hw/ssi/xilinx_spi: Make device endianness configurable

Replace the DEVICE_NATIVE_ENDIAN MemoryRegionOps by a pair of
DEVICE_LITTLE_ENDIAN / DEVICE_BIG_ENDIAN.

Add the "endianness" property to select the device endianness.
This property is unspecified by default, and machines need to
set it explicitly.

Set the proper endianness on the single machine using the
device.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250213122217.62654-7-philmd@linaro.org>

hw/microblaze/petalogix_ml605_mmu.c

@@ -177,6 +177,7 @@ petalogix_ml605_init(MachineState *machine)
         SSIBus *spi;
 
         dev = qdev_new("xlnx.xps-spi");
+        qdev_prop_set_enum(dev, "endianness", endianness);
         qdev_prop_set_uint8(dev, "num-ss-bits", NUM_SPI_FLASHES);
         busdev = SYS_BUS_DEVICE(dev);
         sysbus_realize_and_unref(busdev, &error_fatal);

hw/ssi/xilinx_spi.c

@@ -25,6 +25,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "migration/vmstate.h"
 #include "qemu/module.h"
@@ -32,6 +33,7 @@
 
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
+#include "hw/qdev-properties-system.h"
 #include "hw/ssi/ssi.h"
 #include "qom/object.h"
 
@@ -83,6 +85,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(XilinxSPI, XILINX_SPI)
 struct XilinxSPI {
     SysBusDevice parent_obj;
 
+    EndianMode model_endianness;
     MemoryRegion mmio;
 
     qemu_irq irq;
@@ -313,14 +316,17 @@ done:
     xlx_spi_update_irq(s);
 }
 
-static const MemoryRegionOps spi_ops = {
-    .read = spi_read,
-    .write = spi_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
-    .valid = {
-        .min_access_size = 4,
-        .max_access_size = 4
-    }
+static const MemoryRegionOps spi_ops[2] = {
+    [0 ... 1] = {
+        .read = spi_read,
+        .write = spi_write,
+        .valid = {
+            .min_access_size = 4,
+            .max_access_size = 4,
+        },
+    },
+    [0].endianness = DEVICE_LITTLE_ENDIAN,
+    [1].endianness = DEVICE_BIG_ENDIAN,
 };
 
 static void xilinx_spi_realize(DeviceState *dev, Error **errp)
@@ -329,6 +335,12 @@ static void xilinx_spi_realize(DeviceState *dev, Error **errp)
     XilinxSPI *s = XILINX_SPI(dev);
     int i;
 
+    if (s->model_endianness == ENDIAN_MODE_UNSPECIFIED) {
+        error_setg(errp, TYPE_XILINX_SPI " property 'endianness'"
+                         " must be set to 'big' or 'little'");
+        return;
+    }
+
     DB_PRINT("\n");
 
     s->spi = ssi_create_bus(dev, "spi");
@@ -339,7 +351,8 @@ static void xilinx_spi_realize(DeviceState *dev, Error **errp)
         sysbus_init_irq(sbd, &s->cs_lines[i]);
     }
 
-    memory_region_init_io(&s->mmio, OBJECT(s), &spi_ops, s,
+    memory_region_init_io(&s->mmio, OBJECT(s),
+                          &spi_ops[s->model_endianness == ENDIAN_MODE_BIG], s,
                           "xilinx-spi", R_MAX * 4);
     sysbus_init_mmio(sbd, &s->mmio);
 
@@ -362,6 +375,7 @@ static const VMStateDescription vmstate_xilinx_spi = {
 };
 
 static const Property xilinx_spi_properties[] = {
+    DEFINE_PROP_ENDIAN_NODEFAULT("endianness", XilinxSPI, model_endianness),
     DEFINE_PROP_UINT8("num-ss-bits", XilinxSPI, num_cs, 1),
 };