1 // SPDX-License-Identifier: GPL-2.0
3 * udc-core.c - Core UDC Framework
5 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
7 * Author: Felipe Balbi <balbi@ti.com>
9 * Taken from Linux Kernel v3.19-rc1 (drivers/usb/gadget/udc-core.c) and ported
12 * commit 02e8c96627 : usb: gadget: udc: core: prepend udc_attach_driver with
16 #include <linux/compat.h>
18 #include <asm/cache.h>
19 #include <asm/dma-mapping.h>
22 #include <linux/usb/ch9.h>
23 #include <linux/usb/gadget.h>
26 * struct usb_udc - describes one usb device controller
27 * @driver - the gadget driver pointer. For use by the class code
28 * @dev - the child device to the actual controller
29 * @gadget - the gadget. For use by the class code
30 * @list - for use by the udc class driver
32 * This represents the internal data structure which is used by the UDC-class
33 * to hold information about udc driver and gadget together.
36 struct usb_gadget_driver *driver;
37 struct usb_gadget *gadget;
39 struct list_head list;
42 static struct class *udc_class;
43 static LIST_HEAD(udc_list);
44 DEFINE_MUTEX(udc_lock);
46 /* ------------------------------------------------------------------------- */
48 int usb_gadget_map_request(struct usb_gadget *gadget,
49 struct usb_request *req, int is_in)
54 req->dma = dma_map_single(req->buf, req->length,
55 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
59 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
61 void usb_gadget_unmap_request(struct usb_gadget *gadget,
62 struct usb_request *req, int is_in)
67 dma_unmap_single((void *)(uintptr_t)req->dma, req->length,
68 is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
70 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
72 /* ------------------------------------------------------------------------- */
75 * usb_gadget_giveback_request - give the request back to the gadget layer
76 * Context: in_interrupt()
78 * This is called by device controller drivers in order to return the
79 * completed request back to the gadget layer.
81 void usb_gadget_giveback_request(struct usb_ep *ep,
82 struct usb_request *req)
84 req->complete(ep, req);
86 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
88 /* ------------------------------------------------------------------------- */
90 void usb_gadget_set_state(struct usb_gadget *gadget,
91 enum usb_device_state state)
93 gadget->state = state;
95 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
97 /* ------------------------------------------------------------------------- */
100 * usb_gadget_udc_reset - notifies the udc core that bus reset occurs
101 * @gadget: The gadget which bus reset occurs
102 * @driver: The gadget driver we want to notify
104 * If the udc driver has bus reset handler, it needs to call this when the bus
105 * reset occurs, it notifies the gadget driver that the bus reset occurs as
106 * well as updates gadget state.
108 void usb_gadget_udc_reset(struct usb_gadget *gadget,
109 struct usb_gadget_driver *driver)
111 driver->reset(gadget);
112 usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
114 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
117 * usb_gadget_udc_start - tells usb device controller to start up
118 * @udc: The UDC to be started
120 * This call is issued by the UDC Class driver when it's about
121 * to register a gadget driver to the device controller, before
122 * calling gadget driver's bind() method.
124 * It allows the controller to be powered off until strictly
125 * necessary to have it powered on.
127 * Returns zero on success, else negative errno.
129 static inline int usb_gadget_udc_start(struct usb_udc *udc)
131 return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
135 * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
136 * @gadget: The device we want to stop activity
137 * @driver: The driver to unbind from @gadget
139 * This call is issued by the UDC Class driver after calling
140 * gadget driver's unbind() method.
142 * The details are implementation specific, but it can go as
143 * far as powering off UDC completely and disable its data
146 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
148 udc->gadget->ops->udc_stop(udc->gadget);
152 * usb_udc_release - release the usb_udc struct
153 * @dev: the dev member within usb_udc
155 * This is called by driver's core in order to free memory once the last
156 * reference is released.
158 static void usb_udc_release(struct device *dev)
162 udc = container_of(dev, struct usb_udc, dev);
167 * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
168 * @parent: the parent device to this udc. Usually the controller driver's
170 * @gadget: the gadget to be added to the list.
171 * @release: a gadget release function.
173 * Returns zero on success, negative errno otherwise.
175 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
176 void (*release)(struct device *dev))
181 udc = kzalloc(sizeof(*udc), GFP_KERNEL);
185 dev_set_name(&gadget->dev, "gadget");
186 gadget->dev.parent = parent;
188 udc->dev.release = usb_udc_release;
189 udc->dev.class = udc_class;
190 udc->dev.parent = parent;
192 udc->gadget = gadget;
194 mutex_lock(&udc_lock);
195 list_add_tail(&udc->list, &udc_list);
197 usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
199 mutex_unlock(&udc_lock);
206 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
209 * usb_add_gadget_udc - adds a new gadget to the udc class driver list
210 * @parent: the parent device to this udc. Usually the controller
212 * @gadget: the gadget to be added to the list
214 * Returns zero on success, negative errno otherwise.
216 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
218 return usb_add_gadget_udc_release(parent, gadget, NULL);
220 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
222 static void usb_gadget_remove_driver(struct usb_udc *udc)
224 dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
225 udc->driver->function);
227 usb_gadget_disconnect(udc->gadget);
228 udc->driver->disconnect(udc->gadget);
229 udc->driver->unbind(udc->gadget);
230 usb_gadget_udc_stop(udc);
236 * usb_del_gadget_udc - deletes @udc from udc_list
237 * @gadget: the gadget to be removed.
239 * This, will call usb_gadget_unregister_driver() if
240 * the @udc is still busy.
242 void usb_del_gadget_udc(struct usb_gadget *gadget)
244 struct usb_udc *udc = NULL;
246 mutex_lock(&udc_lock);
247 list_for_each_entry(udc, &udc_list, list)
248 if (udc->gadget == gadget)
251 dev_err(gadget->dev.parent, "gadget not registered.\n");
252 mutex_unlock(&udc_lock);
257 dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
259 list_del(&udc->list);
260 mutex_unlock(&udc_lock);
263 usb_gadget_remove_driver(udc);
265 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
267 /* ------------------------------------------------------------------------- */
269 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
273 dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
276 udc->driver = driver;
278 ret = driver->bind(udc->gadget);
281 ret = usb_gadget_udc_start(udc);
283 driver->unbind(udc->gadget);
286 usb_gadget_connect(udc->gadget);
291 dev_err(&udc->dev, "failed to start %s: %d\n",
292 udc->driver->function, ret);
297 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
299 struct usb_udc *udc = NULL;
302 if (!driver || !driver->bind || !driver->setup)
305 mutex_lock(&udc_lock);
306 list_for_each_entry(udc, &udc_list, list) {
307 /* For now we take the first one */
312 printf("couldn't find an available UDC\n");
313 mutex_unlock(&udc_lock);
316 ret = udc_bind_to_driver(udc, driver);
317 mutex_unlock(&udc_lock);
320 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
322 int usb_gadget_register_driver(struct usb_gadget_driver *driver)
324 return usb_gadget_probe_driver(driver);
326 EXPORT_SYMBOL_GPL(usb_gadget_register_driver);
328 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
330 struct usb_udc *udc = NULL;
333 if (!driver || !driver->unbind)
336 mutex_lock(&udc_lock);
337 list_for_each_entry(udc, &udc_list, list)
338 if (udc->driver == driver) {
339 usb_gadget_remove_driver(udc);
340 usb_gadget_set_state(udc->gadget,
341 USB_STATE_NOTATTACHED);
346 mutex_unlock(&udc_lock);
349 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
351 MODULE_DESCRIPTION("UDC Framework");
352 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
353 MODULE_LICENSE("GPL v2");