Re: [PATCH v2 2/3] tty: Implement default fallback serial8250_rs485_config
From: Peter Hurley <hidden>
Date: 2015-11-07 12:29:12
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Hi Matwey, On 11/07/2015 05:09 AM, Matwey V. Kornilov wrote:
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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 <redacted> --- 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) 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;