diff options
| author | Matwey V. Kornilov <matwey@sai.msu.ru> | 2016-02-01 21:09:22 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-06 22:23:26 -0800 |
| commit | 344cee2470ff70801c95c62ab2762da0834c8c6c (patch) | |
| tree | 327dff8c2a1f20ad1ffd98c0ae4a46ba8e96e190 /drivers | |
| parent | e490c9144cfaa8e2242c1e5d5187230928f27417 (diff) | |
tty: 8250_omap: Use software emulated RS485 direction control
Use software emulated RS485 direction control to provide RS485 API
existed in omap_serial driver. Note that 8250_omap issues interrupt
on shift register empty which is single prerequesite for using software
emulated RS485.
Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index a2c0734c76e2..d710985a2e4f 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -697,6 +697,36 @@ static void omap_8250_throttle(struct uart_port *port) pm_runtime_put_autosuspend(port->dev); } +static int omap_8250_rs485_config(struct uart_port *port, + struct serial_rs485 *rs485) +{ + struct uart_8250_port *up = up_to_u8250p(port); + + /* Clamp the delays to [0, 100ms] */ + rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U); + rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U); + + port->rs485 = *rs485; + + /* + * Both serial8250_em485_init and serial8250_em485_destroy + * are idempotent + */ + if (rs485->flags & SER_RS485_ENABLED) { + int ret = serial8250_em485_init(up); + + if (ret) { + rs485->flags &= ~SER_RS485_ENABLED; + port->rs485.flags &= ~SER_RS485_ENABLED; + } + return ret; + } + + serial8250_em485_destroy(up); + + return 0; +} + static void omap_8250_unthrottle(struct uart_port *port) { unsigned long flags; @@ -1146,6 +1176,7 @@ static int omap8250_probe(struct platform_device *pdev) up.port.shutdown = omap_8250_shutdown; up.port.throttle = omap_8250_throttle; up.port.unthrottle = omap_8250_unthrottle; + up.port.rs485_config = omap_8250_rs485_config; if (pdev->dev.of_node) { const struct of_device_id *id; |