diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/dm/uclass-id.h | 1 | ||||
| -rw-r--r-- | include/i2c.h | 39 |
2 files changed, 40 insertions, 0 deletions
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index bc057d7..777b101 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -35,6 +35,7 @@ enum uclass_id { UCLASS_I2C, /* I2C bus */ UCLASS_I2C_EEPROM, /* I2C EEPROM device */ UCLASS_I2C_GENERIC, /* Generic I2C device */ + UCLASS_I2C_MUX, /* I2C multiplexer */ UCLASS_LED, /* Light-emitting diode (LED) */ UCLASS_LPC, /* x86 'low pin count' interface */ UCLASS_MASS_STORAGE, /* Mass storage device */ diff --git a/include/i2c.h b/include/i2c.h index d191829..6493931 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -445,6 +445,45 @@ struct dm_i2c_ops { #define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops) /** + * struct i2c_mux_ops - operations for an I2C mux + * + * The current mux state is expected to be stored in the mux itself since + * it is the only thing that knows how to make things work. The mux can + * record the current state and then avoid switching unless it is necessary. + * So select() can be skipped if the mux is already in the correct state. + * Also deselect() can be made a nop if required. + */ +struct i2c_mux_ops { + /** + * select() - select one of of I2C buses attached to a mux + * + * This will be called when there is no bus currently selected by the + * mux. This method does not need to deselect the old bus since + * deselect() will be already have been called if necessary. + * + * @mux: Mux device + * @bus: I2C bus to select + * @channel: Channel number correponding to the bus to select + * @return 0 if OK, -ve on error + */ + int (*select)(struct udevice *mux, struct udevice *bus, uint channel); + + /** + * deselect() - select one of of I2C buses attached to a mux + * + * This is used to deselect the currently selected I2C bus. + * + * @mux: Mux device + * @bus: I2C bus to deselect + * @channel: Channel number correponding to the bus to deselect + * @return 0 if OK, -ve on error + */ + int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel); +}; + +#define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops) + +/** * i2c_get_chip() - get a device to use to access a chip on a bus * * This returns the device for the given chip address. The device can then |