i2c: Allow I2C devices to NAK start events
Add a return value to the event handler. Some I2C devices will
NAK if they have no data, so allow them to do this. This required
the following changes:
Go through all the event handlers and change them to return int
and return 0.
Modify i2c_start_transfer to terminate the transaction on a NAK.
Modify smbus handing to not assert if a NAK occurs on a second
operation, and terminate the transaction and return -1 instead.
Add some information on semantics to I2CSlaveClass.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/misc/tmp105.c b/hw/misc/tmp105.c
index f5c2472..04e8378 100644
--- a/hw/misc/tmp105.c
+++ b/hw/misc/tmp105.c
@@ -176,7 +176,7 @@
return 0;
}
-static void tmp105_event(I2CSlave *i2c, enum i2c_event event)
+static int tmp105_event(I2CSlave *i2c, enum i2c_event event)
{
TMP105State *s = TMP105(i2c);
@@ -185,6 +185,7 @@
}
s->len = 0;
+ return 0;
}
static int tmp105_post_load(void *opaque, int version_id)
