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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>
This commit is contained in:
Matwey V. Kornilov 2016-02-01 21:09:22 +03:00 committed by Greg Kroah-Hartman
parent e490c9144c
commit 344cee2470
1 changed files with 31 additions and 0 deletions
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31
drivers/tty/serial/8250/8250_omap.c
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@ -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;