hw/i2c: Add a NULL check for i2c slave init callbacks

Add a NULL check for i2c slave init callbacks, so that we no longer
need to implement empty init functions.
Signed-off-by: NAlastair D'Silva <alastair@d-silva.org>
Message-id: 20161202054617.6749-4-alastair@au1.ibm.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
[PMM: squashed in later tweak from Alistair to if() phrasing]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/arm/pxa2xx.c

@@ -1449,17 +1449,10 @@ static const VMStateDescription vmstate_pxa2xx_i2c = {
     }
 };
 
-static int pxa2xx_i2c_slave_init(I2CSlave *i2c)
-{
-    /* Nothing to do.  */
-    return 0;
-}
-
 static void pxa2xx_i2c_slave_class_init(ObjectClass *klass, void *data)
 {
     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 
-    k->init = pxa2xx_i2c_slave_init;
     k->event = pxa2xx_i2c_event;
     k->recv = pxa2xx_i2c_rx;
     k->send = pxa2xx_i2c_tx;

hw/arm/tosa.c

@@ -202,12 +202,6 @@ static int tosa_dac_recv(I2CSlave *s)
     return -1;
 }
 
-static int tosa_dac_init(I2CSlave *i2c)
-{
-    /* Nothing to do.  */
-    return 0;
-}
-
 static void tosa_tg_init(PXA2xxState *cpu)
 {
     I2CBus *bus = pxa2xx_i2c_bus(cpu->i2c[0]);
@@ -275,7 +269,6 @@ static void tosa_dac_class_init(ObjectClass *klass, void *data)
 {
     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 
-    k->init = tosa_dac_init;
     k->event = tosa_dac_event;
     k->recv = tosa_dac_recv;
     k->send = tosa_dac_send;

hw/arm/z2.c

@@ -263,12 +263,6 @@ static int aer915_recv(I2CSlave *slave)
     return retval;
 }
 
-static int aer915_init(I2CSlave *i2c)
-{
-    /* Nothing to do.  */
-    return 0;
-}
-
 static VMStateDescription vmstate_aer915_state = {
     .name = "aer915",
     .version_id = 1,
@@ -285,7 +279,6 @@ static void aer915_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 
-    k->init = aer915_init;
     k->event = aer915_event;
     k->recv = aer915_recv;
     k->send = aer915_send;

hw/i2c/core.c

@@ -260,7 +260,11 @@ static int i2c_slave_qdev_init(DeviceState *dev)
     I2CSlave *s = I2C_SLAVE(dev);
     I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s);
 
-    return sc->init(s);
+    if (sc->init) {
+        return sc->init(s);
+    }
+
+    return 0;
 }
 
 DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr)

hw/timer/ds1338.c

@@ -198,11 +198,6 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
     return 0;
 }
 
-static int ds1338_init(I2CSlave *i2c)
-{
-    return 0;
-}
-
 static void ds1338_reset(DeviceState *dev)
 {
     DS1338State *s = DS1338(dev);
@@ -220,7 +215,6 @@ static void ds1338_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 
-    k->init = ds1338_init;
     k->event = ds1338_event;
     k->recv = ds1338_recv;
     k->send = ds1338_send;