drivers/usb/gadget/udc/udc-core.c

   1 /**
   2  * udc-core.c - Core UDC Framework
   3  *
   4  * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
   5  *
   6  * Author: Felipe Balbi <balbi@ti.com>
   7  *
   8  * Taken from Linux Kernel v3.19-rc1 (drivers/usb/gadget/udc-core.c) and ported
   9  * to uboot.
  10  *
  11  * commit 02e8c96627 : usb: gadget: udc: core: prepend udc_attach_driver with
  12  *                     usb_
  13  *
  14  * SPDX-License-Identifier:     GPL-2.0
  15  */
  16
  17 #include <linux/compat.h>
  18 #include <malloc.h>
  19 #include <asm/cache.h>
  20 #include <asm/dma-mapping.h>
  21 #include <common.h>
  22
  23 #include <linux/usb/ch9.h>
  24 #include <linux/usb/gadget.h>
  25
  26 /**
  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
  32  *
  33  * This represents the internal data structure which is used by the UDC-class
  34  * to hold information about udc driver and gadget together.
  35  */
  36 struct usb_udc {
  37         struct usb_gadget_driver        *driver;
  38         struct usb_gadget               *gadget;
  39         struct device                   dev;
  40         struct list_head                list;
  41 };
  42
  43 static struct class *udc_class;
  44 static LIST_HEAD(udc_list);
  45 DEFINE_MUTEX(udc_lock);
  46
  47 /* ------------------------------------------------------------------------- */
  48
  49 int usb_gadget_map_request(struct usb_gadget *gadget,
  50                 struct usb_request *req, int is_in)
  51 {
  52         if (req->length == 0)
  53                 return 0;
  54
  55         req->dma = dma_map_single(req->buf, req->length,
  56                                   is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
  57
  58         return 0;
  59 }
  60 EXPORT_SYMBOL_GPL(usb_gadget_map_request);
  61
  62 void usb_gadget_unmap_request(struct usb_gadget *gadget,
  63                 struct usb_request *req, int is_in)
  64 {
  65         if (req->length == 0)
  66                 return;
  67
  68         dma_unmap_single((void *)req->dma, req->length,
  69                          is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
  70 }
  71 EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
  72
  73 /* ------------------------------------------------------------------------- */
  74
  75 /**
  76  * usb_gadget_giveback_request - give the request back to the gadget layer
  77  * Context: in_interrupt()
  78  *
  79  * This is called by device controller drivers in order to return the
  80  * completed request back to the gadget layer.
  81  */
  82 void usb_gadget_giveback_request(struct usb_ep *ep,
  83                 struct usb_request *req)
  84 {
  85         req->complete(ep, req);
  86 }
  87 EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
  88
  89 /* ------------------------------------------------------------------------- */
  90
  91 void usb_gadget_set_state(struct usb_gadget *gadget,
  92                 enum usb_device_state state)
  93 {
  94         gadget->state = state;
  95 }
  96 EXPORT_SYMBOL_GPL(usb_gadget_set_state);
  97
  98 /* ------------------------------------------------------------------------- */
  99
 100 /**
 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
 104  *
 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.
 108  */
 109 void usb_gadget_udc_reset(struct usb_gadget *gadget,
 110                 struct usb_gadget_driver *driver)
 111 {
 112         driver->reset(gadget);
 113         usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
 114 }
 115 EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
 116
 117 /**
 118  * usb_gadget_udc_start - tells usb device controller to start up
 119  * @udc: The UDC to be started
 120  *
 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.
 124  *
 125  * It allows the controller to be powered off until strictly
 126  * necessary to have it powered on.
 127  *
 128  * Returns zero on success, else negative errno.
 129  */
 130 static inline int usb_gadget_udc_start(struct usb_udc *udc)
 131 {
 132         return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
 133 }
 134
 135 /**
 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
 139  *
 140  * This call is issued by the UDC Class driver after calling
 141  * gadget driver's unbind() method.
 142  *
 143  * The details are implementation specific, but it can go as
 144  * far as powering off UDC completely and disable its data
 145  * line pullups.
 146  */
 147 static inline void usb_gadget_udc_stop(struct usb_udc *udc)
 148 {
 149         udc->gadget->ops->udc_stop(udc->gadget);
 150 }
 151
 152 /**
 153  * usb_udc_release - release the usb_udc struct
 154  * @dev: the dev member within usb_udc
 155  *
 156  * This is called by driver's core in order to free memory once the last
 157  * reference is released.
 158  */
 159 static void usb_udc_release(struct device *dev)
 160 {
 161         struct usb_udc *udc;
 162
 163         udc = container_of(dev, struct usb_udc, dev);
 164         kfree(udc);
 165 }
 166
 167 /**
 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
 170  * device.
 171  * @gadget: the gadget to be added to the list.
 172  * @release: a gadget release function.
 173  *
 174  * Returns zero on success, negative errno otherwise.
