diff options
| author | Heiko Schocher <hs@denx.de> | 2019-09-13 08:01:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-04 15:50:01 +0300 |
| commit | 0c11b88883db1a83980633fc88091d3cdd79bd48 (patch) | |
| tree | 586c1a5a1f97fee023f8583587d3784357f7095a /drivers/tty | |
| parent | 39f809192661be91fabc3ee77c2e15f9123c11cf (diff) | |
| download | linux-0c11b88883db1a83980633fc88091d3cdd79bd48.tar.xz | |
tty: 8250_of: Use software emulated RS485 direction control
Use software emulated RS485 direction control to provide RS485 API
Currently it is not possible to use rs485 as pointer to
rs485_config struct in struct uart_port is NULL in case we
configure the port through device tree.
Signed-off-by: Heiko Schocher <hs@denx.de>
Link: https://lore.kernel.org/r/20190913050105.1132080-1-hs@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_of.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c index 0826cfdbd406..92fbf46ce3bd 100644 --- a/drivers/tty/serial/8250/8250_of.c +++ b/drivers/tty/serial/8250/8250_of.c @@ -48,6 +48,36 @@ static inline void tegra_serial_handle_break(struct uart_port *port) } #endif +static int of_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; +} + /* * Fill a struct uart_port for a given device node */ @@ -178,6 +208,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev, port->flags |= UPF_SKIP_TEST; port->dev = &ofdev->dev; + port->rs485_config = of_8250_rs485_config; switch (type) { case PORT_TEGRA: |