[Openchrome-devel] xf86-video-openchrome: src/via_outputs.c

[Kevin Brace]

 src/via_outputs.c |   98 ++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 63 insertions(+), 35 deletions(-)

New commits:
commit 7a98f6584fec8dd7d6f516d6718839b5c96342cc
Author: Kevin Brace <kevinbrace at gmx.com>
Date:   Sat Mar 5 11:33:08 2016 -0800

    Using I2C bus 2 to detect a VGA monitor
    
    Previously, it was assumed that I2C bus 1 is used to detect only a VGA
    monitor. It was also assumed that I2C bus 2 is used to detect a DVI
    monitor or TV encoder. However, for devices with a DVI-I connector,
    VGA signals come out of the connector as well. What this means is that
    I2C bus 2 also has to be used to detect a VGA monitor, in addition to
    I2C bus 1. Furthermore, EDID obtained from the monitor via I2C bus
    will be used to determine whether or not it is an analog type
    (i.e., VGA monitor).
    
    Reported-by: Christopher Havel <laserhawk64 at gmail.com>
    Tested-by: Justin Chevrier <jchevrier at gmail.com>
    Signed-off-by: Kevin Brace <kevinbrace at gmx.com>

diff --git a/src/via_outputs.c b/src/via_outputs.c
index 8034911..31013a4 100644
--- a/src/via_outputs.c
+++ b/src/via_outputs.c
@@ -804,50 +804,78 @@ via_analog_detect(xf86OutputPtr output)
     VIAPtr pVia = VIAPTR(pScrn);
     xf86MonPtr mon;
 
+    /* Probe I2C Bus 1 to see if a VGA monitor is connected. */
+    xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                "Probing for a VGA monitor on I2C Bus 1.\n");
     mon = xf86OutputGetEDID(output, pVia->pI2CBus1);
-    if (mon) {
+    if (mon && (!mon->features.input_type)) {
         xf86OutputSetEDID(output, mon);
-        xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
-                    "I2C Bus 1 detected a VGA monitor.\n");
         status = XF86OutputStatusConnected;
+        xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                    "Detected a VGA monitor on I2C Bus 1.\n");
     } else {
-        vgaHWPtr hwp = VGAHWPTR(pScrn);
-        CARD8 SR01 = hwp->readSeq(hwp, 0x01);
-        CARD8 SR40 = hwp->readSeq(hwp, 0x40);
-        CARD8 CR36 = hwp->readCrtc(hwp, 0x36);
-
-        DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
-                         "Test for CRT with VSYNC\n"));
-        /* We have to power on the display to detect it */
-        ViaSeqMask(hwp, 0x01, 0x00, 0x20);
-        ViaCrtcMask(hwp, 0x36, 0x00, 0xF0);
-
-        /* Wait for vblank */
-        usleep(16);
-
-        /* Detect the load on pins */
-        ViaSeqMask(hwp, 0x40, 0x80, 0x80);
-
-        if ((VIA_CX700 == pVia->Chipset) ||
-            (VIA_VX800 == pVia->Chipset) ||
-            (VIA_VX855 == pVia->Chipset) ||
-            (VIA_VX900 == pVia->Chipset))
-            ViaSeqMask(hwp, 0x40, 0x00, 0x80);
+        xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                    "Did not detect a VGA monitor on I2C Bus 1.\n");
 
-        if (ViaVgahwIn(hwp, 0x3C2) & 0x20)
+        /* Probe I2C Bus 2 to see if a VGA monitor is connected. */
+        xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                    "Probing for a VGA monitor on I2C Bus 2.\n");
+        mon = xf86OutputGetEDID(output, pVia->pI2CBus2);
+        if (mon && (!mon->features.input_type)) {
+            xf86OutputSetEDID(output, mon);
             status = XF86OutputStatusConnected;
+            xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                        "Detected a VGA monitor on I2C Bus 2.\n");
+        } else {
+            xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                        "Did not detect a VGA monitor on I2C Bus 2.\n");
+
+            /* Perform manual detection of a VGA monitor since */
+            /* it was not detected via I2C buses. */
+            xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                        "Now perform manual detection of a VGA "
+                        "monitor.\n");
+            vgaHWPtr hwp = VGAHWPTR(pScrn);
+            CARD8 SR01 = hwp->readSeq(hwp, 0x01);
+            CARD8 SR40 = hwp->readSeq(hwp, 0x40);
+            CARD8 CR36 = hwp->readCrtc(hwp, 0x36);
+
+            /* We have to power on the display to detect it */
+            ViaSeqMask(hwp, 0x01, 0x00, 0x20);
+            ViaCrtcMask(hwp, 0x36, 0x00, 0xF0);
+
+            /* Wait for vblank */
+            usleep(16);
+
+            /* Detect the load on pins */
+            ViaSeqMask(hwp, 0x40, 0x80, 0x80);
+
+            if ((VIA_CX700 == pVia->Chipset) ||
+                (VIA_VX800 == pVia->Chipset) ||
+                (VIA_VX855 == pVia->Chipset) ||
+                (VIA_VX900 == pVia->Chipset))
+                ViaSeqMask(hwp, 0x40, 0x00, 0x80);
+
+            if (ViaVgahwIn(hwp, 0x3C2) & 0x20) {
+                status = XF86OutputStatusConnected;
+                xf86DrvMsg(pScrn->scrnIndex, X_PROBED,
+                            "Detected a VGA monitor using manual "
+                            "detection method.\n");
+            }
 
-        if ((VIA_CX700 == pVia->Chipset) ||
-            (VIA_VX800 == pVia->Chipset) ||
-            (VIA_VX855 == pVia->Chipset) ||
-            (VIA_VX900 == pVia->Chipset))
-            ViaSeqMask(hwp, 0x40, 0x00, 0x80);
+            if ((VIA_CX700 == pVia->Chipset) ||
+                (VIA_VX800 == pVia->Chipset) ||
+                (VIA_VX855 == pVia->Chipset) ||
+                (VIA_VX900 == pVia->Chipset))
+                ViaSeqMask(hwp, 0x40, 0x00, 0x80);
 
-        /* Restore previous state */
-        hwp->writeSeq(hwp, 0x40, SR40);
-        hwp->writeSeq(hwp, 0x01, SR01);
-        hwp->writeCrtc(hwp, 0x36, CR36);
+            /* Restore previous state */
+            hwp->writeSeq(hwp, 0x40, SR40);
+            hwp->writeSeq(hwp, 0x01, SR01);
+            hwp->writeCrtc(hwp, 0x36, CR36);
+        }
     }
+
     return status;
 }