Re: [PATCH/RFC 5/5] serial: sh-sci: Replace SCIx_HAVE_RTSCTS by standard UPF_HARD_FLOW

[Peter Hurley <peter@hurleysoftware.com>]

Hi Geert,

On 03/17/2016 06:47 AM, Geert Uytterhoeven wrote:
> Replace the custom SCIx_HAVE_RTSCTS flag in the
> plat_sci_port.capabilities field by the standard UPF_HARD_FLOW flag in
> the uart_port.flags and plat_sci_port.flags fields.
> Remove the now unused plat_sci_port.capabilities field.
> Legacy pllatform data can enable UPF_HARD_FLOW in plat_sci_port.flags.

UPF_HARD_FLOW is really for indicating the h/w supports automatic
CTS and RTS signalling; ie., RTS is automatically de-asserted when
rx fifo reaches some threshold and CTS will automatically prevent
tx fifo output.

There is no serial core flag for indicating the h/w supports (or does not)
RTS and/or CTS signalling.

Regards,
Peter Hurley

> Note that currently nothing sets the SCIx_HAVE_RTSCTS flag.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  drivers/tty/serial/sh-sci.c | 4 ++--
>  include/linux/serial_sci.h  | 6 ------
>  2 files changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index 6897100ed5197df3..51b436e2334c3efc 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -720,7 +720,7 @@ static void sci_init_pins(struct uart_port *port, unsigned int cflag)
>  	if (!reg->size)
>  		return;
>  
> -	if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
> +	if ((port->flags & UPF_HARD_FLOW) &&
>  	    ((!(cflag & CRTSCTS)))) {
>  		unsigned short status;
>  
> @@ -2247,7 +2247,7 @@ done:
>  	if (reg->size) {
>  		unsigned short ctrl = serial_port_in(port, SCFCR);
>  
> -		if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
> +		if (port->flags & UPF_HARD_FLOW) {
>  			if (termios->c_cflag & CRTSCTS)
>  				ctrl |= SCFCR_MCE;
>  			else
> diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
> index 9f2bfd0557429ac3..95640ee68462190f 100644
> --- a/include/linux/serial_sci.h
> +++ b/include/linux/serial_sci.h
> @@ -48,17 +48,11 @@ struct plat_sci_port_ops {
>  };
>  
>  /*
> - * Port-specific capabilities
> - */
> -#define SCIx_HAVE_RTSCTS	BIT(0)
> -
> -/*
>   * Platform device specific platform_data struct
>   */
>  struct plat_sci_port {
>  	unsigned int	type;			/* SCI / SCIF / IRDA / HSCIF */
>  	upf_t		flags;			/* UPF_* flags */
> -	unsigned long	capabilities;		/* Port features/capabilities */
>  
>  	unsigned int	sampling_rate;
>  	unsigned int	scscr;			/* SCSCR initialization */
>