[Linux-stm32] [PATCH v3] pinctrl: stm32: Add check for clk_enable()

[Mingwei Zheng]

Hi Antonio,

On Sat, Dec 7, 2024 at 9:25 AM Antonio Borneo
<antonio.borneo at foss.st.com> wrote:
>
> On Fri, 2024-12-06 at 16:43 -0500, Mingwei Zheng wrote:
> > Convert the driver to clk_bulk*() API.
> > Add check for the return value of clk_bulk_enable() to catch
> > the potential error.
> >
> > Fixes: 05d8af449d93 ("pinctrl: stm32: Keep pinctrl block clock enabled when LEVEL IRQ requested")
> > Signed-off-by: Mingwei Zheng <zmw12306 at gmail.com>
> > Signed-off-by: Jiasheng Jiang <jiashengjiangcool at gmail.com>
> > ---
> > Changelog:
> >
> > v2 -> v3:
> >
> > 1. Convert clk_disable_unprepare to clk_bulk_disable
> > and clk_bulk_unprepare.
> >
> > v1 -> v2:
> >
> > 1. Move int ret declaration into if block.
> > ---
> >  drivers/pinctrl/stm32/pinctrl-stm32.c | 28 +++++++++++++--------------
> >  1 file changed, 13 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
> > index 5b7fa77c1184..0ef912e82736 100644
> > --- a/drivers/pinctrl/stm32/pinctrl-stm32.c
> > +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
> > @@ -86,7 +86,6 @@ struct stm32_pinctrl_group {
> >
> >  struct stm32_gpio_bank {
> >         void __iomem *base;
> > -       struct clk *clk;
> >         struct reset_control *rstc;
> >         spinlock_t lock;
> >         struct gpio_chip gpio_chip;
> > @@ -108,6 +107,7 @@ struct stm32_pinctrl {
> >         unsigned ngroups;
> >         const char **grp_names;
> >         struct stm32_gpio_bank *banks;
>
> Thanks for your patch!
> While it's growing wider than your initial scope, it looks as a nice improvement.
>
> > +       struct clk_bulk_data *clks;
>
> Maybe I've missed it but, where does this array get allocated?
> There exist clk_bulk_get_all() and devm_clk_bulk_get_all() that do the allocation for you, but they require all the clocks to be listed in the same "clocks" property, while this driver has a clock in
> each DT subnode!
> Some suggestion below.
>
> >         unsigned nbanks;
> >         const struct stm32_pinctrl_match_data *match_data;
> >         struct irq_domain       *domain;
> > @@ -1308,7 +1308,7 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
> >         if (IS_ERR(bank->base))
> >                 return PTR_ERR(bank->base);
> >
> > -       err = clk_prepare_enable(bank->clk);
> > +       err = clk_prepare_enable(pctl->clks[pctl->nbanks].clk);
> >         if (err) {
> >                 dev_err(dev, "failed to prepare_enable clk (%d)\n", err);
> >                 return err;
> > @@ -1397,7 +1397,7 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
> >         return 0;
> >
> >  err_clk:
> > -       clk_disable_unprepare(bank->clk);
> > +       clk_disable_unprepare(pctl->clks[pctl->nbanks].clk);
> >         return err;
> >  }
> >
> > @@ -1631,11 +1631,10 @@ int stm32_pctl_probe(struct platform_device *pdev)
> >                         fwnode_handle_put(child);
> >                         return -EPROBE_DEFER;
> >                 }
> > -
> > -               bank->clk = of_clk_get_by_name(np, NULL);
> > -               if (IS_ERR(bank->clk)) {
> > +               pctl->clks[i].clk = of_clk_get_by_name(np, NULL);
>
> This is the first time the array is used, during stm32_pctl_probe(), so the array should be already allocated before this line.
> The number of banks pctl->nbanks is computed few lines below, so it should be anticipated, or being replaced by a simpler
>   pctl->nbanks = gpiochip_node_count(dev);
>
> then allocation could be done with
>   pctl->clks = devm_kmalloc_array(dev, pctl->nbanks, sizeof(*pctl->clks), GFP_KERNEL);
>
> Also, you never assign `pctl->clks[i].id` which is then used by the error messages in, e.g., clk_bulk_enable().
> We don't mandate the property "clock-names" in the DT subnodes, so no way to get a reasonable value from the DT.
> I presume it's fine to set it to NULL... to be tested.
>
> Regards,
> Antonio
>
>

Thanks for your suggestion. We used devm_kcalloc to allocate clk. We
set `pctl->clks[i].id` to "".

Best,
Mingwei

> > +               if (IS_ERR(pctl->clks[i].clk)) {
> >                         fwnode_handle_put(child);
> > -                       return dev_err_probe(dev, PTR_ERR(bank->clk),
> > +                       return dev_err_probe(dev, PTR_ERR(pctl->clks[i].clk),
> >                                              "failed to get clk\n");
> >                 }
> >                 i++;
> > @@ -1646,8 +1645,8 @@ int stm32_pctl_probe(struct platform_device *pdev)
> >                 if (ret) {
> >                         fwnode_handle_put(child);
> >
> > -                       for (i = 0; i < pctl->nbanks; i++)
> > -                               clk_disable_unprepare(pctl->banks[i].clk);
> > +                       clk_bulk_disable(pctl->nbanks, pctl->clks);
> > +                       clk_bulk_unprepare(pctl->nbanks, pctl->clks);
> >
> >                         return ret;
> >                 }
> > @@ -1726,10 +1725,8 @@ static int __maybe_unused stm32_pinctrl_restore_gpio_regs(
> >  int __maybe_unused stm32_pinctrl_suspend(struct device *dev)
> >  {
> >         struct stm32_pinctrl *pctl = dev_get_drvdata(dev);
> > -       int i;
> >
> > -       for (i = 0; i < pctl->nbanks; i++)
> > -               clk_disable(pctl->banks[i].clk);
> > +       clk_bulk_disable(pctl->nbanks, pctl->clks);
> >
> >         return 0;
> >  }
> > @@ -1738,10 +1735,11 @@ int __maybe_unused stm32_pinctrl_resume(struct device *dev)
> >  {
> >         struct stm32_pinctrl *pctl = dev_get_drvdata(dev);
> >         struct stm32_pinctrl_group *g = pctl->groups;
> > -       int i;
> > +       int i, ret;
> >
> > -       for (i = 0; i < pctl->nbanks; i++)
> > -               clk_enable(pctl->banks[i].clk);
> > +       ret = clk_bulk_enable(pctl->nbanks, pctl->clks);
> > +       if (ret)
> > +               return ret;
> >
> >         for (i = 0; i < pctl->ngroups; i++, g++)
> >                 stm32_pinctrl_restore_gpio_regs(pctl, g->pin);