[U-Boot] [PATCH v3] drivers: spi: migrate cf_spi to DM

[Angelo Dureghello <angelo@sysam.it>]

Hi Simon,

On Fri, Sep 14, 2018 at 12:17:56PM +0200, Simon Glass wrote:
> Hi Angelo,
> 
> On 28 June 2018 at 21:48, Angelo Dureghello <angelo@sysam.it> wrote:
> > Hi Jagan,
> >
> > On Wed, Jun 27, 2018 at 02:54:42PM +0530, Jagan Teki wrote:
> >> On Wed, Jun 27, 2018 at 2:27 PM, Angelo Dureghello <angelo@sysam.it> wrote:
> >> > Hi Jagan,
> >> >
> >> > On Wed, Jun 27, 2018 at 12:08:26PM +0530, Jagan Teki wrote:
> >> >> On Tue, Jun 26, 2018 at 10:28 PM, Angelo Dureghello <angelo@sysam.it> wrote:
> >> >> > This patch adds DM support to cf_spi.c.
> >> >> >
> >> >> > How to use/test it:
> >> >> >
> >> >> > 1) enable the following options,
> >> >> >
> >> >> > CONFIG_DM_SPI
> >> >> > CONFIG_DM_SPI_FLASH
> >> >> >
> >> >> > 2) add similar code into your board.c file
> >> >> >
> >> >> > U_BOOT_DEVICE(coldfire_spi) = {
> >> >> >         .name = "spi_coldfire",
> >> >> >         .platdata = &mcf_spi_plat,
> >> >> > };
> >> >> >
> >> >> > ---
> >> >> > Changes from v1:
> >> >> > - split into 2 patches
> >> >> >
> >> >> > Changes from v2:
> >> >> > - back in a single patch, no need to add fdt support or special
> >> >> >   config options
> >> >> > - doc/driver-model/spi-howto.txt has been re-checked and followed,
> >> >> >   the driver now builds as is.
> >> >>
> >> >> Nice, How about full dm conversion. I have seen few boards using this
> >> >> driver and its quite manageble for full switching. what do you think?
> >> >
> >> > Sorry, what do you mean exactly for full switching ?
> >> > My understanding is, to remove the non-dm part of the driver and add to
> >> > each board proper device struct and config options, correct ?
> >>
> >> yes.
> >>
> >> > In this case, i can only test it on my stmark2 board, but i think could
> >> > be enough.
> >>
> >> yes, for untested ones will ask other board maintainers.
> >
> > I verified right now, for a full switch i should enable CONFIG_DM for
> > the architecture, and then select CONFIG_DM_SPI, moving as his child
> > the CONFIG_CF_SPI.
> >
> > To enable CONFIG_DM for m68k means to add device tree, or there are
> > of_xxx functions unresolved externals errors then.
> >
> > For this small architecture, i am not that happy to add the devicetree
> > support. I should add a fixed 30 KB of binary size and several diffent
> > families/dtsi, with the benefit to configure mainly uart and spi.
> 
> Are you worried about the size of SPL when using device tree?
>

ColdFire/m68k arch is not supporting SPL so this is not a problem.
 
> How about converting m68k to DT in U-Boot proper as a first step?
> 

It was a matter of deadlines, due to the request to switch cf_spi
driver to dm, i preferred to start executing this switch.

Ok, if the switch to DT is by popular demand from our team,
i can start the conversion. 

This patch could still be applied in the meantime, as you prefer.

> >
> > If the devicetree become mandatory/forced, would be nice if you could accept
> > the migration as is (as from doc/driver-model/spi-howto.txt), and i could
> > then work on devicetree in a later step.
> 
> Regards,
> Simon

Regards,
Angelo