uboot usb设备驱动

文章目录

DTS中定义
usb driver
bind
fastboot
fastboot命令处理
fastboot触发

介绍usb device设备驱动

uboot在init_dm中会扫描dtb和代码中driver进行匹配，匹配成功就调用driver驱动进行bind
以dwc3为例进行介绍

DTS中定义

usb0: usb0@ff9d0000 {#address-cells = <2>;#size-cells = <2>;status = "disabled";compatible = "xlnx,zynqmp-dwc3"; //匹配的compatible reg = <0x0 0xff9d0000 0x0 0x100>;clock-names = "bus_clk", "ref_clk";power-domains = <&pd_usb0>;ranges;nvmem-cells = <&soc_revision>;nvmem-cell-names = "soc_revision";dwc3_0: dwc3@fe200000 {compatible = "snps,dwc3";status = "disabled";reg = <0x0 0xfe200000 0x0 0x40000>;interrupt-parent = <&gic>;interrupts = <0 65 4>, <0 69 4>;#stream-id-cells = <1>;iommus = <&smmu 0x860>;snps,quirk-frame-length-adjustment = <0x20>;snps,refclk_fladj;snps,enable_guctl1_resume_quirk;snps,enable_guctl1_ipd_quirk;snps,xhci-stream-quirk;/* dma-coherent; */};
};usb1: usb1@ff9e0000 {#address-cells = <2>;#size-cells = <2>;status = "disabled";compatible = "xlnx,zynqmp-dwc3";reg = <0x0 0xff9e0000 0x0 0x100>;clock-names = "bus_clk", "ref_clk";power-domains = <&pd_usb1>;ranges;nvmem-cells = <&soc_revision>;nvmem-cell-names = "soc_revision";dwc3_1: dwc3@fe300000 {compatible = "snps,dwc3";status = "disabled";reg = <0x0 0xfe300000 0x0 0x40000>;interrupt-parent = <&gic>;interrupts = <0 70 4>, <0 74 4>;#stream-id-cells = <1>;iommus = <&smmu 0x861>;snps,quirk-frame-length-adjustment = <0x20>;snps,refclk_fladj;snps,enable_guctl1_resume_quirk;snps,enable_guctl1_ipd_quirk;snps,xhci-stream-quirk;/* dma-coherent; */};
};

usb driver

drivers\usb\dwc3\dwc3-generic.c

用于match的compatible
static const struct udevice_id dwc3_generic_ids[] = {{ .compatible = "xlnx,zynqmp-dwc3" },{ }
};定义了driver
U_BOOT_DRIVER(dwc3_generic_wrapper) = {.name   = "dwc3-generic-wrapper",.id = UCLASS_MISC,.of_match = dwc3_generic_ids,.bind = dwc3_generic_bind,
};

bind

compatible = “xlnx,zynqmp-dwc3” ，dts和driver匹配成功，定义driver->bind,即dwc3_generic_bind

static int dwc3_generic_bind(struct udevice *parent)
{const void *fdt = gd->fdt_blob;int node;int ret;遍历dts中usb device，一个soc可能包含多个usb控制器for (node = fdt_first_subnode(fdt, parent->of_offset); node > 0;node = fdt_next_subnode(fdt, node)) {const char *name = fdt_get_name(fdt, node, NULL);enum usb_dr_mode dr_mode;struct udevice *dev;debug("%s: subnode name: %s\n", __func__, name);if (strncmp(name, "dwc3@", 4))continue;dr_mode = usb_get_dr_mode(node);//usb 控制器模式，device模式或主机模式switch (dr_mode) {case USB_DR_MODE_PERIPHERAL://device模式case USB_DR_MODE_OTG://otg模式//进一步进行device和driver匹配，驱动name为 "dwc3-generic-peripheral",ret = device_bind_driver_to_node(parent,"dwc3-generic-peripheral",name, node, &dev);break;case USB_DR_MODE_HOST:debug("%s: dr_mode: HOST\n", __func__);ret = device_bind_driver_to_node(parent,"dwc3-generic-host",name, node, &dev);break;default:break;};}return 0;
}

device_bind_driver_to_node–》device_bind–》device_bind_common：匹配了device和驱动，调用uclass-bind和driver bind。

