diff options
| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2022-06-24 23:42:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-27 14:44:20 +0200 |
| commit | 4f768e94774c58c9f7f54ebd38dadf172970046a (patch) | |
| tree | f237520975e9f0839fd2dbbd911d2681288f949e /include/uapi/asm-generic | |
| parent | ae50bb2752836277ae15aa4e9d99074d6d947946 (diff) | |
serial: Support for RS-485 multipoint addresses
Add support for RS-485 multipoint addressing using 9th bit [*]. The
addressing mode is configured through ->rs485_config().
ADDRB in termios indicates 9th bit addressing mode is enabled. In this
mode, 9th bit is used to indicate an address (byte) within the
communication line. ADDRB can only be enabled/disabled through
->rs485_config() that is also responsible for setting the destination and
receiver (filter) addresses.
Add traps to detect unwanted changes to struct serial_rs485 layout using
static_assert().
[*] Technically, RS485 is just an electronic spec and does not itself
specify the 9th bit addressing mode but 9th bit seems at least
"semi-standard" way to do addressing with RS485.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220624204210.11112-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/uapi/asm-generic')
| -rw-r--r-- | include/uapi/asm-generic/termbits-common.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/asm-generic/termbits-common.h b/include/uapi/asm-generic/termbits-common.h index 4d084fe8def5..4a6a79f28b21 100644 --- a/include/uapi/asm-generic/termbits-common.h +++ b/include/uapi/asm-generic/termbits-common.h @@ -46,6 +46,7 @@ typedef unsigned int speed_t; #define EXTA B19200 #define EXTB B38400 +#define ADDRB 0x20000000 /* address bit */ #define CMSPAR 0x40000000 /* mark or space (stick) parity */ #define CRTSCTS 0x80000000 /* flow control */ |