadget, driver);
	284	if (ret)
	285	goto err1;
	286	ret = usb_gadget_udc_start(udc->gadget, driver);
	287	if (ret) {
	288	driver->unbind(udc->gadget);
	289	goto err1;
352c2dc8	290	}
2d7ebbb0	291	usb_gadget_connect(udc->gadget);
2ccea03a FB	292
2ccea03a FB	293	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
2ccea03a	294	return 0;
2ccea03a FB	295	err1:
	296	dev_err(&udc->dev, "failed to start %s: %d\n",
	297	udc->driver->function, ret);
	298	udc->driver = NULL;
	299	udc->dev.driver = NULL;
4c49a5f0 SAS	300	return ret;
	301	}
	302
	303	int udc_attach_driver(const char name, struct usb_gadget_driver driver)
	304	{
	305	struct usb_udc *udc = NULL;
	306	int ret = -ENODEV;
	307
	308	mutex_lock(&udc_lock);
	309	list_for_each_entry(udc, &udc_list, list) {
	310	ret = strcmp(name, dev_name(&udc->dev));
	311	if (!ret)
	312	break;
	313	}
	314	if (ret) {
	315	ret = -ENODEV;
	316	goto out;
	317	}
	318	if (udc->driver) {
	319	ret = -EBUSY;
	320	goto out;
	321	}
	322	ret = udc_bind_to_driver(udc, driver);
	323	out:
	324	mutex_unlock(&udc_lock);
	325	return ret;
	326	}
	327	EXPORT_SYMBOL_GPL(udc_attach_driver);
	328
	329	int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
	330	{
	331	struct usb_udc *udc = NULL;
	332	int ret;
	333
	334	if (!driver \|\| !driver->bind \|\| !driver->setup)
	335	return -EINVAL;
	336
	337	mutex_lock(&udc_lock);
	338	list_for_each_entry(udc, &udc_list, list) {
	339	/* For now we take the first one */
	340	if (!udc->driver)
	341	goto found;
	342	}
	343
	344	pr_debug("couldn't find an available UDC\n");
	345	mutex_unlock(&udc_lock);
	346	return -ENODEV;
	347	found:
	348	ret = udc_bind_to_driver(udc, driver);
2ccea03a FB	349	mutex_unlock(&udc_lock);
	350	return ret;
	351	}
	352	EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
	353
	354	int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
	355	{
	356	struct usb_udc *udc = NULL;
	357	int ret = -ENODEV;
	358
	359	if (!driver \|\| !driver->unbind)
	360	return -EINVAL;
	361
	362	mutex_lock(&udc_lock);
	363	list_for_each_entry(udc, &udc_list, list)
	364	if (udc->driver == driver) {
	365	usb_gadget_remove_driver(udc);
	366	ret = 0;
	367	break;
	368	}
	369
	370	mutex_unlock(&udc_lock);
	371	return ret;
	372	}
	373	EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
	374
	375	/* ------------------------------------------------------------------------- */
	376
	377	static ssize_t usb_udc_srp_store(struct device *dev,
	378	struct device_attribute attr, const char buf, size_t n)
	379	{
1d91a962	380	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
2ccea03a FB	381
	382	if (sysfs_streq(buf, "1"))
	383	usb_gadget_wakeup(udc->gadget);
	384
	385	return n;
	386	}
	387	static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
	388
	389	static ssize_t usb_udc_softconn_store(struct device *dev,
	390	struct device_attribute attr, const char buf, size_t n)
	391	{
865569ba	392	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
2ccea03a FB	393
2ccea03a FB	394	if (sysfs_streq(buf, "connect")) {
2d7ebbb0	395	usb_gadget_udc_start(udc->gadget, udc->driver);
2ccea03a FB	396	usb_gadget_connect(udc->gadget);
2ccea03a FB	397	} else if (sysfs_streq(buf, "disconnect")) {
83a787a7	398	usb_gadget_disconnect(udc->gadget);
2d7ebbb0	399	usb_gadget_udc_stop(udc->gadget, udc->driver);
