[U-Boot] [PATCH v3] regmap: add support for address cell 2

[Heiko Stuebner <heiko@sntech.de>]

Hi Kever,

Am Freitag, 5. Mai 2017, 10:39:35 CEST schrieb Kever Yang:
> ARM64 is using 64bit address which address cell is 2 instead of 1,
> update to support it when of-platdata enabled.
> 
> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>

This helps make OF_PLATDATA work on my firefly-rk3399 so yay :-),
but I don't think it's that easy to solve, see below:

> ---
> 
> Changes in v3:
> - move of_plat_get_number() into lib/of_plat.c
> 
> Changes in v2:
> - rename the fdtdec_get_number() to of_plat_get_number()
> 
>  drivers/core/regmap.c |  9 +++++++++
>  include/of_plat.h     | 22 ++++++++++++++++++++++
>  lib/Makefile          |  3 +++
>  lib/of_plat.c         | 17 +++++++++++++++++
>  4 files changed, 51 insertions(+)
>  create mode 100644 include/of_plat.h
>  create mode 100644 lib/of_plat.c
> 
> diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
> index 3bec3df..c03279e 100644
> --- a/drivers/core/regmap.c
> +++ b/drivers/core/regmap.c
> @@ -12,6 +12,7 @@
>  #include <malloc.h>
>  #include <mapmem.h>
>  #include <regmap.h>
> +#include <of_plat.h>
>  
>  #include <asm/io.h>
>  
> @@ -49,11 +50,19 @@ int regmap_init_mem_platdata(struct udevice *dev, u32 *reg, int count,
>  	if (!map)
>  		return -ENOMEM;
>  
> +#ifdef CONFIG_PHYS_64BIT
> +	map->base = of_plat_get_number(reg, 2);
> +	for (range = map->range; count > 0; reg += 4, range++, count--) {
> +		range->start = of_plat_get_number(reg, 2);
> +		range->size = of_plat_get_number(reg + 2, 2);
> +	}

I may just be missing something, but how can you be sure that the cell-size
is always 2?

For example, there were discussions about 64bit platforms not really
needing to add all the 0x0 elements, when the whole io-registers are well
below the 4GB mark and for example at least one sunxi also uses this, see
for example:
allwinner/sun50i-a64.dtsi, altera/socfpga_stratix10.dtsi,
broadcom/bcm283x.dtsi and problably more using #address-cells = <1>,
#size-cells = <1> for their memory mapped io.

And from what I've seen dtoc simply converts the reg property and just
ignores #address-cells and #size-cells (or I'm overlooking something).

Possible solutions that come to mind would be make dtoc also convert
#address-cells and #size-cells, making regmap and everybody check it
or alternatively make dtoc convert regs to cell-size 2 in all cases when
CONFIG_PHYS_64BIT is set.


Heiko