desktop-tools/input-switch.c

154 lines
4.5 KiB
C

/*
* input-switch.c: switches display input via DDC/CI
*
* Copyright (c) 2017, Přemysl Eric Janouch <p@janouch.name>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
// This makes openat() available even though I set _POSIX_C_SOURCE and
// _XOPEN_SOURCE to a version of POSIX older than 2008
#define _GNU_SOURCE
#include "config.h"
#undef PROGRAM_NAME
#define PROGRAM_NAME "input-switch"
#include "liberty/liberty.c"
#include "ddc-ci.c"
#include <dirent.h>
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static bool
set_input_source (int fd, int input, struct error **e)
{
struct vcp_feature_readout readout = {};
if (!vcp_get_feature (fd, VCP_INPUT_SOURCE, &readout, e))
return false;
if (input < 0 || input > readout.max)
return error_set (e, "input index out of range");
uint8_t set_req[] = { VCP_INPUT_SOURCE, input >> 8, input };
if (!ddc_send (fd, DDC_SET_VCP_FEATURE, set_req, sizeof set_req, e))
return false;
wait_ms (50);
printf ("input set from %d to %d of %d\n", readout.cur, input, readout.max);
return true;
}
static void
i2c (int input)
{
DIR *dev = opendir ("/dev");
if (!dev)
{
print_error ("cannot access %s: %s: %s",
"/dev", "opendir", strerror (errno));
return;
}
struct dirent *entry;
while ((entry = readdir (dev)))
{
if (strncmp (entry->d_name, "i2c-", 4))
continue;
printf ("Trying %s... ", entry->d_name);
int fd = openat (dirfd (dev), entry->d_name, O_RDONLY);
if (fd < 0)
{
print_error ("%s: %s", "openat", strerror (errno));
continue;
}
struct error *e = NULL;
if (!is_a_display (fd, &e)
|| !set_input_source (fd, input, &e))
{
printf ("%s\n", e->message);
error_free (e);
}
close (fd);
}
closedir (dev);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// This list is from the MCCS 2.2a specification
struct
{
int code; ///< Input code
const char *name; ///< Input name
int index; ///< Input index
}
g_inputs[] =
{
{ 0x01, "vga", 1, }, // Analog video (R/G/B) 1
{ 0x02, "vga", 2, }, // Analog video (R/G/B) 2
{ 0x03, "dvi", 1, }, // Digital video (TMDS) 1 DVI 1
{ 0x04, "dvi", 2, }, // Digital video (TMDS) 2 DVI 2
{ 0x05, "composite", 1, }, // Composite video 1
{ 0x06, "composite", 2, }, // Composite video 2
{ 0x07, "s-video", 1, }, // S-video 1
{ 0x08, "s-video", 2, }, // S-video 2
{ 0x09, "tuner", 1, }, // Tuner 1
{ 0x0A, "tuner", 2, }, // Tuner 2
{ 0x0B, "tuner", 3, }, // Tuner 3
{ 0x0C, "component", 1, }, // Component video (YPbPr/YCbCr) 1
{ 0x0D, "component", 2, }, // Component video (YPbPr/YCbCr) 2
{ 0x0E, "component", 3, }, // Component video (YPbPr/YCbCr) 3
{ 0x0F, "dp", 1, }, // DisplayPort 1
{ 0x10, "dp", 2, }, // DisplayPort 2
{ 0x11, "hdmi", 1, }, // Digital Video (TMDS) 3 HDMI 1
{ 0x12, "hdmi", 2, }, // Digital Video (TMDS) 4 HDMI 2
{ 0x15, "tb", 1, }, // Thunderbolt on BenQ PD3220U (no spec)
};
int
main (int argc, char *argv[])
{
g_log_message_real = log_message_custom;
if (argc <= 1)
{
printf ("Usage: %s <input> [<index>]\n", argv[0]);
exit (EXIT_FAILURE);
}
unsigned long input_source = 0;
if (xstrtoul (&input_source, argv[1], 10))
{
i2c (input_source);
exit (EXIT_SUCCESS);
}
unsigned long index = 1;
if (argc > 2 && !xstrtoul (&index, argv[2], 10))
exit_fatal ("given index is not a number: %s", argv[2]);
for (size_t i = 0; i < N_ELEMENTS (g_inputs); i++)
if (!strcasecmp_ascii (g_inputs[i].name, argv[1])
&& g_inputs[i].index == (int) index)
input_source = g_inputs[i].code;
if (!input_source)
exit_fatal ("unknown input source: %s %lu", argv[1], index);
i2c (input_source);
return 0;
}