[PATCH v3 1/3] dm: core: Bind another driver with the same compatible string

[Simon Glass]

Hi Michal,

On Wed, 6 Oct 2021 at 08:19, Michal Simek <michal.simek at xilinx.com> wrote:
>
> When one IP can have multiple configurations (like timer and PWM) covered
> by multiple drivers. Because it is the same IP it should also have the same
> compatible string.
> Current code look for the first driver which matches compatible string and
> call bind function. If this is not the right driver which is express by
> returning -ENODEV ("Driver XYZ refuses to bind") there is no reason not to
> continue over compatible list to try to find out different driver with the
> same compatible string which match it.
>
> When the first compatible string is found core looks for driver bind()
> function. If if assigned driver refuse to bind, core continue in a loop to
> check if there is another driver which match compatible string.
>
> This driver is going to be used with cdnc,ttc driver which has driver as
> timer and also can be used as PWM. The difference is done via #pwm-cells
> property in DT.
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
>
> Changes in v3:
> - New patch in series
>
>  drivers/core/lists.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)

Can you refactor this to avoid the 'goto'? E.g. put the loop in a new function?

Also, if pre_reloc_only, it still quits. Don't you want it to continue
in that case too?

Finally, can you add such a driver to sandbox test.dts and add a check
in test/dm/core.c or similar so that this behaviour is tested?

>
> diff --git a/drivers/core/lists.c b/drivers/core/lists.c
> index 350b9d32687c..199ee3a8e0fc 100644
> --- a/drivers/core/lists.c
> +++ b/drivers/core/lists.c
> @@ -221,12 +221,14 @@ int lists_bind_fdt(struct udevice *parent, ofnode node, struct udevice **devp,
>                 compat = compat_list + i;
>                 log_debug("   - attempt to match compatible string '%s'\n",
>                           compat);
> -
> -               for (entry = driver; entry != driver + n_ents; entry++) {
> +               entry = driver;
> +next:
> +               for (; entry != driver + n_ents; entry++) {
>                         ret = driver_check_compatible(entry->of_match, &id,
>                                                       compat);
>                         if (!ret)
>                                 break;
> +
>                 }
>                 if (entry == driver + n_ents)
>                         continue;
> @@ -246,7 +248,8 @@ int lists_bind_fdt(struct udevice *parent, ofnode node, struct udevice **devp,
>                                                    id->data, node, &dev);
>                 if (ret == -ENODEV) {
>                         log_debug("Driver '%s' refuses to bind\n", entry->name);
> -                       continue;
> +                       entry++;
> +                       goto next;
>                 }
>                 if (ret) {
>                         dm_warn("Error binding driver '%s': %d\n", entry->name,
> --
> 2.33.0
>

Regards,
Simon