127 lines
3.7 KiB
ReStructuredText
127 lines
3.7 KiB
ReStructuredText
vendor host 驱动编写
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===========================
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本节主要介绍如何编写一个 vendor host 驱动。
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- 首先复制一份 class/template/usbh_xxx.c 文件
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- 定义 class 驱动并使用 CLASS_INFO_DEFINE 前缀，这样，枚举完成后，协议栈自动通过 usbd_class_find_driver 来查找对应的驱动。
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.. code-block:: C
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static const struct usbh_class_driver xxx_class_driver = {
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.driver_name = "xxx",
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.connect = usbh_xxx_connect,
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.disconnect = usbh_xxx_disconnect
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};
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CLASS_INFO_DEFINE const struct usbh_class_info xxx_class_info = {
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.match_flags = USB_CLASS_MATCH_INTF_CLASS | USB_CLASS_MATCH_INTF_SUBCLASS | USB_CLASS_MATCH_INTF_PROTOCOL,
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.bInterfaceClass = 0,
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.bInterfaceSubClass = 0,
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.bInterfaceProtocol = 0,
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.id_table = NULL,
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.class_driver = &xxx_class_driver
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};
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- 实现 connect 和 disconnect 函数, 在 connect 函数中，需要分配一个 xxx_class 结构体，在 disconnect 函数中释放 urb 和 xxx_class。
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.. code-block:: C
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struct usbh_xxx {
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struct usbh_hubport *hport;
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struct usb_endpoint_descriptor *xxxin;
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struct usb_endpoint_descriptor *xxxout;
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struct usbh_urb xxxin_urb;
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struct usbh_urb xxxout_urb;
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uint8_t intf; /* interface number */
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uint8_t minor;
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void *user_data;
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};
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static int usbh_xxx_connect(struct usbh_hubport *hport, uint8_t intf)
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{
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struct usb_endpoint_descriptor *ep_desc;
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int ret;
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struct usbh_xxx *xxx_class = usbh_xxx_class_alloc();
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if (xxx_class == NULL) {
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USB_LOG_ERR("Fail to alloc xxx_class\r\n");
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return -USB_ERR_NOMEM;
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}
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return ret;
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}
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static int usbh_xxx_disconnect(struct usbh_hubport *hport, uint8_t intf)
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{
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int ret = 0;
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struct usbh_xxx *xxx_class = (struct usbh_xxx *)hport->config.intf[intf].priv;
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if (xxx_class) {
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if (xxx_class->xxxin) {
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usbh_kill_urb(&xxx_class->xxxin_urb);
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}
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if (xxx_class->xxxout) {
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usbh_kill_urb(&xxx_class->xxxout_urb);
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}
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if (hport->config.intf[intf].devname[0] != '\0') {
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USB_LOG_INFO("Unregister xxx Class:%s\r\n", hport->config.intf[intf].devname);
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usbh_xxx_stop(xxx_class);
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}
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usbh_xxx_class_free(xxx_class);
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}
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return ret;
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}
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- 初始化端点
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.. code-block:: C
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for (uint8_t i = 0; i < hport->config.intf[intf].altsetting[0].intf_desc.bNumEndpoints; i++) {
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ep_desc = &hport->config.intf[intf].altsetting[0].ep[i].ep_desc;
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if (ep_desc->bEndpointAddress & 0x80) {
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USBH_EP_INIT(xxx_class->intin, ep_desc);
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} else {
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USBH_EP_INIT(xxx_class->intout, ep_desc);
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}
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}
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- 最后设计收发 API，根据实际情况设计成同步 or 异步。
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.. code-block:: C
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int usbh_xxx_in_transfer(struct usbh_xxx *xxx_class, uint8_t *buffer, uint32_t buflen, uint32_t timeout)
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{
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int ret;
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struct usbh_urb *urb = &xxx_class->xxxin_urb;
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usbh_xxx_urb_fill(urb, xxx_class->hport, xxx_class->xxxin, buffer, buflen, timeout, NULL, NULL);
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ret = usbh_submit_urb(urb);
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if (ret == 0) {
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ret = urb->actual_length;
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}
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return ret;
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}
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int usbh_xxx_out_transfer(struct usbh_xxx *xxx_class, uint8_t *buffer, uint32_t buflen, uint32_t timeout)
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{
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int ret;
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struct usbh_urb *urb = &xxx_class->xxxout_urb;
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usbh_xxx_urb_fill(urb, xxx_class->hport, xxx_class->xxxout, buffer, buflen, timeout, NULL, NULL);
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ret = usbh_submit_urb(urb);
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if (ret == 0) {
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ret = urb->actual_length;
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}
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return ret;
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} |