diff options
Diffstat (limited to 'include/hw/i2c/i2c.h')
| -rw-r--r-- | include/hw/i2c/i2c.h | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index c4085aa366..2ce611d4c8 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -32,14 +32,22 @@ typedef struct I2CSlaveClass /* Callbacks provided by the device. */ int (*init)(I2CSlave *dev); - /* Master to slave. */ + /* Master to slave. Returns non-zero for a NAK, 0 for success. */ int (*send)(I2CSlave *s, uint8_t data); - /* Slave to master. */ + /* + * Slave to master. This cannot fail, the device should always + * return something here. Negative values probably result in 0xff + * and a possible log from the driver, and shouldn't be used. + */ int (*recv)(I2CSlave *s); - /* Notify the slave of a bus state change. */ - void (*event)(I2CSlave *s, enum i2c_event event); + /* + * Notify the slave of a bus state change. For start event, + * returns non-zero to NAK an operation. For other events the + * return code is not used and should be zero. + */ + int (*event)(I2CSlave *s, enum i2c_event event); } I2CSlaveClass; struct I2CSlave |