gadget驱动框架（二）

快来打我* 2022-10-23 00:50 77阅读 0赞

gadget驱动框架（二）

usb_composite_driver的创建于注册

源码：drivers/usb/legacy/serial.c

  1. //创建usb_composite_driver
  2. static struct usb_composite_driver gserial_driver = {
  3.     .name        = "g_serial",
  4.     .dev        = &device_desc,
  5.     .strings    = dev_strings,
  6.     .max_speed    = USB_SPEED_SUPER,
  7.     .bind        = gs_bind,
  8.     .unbind        = gs_unbind,
  9. };
  11. static int __init init(void)
  12. {
  13.     /* We *could* export two configs; that'd be much cleaner...
  14.      * but neither of these product IDs was defined that way.
  15.      */bConfigurationValue、class、pid等
  16.      //初始化
  17.     if (use_acm) {
  18.         serial_config_driver.label = "CDC ACM config";
  19.         serial_config_driver.bConfigurationValue = 2;
  20.         device_desc.bDeviceClass = USB_CLASS_COMM;
  21.         device_desc.idProduct =
  22.                 cpu_to_le16(GS_CDC_PRODUCT_ID);
  23.     } else if (use_obex) {
  24.         serial_config_driver.label = "CDC OBEX config";
  25.         serial_config_driver.bConfigurationValue = 3;
  26.         device_desc.bDeviceClass = USB_CLASS_COMM;
  27.         device_desc.idProduct =
  28.             cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
  29.     } else {
  30.         serial_config_driver.label = "Generic Serial config";
  31.         serial_config_driver.bConfigurationValue = 1;
  32.         device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
  33.         device_desc.idProduct =
  34.                 cpu_to_le16(GS_PRODUCT_ID);
  35.     }
  36.     strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
  38.     //注册usb_composite_driver与usb_composite_dev
  39.     return usb_composite_probe(&gserial_driver);
  40. }
  41. module_init(init);
  43. static void __exit cleanup(void)
  44. {
  45.     usb_composite_unregister(&gserial_driver);
  46. }
  47. module_exit(cleanup);

usb_gadget_driver的创建与注册

  1. //创建usb_gadget_driver
  2. static const struct usb_gadget_driver composite_driver_template = {
  3.     .bind        = composite_bind,
  4.     .unbind        = composite_unbind,
  6.     .setup        = composite_setup,
  7.     .reset        = composite_disconnect,
  8.     .disconnect    = composite_disconnect,
  10.     .suspend    = composite_suspend,
  11.     .resume        = composite_resume,
  13.     .driver    = {
  14.         .owner        = THIS_MODULE,
  15.     },
  16. };
  18. int usb_composite_probe(struct usb_composite_driver *driver)
  19. {
  20.     struct usb_gadget_driver *gadget_driver;
  22.     if (!driver || !driver->dev || !driver->bind)
  23.         return -EINVAL;
  25.     if (!driver->name)
  26.         driver->name = "composite";
  28.     driver->gadget_driver = composite_driver_template;
  29.     gadget_driver = &driver->gadget_driver;
  31.     gadget_driver->function =  (char *) driver->name;
  32.     gadget_driver->driver.name = driver->name;
  33.     gadget_driver->max_speed = driver->max_speed;
  35.     //注册usb_gadget_driver
  36.     return usb_gadget_probe_driver(gadget_driver);
  37. }
  38. EXPORT_SYMBOL_GPL(usb_composite_probe);
  40. //注册usb_gadget_driver
  41. int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
  42. {
  43.     struct usb_udc        *udc = NULL;
  44.     int            ret = -ENODEV;
  46.     if (!driver || !driver->bind || !driver->setup)
  47.         return -EINVAL;
  49.     mutex_lock(&udc_lock);
  50.     if (driver->udc_name) {
  51.         list_for_each_entry(udc, &udc_list, list) {
  52.             ret = strcmp(driver->udc_name, dev_name(&udc->dev));
  53.             if (!ret)
  54.                 break;
  55.         }
  56.         if (ret)
  57.             ret = -ENODEV;
  58.         else if (udc->driver)
  59.             ret = -EBUSY;
  60.         else
  61.             goto found;
  62.     } else {
  63.         list_for_each_entry(udc, &udc_list, list) {
  64.             /* For now we take the first one */
  65.             if (!udc->driver)
  66.                 goto found;
  67.         }
  68.     }
  70.     //无udc设备，则将usb_gadget_driver添加到gadget_driver_pending_list链表
  71.     if (!driver->match_existing_only) {
  72.         list_add_tail(&driver->pending, &gadget_driver_pending_list);
  73.         pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
  74.             driver->function);
  75.         ret = 0;
  76.     }
  78.     mutex_unlock(&udc_lock);
  79.     return ret;
  80. found:
  81.     //udc设备与usb_gadget_driver绑定
  82.     ret = udc_bind_to_driver(udc, driver);
  83.     mutex_unlock(&udc_lock);
  84.     return ret;
  85. }

