i2c: properly fix up Bus 3 support.

The original code was written 4.5years ago, and brought VIAs crappy
non-xf86i2c code into the proper infrastructure. It was painstakingly
tested remotely on Terry Lewis his acer aspire 135x, and the best i
could do at the time. Now things are sane and trivial and cool in this
code, finally.

1 files changed, 37 insertions, 188 deletions

diff --git a/src/via_i2c.c b/src/via_i2c.c
index 7f99003..d722541 100644
--- a/src/via_i2c.c
+++ b/src/via_i2c.c
@@ -40,14 +40,14 @@
 
 /*
  *
- * CRT I2C
+ * I2C Bus 1 at SR26.
  *
  */
 /*
  *
  */
 static void
-ViaI2C1PutBits(I2CBusPtr Bus, int clock,  int data)
+I2CBus1PutBits(I2CBusPtr Bus, int clock,  int data)
 {
     vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
     CARD8 value = 0x01; /* Enable */
@@ -65,7 +65,7 @@ ViaI2C1PutBits(I2CBusPtr Bus, int clock,  int data)
  *
  */
 static void
-ViaI2C1GetBits(I2CBusPtr Bus, int *clock, int *data)
+I2CBus1GetBits(I2CBusPtr Bus, int *clock, int *data)
 {
     vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
     CARD8 value = hwp->readSeq(hwp, 0x26);
@@ -78,17 +78,17 @@ ViaI2C1GetBits(I2CBusPtr Bus, int *clock, int *data)
  *
  */
 static I2CBusPtr
-ViaI2CBus1Init(int scrnIndex)
+I2CBus1Init(int scrnIndex)
 {
     I2CBusPtr pI2CBus = xf86CreateI2CBusRec();
 
     if (!pI2CBus)
 	return NULL;
 
-    pI2CBus->BusName    = "I2C bus 1";
+    pI2CBus->BusName    = "Bus 1";
     pI2CBus->scrnIndex  = scrnIndex;
-    pI2CBus->I2CPutBits = ViaI2C1PutBits;
-    pI2CBus->I2CGetBits = ViaI2C1GetBits;
+    pI2CBus->I2CPutBits = I2CBus1PutBits;
+    pI2CBus->I2CGetBits = I2CBus1GetBits;
 
     if (!xf86I2CBusInit(pI2CBus)) {
         xf86DestroyI2CBusRec(pI2CBus, TRUE, FALSE);
@@ -100,14 +100,14 @@ ViaI2CBus1Init(int scrnIndex)
 
 /*
  *
- * First data bus I2C: tends to have TV-encoders
+ * I2C Bus 2 at SR31.
  *
  */
 /*
  *
  */
 static void
-ViaI2C2PutBits(I2CBusPtr Bus, int clock,  int data)
+I2CBus2PutBits(I2CBusPtr Bus, int clock,  int data)
 {
     vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
     CARD8 value = 0x01; /* Enable */
@@ -125,7 +125,7 @@ ViaI2C2PutBits(I2CBusPtr Bus, int clock,  int data)
  *
  */
 static void
-ViaI2C2GetBits(I2CBusPtr Bus, int *clock, int *data)
+I2CBus2GetBits(I2CBusPtr Bus, int *clock, int *data)
 {
     vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
     CARD8 value = hwp->readSeq(hwp, 0x31);
@@ -138,17 +138,17 @@ ViaI2C2GetBits(I2CBusPtr Bus, int *clock, int *data)
  *
  */
 static I2CBusPtr
-ViaI2CBus2Init(int scrnIndex)
+I2CBus2Init(int scrnIndex)
 {
     I2CBusPtr pI2CBus = xf86CreateI2CBusRec();
 
     if (!pI2CBus)
 	return NULL;
 
-    pI2CBus->BusName    = "I2C bus 2";
+    pI2CBus->BusName    = "Bus 2";
     pI2CBus->scrnIndex  = scrnIndex;
-    pI2CBus->I2CPutBits = ViaI2C2PutBits;
-    pI2CBus->I2CGetBits = ViaI2C2GetBits;
+    pI2CBus->I2CPutBits = I2CBus2PutBits;
+    pI2CBus->I2CGetBits = I2CBus2GetBits;
 
     if (!xf86I2CBusInit(pI2CBus)) {
         xf86DestroyI2CBusRec(pI2CBus, TRUE, FALSE);
@@ -159,211 +159,60 @@ ViaI2CBus2Init(int scrnIndex)
 }
 
