ref: 5df233610e0148f6781c45c81bae74fdc2b1dba4
dir: /src/backends/m8_libusb.c/
// Copyright 2021 Jonne Kokkonen
// Released under the MIT licence, https://opensource.org/licenses/MIT
// Contains portions of code from libserialport's examples released to the
// public domain
#ifdef USE_LIBUSB
#include <SDL3/SDL.h>
#include <libusb.h>
#include <stdlib.h>
#include <string.h>
static int ep_out_addr = 0x03;
static int ep_in_addr = 0x83;
#define ACM_CTRL_DTR 0x01
#define ACM_CTRL_RTS 0x02
#define M8_VID 0x16c0
#define M8_PID 0x048a
libusb_context *ctx = NULL;
libusb_device_handle *devh = NULL;
static int do_exit = 0;
int m8_list_devices() {
int r;
r = libusb_init(&ctx);
if (r < 0) {
SDL_Log("libusb_init failed: %s", libusb_error_name(r));
return 0;
}
libusb_device **device_list = NULL;
int count = libusb_get_device_list(ctx, &device_list);
for (size_t idx = 0; idx < count; ++idx) {
libusb_device *device = device_list[idx];
struct libusb_device_descriptor desc;
int rc = libusb_get_device_descriptor(device, &desc);
if (rc < 0) {
SDL_Log("Error");
libusb_free_device_list(device_list, 1);
return rc;
}
if (desc.idVendor == M8_VID && desc.idProduct == M8_PID) {
SDL_Log("Found M8 device: %d:%d\n", libusb_get_port_number(device),
libusb_get_bus_number(device));
}
}
libusb_free_device_list(device_list, 1);
return 0;
}
int usb_loop(void *data) {
SDL_SetCurrentThreadPriority(SDL_THREAD_PRIORITY_TIME_CRITICAL);
while (!do_exit) {
int rc = libusb_handle_events(ctx);
if (rc != LIBUSB_SUCCESS) {
SDL_Log("Audio loop error: %s\n", libusb_error_name(rc));
break;
}
}
return 0;
}
static SDL_Thread *usb_thread;
static void LIBUSB_CALL xfr_cb_in(struct libusb_transfer *transfer) {
int *completed = transfer->user_data;
*completed = 1;
}
int bulk_transfer(int endpoint, uint8_t *serial_buf, int count, unsigned int timeout_ms) {
if (devh == NULL) {
return -1;
}
int completed = 0;
struct libusb_transfer *transfer;
transfer = libusb_alloc_transfer(0);
libusb_fill_bulk_transfer(transfer, devh, endpoint, serial_buf, count, xfr_cb_in, &completed,
timeout_ms);
int r = libusb_submit_transfer(transfer);
if (r < 0) {
SDL_Log("Error");
libusb_free_transfer(transfer);
return r;
}
retry:
libusb_lock_event_waiters(ctx);
while (!completed) {
if (!libusb_event_handler_active(ctx)) {
libusb_unlock_event_waiters(ctx);
goto retry;
}
libusb_wait_for_event(ctx, NULL);
}
libusb_unlock_event_waiters(ctx);
int actual_length = transfer->actual_length;
libusb_free_transfer(transfer);
return actual_length;
}
int blocking_write(void *buf, int count, unsigned int timeout_ms) {
return bulk_transfer(ep_out_addr, buf, count, timeout_ms);
}
int m8_process_data(uint8_t *serial_buf, int count) {
return bulk_transfer(ep_in_addr, serial_buf, count, 1);
}
int check_serial_port() {
// Reading will fail anyway when the device is not present anymore
return 1;
}
int init_interface() {
if (devh == NULL) {
SDL_Log("Device not initialised!");
return 0;
}
int rc;
for (int if_num = 0; if_num < 2; if_num++) {
if (libusb_kernel_driver_active(devh, if_num)) {
SDL_Log("Detaching kernel driver for interface %d", if_num);
libusb_detach_kernel_driver(devh, if_num);
}
rc = libusb_claim_interface(devh, if_num);
if (rc < 0) {
SDL_Log("Error claiming interface: %s", libusb_error_name(rc));
libusb_close(devh);
devh = NULL;
return 0;
}
}
/* Start configuring the device:
* - set line state
*/
SDL_Log("Setting line state");
rc = libusb_control_transfer(devh, 0x21, 0x22, ACM_CTRL_DTR | ACM_CTRL_RTS, 0, NULL, 0, 0);
if (rc < 0) {
SDL_Log("Error during control transfer: %s", libusb_error_name(rc));
return 0;
}
/* - set line encoding: here 115200 8N1
* 115200 = 0x01C200 ~> 0x00, 0xC2, 0x01, 0x00 in little endian
*/
SDL_Log("Set line encoding");
unsigned char encoding[] = {0x00, 0xC2, 0x01, 0x00, 0x00, 0x00, 0x08};
rc = libusb_control_transfer(devh, 0x21, 0x20, 0, 0, encoding, sizeof(encoding), 0);
if (rc < 0) {
SDL_Log("Error during control transfer: %s", libusb_error_name(rc));
return 0;
}
usb_thread = SDL_CreateThread(&usb_loop, "USB", NULL);
return 1;
}
int init_serial_with_file_descriptor(int file_descriptor) {
SDL_Log("Initialising serial with file descriptor");
if (file_descriptor <= 0) {
SDL_Log("Invalid file descriptor: %d", file_descriptor);
