uboot/drivers/usb/gadget/udc/udc-core.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/**
   3 * udc-core.c - Core UDC Framework
   4 *
   5 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
   6 *
   7 * Author: Felipe Balbi <balbi@ti.com>
   8 *
   9 * Taken from Linux Kernel v3.19-rc1 (drivers/usb/gadget/udc-core.c) and ported
  10 * to uboot.
  11 *
  12 * commit 02e8c96627 : usb: gadget: udc: core: prepend udc_attach_driver with
  13 *                     usb_
  14 */
  15
  16#include <linux/compat.h>
  17#include <malloc.h>
  18#include <asm/cache.h>
  19#include <asm/dma-mapping.h>
  20#include <common.h>
  21#include <dm.h>
  22#include <dm/device-internal.h>
  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 */
  36struct usb_udc {
  37        struct usb_gadget_driver        *driver;
  38        struct usb_gadget               *gadget;
  39        struct device                   dev;
  40        struct list_head                list;
  41};
  42
  43static struct class *udc_class;
  44static LIST_HEAD(udc_list);
  45DEFINE_MUTEX(udc_lock);
  46
  47/* ------------------------------------------------------------------------- */
  48
  49int 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}
  60EXPORT_SYMBOL_GPL(usb_gadget_map_request);
  61
  62void 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 *)(uintptr_t)req->dma, req->length,
  69                         is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
  70}
  71EXPORT_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 */
  82void usb_gadget_giveback_request(struct usb_ep *ep,
  83                struct usb_request *req)
  84{
  85        req->complete(ep, req);
  86}
  87EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
  88
  89/* ------------------------------------------------------------------------- */
  90
  91void usb_gadget_set_state(struct usb_gadget *gadget,
  92                enum usb_device_state state)
  93{
  94        gadget->state = state;
  95}
  96EXPORT_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 */
 109void 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}
 115EXPORT_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 */
 130static 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 */
 147static 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 */
 159static 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 */
 176int 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
 204err1:
 205        return ret;
 206}
 207EXPORT_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 */
 217int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
 218{
 219        return usb_add_gadget_udc_release(parent, gadget, NULL);
 220}
 221EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 222
 223static 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 */
 243void 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
 257found:
 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}
 266EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
 267
 268/* ------------------------------------------------------------------------- */
 269
 270static 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;
 290err1:
 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
 298int 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;
 316found:
 317        ret = udc_bind_to_driver(udc, driver);
 318        mutex_unlock(&udc_lock);
 319        return ret;
 320}
 321EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
 322
 323int usb_gadget_register_driver(struct usb_gadget_driver *driver)
 324{
 325        return usb_gadget_probe_driver(driver);
 326}
 327EXPORT_SYMBOL_GPL(usb_gadget_register_driver);
 328
 329int 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}
 350EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
 351
 352MODULE_DESCRIPTION("UDC Framework");
 353MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
 354MODULE_LICENSE("GPL v2");
 355