[PATCH] spi: pl022: Add support for chip select extension

[Linus Walleij]

On Wed, Sep 10, 2014 at 4:40 PM, Anders Berg <anders.berg at avagotech.com> wrote:

> Add support for a extended PL022 which has an extra register for controlling up
> to five chip select signals. This controller is found on the AXM5516 SoC.
> Unfortunately the PrimeCell identification registers are identical to a
> standard ARM PL022. To work around this, the peripheral ID must be overridden
> in the device tree using the "arm,primecell-periphid" property with the value
> 0x000b6022.
>
> Signed-off-by: Anders Berg <anders.berg at avagotech.com>
(...)
> +               /*
> +                * PL022 variant that has a chip select control register whih
> +                * allows control of 5 output signals nCS[0:4].
> +                */
> +               .id     = 0x000b6022,

OK so you're defining 0xb6 to the the 8bit ID for LSI.

Do you have some special reason for this, like that it appears
in some other silicon block from LSI? Otherwise I suggest using
0x4c (uppercase 'L') so as to follow the pattern of the other
vendor IDs.

Please patch include/linux/amba/bus.h to add
AMBA_VENDOR_LSI = 0x4c (or 6b) as well, as this is the first
occurence.

Yours,
Linus Walleij