libqdutils: add edid raw data reading support

Add API getEdidRawData to fill the input buffer with
edid raw data(640 bytes)

Change-Id: I993c3fdc01b469f65d78d8f5d05c46c54d4e580d
diff --git a/libqdutils/qd_utils.cpp b/libqdutils/qd_utils.cpp
new file mode 100644
index 0000000..5a457d0
--- /dev/null
+++ b/libqdutils/qd_utils.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of The Linux Foundation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * 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 "qd_utils.h"
+
+
+#define MAX_FRAME_BUFFER_NAME_SIZE      (80)
+#define MAX_DISPLAY_DEVICES             (3)
+
+int getHDMINode(void)
+{
+    FILE *displayDeviceFP = NULL;
+    char fbType[MAX_FRAME_BUFFER_NAME_SIZE];
+    char msmFbTypePath[MAX_FRAME_BUFFER_NAME_SIZE];
+    int j = 0;
+
+    for(j = 0; j < MAX_DISPLAY_DEVICES; j++) {
+        snprintf (msmFbTypePath, sizeof(msmFbTypePath),
+                  "/sys/class/graphics/fb%d/msm_fb_type", j);
+        displayDeviceFP = fopen(msmFbTypePath, "r");
+        if(displayDeviceFP) {
+            fread(fbType, sizeof(char), MAX_FRAME_BUFFER_NAME_SIZE,
+                    displayDeviceFP);
+            if(strncmp(fbType, "dtv panel", strlen("dtv panel")) == 0) {
+                ALOGD("%s: HDMI is at fb%d", __func__, j);
+                fclose(displayDeviceFP);
+                break;
+            }
+            fclose(displayDeviceFP);
+        } else {
+            ALOGE("%s: Failed to open fb node %d", __func__, j);
+        }
+    }
+
+    if (j < MAX_DISPLAY_DEVICES)
+        return j;
+    else
+        ALOGE("%s: Failed to find HDMI node", __func__);
+
+    return -1;
+}
+
+int getEdidRawData(char *buffer)
+{
+    int size;
+    int edidFile;
+    char msmFbTypePath[MAX_FRAME_BUFFER_NAME_SIZE];
+    int node_id = getHDMINode();
+
+    if (node_id < 0) {
+        ALOGE("%s no HDMI node found", __func__);
+        return 0;
+    }
+
+    snprintf(msmFbTypePath, sizeof(msmFbTypePath),
+                 "/sys/class/graphics/fb%d/edid_raw_data", node_id);
+
+   edidFile = open(msmFbTypePath, O_RDONLY, 0);
+
+    if (edidFile < 0) {
+        ALOGE("%s no edid raw data found", __func__);
+        return 0;
+    }
+
+    size = read(edidFile, (char*)buffer, EDID_RAW_DATA_SIZE);
+    close(edidFile);
+    return size;
+}
+