On 2018-06-04 23:33, Daniel Golle wrote:
> Move the non-board-specific part of the RS485 initialization from
> iot2040_rs485_config function to a new generic function used also for
> other boards.
> This allows using TIOCGRS485 and TIOCSRS485 on boards (such as mPCIe
> serial IO modules) which are hard-wired to RS485 or have jumpers for
> their configurations.
If the configuration is hardwired on that board, is it a good idea to
ask userspace to enable the mode also manually? The alternative would be
deriving it from the IDs of those modules - ok, provided they are known...
>
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_exar.c | 38 +++++++++++++++++++----------
> 1 file changed, 25 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
> index e0aa5f03004c..55b4d6d581f0 100644
> --- a/drivers/tty/serial/8250/8250_exar.c
> +++ b/drivers/tty/serial/8250/8250_exar.c
> @@ -275,8 +275,32 @@ static int xr17v35x_register_gpio(struct pci_dev *pcidev,
> return 0;
> }
>
> +static int generic_rs485_config(struct uart_port *port,
> + struct serial_rs485 *rs485)
> +{
> + bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
> + u8 __iomem *p = port->membase;
> + u8 value;
> +
> + value = readb(p + UART_EXAR_FCTR);
> + if (is_rs485)
> + value |= UART_FCTR_EXAR_485;
> + else
> + value &= ~UART_FCTR_EXAR_485;
> +
> + writeb(value, p + UART_EXAR_FCTR);
> +
> + if (is_rs485)
> + writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
> +
> + port->rs485 = *rs485;
> +
> + return 0;
> +}
> +
> static const struct exar8250_platform exar8250_default_platform = {
> .register_gpio = xr17v35x_register_gpio,
> + .rs485_config = generic_rs485_config,
> };
>
> static int iot2040_rs485_config(struct uart_port *port,
> @@ -309,19 +333,7 @@ static int iot2040_rs485_config(struct uart_port *port,
> value |= mode;
> writeb(value, p + UART_EXAR_MPIOLVL_7_0);
>
> - value = readb(p + UART_EXAR_FCTR);
> - if (is_rs485)
> - value |= UART_FCTR_EXAR_485;
> - else
> - value &= ~UART_FCTR_EXAR_485;
> - writeb(value, p + UART_EXAR_FCTR);
> -
> - if (is_rs485)
> - writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
> -
> - port->rs485 = *rs485;
> -
> - return 0;
> + return generic_rs485_config(port, rs485);
> }
>
> static const struct property_entry iot2040_gpio_properties[] = {
>
>From the code perspective, this is fine:
Reviewed-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Jan
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
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