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| author |   Matwey V. Kornilov <matwey@sai.msu.ru> | 2016-02-01 21:09:21 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-06 22:23:26 -0800 |
| commit | e490c9144cfaa8e2242c1e5d5187230928f27417 (patch) | |
| tree | 183cac3bb0d61e0637045d9973e628bd98d9009f /include/linux/serial_8250.h | |
| parent | tty: Move serial8250_stop_rx() in front of serial8250_start_tx() (diff) | |
| download | wireguard-linux-e490c9144cfaa8e2242c1e5d5187230928f27417.tar.xz wireguard-linux-e490c9144cfaa8e2242c1e5d5187230928f27417.zip | |
tty: Add software emulated RS485 support for 8250
Implementation of software emulation of RS485 direction handling is based
on omap_serial driver.
Before and after transmission RTS is set to the appropriate value.
Note that before calling serial8250_em485_init() the caller has to
ensure that UART will interrupt when shift register empty. Otherwise,
emultaion cannot be used.
Both serial8250_em485_init() and serial8250_em485_destroy() are
idempotent functions.
Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/serial_8250.h')
| -rw-r--r-- | include/linux/serial_8250.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h index faa0e0370ce7..434879759725 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -76,6 +76,12 @@ struct uart_8250_ops { void (*release_irq)(struct uart_8250_port *); }; +struct uart_8250_em485 { + struct timer_list start_tx_timer; /* "rs485 start tx" timer */ + struct timer_list stop_tx_timer; /* "rs485 stop tx" timer */ + struct timer_list *active_timer; /* pointer to active timer */ +}; + /* * This should be used by drivers which want to register * their own 8250 ports without registering their own @@ -122,6 +128,8 @@ struct uart_8250_port { /* 8250 specific callbacks */ int (*dl_read)(struct uart_8250_port *); void (*dl_write)(struct uart_8250_port *, int); + + struct uart_8250_em485 *em485; }; static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up) |