Add input-switch

Moving common stuff for DDC/CI communicating programs to ddc-ci.c.

1 files changed, 153 insertions, 0 deletions

diff --git a/input-switch.c b/input-switch.c
new file mode 100644
index 0000000..352c71c
--- /dev/null
+++ b/input-switch.c
@@ -0,0 +1,153 @@
+/*
+ * input-switch.c: switches display input via DDC/CI
+ *
+ * Copyright (c) 2017, Přemysl Janouch <p.janouch@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * 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
+};
+
+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;
+}
+