diff options
Diffstat (limited to 'include/i2c.h')
| -rw-r--r-- | include/i2c.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/include/i2c.h b/include/i2c.h index 33570f5..72e2e8e 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -45,12 +45,26 @@ struct udevice; * represent up to 256 bytes. A value larger than 1 may be * needed for larger devices. * @flags: Flags for this chip (dm_i2c_chip_flags) + * @chip_addr_offset_mask: Mask of offset bits within chip_addr. Used for + * devices which steal addresses as part of offset. + * If offset_len is zero, then the offset is encoded + * completely within the chip address itself. + * e.g. a devce with chip address of 0x2c with 512 + * registers might use the bottom bit of the address + * to indicate which half of the address space is being + * accessed while still only using 1 byte offset. + * This means it will respond to chip address 0x2c and + * 0x2d. + * A real world example is the Atmel AT24C04. It's + * datasheet explains it's usage of this addressing + * mode. * @emul: Emulator for this chip address (only used for emulation) */ struct dm_i2c_chip { uint chip_addr; uint offset_len; uint flags; + uint chip_addr_offset_mask; #ifdef CONFIG_SANDBOX struct udevice *emul; bool test_mode; @@ -262,6 +276,25 @@ int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len); int i2c_get_chip_offset_len(struct udevice *dev); /** + * i2c_set_chip_addr_offset_mask() - set mask of address bits usable by offset + * + * Some devices listen on multiple chip addresses to achieve larger offsets + * than their single or multiple byte offsets would allow for. You can use this + * function to set the bits that are valid to be used for offset overflow. + * + * @mask: The mask to be used for high offset bits within address + * @return 0 if OK, other -ve value on error + */ +int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask); + +/* + * i2c_get_chip_addr_offset_mask() - get mask of address bits usable by offset + * + * @return current chip addr offset mask + */ +uint i2c_get_chip_addr_offset_mask(struct udevice *dev); + +/** * i2c_deblock() - recover a bus that is in an unknown state * * See the deblock() method in 'struct dm_i2c_ops' for full information |