[U-Boot] [PATCH v2 3/5] dm: ns16550: Don't map_physmem for I/O ports

Daniel Schwierzeck daniel.schwierzeck at gmail.com
Mon May 16 20:58:59 CEST 2016



Am 16.05.2016 um 19:44 schrieb Paul Burton:
> If the UART is to be accessed using I/O port accessors (inb & outb) then
> using map_physmem doesn't make sense, since it operates in a different
> memory space. Remove the call to map_physmem when
> CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses
> to not be mangled by the incorrect mapping.
> 
> Signed-off-by: Paul Burton <paul.burton at imgtec.com>

Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
Tested-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>

> ---
> 
> Changes in v2:
> - New patch, part of a simplified approach tackling only a single Malta UART.
> 
>  drivers/serial/ns16550.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index 28da9dd..e58e6aa 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int offset, int value)
>  	unsigned char *addr;
>  
>  	offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> +	addr = (unsigned char *)plat->base + offset;
> +#else
>  	addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif
>  	/*
>  	 * As far as we know it doesn't make sense to support selection of
>  	 * these options at run-time, so use the existing CONFIG options.
> @@ -114,7 +118,11 @@ static int ns16550_readb(NS16550_t port, int offset)
>  	unsigned char *addr;
>  
>  	offset *= 1 << plat->reg_shift;
> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
> +	addr = (unsigned char *)plat->base + offset;
> +#else
>  	addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset;
> +#endif
>  
>  	return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
>  }
> 

-- 
- Daniel

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