hw/pl181: Implement GPIO output pins for card status

Add two GPIO output pins to the PL181 model to indicate the card
present and readonly status information. On ARM boards these usually
are reflected in a system register.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

hw/pl181.c

@@ -47,6 +47,8 @@ typedef struct {
     int linux_hack;
     uint32_t fifo[PL181_FIFO_LEN];
     qemu_irq irq[2];
+    /* GPIO outputs for 'card is readonly' and 'card inserted' */
+    qemu_irq cardstatus[2];
 } pl181_state;
 
 #define PL181_CMD_INDEX     0x3f
@@ -444,6 +446,9 @@ static void pl181_reset(void *opaque)
     s->linux_hack = 0;
     s->mask[0] = 0;
     s->mask[1] = 0;
+
+    /* We can assume our GPIO outputs have been wired up now */
+    sd_set_cb(s->card, s->cardstatus[0], s->cardstatus[1]);
 }
 
 static int pl181_init(SysBusDevice *dev)
@@ -457,6 +462,7 @@ static int pl181_init(SysBusDevice *dev)
     sysbus_init_mmio(dev, 0x1000, iomemtype);
     sysbus_init_irq(dev, &s->irq[0]);
     sysbus_init_irq(dev, &s->irq[1]);
+    qdev_init_gpio_out(&s->busdev.qdev, s->cardstatus, 2);
     dinfo = drive_get_next(IF_SD);
     s->card = sd_init(dinfo ? dinfo->bdrv : NULL, 0);
     qemu_register_reset(pl181_reset, s);