Re: [PATCH v8 3/3] tty: 8250_omap: Use software emulated RS485 direction control

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello,

2016-02-01 21:09 GMT+03:00 "Matwey V. Kornilov" <matwey@xxxxxxxxxx>:
> +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;
> +}

I think that an invocation of serial8250_em485_destroy() should be
performed inside omap8250_remove() as well. However there is a catch -
serial8250_get_port() is only reserved for suspend-resume power
management operations, and I am aware of no other means how to supply
an uart_8250_port to serial8250_em485_destroy() at that point.

Similarly, I got no idea on how to implement handling
"linux,rs485-enabled-at-boot-time" property without using
serial8250_get_port() directly (well, honestly I could try invoking
the corresponding ioctl somehow, but that's gonna be plain ugly at
least).

Regards,
Ilyas G.
--
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



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux