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374
IMX6ULL/doc_pic/12_USB/11_Gadget驱动程序框架.md
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374
IMX6ULL/doc_pic/12_USB/11_Gadget驱动程序框架.md
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# Gadget驱动程序框架 #
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参考资料：
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* Linux下USB gadget设备详解：https://www.docin.com/p-1852320293.html
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* Linux usb gadget框架概述：https://blog.csdn.net/daocaokafei/article/details/114114824
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* USB设备驱动程序-USB Gadget Driver(二)：https://blog.csdn.net/chenzhen1080/article/details/53742924
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* usb gadge驱动设计之我是zero：https://www.bbsmax.com/A/Ae5RvbwM5Q/
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* Linux-USB驱动笔记（四）--USB整体框架: https://qingmu.blog.csdn.net/article/details/119979199
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* USB gadget设备驱动解析: https://www.likecs.com/show-843861.html
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* 调试软件：USB view 、bushound 、及一些硬件USB信号分析仪
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* 可以用[wireshark](https://so.csdn.net/so/search?q=wireshark&spm=1001.2101.3001.7020)+usbmon捕捉usb协议数据包。
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## 1. 笔记
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```shell
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struct usb_gadget - represents a usb slave device
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struct usb_composite_device - represents one composite usb gadget
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struct usb_udc - describes one usb device controller
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```
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```c
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/**
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* struct usb_udc - describes one usb device controller
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* @driver - the gadget driver pointer. For use by the class code
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* @dev - the child device to the actual controller
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* @gadget - the gadget. For use by the class code
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* @list - for use by the udc class driver
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* @vbus - for udcs who care about vbus status, this value is real vbus status;
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* for udcs who do not care about vbus status, this value is always true
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*
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* This represents the internal data structure which is used by the UDC-class
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* to hold information about udc driver and gadget together.
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*/
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struct usb_udc {
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struct usb_gadget_driver *driver;
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struct usb_gadget *gadget;
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struct device dev;
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struct list_head list;
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bool vbus;
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};
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// usb_udc用来表示USB设备控制器，它里面有：
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// 1. usb_gadget : 用来表示硬件信息？represents a usb slave device，比如USB串口？
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// 2. usb_gadget_driver: 用来表示软件信息？driver for usb 'slave' devices
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```
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usb_gadget和usb_composite_dev必定一起出现：usb_gadget描述的是硬件底层信息(?)，usb_composite_dev描述的是硬件的上层信息(？)
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### 1.2 UDC驱动分析
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```shell
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/home/book/100ask_imx6ull-sdk/Linux-4.9.88/drivers/usb/chipidea/ci_hdrc_imx.c
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data->ci_pdev = ci_hdrc_add_device(dev,
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pdev->resource, pdev->num_resources,
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&pdata);
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/home/book/100ask_imx6ull-sdk/Linux-4.9.88/drivers/usb/chipidea/core.c
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static struct platform_driver ci_hdrc_driver = {
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.probe = ci_hdrc_probe,
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.remove = ci_hdrc_remove,
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.driver = {
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.name = "ci_hdrc",
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.pm = &ci_pm_ops,
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},
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};
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```
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中断：
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#### 1.2.1 注册udc
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```c
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// drivers/usb/chipidea/core.c
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ci_hdrc_probe
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ret = ci_hdrc_gadget_init(ci);
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struct ci_role_driver *rdrv;
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rdrv->start = udc_id_switch_for_device;
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rdrv->stop = udc_id_switch_for_host;
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rdrv->irq = udc_irq;
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rdrv->suspend = udc_suspend;
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rdrv->resume = udc_resume;
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rdrv->name = "gadget";
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ret = udc_start(ci);
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ci->gadget.ops = &usb_gadget_ops;
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ci->gadget.speed = USB_SPEED_UNKNOWN;
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ci->gadget.max_speed = USB_SPEED_HIGH;
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ci->gadget.name = ci->platdata->name;
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ci->gadget.otg_caps = otg_caps;
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retval = init_eps(ci);
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hwep->ep.name = hwep->name;
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hwep->ep.ops = &usb_ep_ops;
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if (retval)
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goto free_pools;
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ci->gadget.ep0 = &ci->ep0in->ep;
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retval = usb_add_gadget_udc(dev, &ci->gadget);
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usb_add_gadget_udc_release(parent, gadget, NULL);
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list_add_tail(&udc->list, &udc_list);
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if (!ret)
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ci->roles[CI_ROLE_GADGET] = rdrv;
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platform_set_drvdata(pdev, ci);
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ret = devm_request_irq(dev, ci->irq, ci_irq, IRQF_SHARED,
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ci->platdata->name, ci);
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if (ret)
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goto stop;
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```
