Add input-switch

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

1 files changed, 7 insertions, 211 deletions

diff --git a/brightness.c b/brightness.c
index 3b52fc5..4bf63a7 100644
--- a/brightness.c
+++ b/brightness.c
@@ -17,51 +17,20 @@
  *
  */
 
-// Sources: ddcciv1r1.pdf, i2c-dev.c in Linux, ddccontrol source code,
-//   http://www.boichat.ch/nicolas/ddcci/specs.html was also helpful
-
 // 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
 
-// Undo some dwm Makefile damage and import my everything-library
 #include "config.h"
 #undef PROGRAM_NAME
 #define PROGRAM_NAME "brightness"
 #include "liberty/liberty.c"
 
-#include <sys/ioctl.h>
+#include "ddc-ci.c"
 #include <dirent.h>
 
-#include <linux/i2c-dev.h>
-#ifndef I2C_FUNC_I2C
-// Fuck you, openSUSE, for fucking up the previous file, see e.g.
-// https://github.com/solettaproject/soletta/commit/427f47f
-#include <linux/i2c.h>
-#endif
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static void
-log_message_custom (void *user_data, const char *quote, const char *fmt,
-	va_list ap)
-{
-	(void) user_data;
-	FILE *stream = stdout;
-
-	fprintf (stream, PROGRAM_NAME ": ");
-	fputs (quote, stream);
-	vfprintf (stream, fmt, ap);
-	fputs ("\n", stream);
-}
-
-static void
-wait_ms (long ms)
-{
-	struct timespec ts = { 0, ms * 1000 * 1000 };
-	nanosleep (&ts, NULL);
-}
-
 static bool
 xstrtol (const char *s, long *out)
 {
@@ -73,189 +42,16 @@ xstrtol (const char *s, long *out)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-#define DDC_LENGTH_XOR 0x80
-
-enum
-{
-	DDC_ADDRESS_HOST          = 0x50,   ///< Bus master's base address
-	DDC_ADDRESS_DISPLAY       = 0x6E    ///< The display's base address
-};
-
-enum { I2C_WRITE, I2C_READ };
-
-enum
-{
-	DDC_GET_VCP_FEATURE       = 0x01,   ///< Request info about a feature
-	DDC_GET_VCP_FEATURE_REPLY = 0x02,   ///< Feature info response
-	DDC_SET_VCP_FEATURE       = 0x03    ///< Set or activate a feature
-};
-
-enum
-{
-	VCP_BRIGHTNESS            = 0x10,   ///< Standard VCP opcode for brightness
-	VCP_CONTRAST              = 0x12    ///< Standard VCP opcode for contrast
-};
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-static bool
-check_edid (int fd, struct error **e)
-{
-	uint8_t edid_req[] = { 0x00 };
-	uint8_t buf[8] = "";
-	struct i2c_msg bufs[] =
-	{
-		{ .addr = 0x50, .flags = 0,
-		  .len = 1, .buf = edid_req },
-		{ .addr = 0x50, .flags = I2C_M_RD,
-		  .len = sizeof buf, .buf = buf },
-	};
-
-	struct i2c_rdwr_ioctl_data data;
-	data.msgs = bufs;
-	data.nmsgs = 2;
-
-	if (ioctl (fd, I2C_RDWR, &data) < 0)
-		return error_set (e, "%s: %s", "ioctl", strerror (errno));
-	if (memcmp ("\x00\xFF\xFF\xFF\xFF\xFF\xFF\x00", buf, sizeof buf))
-		return error_set (e, "invalid EDID");
-	return true;
-}
-
-static bool
-is_a_display (int fd, struct error **e)
-{
-	struct stat st;
-	if (fstat (fd, &st) < 0)
-		return error_set (e, "%s: %s", "fstat", strerror (errno));
-
-	unsigned long funcs;
-	if (!(st.st_mode & S_IFCHR)
-	 || ioctl (fd, I2C_FUNCS, &funcs) < 0
-	 || !(funcs & I2C_FUNC_I2C))
-		return error_set (e, "not an I2C device");
-
-	return check_edid (fd, e);
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-static bool
-ddc_send (int fd, unsigned command, void *args, size_t args_len,
-	struct error **e)
-{
-	struct str buf;
-	str_init (&buf);
-	str_pack_u8 (&buf, DDC_ADDRESS_HOST | I2C_READ);
-	str_pack_u8 (&buf, DDC_LENGTH_XOR | (args_len + 1));
-	str_pack_u8 (&buf, command);
-	str_append_data (&buf, args, args_len);
-
-	unsigned xor = DDC_ADDRESS_DISPLAY;
-	for (size_t i = 0; i < buf.len; i++)
-		xor ^= buf.str[i];
-	str_pack_u8 (&buf, xor);
-
-	struct i2c_msg msg =
-	{
-		// The driver unshifts it back
-		.addr = DDC_ADDRESS_DISPLAY >> 1, .flags = 0,
-		.len = buf.len, .buf = (uint8_t *) buf.str,
-	};
-
-	struct i2c_rdwr_ioctl_data data;
-	data.msgs = &msg;
-	data.nmsgs = 1;
-
-	bool failed = ioctl (fd, I2C_RDWR, &data) < 0;
-	str_free (&buf);
-	if (failed)
-		return error_set (e, "%s: %s", "ioctl", strerror (errno));
-	return true;
-}
-
-static bool
-ddc_read (int fd, unsigned *command, void *out_buf, size_t *n_read,
-	struct error **e)
-{
-	uint8_t buf[128] = "";
-	struct i2c_msg msg =
-	{
-		// The driver unshifts it back
-		.addr = DDC_ADDRESS_DISPLAY >> 1, .flags = I2C_M_RD,
-		.len = sizeof buf, .buf = buf,
-	};
-
-	struct i2c_rdwr_ioctl_data data;
-	data.msgs = &msg;
-	data.nmsgs = 1;
-
-	if (ioctl (fd, I2C_RDWR, &data) < 0)
-		return error_set (e, "%s: %s", "ioctl", strerror (errno));
-
-	struct msg_unpacker unpacker;
-	msg_unpacker_init (&unpacker, buf, sizeof buf);
-
-	uint8_t sender, length, cmd;
-	(void) msg_unpacker_u8 (&unpacker, &sender);
-	(void) msg_unpacker_u8 (&unpacker, &length);
-	(void) msg_unpacker_u8 (&unpacker, &cmd);
-
-	if (sender != (DDC_ADDRESS_DISPLAY | I2C_WRITE) || !(length & 0x80))
-		return error_set (e, "invalid response");
-	if (!(length ^= 0x80))
-		return error_set (e, "NULL response");
-
-	// TODO: also check the checksum
-
-	*command = cmd;
-	memcpy (out_buf, unpacker.data + unpacker.offset, (*n_read = length - 1));
-	return true;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 static bool
 set_brightness (int fd, long diff, struct error **e)
 {
-	uint8_t get_req[] = { VCP_BRIGHTNESS };
-	if (!ddc_send (fd, DDC_GET_VCP_FEATURE, get_req, sizeof get_req, e))
+	struct vcp_feature_readout readout;
+	if (!vcp_get_feature (fd, VCP_BRIGHTNESS, &readout, e))
 		return false;
 
