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@hutorny hutorny/ch340.c forked from z4yx/ch340.c
Created Jan 24, 2016

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//libusb+ch340 data transfer demo
//gcc usb.c `pkg-config libusb-1.0 --libs --cflags` -o usb
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/select.h>
#include <termios.h>
#include <libusb.h>
#define EP_DATA_IN (0x2|LIBUSB_ENDPOINT_IN)
#define EP_DATA_OUT (0x2|LIBUSB_ENDPOINT_OUT)
#define CTRL_IN (LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN)
#define CTRL_OUT (LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT)
#define DEFAULT_BAUD_RATE 9600
static struct libusb_device_handle *devh = NULL;
static struct libusb_transfer *recv_bulk_transfer = NULL;
uint8_t dtr = 0;
uint8_t rts = 0;
uint8_t do_exit = 0;
uint8_t recvbuf[1024];
void writeHandshakeByte(void) {
if (libusb_control_transfer(devh, CTRL_OUT, 0xa4, ~((dtr ? 1 << 5 : 0) | (rts ? 1 << 6 : 0)), 0, NULL, 0, 1000) < 0) {
fprintf(stderr, "Faild to set handshake byte\n");
}
}
int setBaudRate(int baudRate){
static int baud[] = {2400, 0xd901, 0x0038, 4800, 0x6402,
0x001f, 9600, 0xb202, 0x0013, 19200, 0xd902, 0x000d, 38400,
0x6403, 0x000a, 115200, 0xcc03, 0x0008};
for (int i = 0; i < sizeof(baud)/sizeof(int) / 3; i++) {
if (baud[i * 3] == baudRate) {
int r = libusb_control_transfer(devh, CTRL_OUT, 0x9a, 0x1312, baud[i * 3 + 1], NULL, 0, 1000);
if (r < 0) {
fprintf(stderr, "failed control transfer 0x9a,0x1312\n");
return r;
}
r = libusb_control_transfer(devh, CTRL_OUT, 0x9a, 0x0f2c, baud[i * 3 + 2], NULL, 0, 1000);
if (r < 0) {
fprintf(stderr, "failed control transfer 0x9a,0x0f2c\n");
return r;
}
return 0;
}
}
fprintf(stderr, "unsupported baudrate\n");
return -1;
}
int init_ch34x()
{
int r;
r = libusb_control_transfer(devh, CTRL_OUT, 0xa1, 0, 0, NULL, 0, 1000);
if (r < 0) {
fprintf(stderr, "failed control transfer 0xa1\n");
return r;
}
r = libusb_control_transfer(devh, CTRL_OUT, 0x9a, 0x2518, 0x0050, NULL, 0, 1000);
if (r < 0) {
fprintf(stderr, "failed control transfer 0x9a,0x2518\n");
return r;
}
r = libusb_control_transfer(devh, CTRL_OUT, 0xa1, 0x501f, 0xd90a, NULL, 0, 1000);
if (r < 0) {
fprintf(stderr, "failed control transfer 0xa1,0x501f\n");
return r;
}
setBaudRate(DEFAULT_BAUD_RATE);
writeHandshakeByte();
return r;
}
static void LIBUSB_CALL cb_img(struct libusb_transfer *transfer)
{
if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
fprintf(stderr, "img transfer status %d?\n", transfer->status);
do_exit = 2;
libusb_free_transfer(transfer);
return;
}
// printf("Data callback[");
for (int i = 0; i < transfer->actual_length; ++i)
{
putchar(recvbuf[i]);
}
fflush(stdout);
// printf("]\n");
if (libusb_submit_transfer(recv_bulk_transfer) < 0)
do_exit = 2;
}
int send_to_uart(void)
{
int r;
unsigned char sendbuf[1024];
if ((r = read(0, sendbuf, sizeof(sendbuf))) < 0) {
return r;
} else {
int transferred, len = r;
r = libusb_bulk_transfer(devh, EP_DATA_OUT, sendbuf, len, &transferred, 200);
// printf("read[%d]transferred[%d]\n", len, transferred);
if(r < 0){
fprintf(stderr, "libusb_bulk_transfer error %d\n", r);
return r;
}
}
return r;
}
int kbhit()
{
struct timeval tv = { 0L, 0L };
fd_set fds;
FD_ZERO(&fds);
FD_SET(0, &fds);
return select(1, &fds, NULL, NULL, &tv);
}
int main(int argc, char **argv)
{
int r = 1;
r = libusb_init(NULL);
if (r < 0) {
fprintf(stderr, "failed to initialise libusb\n");
exit(1);
}
devh = libusb_open_device_with_vid_pid(NULL, 0x1a86, 0x7523);
if (devh == NULL) {
fprintf(stderr, "Could not find/open device\n");
goto out;
}
r = libusb_claim_interface(devh, 0);
if (r < 0) {
fprintf(stderr, "usb_claim_interface error %d\n", r);
goto out;
}
printf("claimed interface\n");
r = init_ch34x();
if (r < 0)
goto out_release;
if(argc > 1)
setBaudRate(atoi(argv[1]));
printf("initialized\n");
recv_bulk_transfer = libusb_alloc_transfer(0);
if (!recv_bulk_transfer){
fprintf(stderr, "libusb_alloc_transfer error\n");
goto out_release;
}
libusb_fill_bulk_transfer(recv_bulk_transfer, devh, EP_DATA_IN, recvbuf,
sizeof(recvbuf), cb_img, NULL, 0);
r = libusb_submit_transfer(recv_bulk_transfer);
if (r < 0){
fprintf(stderr, "libusb_submit_transfer error\n");
goto out_deinit;
}
// set_conio_terminal_mode();
while (!do_exit) {
struct timeval tv = { 0L, 0L };
r = libusb_handle_events_timeout(NULL, &tv);
if (r < 0)
goto out_deinit;
if(kbhit()){
r = send_to_uart();
if (r < 0)
goto out_deinit;
}
}
if (recv_bulk_transfer) {
r = libusb_cancel_transfer(recv_bulk_transfer);
if (r < 0)
goto out_deinit;
}
out_deinit:
libusb_free_transfer(recv_bulk_transfer);
out_release:
libusb_release_interface(devh, 0);
out:
libusb_close(devh);
libusb_exit(NULL);
return r >= 0 ? r : -r;
}
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