2 * udc-core.c - Core UDC Framework
4 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
6 * Author: Felipe Balbi <balbi@ti.com>
8 * Taken from Linux Kernel v3.19-rc1 (drivers/usb/gadget/udc-core.c) and ported
11 * commit 02e8c96627 : usb: gadget: udc: core: prepend udc_attach_driver with
14 * SPDX-License-Identifier: GPL-2.0
17 #include <linux/compat.h>
19 #include <asm/cache.h>
20 #include <asm/dma-mapping.h>
23 #include <linux/usb/ch9.h>
24 #include <linux/usb/gadget.h>
27 * struct usb_udc - describes one usb device controller
28 * @driver - the gadget driver pointer. For use by the class code
29 * @dev - the child device to the actual controller
30 * @gadget - the gadget. For use by the class code
31 * @list - for use by the udc class driver
33 * This represents the internal data structure which is used by the UDC-class
34 * to hold information about udc driver and gadget together.
37 struct usb_gadget_driver *driver;
38 struct usb_gadget *gadget;
40 struct list_head list;
43 static struct class *udc_class;
44 static LIST_HEAD(udc_list);
45 DEFINE_MUTEX(udc_lock);
47 /* ------------------------------------------------------------------------- */
49 int usb_gadget_map_request(struct usb_gadget *gadget,
50 struct usb_request *req, int is_in)
55 req->dma = dma_map_single(req->buf, req->length,
56 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
60 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
62 void usb_gadget_unmap_request(struct usb_gadget *gadget,
63 struct usb_request *req, int is_in)
68 dma_unmap_single((void *)(uintptr_t)req->dma, req->length,
69 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
71 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
73 /* ------------------------------------------------------------------------- */
76 * usb_gadget_giveback_request - give the request back to the gadget layer
77 * Context: in_interrupt()
79 * This is called by device controller drivers in order to return the
80 * completed request back to the gadget layer.
82 void usb_gadget_giveback_request(struct usb_ep *ep,
83 struct usb_request *req)
85 req->complete(ep, req);
87 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
89 /* ------------------------------------------------------------------------- */
91 void usb_gadget_set_state(struct usb_gadget *gadget,
92 enum usb_device_state state)
94 gadget->state = state;
96 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
98 /* ------------------------------------------------------------------------- */
101 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
102 * @gadget: The gadget which bus reset occurs
103 * @driver: The gadget driver we want to notify
105 * If the udc driver has bus reset handler, it needs to call this when the bus
106 * reset occurs, it notifies the gadget driver that the bus reset occurs as
107 * well as updates gadget state.
109 void usb_gadget_udc_reset(struct usb_gadget *gadget,
110 struct usb_gadget_driver *driver)
112 driver->reset(gadget);
113 usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
115 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
118 * usb_gadget_udc_start - tells usb device controller to start up
119 * @udc: The UDC to be started
121 * This call is issued by the UDC Class driver when it's about
122 * to register a gadget driver to the device controller, before
123 * calling gadget driver's bind() method.
125 * It allows the controller to be powered off until strictly
126 * necessary to have it powered on.
128 * Returns zero on success, else negative errno.
130 static inline int usb_gadget_udc_start(struct usb_udc *udc)
132 return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
136 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
137 * @gadget: The device we want to stop activity
138 * @driver: The driver to unbind from @gadget
140 * This call is issued by the UDC Class driver after calling
141 * gadget driver's unbind() method.
143 * The details are implementation specific, but it can go as
144 * far as powering off UDC completely and disable its data
147 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
149 udc->gadget->ops->udc_stop(udc->gadget);
153 * usb_udc_release - release the usb_udc struct
154 * @dev: the dev member within usb_udc
156 * This is called by driver's core in order to free memory once the last
157 * reference is released.
159 static void usb_udc_release(struct device *dev)
163 udc = container_of(dev, struct usb_udc, dev);
168 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
169 * @parent: the parent device to this udc. Usually the controller driver's
171 * @gadget: the gadget to be added to the list.
172 * @release: a gadget release function.
174 * Returns zero on success, negative errno otherwise.
176 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
177 void (*release)(struct device *dev))
182 udc = kzalloc(sizeof(*udc), GFP_KERNEL);
186 dev_set_name(&gadget->dev, "gadget");
187 gadget->dev.parent = parent;
189 udc->dev.release = usb_udc_release;
190 udc->dev.class = udc_class;
191 udc->dev.parent = parent;
193 udc->gadget = gadget;
195 mutex_lock(&udc_lock);
196 list_add_tail(&udc->list, &udc_list);
198 usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
200 mutex_unlock(&udc_lock);
207 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
210 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
211 * @parent: the parent device to this udc. Usually the controller
213 * @gadget: the gadget to be added to the list
215 * Returns zero on success, negative errno otherwise.
217 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
219 return usb_add_gadget_udc_release(parent, gadget, NULL);
221 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
223 static void usb_gadget_remove_driver(struct usb_udc *udc)
225 dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
226 udc->driver->function);
228 usb_gadget_disconnect(udc->gadget);
229 udc->driver->disconnect(udc->gadget);
230 udc->driver->unbind(udc->gadget);
231 usb_gadget_udc_stop(udc);
237 * usb_del_gadget_udc - deletes @udc from udc_list
238 * @gadget: the gadget to be removed.
240 * This, will call usb_gadget_unregister_driver() if
241 * the @udc is still busy.
243 void usb_del_gadget_udc(struct usb_gadget *gadget)
245 struct usb_udc *udc = NULL;
247 mutex_lock(&udc_lock);
248 list_for_each_entry(udc, &udc_list, list)
249 if (udc->gadget == gadget)
252 dev_err(gadget->dev.parent, "gadget not registered.\n");
253 mutex_unlock(&udc_lock);
258 dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
260 list_del(&udc->list);
261 mutex_unlock(&udc_lock);
264 usb_gadget_remove_driver(udc);
266 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
268 /* ------------------------------------------------------------------------- */
270 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
274 dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
277 udc->driver = driver;
279 ret = driver->bind(udc->gadget);
282 ret = usb_gadget_udc_start(udc);
284 driver->unbind(udc->gadget);
287 usb_gadget_connect(udc->gadget);
292 dev_err(&udc->dev, "failed to start %s: %d\n",
293 udc->driver->function, ret);
298 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
300 struct usb_udc *udc = NULL;
303 if (!driver || !driver->bind || !driver->setup)
306 mutex_lock(&udc_lock);
307 list_for_each_entry(udc, &udc_list, list) {
308 /* For now we take the first one */
313 printf("couldn't find an available UDC\n");
314 mutex_unlock(&udc_lock);
317 ret = udc_bind_to_driver(udc, driver);
318 mutex_unlock(&udc_lock);
321 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
323 int usb_gadget_register_driver(struct usb_gadget_driver *driver)
325 return usb_gadget_probe_driver(driver);
327 EXPORT_SYMBOL_GPL(usb_gadget_register_driver);
329 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
331 struct usb_udc *udc = NULL;
334 if (!driver || !driver->unbind)
337 mutex_lock(&udc_lock);
338 list_for_each_entry(udc, &udc_list, list)
339 if (udc->driver == driver) {
340 usb_gadget_remove_driver(udc);
341 usb_gadget_set_state(udc->gadget,
342 USB_STATE_NOTATTACHED);
347 mutex_unlock(&udc_lock);
350 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
352 MODULE_DESCRIPTION("UDC Framework");
353 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
354 MODULE_LICENSE("GPL v2");