usbh_serial
Serial 框架当前支持 cdc acm, ftdi, cp210x, ch34x, pl2303，gsm 驱动。
当前支持两种使用方式，一种是使用源生 CherryUSB usbhost serial API 进行操作，另一种是基于平台封装的 API 操作，比如 rt-thread device API，nuttx posix API。
下面演示的是使用 CherryUSB usbhost serial API 进行串口回环测试，并且使用阻塞发送，异步读取的方式：
struct usbh_serial *serial;
serial = usbh_serial_open("/dev/ttyACM0", USBH_SERIAL_O_RDWR | USBH_SERIAL_O_NONBLOCK);
if (serial == NULL) {
serial = usbh_serial_open("/dev/ttyUSB0", USBH_SERIAL_O_RDWR | USBH_SERIAL_O_NONBLOCK);
if (serial == NULL) {
USB_LOG_RAW("no serial device found\r\n");
goto delete;
}
}
struct usbh_serial_termios termios;
memset(&termios, 0, sizeof(termios));
termios.baudrate = 115200;
termios.stopbits = 0;
termios.parity = 0;
termios.databits = 8;
termios.rtscts = false;
termios.rx_timeout = 0;
ret = usbh_serial_control(serial, USBH_SERIAL_CMD_SET_ATTR, &termios);
if (ret < 0) {
USB_LOG_RAW("set serial attr error, ret:%d\r\n", ret);
goto delete_with_close;
}
serial_tx_bytes = 0;
while (1) {
ret = usbh_serial_write(serial, serial_tx_buffer, sizeof(serial_tx_buffer));
if (ret < 0) {
USB_LOG_RAW("serial write error, ret:%d\r\n", ret);
goto delete_with_close;
} else {
serial_tx_bytes += ret;
if (serial_tx_bytes == SERIAL_TEST_LEN) {
USB_LOG_RAW("send over\r\n");
break;
}
}
}
volatile uint32_t wait_timeout = 0;
serial_rx_bytes = 0;
while (1) {
ret = usbh_serial_read(serial, &serial_rx_data[serial_rx_bytes], SERIAL_TEST_LEN - serial_rx_bytes);
if (ret < 0) {
USB_LOG_RAW("serial read error, ret:%d\r\n", ret);
goto delete_with_close;
} else {
serial_rx_bytes += ret;
if (serial_rx_bytes == SERIAL_TEST_LEN) {
USB_LOG_RAW("receive over\r\n");
for (uint32_t i = 0; i < SERIAL_TEST_LEN; i++) {
if (serial_rx_data[i] != 0xa5) {
USB_LOG_RAW("serial loopback data error at index %d, data: 0x%02x\r\n", (unsigned int)i, serial_rx_data[i]);
goto delete_with_close;
}
}
serial_test_success = true;
break;
}
}
wait_timeout++;
if (wait_timeout > 500) { // 5s
USB_LOG_RAW("serial read timeout\r\n");
goto delete_with_close;
}
usb_osal_msleep(10);
}
usbh_serial_close(serial);
Note
需要注意，例程中使用的是比较简单的先发送后读取的方式，因此发送的总长度不可以超过 CONFIG_USBHOST_SERIAL_RX_SIZE，正常使用 TX/RX 请分开进行。
用户需要考虑以下三种场景：
USB2TTL 设备 + 启用了波特率，这种情况下需要使用 usbh_serial_write 和 usbh_serial_read 进行收发数据， 并且 read 操作需要及时，防止 ringbuf 数据溢出而丢包；
纯 USB 设备 + 未启动波特率，这种情况下可以使用 usbh_serial_cdc_write_async 和 usbh_serial_cdc_read_async 进行异步收发数据。阻塞则可以用 usbh_serial_write ，不可以使用 usbh_serial_read。
纯 USB 设备 + 启动波特率，同 1，但是速率打折扣（因为多了一层 ringbuf）。此时也不可以使用 usbh_serial_cdc_write_async 和 usbh_serial_cdc_read_async。 如果是 GSM 设备请使用第一种场景。
[I/usbh_hub] New full-speed device on Bus 0, Hub 1, Port 1 connected
[I/usbh_core] New device found,idVendor:10c4,idProduct:ea60,bcdDevice:0100
[I/usbh_core] The device has 1 bNumConfigurations
[I/usbh_core] The device has 1 interfaces
[I/usbh_core] Enumeration success, start loading class driver
[I/usbh_core] Loading cp210x class driver on interface 0
[I/usbh_cp210x] chip partnum: 0x02
[I/usbh_cp210x] ulAmountInInQueue: 0, ulAmountInOutQueue: 0
[I/usbh_serial] Ep=81 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Ep=01 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyUSB0 (cp210x)
start serial loopback test, len: 1024
send over
receive over
serial loopback test success
[I/usbh_serial] Unregister Serial Class: /dev/ttyUSB0 (cp210x)
[I/usbh_core] Device on Bus 0, Hub 1, Port 1 disconnected
[I/usbh_hub] New high-speed device on Bus 0, Hub 1, Port 1 connected
[I/usbh_core] New device found,idVendor:0403,idProduct:6010,bcdDevice:0700