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#### 1.2.2 UDC中断处理函数
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```c
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// /home/book/100ask_imx6ull-sdk/Linux-4.9.88/drivers/usb/chipidea/core.c
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ci_irq
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/* Handle device/host interrupt */
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if (ci->role != CI_ROLE_END)
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ret = ci_role(ci)->irq(ci);
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udc_irq
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if (USBi_UI & intr)
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isr_tr_complete_handler(ci);
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/* Only handle setup packet below */
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if (i == 0 &&
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hw_test_and_clear(ci, OP_ENDPTSETUPSTAT, BIT(0)))
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isr_setup_packet_handler(ci);
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```
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#### 1.2.3 控制传输的处理
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isr_setup_packet_handler对于ep0的处理，
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有很多并不需要传递到最上层的composite驱动，
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这个函数的前面代码就自己处理了这些setup包，
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后面无法处理的request才交给上层
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```c
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static void isr_setup_packet_handler(struct ci_hdrc *ci)
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__releases(ci->lock)
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__acquires(ci->lock)
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{
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struct ci_hw_ep *hwep = &ci->ci_hw_ep[0];
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struct usb_ctrlrequest req;
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int type, num, dir, err = -EINVAL;
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u8 tmode = 0;
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/*
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* Flush data and handshake transactions of previous
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* setup packet.
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*/
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_ep_nuke(ci->ep0out);
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_ep_nuke(ci->ep0in);
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/* read_setup_packet */
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do {
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hw_test_and_set_setup_guard(ci);
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memcpy(&req, &hwep->qh.ptr->setup, sizeof(req));
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} while (!hw_test_and_clear_setup_guard(ci));
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type = req.bRequestType;
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ci->ep0_dir = (type & USB_DIR_IN) ? TX : RX;
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switch (req.bRequest) {
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case USB_REQ_CLEAR_FEATURE:
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if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
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le16_to_cpu(req.wValue) ==
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USB_ENDPOINT_HALT) {
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if (req.wLength != 0)
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break;
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num = le16_to_cpu(req.wIndex);
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dir = (num & USB_ENDPOINT_DIR_MASK) ? TX : RX;
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num &= USB_ENDPOINT_NUMBER_MASK;
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if (dir == TX)
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num += ci->hw_ep_max / 2;
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if (!ci->ci_hw_ep[num].wedge) {
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spin_unlock(&ci->lock);
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err = usb_ep_clear_halt(
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&ci->ci_hw_ep[num].ep);
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spin_lock(&ci->lock);
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if (err)
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break;
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}
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err = isr_setup_status_phase(ci);
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} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) &&
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le16_to_cpu(req.wValue) ==
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USB_DEVICE_REMOTE_WAKEUP) {
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if (req.wLength != 0)
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break;
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ci->remote_wakeup = 0;
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err = isr_setup_status_phase(ci);
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} else {
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goto delegate;
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}
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break;
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case USB_REQ_GET_STATUS:
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if ((type != (USB_DIR_IN|USB_RECIP_DEVICE) ||
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le16_to_cpu(req.wIndex) == OTG_STS_SELECTOR) &&
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type != (USB_DIR_IN|USB_RECIP_ENDPOINT) &&
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type != (USB_DIR_IN|USB_RECIP_INTERFACE))
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goto delegate;
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if ((le16_to_cpu(req.wLength) != 2 &&
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le16_to_cpu(req.wLength) != 1) ||
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le16_to_cpu(req.wValue) != 0)
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break;
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err = isr_get_status_response(ci, &req);
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break;
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case USB_REQ_SET_ADDRESS:
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if (type != (USB_DIR_OUT|USB_RECIP_DEVICE))
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goto delegate;
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if (le16_to_cpu(req.wLength) != 0 ||
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le16_to_cpu(req.wIndex) != 0)
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break;
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ci->address = (u8)le16_to_cpu(req.wValue);
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ci->setaddr = true;
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err = isr_setup_status_phase(ci);
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break;
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case USB_REQ_SET_FEATURE:
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if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
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le16_to_cpu(req.wValue) ==
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USB_ENDPOINT_HALT) {
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if (req.wLength != 0)
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break;
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num = le16_to_cpu(req.wIndex);
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dir = (num & USB_ENDPOINT_DIR_MASK) ? TX : RX;
