i2c: have I2C receive operation return uint8_t

It is never supposed to fail and cannot return an error, so just
have it return the proper type.  Have it return 0xff on nothing
available, since that's what would happen on a real bus.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

1 files changed, 13 insertions, 19 deletions

diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index b547259..15237ad 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -191,23 +191,17 @@ int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
         }
         return ret ? -1 : 0;
     } else {
-        if ((QLIST_EMPTY(&bus->current_devs)) || (bus->broadcast)) {
-            return -1;
-        }
-
-        sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
-        if (sc->recv) {
-            s = QLIST_FIRST(&bus->current_devs)->elt;
-            ret = sc->recv(s);
-            trace_i2c_recv(s->address, ret);
-            if (ret < 0) {
-                return ret;
-            } else {
-                *data = ret;
-                return 0;
+        ret = 0xff;
+        if (!QLIST_EMPTY(&bus->current_devs) && !bus->broadcast) {
+            sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
+            if (sc->recv) {
+                s = QLIST_FIRST(&bus->current_devs)->elt;
+                ret = sc->recv(s);
+                trace_i2c_recv(s->address, ret);
             }
         }
-        return -1;
+        *data = ret;
+        return 0;
     }
 }
 
@@ -216,12 +210,12 @@ int i2c_send(I2CBus *bus, uint8_t data)
     return i2c_send_recv(bus, &data, true);
 }
 
-int i2c_recv(I2CBus *bus)
+uint8_t i2c_recv(I2CBus *bus)
 {
-    uint8_t data;
-    int ret = i2c_send_recv(bus, &data, false);
+    uint8_t data = 0xff;
 
-    return ret < 0 ? ret : data;
+    i2c_send_recv(bus, &data, false);
+    return data;
 }
 
 void i2c_nack(I2CBus *bus)