Start E-EDID support in the DDC module.

Since there's no way to safely know how many blocks xf86DoEDID_DDC2 would
return, add a new xf86DoEEDID entrypoint to do that, and implement the
one in terms of the other.

2 files changed, 47 insertions, 29 deletions

diff --git a/hw/xfree86/ddc/xf86DDC.c b/hw/xfree86/ddc/xf86DDC.c
index 28e2ead28..98f60061e 100644
--- a/hw/xfree86/ddc/xf86DDC.c
+++ b/hw/xfree86/ddc/xf86DDC.c
@@ -2,6 +2,14 @@
  * 
  * Copyright 1998,1999 by Egbert Eich <Egbert.Eich@Physik.TU-Darmstadt.DE>
  */
+
+/*
+ * Note that DDC1 does not define any method for returning blocks beyond
+ * the first.  DDC2 does, but the original implementation would only ever
+ * read the first block.  If you want to read and parse all blocks, use
+ * xf86DoEEDID().
+ */
+
 #ifdef HAVE_XORG_CONFIG_H
 #include <xorg-config.h>
 #endif
@@ -31,11 +39,6 @@ static unsigned int *FetchEDID_DDC1(
     register unsigned int (*)(ScrnInfoPtr)
 );
 
-static unsigned char* EDID1Read_DDC2(
-    int scrnIndex, 
-    I2CBusPtr pBus
-);
-
 static unsigned char * DDCRead_DDC2(
     int scrnIndex,
     I2CBusPtr pBus, 
@@ -110,16 +113,22 @@ xf86DoEDID_DDC1(
 /**
  * Attempts to probe the monitor for EDID information, if NoDDC and NoDDC2 are
  * unset.  EDID information blocks are interpreted and the results returned in
- * an xf86MonPtr.
+ * an xf86MonPtr.  Unlike xf86DoEDID_DDC[12](), this function will return
+ * the complete EDID data, including all extension blocks.
  *
  * This function does not affect the list of modes used by drivers -- it is up
  * to the driver to decide policy on what to do with EDID information.
  *
  * @return pointer to a new xf86MonPtr containing the EDID information.
  * @return NULL if no monitor attached or failure to interpret the EDID.
+ *
+ * nblocks is an in/out parameter.  If non-zero, it defines the number of
+ * blocks to read from the monitor; zero (or NULL pointer) means read all.
+ * If non-NULL, on return it will be filled in with the number of blocks
+ * read.
  */
 xf86MonPtr
-xf86DoEDID_DDC2(int scrnIndex, I2CBusPtr pBus)
+xf86DoEEDID(int scrnIndex, I2CBusPtr pBus, int *nblocks)
 {
     ScrnInfoPtr pScrn = xf86Screens[scrnIndex];
     unsigned char *EDID_block = NULL;
@@ -129,7 +138,7 @@ xf86DoEDID_DDC2(int scrnIndex, I2CBusPtr pBus)
     OptionInfoPtr options;
 
     options = xnfalloc(sizeof(DDCOptions));
-    (void)memcpy(options, DDCOptions, sizeof(DDCOptions));
+    memcpy(options, DDCOptions, sizeof(DDCOptions));
     xf86ProcessOptions(pScrn->scrnIndex, pScrn->options, options);
 
     xf86GetOptValBool(options, DDCOPT_NODDC, &noddc);
@@ -139,26 +148,39 @@ xf86DoEDID_DDC2(int scrnIndex, I2CBusPtr pBus)
     if (noddc || noddc2)
 	return NULL;
 
-    EDID_block = EDID1Read_DDC2(scrnIndex,pBus);
+    EDID_block = DDCRead_DDC2(scrnIndex, pBus, 0, EDID1_LEN);
 
-    if (EDID_block){
-	tmp = xf86InterpretEDID(scrnIndex,EDID_block);
-    } else {
-#ifdef DEBUG
-	ErrorF("No EDID block returned\n");
-#endif
-	return NULL;
+    if (EDID_block)
+	tmp = xf86InterpretEDID(scrnIndex, EDID_block);
+
+    if (nblocks) {
+	if (tmp)
+	    *nblocks = tmp->no_sections;
+	else
+	    *nblocks = 0;
     }
-#ifdef DEBUG
-    if (!tmp)
-	ErrorF("Cannot interpret EDID block\n");
-    else
-        ErrorF("Sections to follow: %i\n",tmp->no_sections);
-#endif
-    
+
     return tmp;
 }
 
+/**
+ * Attempts to probe the monitor for EDID information, if NoDDC and NoDDC2 are
+ * unset.  EDID information blocks are interpreted and the results returned in
+ * an xf86MonPtr.
+ *
+ * This function does not affect the list of modes used by drivers -- it is up
+ * to the driver to decide policy on what to do with EDID information.
+ *
+ * @return pointer to a new xf86MonPtr containing the EDID information.
+ * @return NULL if no monitor attached or failure to interpret the EDID.
+ */
+xf86MonPtr
+xf86DoEDID_DDC2(int scrnIndex, I2CBusPtr pBus)
+{
+    int nblocks = 1;
+    return xf86DoEEDID(scrnIndex, pBus, &nblocks);
+}
+
 /* 
  * read EDID record , pass it to callback function to interpret.
  * callback function will store it for further use by calling
@@ -226,12 +248,6 @@ FetchEDID_DDC1(register ScrnInfoPtr pScrn,
     return (ptr);
 }
 
-static unsigned char*
-EDID1Read_DDC2(int scrnIndex, I2CBusPtr pBus)
-{
-    return  DDCRead_DDC2(scrnIndex, pBus, 0, EDID1_LEN);
-}
-
 static unsigned char *
 DDCRead_DDC2(int scrnIndex, I2CBusPtr pBus, int start, int len)
 {
diff --git a/hw/xfree86/ddc/xf86DDC.h b/hw/xfree86/ddc/xf86DDC.h
index 3b072dda7..6e5bf6f7a 100644
--- a/hw/xfree86/ddc/xf86DDC.h
+++ b/hw/xfree86/ddc/xf86DDC.h
@@ -35,6 +35,8 @@ extern xf86MonPtr xf86DoEDID_DDC2(
    I2CBusPtr pBus
 );
 
+extern xf86MonPtr xf86DoEEDID(int scrnIndex, I2CBusPtr pBus, int *nblocks);
+
 extern xf86MonPtr xf86PrintEDID(
     xf86MonPtr monPtr
 );