 /*
- * A third I2C bus implemented by a few IO pins.
- * Requires higher level functions to be used properly.
- * Former via_gpioi2c.
  *
- */
-/*
+ * I2C Bus 3 at SR2C.
  *
  */
-static Bool
-ViaI2C3Start(I2CBusPtr b, int timeout)
-{
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-
-    ViaSeqMask(hwp, 0x2C, 0xF0, 0xF0);
-    b->I2CUDelay(b, b->RiseFallTime);
-
-    ViaSeqMask(hwp, 0x2C, 0x00, 0x10);
-    b->I2CUDelay(b, b->HoldTime);
-    ViaSeqMask(hwp, 0x2C, 0x00, 0x20);
-    b->I2CUDelay(b, b->HoldTime);
-
-    return TRUE;
-}
-
-/*
- *
- */
-static Bool
-ViaI2C3Address(I2CDevPtr d, I2CSlaveAddr addr)
-{
-    I2CBusPtr b = d->pI2CBus;
-
-#ifdef X_NEED_I2CSTART
-    if (b->I2CStart(d->pI2CBus, d->StartTimeout)) {
-#else
-    if (ViaI2C3Start(d->pI2CBus, d->StartTimeout)) {
-#endif
-        if (b->I2CPutByte(d, addr & 0xFF)) {
-            if ((addr & 0xF8) != 0xF0 &&
-                (addr & 0xFE) != 0x00)
-                return TRUE;
-
-            if (b->I2CPutByte(d, (addr >> 8) & 0xFF))
-                return TRUE;
-        }
-
-        b->I2CStop(d);
-    }
-
-    return FALSE;
-}
-
 /*
  *
  */
 static void
-ViaI2C3Stop(I2CDevPtr d)
+I2CBus3PutBits(I2CBusPtr Bus, int clock,  int data)
 {
-    I2CBusPtr b = d->pI2CBus;
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-
-    ViaSeqMask(hwp, 0x2C, 0xC0, 0xF0);
-    b->I2CUDelay(b, b->RiseFallTime);
+    vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
+    CARD8 value = 0xC0; /* enable control lines for sda/scl */
 
-    ViaSeqMask(hwp, 0x2C, 0x20, 0x20);
-    b->I2CUDelay(b, b->HoldTime);
+    if (clock)
+        value |= SCL_WRITE;
 
-    ViaSeqMask(hwp, 0x2C, 0x10, 0x10);
-    b->I2CUDelay(b, b->HoldTime);
+    if (data)
+        value |= SDA_WRITE;
 
-    ViaSeqMask(hwp, 0x2C, 0x00, 0x20);
-    b->I2CUDelay(b, b->HoldTime);
+    ViaSeqMask(hwp, 0x2C, value, 0xC0 | SCL_WRITE | SDA_WRITE);
 }
 