return 0;
}
int r;
r = libusb_set_option(NULL, LIBUSB_OPTION_NO_DEVICE_DISCOVERY, NULL);
if (r != LIBUSB_SUCCESS) {
SDL_Log("libusb_set_option failed: %s", libusb_error_name(r));
return 0;
}
r = libusb_init(&ctx);
if (r < 0) {
SDL_Log("libusb_init failed: %s", libusb_error_name(r));
return 0;
}
r = libusb_wrap_sys_device(ctx, (intptr_t)file_descriptor, &devh);
if (r < 0) {
SDL_Log("libusb_wrap_sys_device failed: %s", libusb_error_name(r));
return 0;
} else if (devh == NULL) {
SDL_Log("libusb_wrap_sys_device returned invalid handle");
return 0;
}
SDL_Log("USB device init success");
return init_interface();
}
int m8_initialize(int verbose, char *preferred_device) {
if (devh != NULL) {
return 1;
}
int r;
r = libusb_init(&ctx);
if (r < 0) {
SDL_Log("libusb_init failed: %s", libusb_error_name(r));
return 0;
}
if (preferred_device == NULL) {
devh = libusb_open_device_with_vid_pid(ctx, M8_VID, M8_PID);
} else {
char *port;
char *saveptr = NULL;
char *bus;
port = SDL_strtok_r(preferred_device, ":", &saveptr);
bus = SDL_strtok_r(NULL, ":", &saveptr);
libusb_device **device_list = NULL;
int count = libusb_get_device_list(ctx, &device_list);
for (size_t idx = 0; idx < count; ++idx) {
libusb_device *device = device_list[idx];
struct libusb_device_descriptor desc;
r = libusb_get_device_descriptor(device, &desc);
if (r < 0) {
SDL_Log("libusb_get_device_descriptor failed: %s", libusb_error_name(r));
libusb_free_device_list(device_list, 1);
return 0;
}
if (desc.idVendor == M8_VID && desc.idProduct == M8_PID) {
SDL_Log("Searching for port %s and bus %s", port, bus);
if (libusb_get_port_number(device) == SDL_atoi(port) &&
libusb_get_bus_number(device) == SDL_atoi(bus)) {
SDL_Log("Preferred device found, connecting");
r = libusb_open(device, &devh);
if (r < 0) {
SDL_Log("libusb_open failed: %s", libusb_error_name(r));
return 0;
}
}
}
}
libusb_free_device_list(device_list, 1);
if (devh == NULL) {
SDL_Log("Preferred device %s not found, using first available", preferred_device);
devh = libusb_open_device_with_vid_pid(ctx, M8_VID, M8_PID);
}
}
if (devh == NULL) {
SDL_LogDebug(SDL_LOG_CATEGORY_SYSTEM,
"libusb_open_device_with_vid_pid returned invalid handle");
return 0;
}
SDL_Log("USB device init success");
return init_interface();
}
int m8_reset_display() {
int result;
SDL_Log("Reset display\n");
char buf[1] = {'R'};
result = blocking_write(buf, 1, 5);
if (result != 1) {
SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error resetting M8 display, code %d", result);
return 0;
}
return 1;
}
int m8_enable_and_reset_display() {
if (devh == NULL) {
return 0;
}
int result;
SDL_Log("Enabling and resetting M8 display\n");
char buf[1] = {'E'};
result = blocking_write(buf, 1, 5);
if (result != 1) {
SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error enabling M8 display, code %d", result);
return 0;
}
SDL_Delay(5);
result = m8_reset_display();
return result;
}
int m8_close() {
char buf[1] = {'D'};
int result;
SDL_Log("Disconnecting M8\n");
result = blocking_write(buf, 1, 5);
if (result != 1) {
SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error sending disconnect, code %d", result);
return -1;
}
int rc;
if (devh != NULL) {
for (int if_num = 0; if_num < 2; if_num++) {
rc = libusb_release_interface(devh, if_num);
if (rc < 0) {
SDL_Log("Error releasing interface: %s", libusb_error_name(rc));
return 0;
}
}
do_exit = 1;
libusb_close(devh);
}
SDL_WaitThread(usb_thread, NULL);
libusb_exit(ctx);
return 1;
}
int m8_send_msg_controller(uint8_t input) {
char buf[2] = {'C', input};
int nbytes = 2;
int result;
result = blocking_write(buf, nbytes, 5);
if (result != nbytes) {
SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error sending input, code %d", result);
return -1;
}
return 1;
}
int m8_send_msg_keyjazz(uint8_t note, uint8_t velocity) {
if (velocity > 0x7F)
velocity = 0x7F;
char buf[3] = {'K', note, velocity};
int nbytes = 3;
int result;
result = blocking_write(buf, nbytes, 5);
if (result != nbytes) {
SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error sending keyjazz, code %d", result);
return -1;
}
return 1;
}
// These shouldn't be needed with serial
int m8_pause_processing(void) { return 1; }
int m8_resume_processing(void) { return 1; }
#endif