 175  */
 176 int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 177                 void (*release)(struct device *dev))
 178 {
 179         struct usb_udc          *udc;
 180         int                     ret = -ENOMEM;
 181
 182         udc = kzalloc(sizeof(*udc), GFP_KERNEL);
 183         if (!udc)
 184                 goto err1;
 185
 186         dev_set_name(&gadget->dev, "gadget");
 187         gadget->dev.parent = parent;
 188
 189         udc->dev.release = usb_udc_release;
 190         udc->dev.class = udc_class;
 191         udc->dev.parent = parent;
 192
 193         udc->gadget = gadget;
 194
 195         mutex_lock(&udc_lock);
 196         list_add_tail(&udc->list, &udc_list);
 197
 198         usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
 199
 200         mutex_unlock(&udc_lock);
 201
 202         return 0;
 203
 204 err1:
 205         return ret;
 206 }
 207 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
 208
 209 /**
 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
 212  * driver's device.
 213  * @gadget: the gadget to be added to the list
 214  *
 215  * Returns zero on success, negative errno otherwise.
 216  */
 217 int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
 218 {
 219         return usb_add_gadget_udc_release(parent, gadget, NULL);
 220 }
 221 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 222
 223 static void usb_gadget_remove_driver(struct usb_udc *udc)
 224 {
 225         dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
 226                         udc->driver->function);
 227
 228         usb_gadget_disconnect(udc->gadget);
 229         udc->driver->disconnect(udc->gadget);
 230         udc->driver->unbind(udc->gadget);
 231         usb_gadget_udc_stop(udc);
 232
 233         udc->driver = NULL;
 234 }
 235
 236 /**
 237  * usb_del_gadget_udc - deletes @udc from udc_list
 238  * @gadget: the gadget to be removed.
 239  *
 240  * This, will call usb_gadget_unregister_driver() if
 241  * the @udc is still busy.
 242  */
 243 void usb_del_gadget_udc(struct usb_gadget *gadget)
 244 {
 245         struct usb_udc          *udc = NULL;
 246
 247         mutex_lock(&udc_lock);
 248         list_for_each_entry(udc, &udc_list, list)
 249                 if (udc->gadget == gadget)
 250                         goto found;
 251
 252         dev_err(gadget->dev.parent, "gadget not registered.\n");
 253         mutex_unlock(&udc_lock);
 254
 255         return;
 256
 257 found:
 258         dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
 259
 260         list_del(&udc->list);
 261         mutex_unlock(&udc_lock);
 262
 263         if (udc->driver)
 264                 usb_gadget_remove_driver(udc);
 265 }
 266 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
 267
 268 /* ------------------------------------------------------------------------- */
 269
 270 static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
 271 {
 272         int ret;
 273
 274         dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
 275                         driver->function);
 276
 277         udc->driver = driver;
 278
 279         ret = driver->bind(udc->gadget);
 280         if (ret)
 281                 goto err1;
 282         ret = usb_gadget_udc_start(udc);
 283         if (ret) {
 284                 driver->unbind(udc->gadget);
 285                 goto err1;
 286         }
 287         usb_gadget_connect(udc->gadget);
 288
 289         return 0;
 290 err1:
 291         if (ret != -EISNAM)
 292                 dev_err(&udc->dev, "failed to start %s: %d\n",
 293                         udc->driver->function, ret);
 294         udc->driver = NULL;
 295         return ret;
 296 }
 297
 298 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 299 {
 300         struct usb_udc          *udc = NULL;
 301         int                     ret;
 302
 303         if (!driver || !driver->bind || !driver->setup)
 304                 return -EINVAL;
 305
 306         mutex_lock(&udc_lock);
 307         list_for_each_entry(udc, &udc_list, list) {
 308                 /* For now we take the first one */
 309                 if (!udc->driver)
 310                         goto found;
 311         }
 312
 313         printf("couldn't find an available UDC\n");
 314         mutex_unlock(&udc_lock);
 315         return -ENODEV;
 316 found:
 317         ret = udc_bind_to_driver(udc, driver);
 318         mutex_unlock(&udc_lock);
 319         return ret;
 320 }
 321 EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
 322
 323 int usb_gadget_register_driver(struct usb_gadget_driver *driver)
 324 {
 325         return usb_gadget_probe_driver(driver);
 326 }
 327 EXPORT_SYMBOL_GPL(usb_gadget_register_driver);
 328
 329 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 330 {
 331         struct usb_udc          *udc = NULL;
 332         int                     ret = -ENODEV;
 333
 334         if (!driver || !driver->unbind)
 335                 return -EINVAL;
 336
 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);
 343                         ret = 0;
 344                         break;
 345                 }
 346
 347         mutex_unlock(&udc_lock);
 348         return ret;
 349 }
 350 EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
 351
 352 MODULE_DESCRIPTION("UDC Framework");
 353 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
 354 MODULE_LICENSE("GPL v2");