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Diffstat (limited to 'Documentation/ABI/testing/sysfs-tty')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-tty | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-tty b/Documentation/ABI/testing/sysfs-tty index ad22fb0ee765..9eb3c2b6b040 100644 --- a/Documentation/ABI/testing/sysfs-tty +++ b/Documentation/ABI/testing/sysfs-tty @@ -138,3 +138,19 @@ Description: These sysfs values expose the TIOCGSERIAL interface via sysfs rather than via ioctls. + +What: /sys/class/tty/ttyS0/rx_trig_bytes +Date: May 2014 +Contact: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> +Description: + Shows current RX interrupt trigger bytes or sets the + user specified value to change it for the FIFO buffer. + Users can show or set this value regardless of opening the + serial device file or not. + + The RX trigger can be set one of four kinds of values for UART + serials. When users input a meaning less value to this I/F, + the RX trigger is changed to the nearest lower value for the + device specification. For example, when user sets 7bytes on + 16550A, which has 1/4/8/14 bytes trigger, the RX trigger is + automatically changed to 4 bytes. |