Re: [PATCH v3 2/4] MIPS: Add Realtek RTL838x/RTL839x support as generic MIPS system

[Thomas Bogendoerfer]

On Wed, Dec 30, 2020 at 10:22:03PM +0100, Bert Vermeulen wrote:
> This is just enough system to boot the kernel with earlycon working.
> 
> Signed-off-by: Bert Vermeulen <bert@xxxxxxxx>
> Signed-off-by: Sander Vanheule <sander@xxxxxxxxxxxxx>
> ---
>  arch/mips/Kconfig                       | 21 ++++++++++++++++++
>  arch/mips/generic/Platform              |  1 +
>  arch/mips/include/asm/realtek/ioremap.h | 29 +++++++++++++++++++++++++
>  3 files changed, 51 insertions(+)
>  create mode 100644 arch/mips/include/asm/realtek/ioremap.h
> [..]
> diff --git a/arch/mips/include/asm/realtek/ioremap.h b/arch/mips/include/asm/realtek/ioremap.h
> new file mode 100644
> index 000000000000..ea51af023e26
> --- /dev/null
> +++ b/arch/mips/include/asm/realtek/ioremap.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef _REALTEK_RTL_IOREMAP_H_
> +#define _REALTEK_RTL_IOREMAP_H_
> +
> +static inline int is_rtl8380_internal_registers(phys_addr_t offset)
> +{
> +	/* IO Block */
> +	if (offset >= 0xb8000000 && offset < 0xb9000000)
> +		return 1;
> +	/* Switch block */
> +	if (offset >= 0xbb000000 && offset < 0xbc000000)
> +		return 1;
> +	return 0;
> +}
> +
> +static inline void __iomem *plat_ioremap(phys_addr_t offset, unsigned long size,
> +					 unsigned long flags)
> +{
> +	if (is_rtl8380_internal_registers(offset))
> +		return (void __iomem *)offset;
> +	return NULL;
> +}
> +
> +static inline int plat_iounmap(const volatile void __iomem *addr)
> +{
> +	return is_rtl8380_internal_registers((unsigned long)addr);
> +}
> +
> +#endif /* _REALTEK_RTL_IOREMAP_H_ */

this looks like papering over using KSEG1 addresses instead of
physical addresses in your DT. You should be able to drop this file
and use 0x18000000/0x1B000000 instead of 0xb8000000/0xbb000000
in the DT file.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]