2015-11-07 15:29 GMT+03:00 Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>: > Hi Matwey, > > On 11/07/2015 05:09 AM, Matwey V. Kornilov wrote: >> When 8250 driver doesn't have its own hardware RS485 support and doesn't >> want to override rs485_config callback, then default >> serial8250_rs485_config is used. It just stores supplied by user-space >> config. >> >> Signed-off-by: Matwey V. Kornilov <matwey@xxxxxxxxxx> >> --- >> drivers/tty/serial/8250/8250_core.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c >> index 3912646..8f292da 100644 >> --- a/drivers/tty/serial/8250/8250_core.c >> +++ b/drivers/tty/serial/8250/8250_core.c >> @@ -395,6 +395,12 @@ static void serial8250_release_rsa_resource(struct uart_8250_port *up) >> } >> } >> #endif >> +static int serial8250_rs485_config(struct uart_port *port, >> + struct serial_rs485 *rs485) >> +{ >> + port->rs485 = *rs485; >> + return 0; >> +} >> >> static const struct uart_ops *base_ops; >> static struct uart_ops univ8250_port_ops; >> @@ -990,6 +996,10 @@ int serial8250_register_8250_port(struct uart_8250_port *up) >> uart->port.rs485 = up->port.rs485; >> uart->dma = up->dma; >> >> + /* Use software RS485 support when hardware one is not available */ >> + if (!(uart->capabilities & UART_CAP_HW485) && !uart->port.rs485_config) >> + uart->port.rs485_config = serial8250_rs485_config; > > To setup a default 8250 port function, > 1. define the default 8250 port function in 8250/8250_port.c > 2. add the port function to the dispatch table (serial8250_pops) rs485_config is not a member of struct uart_ops, should I add it there? > 3. add a test for 8250 sub-driver override in serial8250_register_8250_port() > Eg., > > if (up->port.rs485_config) > uart->port.rs485_config = up->port.rs485_config; > > Regards, > Peter Hurley > >> /* Take tx_loadsz from fifosize if it wasn't set separately */ >> if (uart->port.fifosize && !uart->tx_loadsz) >> uart->tx_loadsz = uart->port.fifosize; >> > -- With best regards, Matwey V. Kornilov. Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html