"dwc3-generic-peripheral"驱动

U_BOOT_DRIVER(dwc3_generic_peripheral) = {.name = "dwc3-generic-peripheral",.id  = UCLASS_USB_DEV_GENERIC,.ofdata_to_platdata = dwc3_generic_peripheral_ofdata_to_platdata,.probe = dwc3_generic_peripheral_probe,.remove = dwc3_generic_peripheral_remove,.bind = dwc3_generic_peripheral_bind,.platdata_auto_alloc_size = sizeof(struct usb_platdata),.priv_auto_alloc_size = sizeof(struct dwc3),.flags    = DM_FLAG_ALLOC_PRIV_DMA,
};

dwc3_generic_peripheral_bind–》device_probe–》dev->drv->probe》dwc3_generic_peripheral_probe
调用了dwc3_generic_peripheral_probe–》dwc3_init进行dwc3初始化

–》dwc3_core_init_mode–》dwc3_gadget_init–》usb_add_gadget_udc
初始了gadget功能，并向udc core注册。
具体初始化过程不再描述。
完成了底层usb device和驱动初始化，上层抽象功能在进行初始化，比如，网络，鼠标等等。

fastboot

以fastboot为例，分析function驱动初始注册。
f_fastboot.c
DECLARE_GADGET_BIND_CALLBACK(usb_dnl_fastboot, fastboot_add);
声明定义了g_dnl_bind_callback 结构的fastboot function功能。

/** @usb_fname: unescaped USB function name* @callback_ptr: bind callback, one per function name*/
#define DECLARE_GADGET_BIND_CALLBACK(usb_fname, callback_ptr) \ll_entry_declare(struct g_dnl_bind_callback, \__usb_function_name_##usb_fname, \g_dnl_bind_callbacks) = { \.usb_function_name = #usb_fname, \.fptr = callback_ptr \}typedef int (*g_dnl_bind_callback_f)(struct usb_configuration *);/* used in Gadget downloader callback linker list */
struct g_dnl_bind_callback {const char *usb_function_name;g_dnl_bind_callback_f fptr;
};

do_fastboot中调用注册了fastboot驱动，

do_fastboot--》g_dnl_register("usb_dnl_fastboot");--》
g_dnl_driver.name = name;
usb_composite_register(&g_dnl_driver);--》
composite = driver;
usb_gadget_register_driver(&composite_driver);
--》usb_gadget_probe_driver
找到一个udc，前面usb初始化已经向usb core注册了udc
list_for_each_entry(udc, &udc_list, list) {/* For now we take the first one */if (!udc->driver)goto found;}ret = udc_bind_to_driver(udc, driver);---》driver->bind(udc->gadget); 回调g_dnl_bindusb_gadget_udc_start(udc); 开启usb func功能，触发usb device和usb host交互usb_gadget_connect(udc->gadget);

g_dnl_bind–》g_dnl_config_register

一些usb 设备的configconfig->label = name;config->bmAttributes = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER;config->bConfigurationValue = CONFIGURATION_NUMBER;config->iConfiguration = STRING_USBDOWN;config->bind = g_dnl_do_config;
usb_add_config--》config->bind(config);--》 g_dnl_do_config
static int g_dnl_do_config(struct usb_configuration *c)
{const char *s = c->cdev->driver->name;struct g_dnl_bind_callback *callback = g_dnl_bind_callback_first();for (; callback != g_dnl_bind_callback_end(); callback++)if (!strcmp(s, callback->usb_function_name))return callback->fptr(c); //回调所有dnl类型的function功能return -ENODEV;
}
--》fastboot_add进行functiong功能注册
以上过程就是function对应设备接口，配置和端点注册过程

