diff --git a/hw/arm/spitz.c b/hw/arm/spitz.c
index ba40f8302bc6..41cc2eeeb1ba 100644
--- a/hw/arm/spitz.c
+++ b/hw/arm/spitz.c
@@ -598,15 +598,13 @@ static uint32_t spitz_lcdtg_transfer(SSISlave *dev, uint32_t value)
     return 0;
 }
 
-static int spitz_lcdtg_init(SSISlave *dev)
+static void spitz_lcdtg_realize(SSISlave *dev, Error **errp)
 {
     SpitzLCDTG *s = FROM_SSI_SLAVE(SpitzLCDTG, dev);
 
     spitz_lcdtg = s;
     s->bl_power = 0;
     s->bl_intensity = 0x20;
-
-    return 0;
 }
 
 /* SSP devices */
@@ -666,7 +664,7 @@ static void spitz_adc_temp_on(void *opaque, int line, int level)
         max111x_set_input(max1111, MAX1111_BATT_TEMP, 0);
 }
 
-static int corgi_ssp_init(SSISlave *d)
+static void corgi_ssp_realize(SSISlave *d, Error **errp)
 {
     DeviceState *dev = DEVICE(d);
     CorgiSSPState *s = FROM_SSI_SLAVE(CorgiSSPState, d);
@@ -675,8 +673,6 @@ static int corgi_ssp_init(SSISlave *d)
     s->bus[0] = ssi_create_bus(dev, "ssi0");
     s->bus[1] = ssi_create_bus(dev, "ssi1");
     s->bus[2] = ssi_create_bus(dev, "ssi2");
-
-    return 0;
 }
 
 static void spitz_ssp_attach(PXA2xxState *cpu)
@@ -1121,7 +1117,7 @@ static void corgi_ssp_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = corgi_ssp_init;
+    k->realize = corgi_ssp_realize;
     k->transfer = corgi_ssp_transfer;
     dc->vmsd = &vmstate_corgi_ssp_regs;
 }
@@ -1150,7 +1146,7 @@ static void spitz_lcdtg_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = spitz_lcdtg_init;
+    k->realize = spitz_lcdtg_realize;
     k->transfer = spitz_lcdtg_transfer;
     dc->vmsd = &vmstate_spitz_lcdtg_regs;
 }
diff --git a/hw/arm/tosa.c b/hw/arm/tosa.c
index 4e9494f94c20..2db66508b5b6 100644
--- a/hw/arm/tosa.c
+++ b/hw/arm/tosa.c
@@ -127,10 +127,9 @@ static uint32_t tosa_ssp_tansfer(SSISlave *dev, uint32_t value)
     return 0;
 }
 
-static int tosa_ssp_init(SSISlave *dev)
+static void tosa_ssp_realize(SSISlave *dev, Error **errp)
 {
     /* Nothing to do.  */
-    return 0;
 }
 
 #define TYPE_TOSA_DAC "tosa_dac"
@@ -283,7 +282,7 @@ static void tosa_ssp_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = tosa_ssp_init;
+    k->realize = tosa_ssp_realize;
     k->transfer = tosa_ssp_tansfer;
 }
 
diff --git a/hw/arm/z2.c b/hw/arm/z2.c
index aea895a500ef..68a92f3184d7 100644
--- a/hw/arm/z2.c
+++ b/hw/arm/z2.c
@@ -151,14 +151,12 @@ static void z2_lcd_cs(void *opaque, int line, int level)
     z2_lcd->selected = !level;
 }
 
-static int zipit_lcd_init(SSISlave *dev)
+static void zipit_lcd_realize(SSISlave *dev, Error **errp)
 {
     ZipitLCD *z = FROM_SSI_SLAVE(ZipitLCD, dev);
     z->selected = 0;
     z->enabled = 0;
     z->pos = 0;
-
-    return 0;
 }
 
 static VMStateDescription vmstate_zipit_lcd_state = {
@@ -181,7 +179,7 @@ static void zipit_lcd_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = zipit_lcd_init;
+    k->realize = zipit_lcd_realize;
     k->transfer = zipit_lcd_transfer;
     dc->vmsd = &vmstate_zipit_lcd_state;
 }
diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
index 326b688e8328..3cdcfce07ba9 100644
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -28,6 +28,7 @@
 #include "hw/ssi/ssi.h"
 #include "qemu/bitops.h"
 #include "qemu/log.h"
+#include "qapi/error.h"
 
 #ifndef M25P80_ERR_DEBUG
 #define M25P80_ERR_DEBUG 0
@@ -1132,7 +1133,7 @@ static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t tx)
     return r;
 }
 
-static int m25p80_init(SSISlave *ss)
+static void m25p80_realize(SSISlave *ss, Error **errp)
 {
     DriveInfo *dinfo;
     Flash *s = M25P80(ss);
@@ -1153,18 +1154,15 @@ static int m25p80_init(SSISlave *ss)
 
         s->storage = blk_blockalign(s->blk, s->size);
 
-        /* FIXME: Move to late init */
         if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
-            fprintf(stderr, "Failed to initialize SPI flash!\n");
-            return 1;
+            error_setg(errp, "failed to read the initial flash content");
+            return;
         }
     } else {
         DB_PRINT_L(0, "No BDRV - binding to RAM\n");
         s->storage = blk_blockalign(NULL, s->size);
         memset(s->storage, 0xFF, s->size);
     }
-
-    return 0;
 }
 
 static void m25p80_reset(DeviceState *d)
@@ -1224,7 +1222,7 @@ static void m25p80_class_init(ObjectClass *klass, void *data)
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
     M25P80Class *mc = M25P80_CLASS(klass);
 
-    k->init = m25p80_init;
+    k->realize = m25p80_realize;
     k->transfer = m25p80_transfer8;
     k->set_cs = m25p80_cs;
     k->cs_polarity = SSI_CS_LOW;
diff --git a/hw/display/ads7846.c b/hw/display/ads7846.c
index 05aa2d1e6b6e..166edade7dc0 100644
--- a/hw/display/ads7846.c
+++ b/hw/display/ads7846.c
@@ -133,7 +133,7 @@ static const VMStateDescription vmstate_ads7846 = {
     }
 };
 
-static int ads7846_init(SSISlave *d)
+static void ads7846_realize(SSISlave *d, Error **errp)
 {
     DeviceState *dev = DEVICE(d);
     ADS7846State *s = FROM_SSI_SLAVE(ADS7846State, d);
@@ -152,14 +152,13 @@ static int ads7846_init(SSISlave *d)
     ads7846_int_update(s);
 
     vmstate_register(NULL, -1, &vmstate_ads7846, s);
-    return 0;
 }
 
 static void ads7846_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = ads7846_init;
+    k->realize = ads7846_realize;
     k->transfer = ads7846_transfer;
 }
 
diff --git a/hw/display/ssd0323.c b/hw/display/ssd0323.c
index 14c1bf339ccf..6d1faf44afd7 100644
--- a/hw/display/ssd0323.c
+++ b/hw/display/ssd0323.c
@@ -361,7 +361,7 @@ static const GraphicHwOps ssd0323_ops = {
     .gfx_update  = ssd0323_update_display,
 };
 
-static int ssd0323_init(SSISlave *d)
+static void ssd0323_realize(SSISlave *d, Error **errp)
 {
     DeviceState *dev = DEVICE(d);
     ssd0323_state *s = FROM_SSI_SLAVE(ssd0323_state, d);
@@ -375,14 +375,13 @@ static int ssd0323_init(SSISlave *d)
 
     register_savevm(dev, "ssd0323_oled", -1, 1,
                     ssd0323_save, ssd0323_load, s);
-    return 0;
 }
 
 static void ssd0323_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = ssd0323_init;
+    k->realize = ssd0323_realize;
     k->transfer = ssd0323_transfer;
     k->cs_polarity = SSI_CS_HIGH;
 }
diff --git a/hw/misc/max111x.c b/hw/misc/max111x.c
index 9014f0f705d6..2a277bdb86dd 100644
--- a/hw/misc/max111x.c
+++ b/hw/misc/max111x.c
@@ -147,14 +147,14 @@ static int max111x_init(SSISlave *d, int inputs)
     return 0;
 }
 
-static int max1110_init(SSISlave *dev)
+static void max1110_realize(SSISlave *dev, Error **errp)
 {
-    return max111x_init(dev, 8);
+    max111x_init(dev, 8);
 }
 
-static int max1111_init(SSISlave *dev)
+static void max1111_realize(SSISlave *dev, Error **errp)
 {
-    return max111x_init(dev, 4);
+    max111x_init(dev, 4);
 }
 
 void max111x_set_input(DeviceState *dev, int line, uint8_t value)
@@ -183,7 +183,7 @@ static void max1110_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = max1110_init;
+    k->realize = max1110_realize;
 }
 
 static const TypeInfo max1110_info = {
@@ -196,7 +196,7 @@ static void max1111_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = max1111_init;
+    k->realize = max1111_realize;
 }
 
 static const TypeInfo max1111_info = {
diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index 075e4ed5df85..3ff0886dd55d 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -15,6 +15,7 @@
 #include "sysemu/blockdev.h"
 #include "hw/ssi/ssi.h"
 #include "hw/sd/sd.h"
+#include "qapi/error.h"
 
 //#define DEBUG_SSI_SD 1
 
@@ -249,7 +250,7 @@ static int ssi_sd_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static int ssi_sd_init(SSISlave *d)
+static void ssi_sd_realize(SSISlave *d, Error **errp)
 {
     DeviceState *dev = DEVICE(d);
     ssi_sd_state *s = FROM_SSI_SLAVE(ssi_sd_state, d);
@@ -260,17 +261,17 @@ static int ssi_sd_init(SSISlave *d)
     dinfo = drive_get_next(IF_SD);
     s->sd = sd_init(dinfo ? blk_by_legacy_dinfo(dinfo) : NULL, true);
     if (s->sd == NULL) {
-        return -1;
+        error_setg(errp, "Device initialization failed.");
+        return;
     }
     register_savevm(dev, "ssi_sd", -1, 1, ssi_sd_save, ssi_sd_load, s);
-    return 0;
 }
 
 static void ssi_sd_class_init(ObjectClass *klass, void *data)
 {
     SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
 
-    k->init = ssi_sd_init;
+    k->realize = ssi_sd_realize;
     k->transfer = ssi_sd_transfer;
     k->cs_polarity = SSI_CS_LOW;
 }
diff --git a/hw/ssi/ssi.c b/hw/ssi/ssi.c
index 9791c0d94714..7eaaf565fd67 100644
--- a/hw/ssi/ssi.c
+++ b/hw/ssi/ssi.c
@@ -54,7 +54,7 @@ static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
     return 0;
 }
 
-static int ssi_slave_init(DeviceState *dev)
+static void ssi_slave_realize(DeviceState *dev, Error **errp)
 {
     SSISlave *s = SSI_SLAVE(dev);
     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
@@ -64,7 +64,7 @@ static int ssi_slave_init(DeviceState *dev)
         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
     }
 
-    return ssc->init(s);
+    ssc->realize(s, errp);
 }
 
 static void ssi_slave_class_init(ObjectClass *klass, void *data)
@@ -72,7 +72,7 @@ static void ssi_slave_class_init(ObjectClass *klass, void *data)
     SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    dc->init = ssi_slave_init;
+    dc->realize = ssi_slave_realize;
     dc->bus_type = TYPE_SSI_BUS;
     if (!ssc->transfer_raw) {
         ssc->transfer_raw = ssi_transfer_raw_default;
diff --git a/include/hw/ssi/ssi.h b/include/hw/ssi/ssi.h
index 4a0a53903c66..6a0c3c3cdb28 100644
--- a/include/hw/ssi/ssi.h
+++ b/include/hw/ssi/ssi.h
@@ -37,7 +37,7 @@ enum SSICSMode {
 struct SSISlaveClass {
     DeviceClass parent_class;
 
-    int (*init)(SSISlave *dev);
+    void (*realize)(SSISlave *dev, Error **errp);
 
     /* if you have standard or no CS behaviour, just override transfer.
      * This is called when the device cs is active (true by default).
