l4re-base-25.08.0

src/l4/pkg/libedid/Control

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+requires: libc
+provides: libedid
+maintainer: matthias.lange@kernkonzept.com

src/l4/pkg/libedid/Makefile

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+PKGDIR	?= .
+L4DIR	?= $(PKGDIR)/../..
+
+include $(L4DIR)/mk/subdir.mk

src/l4/pkg/libedid/doc/files.cfg

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+INPUT += l4/libedid

src/l4/pkg/libedid/include/Makefile

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+PKGDIR	?= ..
+L4DIR	?= $(PKGDIR)/../..
+
+include $(L4DIR)/mk/include.mk

src/l4/pkg/libedid/include/edid.h

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+/**
+ * \file
+ */
+/*
+ * (c) 2014 Matthias Lange <matthias.lange@kernkonzept.com>
+ *
+ * This file is part of TUD:OS and distributed under the terms of the
+ * GNU Lesser General Public License 2.1.
+ * Please see the COPYING-LGPL-2.1 file for details.
+ */
+#pragma once
+
+#include <l4/sys/compiler.h>
+
+/**
+ * \defgroup libedid EDID parsing functionality
+ * @{
+ */
+
+/**
+ * \brief EDID constants
+ */
+enum Libedid_consts
+{
+  Libedid_block_size = 128, ///< Size of one EDID block in bytes
+};
+
+__BEGIN_DECLS
+
+/**
+ * \brief Check for valid EDID header
+ *
+ * \param edid  Pointer to a 128byte EDID block
+ *
+ * \return 0 if the header is correct, -EINVAL otherwise
+ */
+int libedid_check_header(const unsigned char *edid);
+
+/**
+ * \brief Calculates the EDID checksum
+ *
+ * \param edid  Pointer to a 128byte EDID block
+ *
+ * \return 0 if checksum is correct, -EINVAL otherwise
+ */
+int libedid_checksum(const unsigned char *edid);
+
+/**
+ * \brief Returns the EDID version number
+ *
+ * \param edid  Pointer to a 128byte EDID block
+ *
+ * \return Version number
+ */
+unsigned libedid_version(const unsigned char *edid);
+
+/**
+ * \brief Returns the EDID revision number
+ *
+ * \param edid  Pointer to a 128 EDID block
+ *
+ * \return Revision number
+ */
+unsigned libedid_revision(const unsigned char *edid);
+
+/**
+ * \brief Extracts the display's PnP ID
+ *
+ * \param      edid  Pointer to a 128byte EDID block
+ * \param[out] id    Return the PnP id. Must point to 4 bytes.
+ */
+void libedid_pnp_id(const unsigned char *edid, unsigned char *id);
+
+/**
+ * \brief Extract the display's prefered mode
+ *
+ * \param      edid  Pointer to a 128byte EDID block
+ * \param[out] w     X resolution of prefered video mode in pixels.
+ * \param[out] h     Y resolution of prefered video mode in pixels.
+ */
+void libedid_prefered_resolution(const unsigned char *edid,
+                                 unsigned *w, unsigned *h);
+
+/**
+ * \brief Get the number of EDID extension blocks
+ *
+ * \param edid Pointer to a 128byte EDID block
+ *
+ * \return Number of EDID extension blocks
+ */
+unsigned libedid_num_ext_blocks(const unsigned char *edid);
+
+/**
+ * \brief Dump the standard timings to stdout
+ *
+ * \param edid Pointer to a 128byte EDID block
+ *
+ * \return Number of standard timings stored in EDID
+ */
+unsigned libedid_dump_standard_timings(const unsigned char *edid);
+
+/**
+ * \brief Dump raw EDID data to stdout
+ *
+ * \param edid Pointer to a 128byte EDID block
+ */
+void libedid_dump(const unsigned char *edid);
+
+/**@}*/
+
+__END_DECLS

src/l4/pkg/libedid/lib/Makefile

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+PKGDIR	?= ..
+L4DIR	?= $(PKGDIR)/../..
+
+include $(L4DIR)/mk/subdir.mk