static inline int usb_gadget_udc_start(struct usb_udc *udc)
{return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
}

fastboot_add功能添加

static int fastboot_add(struct usb_configuration *c)
{struct f_fastboot *f_fb = fastboot_func;int status;debug("%s: cdev: 0x%p\n", __func__, c->cdev);if (!f_fb) {f_fb = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*f_fb));if (!f_fb)return -ENOMEM;fastboot_func = f_fb;memset(f_fb, 0, sizeof(*f_fb));}f_fb->usb_function.name = "f_fastboot";f_fb->usb_function.bind = fastboot_bind;f_fb->usb_function.unbind = fastboot_unbind;f_fb->usb_function.set_alt = fastboot_set_alt;f_fb->usb_function.disable = fastboot_disable;f_fb->usb_function.strings = fastboot_strings;status = usb_add_function(c, &f_fb->usb_function);return status;
}

在接口配置设置时回调f_fb->usb_function.set_alt = fastboot_set_alt;
fastboot_set_alt中配置了端点回调函数，并且使能了端点。
f_fb->out_req->complete = rx_handler_command; 从host接收到usb包，回调函数
f_fb->in_req->complete = fastboot_complete; 发送一个usb包，回调函数

fastboot命令处理

rx_handler_command中解析接收到usb数据，并匹配是否含有定义的fastboot协议命令

static void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
{char *cmdbuf = req->buf;void (*func_cb)(struct usb_ep *ep, struct usb_request *req) = NULL;int i;匹配命令for (i = 0; i < ARRAY_SIZE(cmd_dispatch_info); i++) {if (!strcmp_l1(cmd_dispatch_info[i].cmd, cmdbuf)) {func_cb = cmd_dispatch_info[i].cb;break;}}if (req->actual < req->length) {u8 *buf = (u8 *)req->buf;buf[req->actual] = 0;func_cb(ep, req); //处理命令}*cmdbuf = '\0';req->actual = 0;usb_ep_queue(ep, req, 0);
}

static const struct cmd_dispatch_info cmd_dispatch_info[] = {{.cmd = "reboot",.cb = cb_reboot,}, {.cmd = "getvar:",.cb = cb_getvar,}, {.cmd = "download:",.cb = cb_download,}, {.cmd = "boot",.cb = cb_boot,}, {.cmd = "continue",.cb = cb_continue,},
#ifdef CONFIG_FASTBOOT_FLASH{.cmd = "flash",.cb = cb_flash,}, {.cmd = "erase",.cb = cb_erase,},
#endif{.cmd = "oem",.cb = cb_oem,},
};

fastboot触发

上一节分析了fastboot功能的注册。
命令fastboot触发fastboot功能进行初始化注册，并继续后续处理。

U_BOOT_CMD(fastboot, 2, 1, do_fastboot,"use USB Fastboot protocol","<USB_controller>\n""    - run as a fastboot usb device"
);

static int do_fastboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{int controller_index;char *usb_controller;int ret;if (argc < 2)return CMD_RET_USAGE;usb_controller = argv[1];controller_index = simple_strtoul(usb_controller, NULL, 0);ret = board_usb_init(controller_index, USB_INIT_DEVICE);if (ret) {error("USB init failed: %d", ret);return CMD_RET_FAILURE;}g_dnl_clear_detach();ret = g_dnl_register("usb_dnl_fastboot");if (ret)return ret;if (!g_dnl_board_usb_cable_connected()) {puts("\rUSB cable not detected.\n" \"Command exit.\n");ret = CMD_RET_FAILURE;goto exit;}前面注册usb fastboot驱动下面是和host交互命令处理while (1) {if (g_dnl_detach())break;if (ctrlc())break;usb_gadget_handle_interrupts(controller_index); 中断处理，处理event buf，回调上面的out_req->complete和in_req->complete}ret = CMD_RET_SUCCESS;return ret;
}