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author | Corey Minyard <cminyard@mvista.com> | 2017-01-09 11:40:20 +0000 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2017-01-09 11:40:20 +0000 |
commit | d307c28ca9dba7a0677035c9244198b05164c873 (patch) | |
tree | ee942307fac668f7a2d531bf6b86e6db025cdfd0 /hw/i2c/smbus.c | |
parent | ffe22bf51065dd33022cf91f77a821d1f11c250d (diff) | |
download | qemu-d307c28ca9dba7a0677035c9244198b05164c873.zip qemu-d307c28ca9dba7a0677035c9244198b05164c873.tar.gz qemu-d307c28ca9dba7a0677035c9244198b05164c873.tar.bz2 |
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>
Diffstat (limited to 'hw/i2c/smbus.c')
-rw-r--r-- | hw/i2c/smbus.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/hw/i2c/smbus.c b/hw/i2c/smbus.c index 5b4dd3e..2d1b79a 100644 --- a/hw/i2c/smbus.c +++ b/hw/i2c/smbus.c @@ -67,7 +67,7 @@ static void smbus_do_write(SMBusDevice *dev) } } -static void smbus_i2c_event(I2CSlave *s, enum i2c_event event) +static int smbus_i2c_event(I2CSlave *s, enum i2c_event event) { SMBusDevice *dev = SMBUS_DEVICE(s); @@ -148,6 +148,8 @@ static void smbus_i2c_event(I2CSlave *s, enum i2c_event event) break; } } + + return 0; } static int smbus_i2c_recv(I2CSlave *s) @@ -249,7 +251,8 @@ int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command) } i2c_send(bus, command); if (i2c_start_transfer(bus, addr, 1)) { - assert(0); + i2c_end_transfer(bus); + return -1; } data = i2c_recv(bus); i2c_nack(bus); @@ -276,7 +279,8 @@ int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command) } i2c_send(bus, command); if (i2c_start_transfer(bus, addr, 1)) { - assert(0); + i2c_end_transfer(bus); + return -1; } data = i2c_recv(bus); data |= i2c_recv(bus) << 8; @@ -307,7 +311,8 @@ int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data) } i2c_send(bus, command); if (i2c_start_transfer(bus, addr, 1)) { - assert(0); + i2c_end_transfer(bus); + return -1; } len = i2c_recv(bus); if (len > 32) { |