lkml.org 
[lkml]   [2016]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v8 3/3] tty: 8250_omap: Use software emulated RS485 direction control
Date
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>
---
drivers/tty/serial/8250/8250_omap.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index a2c0734..d710985 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;
--
2.7.0
\
 
 \ /
  Last update: 2016-02-01 19:21    [W:0.391 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site