Re: [PATCH] fix pinctrl setup for i.IMX6

[Tony Lindgren <tony@atomide.com>]

* Linus Walleij <linus.walleij@linaro.org> [170314 07:50]:
> On Tue, Feb 28, 2017 at 7:00 AM, Mika Penttilä
> <mika.penttila@nextfour.com> wrote:
> 
> > Recent pulls for mainline pre 4.11 introduced pinctrl setup changes and moved pinctrl-imx to
> > use generic helpers.
> >
> > Net effect was that hog group could not be resolved. I made it work for myself
> > with a two stage setup with create and start separated, and dt probe in between them.
> >
> >
> > Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
> 
> Sorry for including the whole mail body, some people may have missed the
> mail. Notably the i.MX maintainers.
> 
> Your patch reminds me of the pinctrl_register() vs pinctrl_register_and_init()
> introduced by Tony Lindgren, can you look into this in commit
> 950b0d91dc108f54bccca5a2f75bb46f2df63d29
> "pinctrl: core: Fix regression caused by delayed work for hogs"?
> 
> Does switching pinctrl_register_and_init() back to pinctrl_register()
> solve your problem?

Hmm well I posted a suggested fix several days ago waiting for your
comments. Seems you're missing some emails you're being Cc:ed on?

Please check thread "[REGRESSION] pinctrl, of, unable to find hogs"
if you have it.

I basically split the functions further and was wondering if we
should bail out on pinctrl_register_and_init() type helpers in
favor of calling them separately because that still has this
issue.

Mika's devm_pinctrl_register_and_init_nostart() + start seems fine
with me too. We may still want to get rid of pinctrl_register_and_init()
though and replace it with devm_pinctrl_register_and_init_nostart() +
start.

Regards,

Tony

> Gary: have you seen any problem like this?
> 
> Yours,
> Linus Walleij
> 
> 
> > ---
> >
> > diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
> > index d690465..33659c5a 100644
> > --- a/drivers/pinctrl/core.c
> > +++ b/drivers/pinctrl/core.c
> > @@ -2237,6 +2237,47 @@ int devm_pinctrl_register_and_init(struct device *dev,
> >  }
> >  EXPORT_SYMBOL_GPL(devm_pinctrl_register_and_init);
> >
> > +int devm_pinctrl_register_and_init_nostart(struct device *dev,
> > +                                       struct pinctrl_desc *pctldesc,
> > +                                       void *driver_data,
> > +                                       struct pinctrl_dev **pctldev)
> > +{
> > +       struct pinctrl_dev **ptr;
> > +       struct pinctrl_dev *p;
> > +
> > +       ptr = devres_alloc(devm_pinctrl_dev_release, sizeof(*ptr), GFP_KERNEL);
> > +       if (!ptr)
> > +               return -ENOMEM;
> > +
> > +       p = pinctrl_init_controller(pctldesc, dev, driver_data);
> > +       if (IS_ERR(p)) {
> > +               devres_free(ptr);
> > +               return PTR_ERR(p);
> > +       }
> > +
> > +       *ptr = p;
> > +       devres_add(dev, ptr);
> > +       *pctldev = p;
> > +
> > +       return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(devm_pinctrl_register_and_init_nostart);
> > +
> > +int devm_pinctrl_start(struct device *dev,
> > +               struct pinctrl_dev *pctldev)
> > +{
> > +       int error = 0;
> > +
> > +       error = pinctrl_create_and_start(pctldev);
> > +       if (error) {
> > +               mutex_destroy(&pctldev->mutex);
> > +               return error;
> > +       }
> > +
> > +       return error;
> > +}
> > +EXPORT_SYMBOL_GPL(devm_pinctrl_start);
> > +
> >  /**
> >   * devm_pinctrl_unregister() - Resource managed version of pinctrl_unregister().
> >   * @dev: device for which which resource was allocated
> > diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
> > index a7ace9e..3644aed 100644
> > --- a/drivers/pinctrl/freescale/pinctrl-imx.c
> > +++ b/drivers/pinctrl/freescale/pinctrl-imx.c
> > @@ -686,16 +686,6 @@ static int imx_pinctrl_probe_dt(struct platform_device *pdev,
> >         return 0;
> >  }
> >
> > -/*
> > - * imx_free_resources() - free memory used by this driver
> > - * @info: info driver instance
> > - */
> > -static void imx_free_resources(struct imx_pinctrl *ipctl)
> > -{
> > -       if (ipctl->pctl)
> > -               pinctrl_unregister(ipctl->pctl);
> > -}
> > -
> >  int imx_pinctrl_probe(struct platform_device *pdev,
> >                       struct imx_pinctrl_soc_info *info)
> >  {
> > @@ -774,26 +764,30 @@ int imx_pinctrl_probe(struct platform_device *pdev,
> >         ipctl->info = info;
> >         ipctl->dev = info->dev;
> >         platform_set_drvdata(pdev, ipctl);
> > -       ret = devm_pinctrl_register_and_init(&pdev->dev,
> > -                                            imx_pinctrl_desc, ipctl,
> > -                                            &ipctl->pctl);
> > +
> > +       ret = devm_pinctrl_register_and_init_nostart(&pdev->dev,
> > +                                               imx_pinctrl_desc, ipctl,
> > +                                               &ipctl->pctl);
> > +
> >         if (ret) {
> >                 dev_err(&pdev->dev, "could not register IMX pinctrl driver\n");
> > -               goto free;
> > +               return ret;
> >         }
> >
> >         ret = imx_pinctrl_probe_dt(pdev, ipctl);
> >         if (ret) {
> >                 dev_err(&pdev->dev, "fail to probe dt properties\n");
> > -               goto free;
> > +               return ret;
> > +       }
> > +
> > +       ret = devm_pinctrl_start(&pdev->dev, ipctl->pctl);
> > +       if (ret) {
> > +               dev_err(&pdev->dev, "could not start IMX pinctrl driver\n");
> > +               return ret;
> >         }
> >
> >         dev_info(&pdev->dev, "initialized IMX pinctrl driver\n");
> >
> >         return 0;
> >
> > -free:
> > -       imx_free_resources(ipctl);
> > -
> > -       return ret;
> >  }
> > diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
> > index 8ce2d87..e7020f0 100644
> > --- a/include/linux/pinctrl/pinctrl.h
> > +++ b/include/linux/pinctrl/pinctrl.h
> > @@ -153,9 +153,17 @@ extern struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
> >  extern void pinctrl_unregister(struct pinctrl_dev *pctldev);
> >
> >  extern int devm_pinctrl_register_and_init(struct device *dev,
> > -                               struct pinctrl_desc *pctldesc,
> > -                               void *driver_data,
> > -                               struct pinctrl_dev **pctldev);
> > +                                       struct pinctrl_desc *pctldesc,
> > +                                       void *driver_data,
> > +                                       struct pinctrl_dev **pctldev);
> > +
> > +extern int devm_pinctrl_register_and_init_nostart(struct device *dev,
> > +                                               struct pinctrl_desc *pctldesc,
> > +                                               void *driver_data,
> > +                                               struct pinctrl_dev **pctldev);
> > +
> > +extern int devm_pinctrl_start(struct device *dev,
> > +                       struct pinctrl_dev *pctldev);
> >
> >  /* Please use devm_pinctrl_register_and_init() instead */
> >  extern struct pinctrl_dev *devm_pinctrl_register(struct device *dev,