by Philipp Zabel

[permalink] [raw]

Subject: Re: [PATCH v6 08/17] reset: npcm: using syscon instead of device data

On Do, 2022-06-30 at 14:20 +0300, Tomer Maimon wrote:
> Hi Philipp,
>
> Thanks for your comment.
>
> On Thu, 30 Jun 2022 at 13:59, Philipp Zabel <[email protected]> wrote:
> >
> > Hi Tomer,
> >
> > On Do, 2022-06-30 at 13:35 +0300, Tomer Maimon wrote:
> > Using syscon device tree property instead of device data to handle the
> > NPCM general control registers.
> >
> > In case the syscon not found the code still search for nuvoton,npcm750-gcr
> > to support DTS backward compatibility.
> >
> > Signed-off-by: Tomer Maimon <[email protected]>
> > ---
> > drivers/reset/reset-npcm.c | 17 ++++++++---------
> > 1 file changed, 8 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/reset/reset-npcm.c b/drivers/reset/reset-npcm.c
> > index 2ea4d3136e15..431ff2b602c5 100644
> > --- a/drivers/reset/reset-npcm.c
> > +++ b/drivers/reset/reset-npcm.c
> > @@ -138,8 +138,7 @@ static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
> > }
> >
> >
> > static const struct of_device_id npcm_rc_match[] = {
> > - { .compatible = "nuvoton,npcm750-reset",
> > - .data = (void *)"nuvoton,npcm750-gcr" },
> > + { .compatible = "nuvoton,npcm750-reset"},
> >
> > Add a space. ^^
> Will modify in V7
> >
> >         { }
> > };
> >
> >
> > @@ -155,15 +154,15 @@ static int npcm_usb_reset(struct platform_device *pdev, struct npcm_rc_data *rc)
> >         u32 ipsrst1_bits = 0;
> >         u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
> >         u32 ipsrst3_bits = 0;
> > - const char *gcr_dt;
> >
> >
> > - gcr_dt = (const char *)
> > - of_match_device(dev->driver->of_match_table, dev)->data;
> > -
> > - gcr_regmap = syscon_regmap_lookup_by_compatible(gcr_dt);
> > + gcr_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "nuvoton,sysgcr");
> >         if (IS_ERR(gcr_regmap)) {
> > - dev_err(&pdev->dev, "Failed to find %s\n", gcr_dt);
> > - return PTR_ERR(gcr_regmap);
> > + dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr search for nuvoton,npcm750-gcr for Poleg backward compatibility");
> >
> > Is this warning useful to the user? Maybe add suggestion like "please
> > update the device tree". Also there is no further message if
> > nuvoton,npcm750-gcr is found and all is well.
>
> O.K.
> I think about two options:
>
> 1. Modify the message "Failed to find nuvoton,sysgcr property, please
> update the device tree\n Search for nuvoton,npcm750-gcr for Poleg
> backward compatibility"

I would replace "Search for" with "Using"
The second line probably should be dev_info() level.

> OR
>
> 2.
>         if (IS_ERR(rc->gcr_regmap)) {
>                 dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr
> please update the device tree");
>                 rc->gcr_regmap =
> syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
>                 if (IS_ERR(rc->gcr_regmap)) {
>                         dev_err(&pdev->dev, "Failed to find
> nuvoton,npcm750-gcr");
>                         return PTR_ERR(rc->gcr_regmap);
>                 }
>                  dev_info(&pdev->dev, "found nuvoton,npcm750-gcr for
> Poleg backward compatibility");
>         }
>
> The only problem that I have with option 2 is if our customers will
> use the latest reset driver and they will not update their device tree
> they will see all the time the dev_info message.
>
> What do you think?

I'm fine with either. With the "please update DT" prompt it's clear how
to get rid of the warning.

regards
Philipp