 /*
  *
  */
 static void
-ViaI2C3PutBit(I2CBusPtr b, Bool sda, int timeout)
-{
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-
-    if (sda)
-        ViaSeqMask(hwp, 0x2C, 0x50, 0x50);
-    else
-        ViaSeqMask(hwp, 0x2C, 0x40, 0x50);
-    b->I2CUDelay(b, b->RiseFallTime/5);
-
-    ViaSeqMask(hwp, 0x2C, 0xA0, 0xA0);
-    b->I2CUDelay(b, b->HoldTime);
-    b->I2CUDelay(b, timeout);
-
-    ViaSeqMask(hwp, 0x2C, 0x80, 0xA0);
-    b->I2CUDelay(b, b->RiseFallTime/5);
-}
-
-/*
- *
- */
-static Bool
-ViaI2C3PutByte(I2CDevPtr d, I2CByte data)
+I2CBus3GetBits(I2CBusPtr Bus, int *clock, int *data)
 {
-    I2CBusPtr b = d->pI2CBus;
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-    Bool ret;
-    int     i;
-
-    for (i = 7; i >= 0; i--)
-        ViaI2C3PutBit(b, (data >> i) & 0x01, b->BitTimeout);
-
-    /* raise first to avoid false positives */
-    ViaSeqMask(hwp, 0x2C, 0x50, 0x50);
-    ViaSeqMask(hwp, 0x2C, 0x00, 0x40);
-    b->I2CUDelay(b, b->RiseFallTime);
-    ViaSeqMask(hwp, 0x2C, 0xA0, 0xA0);
-
-    if (hwp->readSeq(hwp, 0x2C) & 0x04)
-        ret = FALSE;
-    else
-        ret = TRUE;
-
-    ViaSeqMask(hwp, 0x2C, 0x80, 0xA0);
-    b->I2CUDelay(b, b->RiseFallTime);
-
-    return ret;
-}
-
-/*
- *
- */
-static Bool
-ViaI2C3GetBit(I2CBusPtr b, int timeout)
-{
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-    Bool ret;
-
-    ViaSeqMask(hwp, 0x2C, 0x00, 0x40);
-    b->I2CUDelay(b, b->RiseFallTime/5);
-
-    ViaSeqMask(hwp, 0x2C, 0xA0, 0xA0);
-
-    if (hwp->readSeq(hwp, 0x2C) & 0x04)
-        ret = TRUE;
-    else
-        ret = FALSE;
-
-    ViaSeqMask(hwp, 0x2C, 0x80, 0xA0);
-    b->I2CUDelay(b, b->RiseFallTime/5);
-
-    return ret;
-}
-
-/*
- *
- */
-static Bool
-ViaI2C3GetByte(I2CDevPtr d, I2CByte *data, Bool last)
-{
-    I2CBusPtr b = d->pI2CBus;
-    vgaHWPtr hwp = VGAHWPTR(xf86Screens[b->scrnIndex]);
-    int     i;
-
-    *data = 0x00;
-
-    for (i = 7; i >= 0; i--)
-        if (ViaI2C3GetBit(b, b->BitTimeout))
-            *data |= 0x01 << i;
-
-    if (last) /* send NACK */
-	ViaSeqMask(hwp, 0x2C, 0x50, 0x50);
-    else /* send ACK */
-	ViaSeqMask(hwp, 0x2C, 0x40, 0x50);
-
-    ViaSeqMask(hwp, 0x2C, 0xA0, 0xA0);
-    b->I2CUDelay(b, b->HoldTime);
-
-    ViaSeqMask(hwp, 0x2C, 0x80, 0xA0);
+    vgaHWPtr hwp = VGAHWPTR(xf86Screens[Bus->scrnIndex]);
+    CARD8 value = hwp->readSeq(hwp, 0x2C);
 
-    return TRUE;
+    *clock = (value & SCL_READ) != 0;
+    *data  = (value & SDA_READ) != 0;
 }
 
 /*
  *
  */
 static I2CBusPtr
-ViaI2CBus3Init(int scrnIndex)
+I2CBus3Init(int scrnIndex)
 {
     I2CBusPtr pI2CBus = xf86CreateI2CBusRec();
 
     if (!pI2CBus)
 	return NULL;
 
-    pI2CBus->BusName    = "I2C bus 3";
+    pI2CBus->BusName    = "Bus 3";
     pI2CBus->scrnIndex  = scrnIndex;
-    pI2CBus->I2CAddress = ViaI2C3Address;
-#ifdef X_NEED_I2CSTART
-    pI2CBus->I2CStart = ViaI2C3Start;
-#endif
-    pI2CBus->I2CStop = ViaI2C3Stop;
-    pI2CBus->I2CPutByte = ViaI2C3PutByte;
-    pI2CBus->I2CGetByte = ViaI2C3GetByte;
+    pI2CBus->I2CPutBits = I2CBus3PutBits;
+    pI2CBus->I2CGetBits = I2CBus3GetBits;
 
     if (!xf86I2CBusInit(pI2CBus)) {
-	xf86DestroyI2CBusRec(pI2CBus, TRUE, FALSE);
-	return NULL;
+        xf86DestroyI2CBusRec(pI2CBus, TRUE, FALSE);
+        return NULL;
     }
 
     return pI2CBus;
@@ -379,7 +228,7 @@ ViaI2CInit(ScrnInfoPtr pScrn)
 
     VIAFUNC(pScrn);
 
-    pVia->pI2CBus1 = ViaI2CBus1Init(pScrn->scrnIndex);
-    pVia->pI2CBus2 = ViaI2CBus2Init(pScrn->scrnIndex);
-    pVia->pI2CBus3 = ViaI2CBus3Init(pScrn->scrnIndex);
+    pVia->pI2CBus1 = I2CBus1Init(pScrn->scrnIndex);
+    pVia->pI2CBus2 = I2CBus2Init(pScrn->scrnIndex);
+    pVia->pI2CBus3 = I2CBus3Init(pScrn->scrnIndex);
 }