From d307c28ca9dba7a0677035c9244198b05164c873 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Mon, 9 Jan 2017 11:40:20 +0000 Subject: 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 Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/timer/ds1338.c | 4 +++- hw/timer/twl92230.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'hw/timer') diff --git a/hw/timer/ds1338.c b/hw/timer/ds1338.c index f5d04dd..3849b74 100644 --- a/hw/timer/ds1338.c +++ b/hw/timer/ds1338.c @@ -94,7 +94,7 @@ static void inc_regptr(DS1338State *s) } } -static void ds1338_event(I2CSlave *i2c, enum i2c_event event) +static int ds1338_event(I2CSlave *i2c, enum i2c_event event) { DS1338State *s = DS1338(i2c); @@ -113,6 +113,8 @@ static void ds1338_event(I2CSlave *i2c, enum i2c_event event) default: break; } + + return 0; } static int ds1338_recv(I2CSlave *i2c) diff --git a/hw/timer/twl92230.c b/hw/timer/twl92230.c index 7ba4e9a..b8d914e 100644 --- a/hw/timer/twl92230.c +++ b/hw/timer/twl92230.c @@ -713,12 +713,14 @@ static void menelaus_write(void *opaque, uint8_t addr, uint8_t value) } } -static void menelaus_event(I2CSlave *i2c, enum i2c_event event) +static int menelaus_event(I2CSlave *i2c, enum i2c_event event) { MenelausState *s = TWL92230(i2c); if (event == I2C_START_SEND) s->firstbyte = 1; + + return 0; } static int menelaus_tx(I2CSlave *i2c, uint8_t data) -- cgit v1.1