树莓派4b移植4G USB驱动Quectel EC200T以及ppp拨号

1. 准备编译环境

1.1 下载linux内核，准备编译环境，请参看“RaspberryPi4B 树莓派4B Linux5.4.y 内核编译”

1.2 修改usb串口驱动， drivers/usb/serial/option.c

static const struct usb_device_id option_ids[] = {#if 1 //Added by Quectel{ USB_DEVICE(QUALCOMM_VENDOR_ID, 0x9215) }, /* Quectel EC20 */{ USB_DEVICE(QUECTEL_VENDOR_ID, 0x6026) }, /* Quectel EC200 */{ USB_DEVICE(QUECTEL_VENDOR_ID, 0x6120) }, /* Quectel UC200 */{ USB_DEVICE(QUECTEL_VENDOR_ID, 0x6000) }, /* Quectel EC200/UC200 */#endif

1.3 增加休眠后唤醒接口

static struct usb_serial_driver option_1port_device = {.driver = {.owner =THIS_MODULE,.name ="option1",},.description = "GSM modem (1-port)",...#ifdef CONFIG_PM.suspend = usb_wwan_suspend,.resume = usb_wwan_resume,#if 1 //add by Quecte