shithub: m8c

ref: 6158be32c845812db304c6add83416ba757722f0
dir: /usb.c/

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// 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 <SDL.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libusb.h>

#include "serial.h"


static int ep_out_addr = 0x03;
static int ep_in_addr = 0x83;

#define ACM_CTRL_DTR   0x01
#define ACM_CTRL_RTS   0x02

usb_callback_t init_callback = NULL;
usb_callback_t destroy_callback = NULL;
libusb_device_handle *devh = NULL;

void set_usb_init_callback(usb_callback_t callback) {
    init_callback = callback;
}

void set_usb_destroy_callback(usb_callback_t callback) {
    destroy_callback = callback;
}

int blocking_write(void *buf,
                   int count, unsigned int timeout_ms) {
    int actual_length;
    int rc;
    rc = libusb_bulk_transfer(devh, ep_out_addr, buf, count,
                         &actual_length, timeout_ms);
    if (rc < 0) {
        SDL_Log("Error while sending char: %s", libusb_error_name(rc));
        return -1;
    }
    return actual_length;
}

int serial_read(uint8_t *serial_buf, int count) {
    int actual_length;
    int rc = libusb_bulk_transfer(devh, ep_in_addr, serial_buf, count, &actual_length,
                                  10);
    if (rc == LIBUSB_ERROR_TIMEOUT) {
        return 0;
    } else if (rc < 0) {
        SDL_Log("Error while waiting for char: %s", libusb_error_name(rc));
        return -1;
    }

    return actual_length;
}

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));
            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;
    }

    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(NULL);
    if (r < 0) {
        SDL_Log("libusb_init failed: %s", libusb_error_name(r));
        return 0;
    }
    r = libusb_wrap_sys_device(NULL, (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");

    if (init_callback != NULL) {
        r = init_callback(devh);

        if (r < 0) {
            SDL_Log("Init callback failed: %d", r);
            return 0;
        }
    }

    return init_interface();
}

int init_serial(int verbose) {

    if (devh != NULL) {
        return 1;
    }

    int r;
    r = libusb_init(NULL);
    if (r < 0) {
        SDL_Log("libusb_init failed: %s", libusb_error_name(r));
        return 0;
    }
    devh = libusb_open_device_with_vid_pid(NULL, 0x16c0, 0x048a);
    if (devh == NULL) {
        SDL_Log("libusb_open_device_with_vid_pid returned invalid handle");
        return 0;
    }
    SDL_Log("USB device init success");

    if (init_callback != NULL) {
        r = init_callback(devh);

        if (r < 0) {
            SDL_Log("Init callback failed: %d", r);
            return 0;
        }
    }

    return init_interface();
}

int reset_display() {
    SDL_Log("Reset display\n");
    uint8_t buf[2];
    int result;

    buf[0] = 0x45;
    buf[1] = 0x52;

    result = blocking_write(buf, 2, 5);
    if (result != 2) {
        SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Error resetting M8 display, code %d",
                     result);
        return 0;
    }
    return 1;
}

int enable_and_reset_display() {
    uint8_t buf[1];
    int result;

    SDL_Log("Enabling and resetting M8 display\n");

    buf[0] = 0x44;
    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 = reset_display();
    if (result == 1)
        return 1;
    else
        return 0;
}

int disconnect() {

    char buf[1] = {'D'};
    int result;

    if (destroy_callback != NULL) {
        result = destroy_callback(devh);

        if (result < 0) {
            SDL_Log("Destroy callback failed: %d", result);
            return 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;

    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;
        }
    }

    if (devh != NULL) {
        libusb_close(devh);
    }

    libusb_exit(NULL);

    return 1;
}

int 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 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;
}

#endif