Re: [PATCH/RFC 3/4] Revert "serial: sh-sci: Compute the regshift value for SCI ports"

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Geert,

Thank you for the patch.

On Monday, 6 August 2018 17:07:54 EEST Geert Uytterhoeven wrote:
> This reverts commit dfc80387aefb78161f83732804c6d01c89c24595.
> 
> Deriving the proper regshift value from the register block size is
> fragile, as it may have been rounded up.
> 
> Furthermore we will need plat_sci_port.regshift again.

Won't this break bisection ? Shouldn't you squash patches 3 and 4 together ?

Does this mechanism break anything on non-DT platforms ? If not I'd rather 
keep it for them, and only use compat strings for DT platforms, to avoiding 
adding back a platform data field.

> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  arch/sh/kernel/cpu/sh3/setup-sh770x.c |  1 +
>  arch/sh/kernel/cpu/sh4/setup-sh7750.c |  3 ++-
>  arch/sh/kernel/cpu/sh4/setup-sh7760.c | 10 ++--------
>  drivers/tty/serial/sh-sci.c           |  8 +-------
>  include/linux/serial_sci.h            |  1 +
>  5 files changed, 7 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/sh/kernel/cpu/sh3/setup-sh770x.c
> b/arch/sh/kernel/cpu/sh3/setup-sh770x.c index
> 59a88611df55ac8f..592cd9ab30c4272f 100644
> --- a/arch/sh/kernel/cpu/sh3/setup-sh770x.c
> +++ b/arch/sh/kernel/cpu/sh3/setup-sh770x.c
> @@ -111,6 +111,7 @@ static struct platform_device rtc_device = {
>  static struct plat_sci_port scif0_platform_data = {
>  	.type		= PORT_SCI,
>  	.ops		= &sh770x_sci_port_ops,
> +	.regshift	= 1,
>  };
> 
>  static struct resource scif0_resources[] = {
> diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7750.c
> b/arch/sh/kernel/cpu/sh4/setup-sh7750.c index
> 57d30689204d03b9..d98a55416306baef 100644
> --- a/arch/sh/kernel/cpu/sh4/setup-sh7750.c
> +++ b/arch/sh/kernel/cpu/sh4/setup-sh7750.c
> @@ -39,10 +39,11 @@ static struct platform_device rtc_device = {
> 
>  static struct plat_sci_port sci_platform_data = {
>  	.type		= PORT_SCI,
> +	.regshift	= 2,
>  };
> 
>  static struct resource sci_resources[] = {
> -	DEFINE_RES_MEM(0xffe00000, 0x20),
> +	DEFINE_RES_MEM(0xffe00000, 0x100),
>  	DEFINE_RES_IRQ(evt2irq(0x4e0)),
>  };
> 
> diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7760.c
> b/arch/sh/kernel/cpu/sh4/setup-sh7760.c index
> e51fe1734e1368e8..0c0cdfc69dcc3e33 100644
> --- a/arch/sh/kernel/cpu/sh4/setup-sh7760.c
> +++ b/arch/sh/kernel/cpu/sh4/setup-sh7760.c
> @@ -200,18 +200,12 @@ static struct platform_device scif2_device = {
>  };
> 
>  static struct plat_sci_port scif3_platform_data = {
> -	/*
> -	 * This is actually a SIM card module serial port, based on an SCI with
> -	 * additional registers. The sh-sci driver doesn't support the SIM port
> -	 * type, declare it as a SCI. Don't declare the additional registers in
> -	 * the memory resource or the driver will compute an incorrect regshift
> -	 * value.
> -	 */
>  	.type		= PORT_SCI,
> +	.regshift	= 2,
>  };
> 
>  static struct resource scif3_resources[] = {
> -	DEFINE_RES_MEM(0xfe480000, 0x10),
> +	DEFINE_RES_MEM(0xfe480000, 0x100),
>  	DEFINE_RES_IRQ(evt2irq(0xc00)),
>  	DEFINE_RES_IRQ(evt2irq(0xc20)),
>  	DEFINE_RES_IRQ(evt2irq(0xc40)),
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index caf4422d9e2e59e4..955c057dff6e8c78 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -2895,15 +2895,9 @@ static int sci_init_single(struct platform_device
> *dev,
> 
>  	port->type		= p->type;
>  	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
> +	port->regshift		= p->regshift;
>  	port->fifosize		= sci_port->params->fifosize;
> 
> -	if (port->type == PORT_SCI) {
> -		if (sci_port->reg_size >= 0x20)
> -			port->regshift = 2;
> -		else
> -			port->regshift = 1;
> -	}
> -
>  	if (regtype == SCIx_SH4_SCIF_REGTYPE)
>  		if (sci_port->reg_size >= 0x20)
>  			port->regshift = 1;
> diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
> index c0e795d95477daea..eebb12fc473f49a2 100644
> --- a/include/linux/serial_sci.h
> +++ b/include/linux/serial_sci.h
> @@ -57,6 +57,7 @@ struct plat_sci_port {
>  	/*
>  	 * Platform overrides if necessary, defaults otherwise.
>  	 */
> +	unsigned char	regshift;
>  	unsigned char	regtype;
> 
>  	struct plat_sci_port_ops	*ops;

-- 
Regards,

Laurent Pinchart