usb_gadget的创建及注册

源码：linux4.19.123-drivers/usb/gadget/udc/s3c2410_udc.c

  1. static const struct usb_ep_ops s3c2410_ep_ops = {
  2.     .enable        = s3c2410_udc_ep_enable,
  3.     .disable    = s3c2410_udc_ep_disable,
  5.     .alloc_request    = s3c2410_udc_alloc_request,
  6.     .free_request    = s3c2410_udc_free_request,
  8.     .queue        = s3c2410_udc_queue,
  9.     .dequeue    = s3c2410_udc_dequeue,
  11.     .set_halt    = s3c2410_udc_set_halt,
  12. };
  14. static const struct usb_gadget_ops s3c2410_ops = {
  15.     .get_frame        = s3c2410_udc_get_frame,
  16.     .wakeup            = s3c2410_udc_wakeup,
  17.     .set_selfpowered    = s3c2410_udc_set_selfpowered,
  18.     .pullup            = s3c2410_udc_pullup,
  19.     .vbus_session        = s3c2410_udc_vbus_session,
  20.     .vbus_draw        = s3c2410_vbus_draw,
  21.     .udc_start        = s3c2410_udc_start,
  22.     .udc_stop        = s3c2410_udc_stop,
  23. };
  25. /*---------------------------------------------------------------------------*/
  26. static struct s3c2410_udc memory = {
  27.     //usb_gadget初始化
  28.     .gadget = {
  29.         .ops        = &s3c2410_ops,
  30.         .ep0        = &memory.ep[0].ep,
  31.         .name        = gadget_name,
  32.         .dev = {
  33.             .init_name    = "gadget",
  34.         },
  35.     },
  37.     /* control endpoint */
  38.     .ep[0] = {
  39.         .num        = 0,
  40.         .ep = {
  41.             .name        = ep0name,
  42.             .ops        = &s3c2410_ep_ops,
  43.             .maxpacket    = EP0_FIFO_SIZE,
  44.             .caps        = USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL,
  45.                         USB_EP_CAPS_DIR_ALL),
  46.         },
  47.         .dev        = &memory,
  48.     },
  50.     /* first group of endpoints */
  51.     .ep[1] = {
  52.         .num        = 1,
  53.         .ep = {
  54.             .name        = "ep1-bulk",
  55.             .ops        = &s3c2410_ep_ops,
  56.             .maxpacket    = EP_FIFO_SIZE,
  57.             .caps        = USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK,
  58.                         USB_EP_CAPS_DIR_ALL),
  59.         },
  60.         .dev        = &memory,
  61.         .fifo_size    = EP_FIFO_SIZE,
  62.         .bEndpointAddress = 1,
  63.         .bmAttributes    = USB_ENDPOINT_XFER_BULK,
  64.     },
  65.     .ep[2] = {
  66.         .num        = 2,
  67.         .ep = {
  68.             .name        = "ep2-bulk",
  69.             .ops        = &s3c2410_ep_ops,
  70.             .maxpacket    = EP_FIFO_SIZE,
  71.             .caps        = USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK,
  72.                         USB_EP_CAPS_DIR_ALL),
  73.         },
  74.         .dev        = &memory,
  75.         .fifo_size    = EP_FIFO_SIZE,
  76.         .bEndpointAddress = 2,
  77.         .bmAttributes    = USB_ENDPOINT_XFER_BULK,
  78.     },
  79.     .ep[3] = {
  80.         .num        = 3,
  81.         .ep = {
  82.             .name        = "ep3-bulk",
  83.             .ops        = &s3c2410_ep_ops,
  84.             .maxpacket    = EP_FIFO_SIZE,
  85.             .caps        = USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK,
  86.                         USB_EP_CAPS_DIR_ALL),
  87.         },
  88.         .dev        = &memory,
  89.         .fifo_size    = EP_FIFO_SIZE,
  90.         .bEndpointAddress = 3,
  91.         .bmAttributes    = USB_ENDPOINT_XFER_BULK,
  92.     },
  93.     .ep[4] = {
  94.         .num        = 4,
  95.         .ep = {
  96.             .name        = "ep4-bulk",
  97.             .ops        = &s3c2410_ep_ops,
  98.             .maxpacket    = EP_FIFO_SIZE,
  99.             .caps        = USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK,
  100.                         USB_EP_CAPS_DIR_ALL),
  101.         },
  102.         .dev        = &memory,
  103.         .fifo_size    = EP_FIFO_SIZE,
  104.         .bEndpointAddress = 4,
  105.         .bmAttributes    = USB_ENDPOINT_XFER_BULK,
  106.     }
  108. };
  109. /*
  110.  *    probe - binds to the platform device
  111.  */
  112. static int s3c2410_udc_probe(struct platform_device *pdev)
  113. {
  114.     struct s3c2410_udc *udc = &memory;
  115.     struct device *dev = &pdev->dev;
  116.     int retval;
  117.     int irq;
  119.     dev_dbg(dev, "%s()\n", __func__);
  121.     ......
  123.     //创建/注册udc，注册usb_gadget
  124.     retval = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
  125.     if (retval)
  126.         goto err_add_udc;
  128.     ......
  130.     return 0;
  132. err_add_udc:
  133.     if (udc_info && !udc_info->udc_command &&
  134.             gpio_is_valid(udc_info->pullup_pin))
  135.         gpio_free(udc_info->pullup_pin);
  136. err_vbus_irq:
  137.     if (udc_info && udc_info->vbus_pin > 0)
  138.         free_irq(gpio_to_irq(udc_info->vbus_pin), udc);
  139. err_gpio_claim:
  140.     if (udc_info && udc_info->vbus_pin > 0)
  141.         gpio_free(udc_info->vbus_pin);
  142. err_int:
  143.     free_irq(IRQ_USBD, udc);
  144. err_map:
  145.     iounmap(base_addr);
  146. err_mem:
  147.     release_mem_region(rsrc_start, rsrc_len);
  149.     return retval;
  150. }

