serial: start making SerialMM a sysbus device

Memory mapped serial device is in fact a sysbus device. The following
patches will make use of sysbus facilities for resource and
registration. In particular, "serial-mm: use sysbus facilities" will
move internal serial realization to serial_mm_realize callback to
follow qdev best practices.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

hw/char/omap_uart.c

@@ -27,7 +27,7 @@
 struct omap_uart_s {
     MemoryRegion iomem;
     hwaddr base;
-    SerialState *serial; /* TODO */
+    SerialMM *serial; /* TODO */
     struct omap_target_agent_s *ta;
     omap_clk fclk;
     qemu_irq irq;

hw/char/serial.c

@@ -1032,16 +1032,28 @@ static const TypeInfo serial_info = {
 static uint64_t serial_mm_read(void *opaque, hwaddr addr,
                                unsigned size)
 {
-    SerialState *s = opaque;
-    return serial_ioport_read(s, addr >> s->it_shift, 1);
+    SerialMM *s = SERIAL_MM(opaque);
+    return serial_ioport_read(&s->serial, addr >> s->it_shift, 1);
 }
 
 static void serial_mm_write(void *opaque, hwaddr addr,
                             uint64_t value, unsigned size)
 {
-    SerialState *s = opaque;
+    SerialMM *s = SERIAL_MM(opaque);
     value &= 255;
-    serial_ioport_write(s, addr >> s->it_shift, value, 1);
+    serial_ioport_write(&s->serial, addr >> s->it_shift, value, 1);
+}
+
+static void serial_mm_realize(DeviceState *dev, Error **errp)
+{
+    SerialMM *s = SERIAL_MM(dev);
+    Error *local_err = NULL;
+
+    object_property_set_bool(OBJECT(&s->serial), true, "realized", &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
 }
 
 static const MemoryRegionOps serial_mm_ops[3] = {
@@ -1068,30 +1080,56 @@ static const MemoryRegionOps serial_mm_ops[3] = {
     },
 };
 
-SerialState *serial_mm_init(MemoryRegion *address_space,
-                            hwaddr base, int it_shift,
-                            qemu_irq irq, int baudbase,
-                            Chardev *chr, enum device_endian end)
+SerialMM *serial_mm_init(MemoryRegion *address_space,
+                         hwaddr base, int it_shift,
+                         qemu_irq irq, int baudbase,
+                         Chardev *chr, enum device_endian end)
 {
-    DeviceState *dev = DEVICE(object_new(TYPE_SERIAL));
-    SerialState *s = SERIAL(dev);
+    SerialMM *smm = SERIAL_MM(qdev_create(NULL, TYPE_SERIAL_MM));
+    SerialState *s = &smm->serial;
 
-    s->it_shift = it_shift;
+    smm->it_shift = it_shift;
     s->irq = irq;
-    qdev_prop_set_uint32(dev, "baudbase", baudbase);
-    qdev_prop_set_chr(dev, "chardev", chr);
-    qdev_set_legacy_instance_id(dev, base, 2);
-    qdev_init_nofail(dev);
+    qdev_prop_set_uint32(DEVICE(s), "baudbase", baudbase);
+    qdev_prop_set_chr(DEVICE(s), "chardev", chr);
+    qdev_set_legacy_instance_id(DEVICE(s), base, 2);
 
-    memory_region_init_io(&s->io, NULL, &serial_mm_ops[end], s,
+    qdev_init_nofail(DEVICE(smm));
+
+    memory_region_init_io(&s->io, NULL, &serial_mm_ops[end], smm,
                           "serial", 8 << it_shift);
     memory_region_add_subregion(address_space, base, &s->io);
-    return s;
+
+    return smm;
+}
+
+static void serial_mm_instance_init(Object *o)
+{
+    SerialMM *smm = SERIAL_MM(o);
+
+    object_initialize_child(o, "serial", &smm->serial, sizeof(smm->serial),
+                            TYPE_SERIAL, &error_abort, NULL);
 }
 
+static void serial_mm_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = serial_mm_realize;
+}
+
+static const TypeInfo serial_mm_info = {
+    .name = TYPE_SERIAL_MM,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .class_init = serial_mm_class_init,
+    .instance_init = serial_mm_instance_init,
+    .instance_size = sizeof(SerialMM),
+};
+
 static void serial_register_types(void)
 {
     type_register_static(&serial_info);
+    type_register_static(&serial_mm_info);
 }
 
 type_init(serial_register_types)

hw/mips/boston.c

@@ -50,7 +50,7 @@ typedef struct {
 
     MachineState *mach;
     MIPSCPSState cps;
-    SerialState *uart;
+    SerialMM *uart;
 
     CharBackend lcd_display;
     char lcd_content[8];

hw/mips/mips_malta.c

@@ -83,7 +83,7 @@ typedef struct {
     uint32_t i2csel;
     CharBackend display;
     char display_text[9];
-    SerialState *uart;
+    SerialMM *uart;
     bool display_inited;
 } MaltaFPGAState;
 

include/hw/char/serial.h

@@ -57,7 +57,6 @@ typedef struct SerialState {
     qemu_irq irq;
     CharBackend chr;
     int last_break_enable;
-    int it_shift;
     uint32_t baudbase;
     uint32_t tsr_retry;
     guint watch_tag;
@@ -80,6 +79,14 @@ typedef struct SerialState {
     MemoryRegion io;
 } SerialState;
 
+typedef struct SerialMM {
+    SysBusDevice parent;
+
+    SerialState serial;
+
+    int it_shift;
+} SerialMM;
+
 extern const VMStateDescription vmstate_serial;
 extern const MemoryRegionOps serial_io_ops;
 
@@ -88,12 +95,15 @@ void serial_set_frequency(SerialState *s, uint32_t frequency);
 #define TYPE_SERIAL "serial"
 #define SERIAL(s) OBJECT_CHECK(SerialState, (s), TYPE_SERIAL)
 
+#define TYPE_SERIAL_MM "serial-mm"
+#define SERIAL_MM(s) OBJECT_CHECK(SerialMM, (s), TYPE_SERIAL_MM)
+
 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
                          Chardev *chr, MemoryRegion *system_io);
-SerialState *serial_mm_init(MemoryRegion *address_space,
-                            hwaddr base, int it_shift,
-                            qemu_irq irq, int baudbase,
-                            Chardev *chr, enum device_endian end);
+SerialMM *serial_mm_init(MemoryRegion *address_space,
+                         hwaddr base, int it_shift,
+                         qemu_irq irq, int baudbase,
+                         Chardev *chr, enum device_endian end);
 
 /* serial-isa.c */