spi-oc-tiny.c and microwatt chip select

spi-oc-tiny.c and microwatt chip select

[Benjamin Herrenschmidt]

Hi !

I've cooked up a little SPI controller VHDL for the Microwatt project
(https://github.com/antonblanchard/microwatt, though the SPI isnt
merged yet), to control the flash connected to the FPGA (it contains
the bitfile and the SW payload, such as Linux).

Now I could write yet-another bitbang driver for Linux for it, or I
could make my controller look like an existing one :) It's very simple,
but I should be able to make it look like spi-oc-tiny.c quite easily.

Now as for chip-selects... I could also add some concept of GPIOs,
write a simple MMIO GPIO controller etc... or I could for now make my
life easier and send a patch adding an extra register to control chip
select to spi-oc-tiny.c keyd off a device-tree property (or the
compatible property) :-)

Any objection to the "easy/fast" way :-) ?

Cheers,
Ben.

Re: spi-oc-tiny.c and microwatt chip select

[Mark Brown]

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On Sat, Jun 06, 2020 at 06:50:37PM +1000, Benjamin Herrenschmidt wrote:

> Now as for chip-selects... I could also add some concept of GPIOs,
> write a simple MMIO GPIO controller etc... or I could for now make my
> life easier and send a patch adding an extra register to control chip
> select to spi-oc-tiny.c keyd off a device-tree property (or the
> compatible property) :-)

> Any objection to the "easy/fast" way :-) ?

That sounds fine (I'd go with a different compatible).

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Re: spi-oc-tiny.c and microwatt chip select

[Benjamin Herrenschmidt]

On Sat, 2020-06-06 at 12:37 +0100, Mark Brown wrote:
> On Sat, Jun 06, 2020 at 06:50:37PM +1000, Benjamin Herrenschmidt
> wrote:
> 
> > Now as for chip-selects... I could also add some concept of GPIOs,
> > write a simple MMIO GPIO controller etc... or I could for now make
> > my
> > life easier and send a patch adding an extra register to control
> > chip
> > select to spi-oc-tiny.c keyd off a device-tree property (or the
> > compatible property) :-)
> > Any objection to the "easy/fast" way :-) ?
> 
> That sounds fine (I'd go with a different compatible).

Great ! Thanks.

Cheers,
Ben.