dmrconfig/hid-libusb.c
2018-09-17 23:43:46 -07:00

247 lines
7.8 KiB
C

/*
* HID routines for Linux, via libusb-1.0.
*
* Copyright (C) 2018 Serge Vakulenko, KK6ABQ
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libusb-1.0/libusb.h>
#include "util.h"
static libusb_context *ctx = NULL; // libusb context
static libusb_device_handle *dev; // libusb device
static struct libusb_transfer *transfer; // async transfer descriptor
static unsigned char receive_buf[42]; // receive buffer
static volatile int nbytes_received = 0; // receive result
#define HID_INTERFACE 0 // interface index
#define TIMEOUT_MSEC 500 // receive timeout
//
// Callback function for asynchronous receive.
// Needs to fill the receive_buf and set nbytes_received.
//
static void read_callback(struct libusb_transfer *t)
{
switch (t->status) {
case LIBUSB_TRANSFER_COMPLETED:
//fprintf(stderr, "%s: Transfer complete, %d bytes\n", __func__, t->actual_length);
memcpy(receive_buf, t->buffer, t->actual_length);
nbytes_received = t->actual_length;
break;
case LIBUSB_TRANSFER_CANCELLED:
//fprintf(stderr, "%s: Transfer cancelled\n", __func__);
nbytes_received = LIBUSB_ERROR_INTERRUPTED;
return;
case LIBUSB_TRANSFER_NO_DEVICE:
//fprintf(stderr, "%s: No device\n", __func__);
nbytes_received = LIBUSB_ERROR_NO_DEVICE;
return;
case LIBUSB_TRANSFER_TIMED_OUT:
//fprintf(stderr, "%s: Timeout (normal)\n", __func__);
nbytes_received = LIBUSB_ERROR_TIMEOUT;
break;
default:
//fprintf(stderr, "%s: Unknown transfer code: %d\n", __func__, t->status);
nbytes_received = LIBUSB_ERROR_IO;
}
}
//
// Write data to the device and receive reply.
// Return negative status on error.
// Return received byte count of success.
// On timeout, repeat the transaction.
// Need to use callback for receive interrupt transfer.
//
static int write_read(const unsigned char *data, unsigned length, unsigned char *reply, unsigned rlength)
{
if (! transfer) {
// Allocate transfer descriptor on first invocation.
transfer = libusb_alloc_transfer(0);
}
libusb_fill_interrupt_transfer(transfer, dev,
LIBUSB_RECIPIENT_INTERFACE|LIBUSB_ENDPOINT_IN,
reply, rlength, read_callback, 0, TIMEOUT_MSEC);
again:
nbytes_received = 0;
libusb_submit_transfer(transfer);
int result = libusb_control_transfer(dev,
LIBUSB_REQUEST_TYPE_CLASS|LIBUSB_RECIPIENT_INTERFACE|LIBUSB_ENDPOINT_OUT,
0x09/*HID Set_Report*/, (2/*HID output*/ << 8) | 0,
HID_INTERFACE, (unsigned char*)data, length, TIMEOUT_MSEC);
if (result < 0) {
fprintf(stderr, "Error %d transmitting data via control transfer: %s\n",
result, libusb_strerror(result));
libusb_cancel_transfer(transfer);
return -1;
}
while (nbytes_received == 0) {
result = libusb_handle_events(ctx);
if (result < 0) {
/* Break out of this loop only on fatal error.*/
if (result != LIBUSB_ERROR_BUSY &&
result != LIBUSB_ERROR_TIMEOUT &&
result != LIBUSB_ERROR_OVERFLOW &&
result != LIBUSB_ERROR_INTERRUPTED) {
fprintf(stderr, "Error %d receiving data via interrupt transfer: %s\n",
result, libusb_strerror(result));
return result;
}
}
}
if (nbytes_received == LIBUSB_ERROR_TIMEOUT) {
if (trace_flag > 0) {
fprintf(stderr, "No response from HID device!\n");
}
goto again;
}
return nbytes_received;
}
//
// Send a request to the device.
// Store the reply into the rdata[] array.
// Terminate in case of errors.
//
void hid_send_recv(const unsigned char *data, unsigned nbytes, unsigned char *rdata, unsigned rlength)
{
unsigned char buf[42];
unsigned char reply[42];
unsigned k;
int reply_len;
memset(buf, 0, sizeof(buf));
buf[0] = 1;
buf[1] = 0;
buf[2] = nbytes;
buf[3] = nbytes >> 8;
if (nbytes > 0)
memcpy(buf+4, data, nbytes);
nbytes += 4;
if (trace_flag > 0) {
fprintf(stderr, "---Send");
for (k=0; k<nbytes; ++k) {
if (k != 0 && (k & 15) == 0)
fprintf(stderr, "\n ");
fprintf(stderr, " %02x", buf[k]);
}
fprintf(stderr, "\n");
}
reply_len = write_read(buf, sizeof(buf), reply, sizeof(reply));
if (reply_len < 0) {
exit(-1);
}
if (reply_len != sizeof(reply)) {
fprintf(stderr, "Short read: %d bytes instead of %d!\n",
reply_len, (int)sizeof(reply));
exit(-1);
}
if (trace_flag > 0) {
fprintf(stderr, "---Recv");
for (k=0; k<reply_len; ++k) {
if (k != 0 && (k & 15) == 0)
fprintf(stderr, "\n ");
fprintf(stderr, " %02x", reply[k]);
}
fprintf(stderr, "\n");
}
if (reply[0] != 3 || reply[1] != 0 || reply[3] != 0) {
fprintf(stderr, "incorrect reply\n");
exit(-1);
}
if (reply[2] != rlength) {
fprintf(stderr, "incorrect reply length %d, expected %d\n",
reply[2], rlength);
exit(-1);
}
memcpy(rdata, reply+4, rlength);
}
//
// Connect to the specified device.
// Initiate the programming session.
//
int hid_init(int vid, int pid)
{
int error = libusb_init(&ctx);
if (error < 0) {
fprintf(stderr, "libusb init failed: %d: %s\n",
error, libusb_strerror(error));
exit(-1);
}
dev = libusb_open_device_with_vid_pid(ctx, vid, pid);
if (!dev) {
if (trace_flag) {
fprintf(stderr, "Cannot find USB device %04x:%04x\n",
vid, pid);
}
libusb_exit(ctx);
ctx = 0;
return -1;
}
if (libusb_kernel_driver_active(dev, 0)) {
libusb_detach_kernel_driver(dev, 0);
}
error = libusb_claim_interface(dev, HID_INTERFACE);
if (error < 0) {
fprintf(stderr, "Failed to claim USB interface: %d: %s\n",
error, libusb_strerror(error));
libusb_close(dev);
libusb_exit(ctx);
ctx = 0;
exit(-1);
}
return 0;
}
void hid_close()
{
if (!ctx)
return;
if (transfer) {
libusb_free_transfer(transfer);
transfer = 0;
}
libusb_release_interface(dev, HID_INTERFACE);
libusb_close(dev);
libusb_exit(ctx);
ctx = 0;
}