[PULL 02/23] dp8393x: Always use 32-bit accesses

[Jason Wang <jasowang@redhat.com>]

From: Finn Thain <fthain@telegraphics.com.au>

The DP83932 and DP83934 have 32 data lines. The datasheet says,

    Data Bus: These bidirectional lines are used to transfer data on the
    system bus. When the SONIC is a bus master, 16-bit data is transferred
    on D15-D0 and 32-bit data is transferred on D31-D0. When the SONIC is
    accessed as a slave, register data is driven onto lines D15-D0.
    D31-D16 are held TRI-STATE if SONIC is in 16-bit mode. If SONIC is in
    32-bit mode, they are driven, but invalid.

Always use 32-bit accesses both as bus master and bus slave.

Force the MSW to zero in bus master mode.

This gets the Linux 'jazzsonic' driver working, and avoids the need for
prior hacks to make the NetBSD 'sn' driver work.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/dp8393x.c | 47 +++++++++++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 18 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 216d44b..51b71da 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -246,9 +246,19 @@ static void dp8393x_put(dp8393xState *s, int width, int offset,
                         uint16_t val)
 {
     if (s->big_endian) {
-        s->data[offset * width + width - 1] = cpu_to_be16(val);
+        if (width == 2) {
+            s->data[offset * 2] = 0;
+            s->data[offset * 2 + 1] = cpu_to_be16(val);
+        } else {
+            s->data[offset] = cpu_to_be16(val);
+        }
     } else {
-        s->data[offset * width] = cpu_to_le16(val);
+        if (width == 2) {
+            s->data[offset * 2] = cpu_to_le16(val);
+            s->data[offset * 2 + 1] = 0;
+        } else {
+            s->data[offset] = cpu_to_le16(val);
+        }
     }
 }
 
@@ -590,7 +600,7 @@ static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
 
     DPRINTF("read 0x%04x from reg %s\n", val, reg_names[reg]);
 
-    return val;
+    return s->big_endian ? val << 16 : val;
 }
 
 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
@@ -598,13 +608,14 @@ static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
 {
     dp8393xState *s = opaque;
     int reg = addr >> s->it_shift;
+    uint32_t val = s->big_endian ? data >> 16 : data;
 
-    DPRINTF("write 0x%04x to reg %s\n", (uint16_t)data, reg_names[reg]);
+    DPRINTF("write 0x%04x to reg %s\n", (uint16_t)val, reg_names[reg]);
 
     switch (reg) {
         /* Command register */
         case SONIC_CR:
-            dp8393x_do_command(s, data);
+            dp8393x_do_command(s, val);
             break;
         /* Prevent write to read-only registers */
         case SONIC_CAP2:
@@ -617,36 +628,36 @@ static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
         /* Accept write to some registers only when in reset mode */
         case SONIC_DCR:
             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
-                s->regs[reg] = data & 0xbfff;
+                s->regs[reg] = val & 0xbfff;
             } else {
                 DPRINTF("writing to DCR invalid\n");
             }
             break;
         case SONIC_DCR2:
             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
-                s->regs[reg] = data & 0xf017;
+                s->regs[reg] = val & 0xf017;
             } else {
                 DPRINTF("writing to DCR2 invalid\n");
             }
             break;
         /* 12 lower bytes are Read Only */
         case SONIC_TCR:
-            s->regs[reg] = data & 0xf000;
+            s->regs[reg] = val & 0xf000;
             break;
         /* 9 lower bytes are Read Only */
         case SONIC_RCR:
-            s->regs[reg] = data & 0xffe0;
+            s->regs[reg] = val & 0xffe0;
             break;
         /* Ignore most significant bit */
         case SONIC_IMR:
-            s->regs[reg] = data & 0x7fff;
+            s->regs[reg] = val & 0x7fff;
             dp8393x_update_irq(s);
             break;
         /* Clear bits by writing 1 to them */
         case SONIC_ISR:
-            data &= s->regs[reg];
-            s->regs[reg] &= ~data;
-            if (data & SONIC_ISR_RBE) {
+            val &= s->regs[reg];
+            s->regs[reg] &= ~val;
+            if (val & SONIC_ISR_RBE) {
                 dp8393x_do_read_rra(s);
             }
             dp8393x_update_irq(s);
@@ -659,17 +670,17 @@ static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
         case SONIC_REA:
         case SONIC_RRP:
         case SONIC_RWP:
-            s->regs[reg] = data & 0xfffe;
+            s->regs[reg] = val & 0xfffe;
             break;
         /* Invert written value for some registers */
         case SONIC_CRCT:
         case SONIC_FAET:
         case SONIC_MPT:
-            s->regs[reg] = data ^ 0xffff;
+            s->regs[reg] = val ^ 0xffff;
             break;
         /* All other registers have no special contrainst */
         default:
-            s->regs[reg] = data;
+            s->regs[reg] = val;
     }
 
     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
@@ -680,8 +691,8 @@ static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
 static const MemoryRegionOps dp8393x_ops = {
     .read = dp8393x_read,
     .write = dp8393x_write,
-    .impl.min_access_size = 2,
-    .impl.max_access_size = 2,
+    .impl.min_access_size = 4,
+    .impl.max_access_size = 4,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
-- 
2.5.0