usb_udc的创建及注册

源码：linux-4.19.123-drivers/usb/gadget/udc/core.c

  1. int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
  2. {
  3.     return usb_add_gadget_udc_release(parent, gadget, NULL);
  4. }
  5. EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
  7. /**
  8.  * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
  9.  * @parent: the parent device to this udc. Usually the controller driver's
  10.  * device.
  11.  * @gadget: the gadget to be added to the list.
  12.  * @release: a gadget release function.
  13.  *
  14.  * Returns zero on success, negative errno otherwise.
  15.  * Calls the gadget release function in the latter case.
  16.  */
  17. int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
  18.         void (*release)(struct device *dev))
  19. {
  20.     struct usb_udc        *udc;
  21.     int            ret = -ENOMEM;
  23.     dev_set_name(&gadget->dev, "gadget");
  24.     INIT_WORK(&gadget->work, usb_gadget_state_work);
  25.     gadget->dev.parent = parent;
  27.     if (release)
  28.         gadget->dev.release = release;
  29.     else
  30.         gadget->dev.release = usb_udc_nop_release;
  32.     device_initialize(&gadget->dev);
  34.     //创建usb_udc
  35.     udc = kzalloc(sizeof(*udc), GFP_KERNEL);
  36.     if (!udc)
  37.         goto err_put_gadget;
  39.     device_initialize(&udc->dev);
  40.     udc->dev.release = usb_udc_release;
  41.     udc->dev.class = udc_class;
  42.     udc->dev.groups = usb_udc_attr_groups;
  43.     udc->dev.parent = parent;
  44.     ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
  45.     if (ret)
  46.         goto err_put_udc;
  48.     ret = device_add(&gadget->dev);
  49.     if (ret)
  50.         goto err_put_udc;
  52.     udc->gadget = gadget;
  53.     gadget->udc = udc;
  55.     mutex_lock(&udc_lock);
  56.     //将新创建的usb_udc添加到udc_list链表中
  57.     list_add_tail(&udc->list, &udc_list);
  59.     ret = device_add(&udc->dev);
  60.     if (ret)
  61.         goto err_unlist_udc;
  63.     usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
  64.     udc->vbus = true;
  66.     /* pick up one of pending gadget drivers */
  67.     ret = check_pending_gadget_drivers(udc);
  68.     if (ret)
  69.         goto err_del_udc;
  71.     mutex_unlock(&udc_lock);
  73.     return 0;
  75.  err_del_udc:
  76.     device_del(&udc->dev);
  78.  err_unlist_udc:
  79.     list_del(&udc->list);
  80.     mutex_unlock(&udc_lock);
  82.     device_del(&gadget->dev);
  84.  err_put_udc:
  85.     put_device(&udc->dev);
  87.  err_put_gadget:
  88.     put_device(&gadget->dev);
  89.     return ret;
  90. }

小结

至此，已完成usb_gadget_driver、usb_composite_driver、usb_gadget、usb_udc等几个核心结构体的创建及注册。后面将介绍usb_composite_dev等的创建及注册，以及usb_gadget_driver与usb_udc的绑定过程。

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