[Qemu-devel] [PATCH 1/2] m48t59: use mmio for the m48t08 model of the m48t59_isa card

[Artyom Tarasenko <atar4qemu@gmail.com>]

PrEP and SPARC machines use slightly different variations of
a Mostek NVRAM chip. Since the SPARC variant is much closer
to a m48t08 type, the model can be used to differentiate between
the PIO and MMIO accesses.

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
---
 hw/timer/m48t59.c |   38 +++++++++++++++++++++++++++++++++++---
 1 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/hw/timer/m48t59.c b/hw/timer/m48t59.c
index 5019e06..00ad417 100644
--- a/hw/timer/m48t59.c
+++ b/hw/timer/m48t59.c
@@ -632,6 +632,33 @@ static const MemoryRegionOps m48t59_io_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
+{
+    M48t59State *NVRAM = opaque;
+    uint32_t retval;
+
+    retval = m48t59_read(NVRAM, addr);
+    return retval;
+}
+
+static void nvram_write(void *opaque, hwaddr addr, uint64_t value,
+                         unsigned size)
+{
+    M48t59State *NVRAM = opaque;
+
+    m48t59_write(NVRAM, addr, value & 0xff);
+}
+
+static const MemoryRegionOps m48t59_mmio_ops = {
+    .read = nvram_read,
+    .write = nvram_write,
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 1,
+    },
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 /* Initialisation routine */
 M48t59State *m48t59_init(qemu_irq IRQ, hwaddr mem_base,
                          uint32_t io_base, uint16_t size, int model)
@@ -676,7 +703,11 @@ M48t59State *m48t59_init_isa(ISABus *bus, uint32_t io_base, uint16_t size,
     d = DO_UPCAST(M48t59ISAState, busdev, dev);
     s = &d->state;
 
-    memory_region_init_io(&d->io, &m48t59_io_ops, s, "m48t59", 4);
+    if (model == 59) {
+        memory_region_init_io(&d->io, &m48t59_io_ops, s, "m48t59", 4);
+    } else {
+        memory_region_init_io(&d->io, &m48t59_mmio_ops, s, "m48t59", size);
+    }
     if (io_base != 0) {
         isa_register_ioport(dev, &d->io, io_base);
     }
@@ -700,8 +731,9 @@ static int m48t59_init_isa1(ISADevice *dev)
 {
     M48t59ISAState *d = DO_UPCAST(M48t59ISAState, busdev, dev);
     M48t59State *s = &d->state;
-
-    isa_init_irq(dev, &s->IRQ, 8);
+    if (s->model == 59) {
+        isa_init_irq(dev, &s->IRQ, 8);
+    }
     m48t59_init_common(s);
 
     return 0;
-- 
1.7.1