【海思Hi3520D开发笔记】移植EC20（未完结）

环境：Ubuntu 12.04-64bit
硬件平台：Hi3520D_V100
关键词：Hi3520编译内核 移植EC20
摘要：介绍Hi3520 修改内核文件，制作内核镜像。使用EC20
参考资料：Quectel_LTE&5G_Linux_USB_Driver_User_Guide_V2.0.pdf

USB Serial Option Driver
1、Add VID and PID
In order to recognize the module, the module’s VID and PID information as below need to be added to the
file [KERNEL]/drivers/usb/serial/option.c.

static const struct usb_device_id option_ids[] = {
#if 1 //Added by Quectel
{ USB_DEVICE(0x2C7C, 0x0125) }, /* Quectel EC20 R2.0/EC20 R2.1/EC25/EG25-G/EM05 */
{ USB_DEVICE(0x2C7C, 0x0121) }, /* Quectel EC21/EG21-G */
{ USB_DEVICE(0x2C7C, 0x0191) }, /* Quectel EG91 */
{ USB_DEVICE(0x2C7C, 0x0195) }, /* Quectel EG95 */
{ USB_DEVICE(0x2C7C, 0x0306) }, /* Quectel EG06/EP06/EM06 */
{ USB_DEVICE(0x2C7C, 0x0512) }, /* Quectel EG12/EM12/EG18 */
{ USB_DEVICE(0x2C7C, 0x0296) }, /* Quectel BG96 */
{ USB_DEVICE(0x2C7C, 0x0700) }, /* Quectel BG95/BG77/BG600L-M3/BC69 */
{ USB_DEVICE(0x2C7C, 0x0435) }, /* Quectel AG35 */
{ USB_DEVICE(0x2C7C, 0x0415) }, /* Quectel AG15 */
{ USB_DEVICE(0x2C7C, 0x0452) }, /* Quectel AG520R */
{ USB_DEVICE(0x2C7C, 0x0455) }, /* Quectel AG550R */
{ USB_DEVICE(0x2C7C, 0x0620) }, /* Quectel EG20 */
{ USB_DEVICE(0x2C7C, 0x0800) }, /* Quectel RG500Q/RM500Q/RG510Q/RM510Q */
#endif

2、Add the Zero Packet Mechanism
As required by the USB protocol, the mechanism for processing zero packets needs to be added during
bulk-out transmission by adding the following statements.
 For Linux kernel version higher than 2.6.34, add the following statements to the file
[KERNEL]/drivers/usb/serial/usb_wwan.c.

static struct urb *usb_wwan_setup_urb(struct usb_serial *serial, int endpoint,
int dir, void *ctx, char *buf, int len,void (*callback) (struct urb *))
{
……
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev, endpoint) | dir,
buf, len, callback, ctx);
#if 1 //Added by Quectel for zero packet
if (dir == USB_DIR_OUT) {
struct usb_device_descriptor *desc = &serial->dev->descriptor;
if (desc->idVendor == cpu_to_le16(0x2C7C))
urb->transfer_flags |= URB_ZERO_PACKET;
}
#endif
return urb;
}

3、Add Reset-resume Mechanism
Some USB host controllers/USB hubs will lose power or be reset when MCU enters the Suspend/Sleep
mode, and cannot be used for USB resume after MCU exits from the Suspend/Sleep mode. The
reset-resume mechanism needs to be enabled by adding the following statements.
 For Linux kernel version lower than 3.5, add the following statements to the file
[KERNEL]/drivers/usb/serial/usb-serial.c.

/* Driver structure we register with the USB core */
static struct usb_driver usb_serial_driver = {
.name = "usbserial",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.suspend = usb_serial_suspend,
.resume = usb_serial_resume,
#if 1 //Added by Quectel
.reset_resume = usb_serial_resume,
#endif
.no_dynamic_id = 1,
.supports_autosuspend = 1,
}

4、Use MBIM, GobiNet or QMI_WWAN Driver
If MBIM, GobiNet or QMI_WWAN driver is required, add the following statements to prevent the module’s
interface 4 from being used as a USB serial device.
 For Linux kernel version higher than 2.6.30, add the following statements to the file
[KERNEL]/drivers/usb/serial/option.c.

static int option_probe(struct usb_serial *serial, const struct usb_device_id *id) {
struct usb_wwan_intf_private *data;
……
#if 1
//Added by Quectel
//Quectel modules’s interface 4 can be used as USB network device
if (serial->dev->descriptor.idVendor == cpu_to_le16(0x2C7C)) {
//some interfaces can be used as USB Network device (ecm, rndis, mbim)
if (serial->interface->cur_altsetting->desc.bInterfaceClass != 0xFF) {
return -ENODEV;
}
//interface 4 can be used as USB Network device (qmi)
else if (serial->interface->cur_altsetting->desc.bInterfaceNumber >= 4) {
return -ENODEV;
}
}
#endif
/* Store device id so we can use it during attach. */
usb_set_serial_data(serial, (void *)id);
return 0;
}