2ccea03a FB	400	} else {
	401	dev_err(dev, "unsupported command '%s'\n", buf);
	402	return -EINVAL;
	403	}
	404
	405	return n;
	406	}
	407	static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store);
	408
d327ab5b MN	409	#define USB_UDC_SPEED_ATTR(name, param) \
	410	ssize_t usb_udc_##param##_show(struct device *dev, \
	411	struct device_attribute attr, char buf) \
	412	{ \
	413	struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
	414	return snprintf(buf, PAGE_SIZE, "%s\n", \
	415	usb_speed_string(udc->gadget->param)); \
	416	} \
	417	static DEVICE_ATTR(name, S_IRUSR, usb_udc_##param##_show, NULL)
	418
	419	static USB_UDC_SPEED_ATTR(current_speed, speed);
	420	static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
	421
2ccea03a FB	422	#define USB_UDC_ATTR(name) \
	423	ssize_t usb_udc_##name##_show(struct device *dev, \
	424	struct device_attribute attr, char buf) \
	425	{ \
019f976e	426	struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
2ccea03a FB	427	struct usb_gadget *gadget = udc->gadget; \
	428	\
	429	return snprintf(buf, PAGE_SIZE, "%d\n", gadget->name); \
	430	} \
59d81f81	431	static DEVICE_ATTR(name, S_IRUGO, usb_udc_##name##_show, NULL)
2ccea03a	432
2ccea03a FB	433	static USB_UDC_ATTR(is_otg);
	434	static USB_UDC_ATTR(is_a_peripheral);
	435	static USB_UDC_ATTR(b_hnp_enable);
	436	static USB_UDC_ATTR(a_hnp_support);
	437	static USB_UDC_ATTR(a_alt_hnp_support);
	438
	439	static struct attribute *usb_udc_attrs[] = {
	440	&dev_attr_srp.attr,
	441	&dev_attr_soft_connect.attr,
d327ab5b MN	442	&dev_attr_current_speed.attr,
d327ab5b MN	443	&dev_attr_maximum_speed.attr,
2ccea03a	444
2ccea03a FB	445	&dev_attr_is_otg.attr,
	446	&dev_attr_is_a_peripheral.attr,
	447	&dev_attr_b_hnp_enable.attr,
	448	&dev_attr_a_hnp_support.attr,
	449	&dev_attr_a_alt_hnp_support.attr,
	450	NULL,
	451	};
	452
	453	static const struct attribute_group usb_udc_attr_group = {
	454	.attrs = usb_udc_attrs,
	455	};
	456
	457	static const struct attribute_group *usb_udc_attr_groups[] = {
	458	&usb_udc_attr_group,
	459	NULL,
	460	};
	461
	462	static int usb_udc_uevent(struct device dev, struct kobj_uevent_env env)
	463	{
	464	struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
	465	int ret;
	466
	467	ret = add_uevent_var(env, "USB_UDC_NAME=%s", udc->gadget->name);
	468	if (ret) {
	469	dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
	470	return ret;
	471	}
	472
	473	if (udc->driver) {
	474	ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
	475	udc->driver->function);
	476	if (ret) {
	477	dev_err(dev, "failed to add uevent USB_UDC_DRIVER\n");
	478	return ret;
	479	}
	480	}
	481
	482	return 0;
	483	}
	484
	485	static int __init usb_udc_init(void)
	486	{
	487	udc_class = class_create(THIS_MODULE, "udc");
	488	if (IS_ERR(udc_class)) {
	489	pr_err("failed to create udc class --> %ld\n",
	490	PTR_ERR(udc_class));
	491	return PTR_ERR(udc_class);
	492	}
	493
	494	udc_class->dev_uevent = usb_udc_uevent;
2ccea03a FB	495	return 0;
	496	}
	497	subsys_initcall(usb_udc_init);
	498
	499	static void __exit usb_udc_exit(void)
	500	{
	501	class_destroy(udc_class);
	502	}
	503	module_exit(usb_udc_exit);
	504
	505	MODULE_DESCRIPTION("UDC Framework");
	506	MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
	507	MODULE_LICENSE("GPL v2");