src/l4/pkg/libedid/lib/src/Makefile

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+PKGDIR ?= ../..
+L4DIR  ?= $(PKGDIR)/../..
+
+TARGET	= libedid.a libedid.so
+SRC_C	= edid.c
+
+include $(L4DIR)/mk/lib.mk

src/l4/pkg/libedid/lib/src/edid.c

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+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include <l4/libedid/edid.h>
+
+/// Defines various EDID length
+enum
+{
+  Libedid_header_size     = 8,   ///< Size of the EDID header in bytes
+  Libedid_num_st_timings  = 8,   ///< Up to 8 optional standard timings of 16byte each are defined in EDID 1.4
+};
+
+/// Defines addresses of EDID data structures
+enum
+{
+  Libedid_pnp_id       = 0x8,    ///< EDID vendor and product identification
+  Libedid_version      = 0x12,   ///< EDID version
+  Libedid_revision     = 0x13,   ///< EDID revision
+  Libedid_st           = 0x26,   ///< EDID standard timings
+  Libedid_descriptors  = 0x36,   ///< EDID 18byte descriptors
+  Libedid_ext_blocks   = 0x126,  ///< Number of EDID extension blocks
+};
+
+static unsigned char edid_v1_header[Libedid_header_size]
+   = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 };
+
+int libedid_check_header(const unsigned char *edid)
+{
+  if (memcmp(edid, edid_v1_header, Libedid_header_size))
+    return -EINVAL;
+
+  return 0;
+}
+
+int libedid_checksum(const unsigned char *edid)
+{
+  unsigned char sum = 0;
+
+  for (unsigned i = 0; i < Libedid_block_size; ++i)
+    sum += edid[i];
+
+  if (sum)
+    return -EINVAL;
+
+  return 0;
+}
+
+unsigned libedid_version(const unsigned char *edid)
+{
+  return edid[Libedid_version];
+}
+
+unsigned libedid_revision(const unsigned char *edid)
+{
+  return edid[Libedid_revision];
+}
+
+void libedid_pnp_id(const unsigned char *edid, unsigned char *id)
+{
+  const unsigned char *m_id = edid + Libedid_pnp_id;
+  id[0] = ((m_id[0] & 0x7c) >> 2) + '@';
+  id[1] = (((m_id[0] & 0x2) << 3) | ((m_id[1] & 0xe0) >> 5)) + '@';
+  id[2] = (m_id[1] & 0x1f) + '@';
+  id[3] = 0;
+}
+
+void libedid_prefered_resolution(const unsigned char *edid,
+                                 unsigned *w, unsigned *h)
+{
+  const unsigned char *block = edid + Libedid_descriptors;
+
+  *w = (block[2] & 0xff) | ((block[4] & 0xf0) << 4);
+  *h = (block[5] & 0xff) | ((block[7] & 0xf0) << 4);
+}
+
+unsigned libedid_num_ext_blocks(const unsigned char *edid)
+{
+  return edid[Libedid_ext_blocks];
+}
+
+unsigned libedid_dump_standard_timings(const unsigned char *edid)
+{
+  const unsigned char *st = edid + Libedid_st;
+  unsigned hpx = 0, vpx = 0;
+  unsigned i = 0;
+
+  for (i = 0; i < Libedid_num_st_timings; ++i)
+    {
+      if (st[0] == 0)
+        break;
+
+      hpx = ((st[0] & 0xff) + 31) * 8;
+      switch (((st[1] & 0xc0) >> 6))
+        {
+      case 0: // 16:10
+        vpx = hpx * 10 / 16;
+        break;
+      case 1: // 4:3
+        vpx = hpx * 3 / 4;
+        break;
+      case 2: // 5:4
+        vpx = hpx * 4 / 5;
+        break;
+      case 3: // 16:9
+        vpx = hpx * 9 / 16;
+        break;
+        }
+      printf("%dx%d (AR=%d)\n", hpx, vpx, (st[1] & 0xc0) >> 6);
+      st += 2;
+    }
+
+  return i;
+}
+
+void libedid_dump(const unsigned char *edid)
+{
+  for (unsigned i = 0; i < Libedid_block_size; ++i)
+    {
+      printf("0x%02x ", edid[i]);
+      if ((i % 16) == 15)
+        printf("\n");
+    }
+  printf("\n");
+}