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num &= USB_ENDPOINT_NUMBER_MASK;
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if (dir == TX)
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num += ci->hw_ep_max / 2;
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spin_unlock(&ci->lock);
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err = _ep_set_halt(&ci->ci_hw_ep[num].ep, 1, false);
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spin_lock(&ci->lock);
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if (!err)
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isr_setup_status_phase(ci);
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} else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE)) {
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if (req.wLength != 0)
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break;
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switch (le16_to_cpu(req.wValue)) {
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case USB_DEVICE_REMOTE_WAKEUP:
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ci->remote_wakeup = 1;
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err = isr_setup_status_phase(ci);
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break;
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case USB_DEVICE_TEST_MODE:
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tmode = le16_to_cpu(req.wIndex) >> 8;
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switch (tmode) {
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case TEST_J:
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case TEST_K:
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case TEST_SE0_NAK:
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case TEST_PACKET:
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case TEST_FORCE_EN:
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ci->test_mode = tmode;
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err = isr_setup_status_phase(
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ci);
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break;
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case TEST_OTG_SRP_REQD:
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err = otg_srp_reqd(ci);
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break;
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case TEST_OTG_HNP_REQD:
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err = otg_hnp_reqd(ci);
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break;
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default:
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break;
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}
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break;
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case USB_DEVICE_B_HNP_ENABLE:
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if (ci_otg_is_fsm_mode(ci)) {
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ci->gadget.b_hnp_enable = 1;
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err = isr_setup_status_phase(
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ci);
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}
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break;
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case USB_DEVICE_A_ALT_HNP_SUPPORT:
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if (ci_otg_is_fsm_mode(ci))
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err = otg_a_alt_hnp_support(ci);
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break;
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case USB_DEVICE_A_HNP_SUPPORT:
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if (ci_otg_is_fsm_mode(ci)) {
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ci->gadget.a_hnp_support = 1;
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err = isr_setup_status_phase(
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ci);
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}
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break;
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default:
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goto delegate;
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}
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} else {
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goto delegate;
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}
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break;
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default:
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delegate:
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if (req.wLength == 0) /* no data phase */
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ci->ep0_dir = TX;
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spin_unlock(&ci->lock);
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err = ci->driver->setup(&ci->gadget, &req);
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// composite_driver_template.setup
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composite_setup
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spin_lock(&ci->lock);
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break;
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}
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if (err < 0) {
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spin_unlock(&ci->lock);
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if (_ep_set_halt(&hwep->ep, 1, false))
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dev_err(ci->dev, "error: _ep_set_halt\n");
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spin_lock(&ci->lock);
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}
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}
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```
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####
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#### 1.2.4 EP什么时候使能
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```c
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static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
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{
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int ret;
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dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
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driver->function);
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udc->driver = driver;
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udc->dev.driver = &driver->driver;
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udc->gadget->dev.driver = &driver->driver;
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ret = driver->bind(udc->gadget, driver);
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if (ret)
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goto err1;
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ret = usb_gadget_udc_start(udc);
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return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
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ci_udc_start
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```
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BIN
IMX6ULL/doc_pic/12_USB/pic/78_gadget_composite_dev.png
Normal file
BIN
IMX6ULL/doc_pic/12_USB/pic/78_gadget_composite_dev.png
Normal file
Binary file not shown.
|
After Width: | Height: | Size: 41 KiB |
BIN
IMX6ULL/doc_pic/12_USB/pic/79_imx_otg.png
Normal file
BIN
IMX6ULL/doc_pic/12_USB/pic/79_imx_otg.png
Normal file
Binary file not shown.
|
After Width: | Height: | Size: 107 KiB |
BIN
IMX6ULL/doc_pic/12_USB/pic/80_interrupt_imx6ull_otg.png
Normal file
BIN
IMX6ULL/doc_pic/12_USB/pic/80_interrupt_imx6ull_otg.png
Normal file
Binary file not shown.
|
After Width: | Height: | Size: 57 KiB |
BIN
IMX6ULL/doc_pic/12_USB/pic/81_ci_udc_start.png
Normal file
BIN
IMX6ULL/doc_pic/12_USB/pic/81_ci_udc_start.png
Normal file
Binary file not shown.
|
After Width: | Height: | Size: 98 KiB |
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