[I/usbh_core] The device has 1 bNumConfigurations
[I/usbh_core] The device has 2 interfaces
[I/usbh_core] Enumeration success, start loading class driver
[I/usbh_core] Loading ftdi class driver on interface 0
[I/usbh_ftdi] chip name: FT2232H
[I/usbh_serial] Ep=81 Attr=02 Mps=512 Interval=00 Mult=00
[I/usbh_serial] Ep=02 Attr=02 Mps=512 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyUSB0 (ftdi)
[I/usbh_core] Loading ftdi class driver on interface 1
[I/usbh_ftdi] chip name: FT2232H
[I/usbh_serial] Ep=83 Attr=02 Mps=512 Interval=00 Mult=00
[I/usbh_serial] Ep=04 Attr=02 Mps=512 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyUSB1 (ftdi)
start serial loopback test, len: 1024
send over
receive over
serial loopback test success
[I/usbh_serial] Unregister Serial Class: /dev/ttyUSB0 (ftdi)
[I/usbh_serial] Unregister Serial Class: /dev/ttyUSB1 (ftdi)
[I/usbh_core] Device on Bus 0, Hub 1, Port 1 disconnected
[I/usbh_hub] New full-speed device on Bus 0, Hub 1, Port 1 connected
[I/usbh_core] New device found,idVendor:067b,idProduct:2303,bcdDevice:0300
[I/usbh_core] The device has 1 bNumConfigurations
[I/usbh_core] The device has 1 interfaces
[I/usbh_core] Enumeration success, start loading class driver
[I/usbh_core] Loading pl2303 class driver on interface 0
[I/usbh_pl2303] Ep=81 Attr=03 Mps=10 Interval=01 Mult=00
[I/usbh_pl2303] chip type: PL2303HX
[I/usbh_serial] Ep=02 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Ep=83 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyUSB0 (pl2303)
start serial loopback test, len: 1024
send over
receive over
serial loopback test success
[I/usbh_serial] Unregister Serial Class: /dev/ttyUSB0 (pl2303)
[I/usbh_core] Device on Bus 0, Hub 1, Port 1 disconnected
[W/usbh_hub] Failed to enable port 1
[I/usbh_hub] New full-speed device on Bus 0, Hub 1, Port 1 connected
[I/usbh_core] New device found,idVendor:1a86,idProduct:7523,bcdDevice:0264
[I/usbh_core] The device has 1 bNumConfigurations
[I/usbh_core] The device has 1 interfaces
[I/usbh_core] Enumeration success, start loading class driver
[I/usbh_core] Loading ch34x class driver on interface 0
[I/usbh_ch43x] Ep=81 Attr=03 Mps=8 Interval=01 Mult=00
[I/usbh_ch43x] chip version: 0x31
[I/usbh_serial] Ep=82 Attr=02 Mps=32 Interval=00 Mult=00
[I/usbh_serial] Ep=02 Attr=02 Mps=32 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyUSB0 (ch34x)
start serial loopback test, len: 1024
send over
receive over
serial loopback test success
[I/usbh_serial] Unregister Serial Class: /dev/ttyUSB0 (ch34x)
[I/usbh_core] Device on Bus 0, Hub 1, Port 1 disconnected
[I/usbh_hub] New full-speed device on Bus 0, Hub 1, Port 1 connected
[I/usbh_core] New device found,idVendor:42bf,idProduct:b210,bcdDevice:0217
[I/usbh_core] The device has 1 bNumConfigurations
[I/usbh_core] The device has 3 interfaces
[I/usbh_core] Enumeration success, start loading class driver
[E/usbh_core] Do not support Class:0xff, Subclass:0x01, Protocl:0x00 on interface 0
[I/usbh_core] Loading cdc_acm class driver on interface 1
[I/usbh_cdc_acm] Ep=85 Attr=03 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Ep=04 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Ep=83 Attr=02 Mps=64 Interval=00 Mult=00
[I/usbh_serial] Register Serial Class: /dev/ttyACM0 (cdc_acm)
[I/usbh_core] Loading cdc_data class driver on interface 2
start serial loopback test, len: 1024
send over
receive over
serial loopback test success
[I/usbh_serial] Unregister Serial Class: /dev/ttyACM0 (cdc_acm)
[I/usbh_core] Device on Bus 0, Hub 1, Port 1 disconnected