-	wait_ms (40);
-
-	unsigned command = 0;
-	uint8_t buf[128] = "";
-	size_t len = 0;
-	if (!ddc_read (fd, &command, buf, &len, e))
-		return false;
-
-	if (command != DDC_GET_VCP_FEATURE_REPLY || len != 7)
-		return error_set (e, "invalid response");
-
-	struct msg_unpacker unpacker;
-	msg_unpacker_init (&unpacker, buf, len);
-
-	uint8_t result;     msg_unpacker_u8  (&unpacker, &result);
-	uint8_t vcp_opcode; msg_unpacker_u8  (&unpacker, &vcp_opcode);
-	uint8_t type;       msg_unpacker_u8  (&unpacker, &type);
-	int16_t max;        msg_unpacker_i16 (&unpacker, &max);
-	int16_t cur;        msg_unpacker_i16 (&unpacker, &cur);
-
-	if (result == 0x01)
-		return error_set (e, "error reported by monitor");
-
-	if (result != 0x00
-	 || vcp_opcode != VCP_BRIGHTNESS)
-		return error_set (e, "invalid response");
-
-	// These are unsigned but usually just one byte long
-	if (max < 0 || cur < 0)
-		return error_set (e, "capability range overflow");
-
-	int16_t req = (cur * 100 + diff * max + 50) / 100;
-	if (req > max) req = max;
-	if (req < 0)   req = 0;
+	int16_t req = (readout.cur * 100 + diff * readout.max + 50) / 100;
+	req = MIN (req, readout.max);
+	req = MAX (req, 0);
 
 	uint8_t set_req[] = { VCP_BRIGHTNESS, req >> 8, req };
 	if (!ddc_send (fd, DDC_SET_VCP_FEATURE, set_req, sizeof set_req, e))
@@ -263,7 +59,7 @@ set_brightness (int fd, long diff, struct error **e)
 
 	wait_ms (50);
 
-	printf ("brightness set to %.2f%%\n", 100. * req / max);
+	printf ("brightness set to %.2f%%\n", 100. * req / readout.max);
 	return true;
 }