[U-Boot] [PATCH v1] usb: ehci-mx6: Fix bus enumeration for iMX7 SoCs

[Igor Opaniuk]

Hi Marek

On Thu, Oct 10, 2019 at 2:47 PM Marek Vasut <marex at denx.de> wrote:
>
> On 10/10/19 1:25 PM, Igor Opaniuk wrote:
> [...]
> >        * from which it derives offsets in the PHY and ANATOP register sets.
> >        *
> >        * Here we attempt to calculate these indexes from DT information as
> > -      * well as we can. The USB controllers on all existing iMX6/iMX7 SoCs
> > -      * are placed next to each other, at addresses incremented by 0x200.
> > -      * Thus, the index is derived from the multiple of 0x200 offset from
> > -      * the first controller address.
> > +      * well as we can. The USB controllers on all existing iMX6 SoCs
> > +      * are placed next to each other, at addresses incremented by 0x200,
> > +      * and iMX7 their addresses are shifted by 0x1000.
> > +      * Thus, the index is derived from the multiple of 0x200 (0x1000 for
> > +      * iMX7) offset from the first controller address.
> >        *
> >        * However, to complete conversion of this driver to DT probing, the
> >        * following has to be done:
> > @@ -531,10 +532,14 @@ static int ehci_usb_bind(struct udevice *dev)
> >        * With these changes in place, the ad-hoc indexing goes away and
> >        * the driver is fully converted to DT probing.
> >        */
> > -     fdt_size_t size;
> > -     fdt_addr_t addr = devfdt_get_addr_size_index(dev, 0, &size);
> > +#if defined(CONFIG_MX6)
> > +     u32 controller_spacing = 0x200;
> > +#elif defined(CONFIG_MX7)
> > +     u32 controller_spacing = 0x10000;
> > +#endif
> > +     fdt_addr_t addr = devfdt_get_addr_size_index(dev, 0, NULL);
>
> This won't work with U-Boot that's compiled for both platforms, so you
> need some other way to discern those two things. Either something like
> cpu_is_...() or some DT match.

So in that case existing ehci_hcd_init() implementation
won't work either, as it does the same.
So if we want to address this case (anyway, is it the real case when both
CONFIG_MX6 and CONFIG_MX7 are defined?), we will have to reimplement
other parts of the driver.

But taking into account that it's a temporary workaround and should be fully
reimplemented,why not to proceed with a pretty simple solution for now
as what is done in ehci-vf.c :

295 static int vf_usb_bind(struct udevice *dev)
296 {
297         static int num_controllers;
298
299         /*
300          * Without this hack, if we return ENODEV for USB
Controller 0, on
301          * probe for the next controller, USB Controller 1 will be
given a
302          * sequence number of 0. This conflicts with our
requirement of
303          * sequence numbers while initialising the peripherals.
304          */
305         dev->req_seq = num_controllers;
306         num_controllers++;
307
308         return 0;
309 }

Thanks

-- 
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Igor Opaniuk

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