RE: [PATCH v4 2/3] pinctrl: renesas: Renesas RZ/N1 pinctrl driver

[Phil Edworthy]

Hi Geert,

On 24 September 2018 12:59 Geert Uytterhoeven wrote:
> On Wed, Sep 19, 2018 at 4:24 PM Phil Edworthy wrote:
> > This provides a pinctrl driver for the Renesas RZ/N1 device family.
> >
> > Based on a patch originally written by Michel Pollet at Renesas.
> >
> > Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> 
> Thanks for your patch!
> 
> > --- /dev/null
> > +++ b/drivers/pinctrl/pinctrl-rzn1.c
> 
> > +/*
> > + * Structure detailing the HW registers on the RZ/N1 devices.
> > + * Both the Level 1 mux registers and Level 2 mux registers have the
> > +same
> > + * structure. The only difference is that Level 2 has additional MDIO
> > +registers
> > + * at the end.
> > + */
> > +struct rzn1_pinctrl_regs {
> > +       union {
> > +               u32     conf[170];
> > +               u8      pad0[0x400];
> 
> This looks a bit confusing, and isn't really padding, as you use a union.
> What about getting rid of the union, and making it real padding?
> 
>         u32 conf[170];
>         u32 pad0[86];
> 
> > +       };
> > +       u32     status_protect; /* 0x400 */
> > +       /* MDIO mux registers, level2 only */
> > +       u32     l2_mdio[2];
> > +};
> 
> BTW, while using a struct instead of register offset definitions has its merits,
> it also has its drawbacks, like the need for the "0x400" comment.
> You don't have to change it, though.
> 
> > +static const struct rzn1_pin_group *rzn1_pinctrl_find_group_by_name(
> > +       const struct rzn1_pinctrl *ipctl, const char *name) {
> > +       const struct rzn1_pin_group *grp = NULL;
> > +       int i;
> 
> unsigned int i;
> (rzn1_pinctrl.ngroups is unsigned int)
> 
> > +
> > +       for (i = 0; i < ipctl->ngroups; i++) {
> > +               if (!strcmp(ipctl->groups[i].name, name)) {
> > +                       grp = &ipctl->groups[i];
> > +                       break;
> > +               }
> > +       }
> > +
> > +       return grp;
> > +}
> 
> > +static int rzn1_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
> > +                           unsigned long *configs, unsigned int
> > +num_configs) {
> > +       struct rzn1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
> > +       enum pin_config_param param;
> > +       int i;
> 
> unsigned int i;
> 
> > +       u32 arg;
> > +       u32 l1, l1_cache;
> > +       u32 drv;
> > +
> > +       if (pin >= ARRAY_SIZE(ipctl->lev1->conf))
> > +               return -EINVAL;
> > +
> > +       l1 = readl(&ipctl->lev1->conf[pin]);
> > +       l1_cache = l1;
> > +
> > +       for (i = 0; i < num_configs; i++) {
> 
> > +static int rzn1_pinconf_group_get(struct pinctrl_dev *pctldev,
> > +                                 unsigned int selector,
> > +                                 unsigned long *config) {
> > +       struct rzn1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
> > +       struct rzn1_pin_group *grp = &ipctl->groups[selector];
> > +       unsigned long old = 0;
> > +       int i;
> 
> unsigned int i;
> 
> > +
> > +       dev_dbg(ipctl->dev, "group get %s selector:%d\n", grp->name,
> > + selector);
> 
> %u to format unsigned int.
> 
> > +
> > +       for (i = 0; i < grp->npins; i++) {
> 
> > +static int rzn1_pinconf_group_set(struct pinctrl_dev *pctldev,
> > +                                 unsigned int selector,
> > +                                 unsigned long *configs,
> > +                                 unsigned int num_configs) {
> > +       struct rzn1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
> > +       struct rzn1_pin_group *grp = &ipctl->groups[selector];
> > +       int ret, i;
> 
> unsigned int i;
> 
> > +
> > +       dev_dbg(ipctl->dev, "group set %s selector:%d
> > + configs:%p/%d\n",
> 
> %u
> 
> > +               grp->name, selector, configs, num_configs);
> > +
> > +       for (i = 0; i < grp->npins; i++) {
> > +               unsigned int pin = grp->pins[i];
> > +
> > +               ret = rzn1_pinconf_set(pctldev, pin, configs, num_configs);
> > +               if (ret)
> > +                       return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> 
> 
> > +static int rzn1_pinctrl_parse_functions(struct device_node *np,
> > +                                       struct rzn1_pinctrl *ipctl,
> > +u32 index)
> 
> Why u32 instead of plain unsigned int?
> 
> > +{
> > +       struct device_node *child;
> > +       struct rzn1_pmx_func *func;
> > +       struct rzn1_pin_group *grp;
> > +       u32 i = 0;
> 
> Why not plain unsigned int?
> 
> > +       int ret;
> > +
> > +       func = &ipctl->functions[index];
> > +
> > +       /* Initialise function */
> > +       func->name = np->name;
> > +       func->num_groups = rzn1_pinctrl_count_function_groups(np);
> > +       if (func->num_groups == 0) {
> > +               dev_err(ipctl->dev, "no groups defined in %pOF\n", np);
> > +               return -EINVAL;
> > +       }
> > +       dev_dbg(ipctl->dev, "function %s has %d groups\n",
> > +               np->name, func->num_groups);
> > +
> > +       func->groups = devm_kmalloc_array(ipctl->dev,
> > +                                         func->num_groups, sizeof(char *),
> > +                                         GFP_KERNEL);
> > +       if (!func->groups)
> > +               return -ENOMEM;
> > +
> > +       if (of_property_count_u32_elems(np, RZN1_PINS_PROP) > 0) {
> > +               func->groups[i] = np->name;
> > +               grp = &ipctl->groups[ipctl->ngroups];
> > +               grp->func = func->name;
> > +               ret = rzn1_pinctrl_parse_groups(np, grp, ipctl);
> > +               if (ret < 0)
> > +                       return ret;
> > +               i++;
> > +               ipctl->ngroups++;
> > +       }
> > +
> > +       for_each_child_of_node(np, child) {
> > +               func->groups[i] = child->name;
> > +               grp = &ipctl->groups[ipctl->ngroups];
> > +               grp->func = func->name;
> > +               ret = rzn1_pinctrl_parse_groups(child, grp, ipctl);
> > +               if (ret < 0)
> > +                       return ret;
> > +               i++;
> > +               ipctl->ngroups++;
> > +       }
> > +
> > +       dev_dbg(ipctl->dev, "function %s parsed %d/%d groups\n",
> 
> %u/%u
> 
> > +               np->name, i, func->num_groups);
> > +
> > +       return 0;
> > +}
> > +
> > +static int rzn1_pinctrl_probe_dt(struct platform_device *pdev,
> > +                                struct rzn1_pinctrl *ipctl) {
> > +       struct device_node *np = pdev->dev.of_node;
> > +       struct device_node *child;
> > +       unsigned int maxgroups = 0;
> > +       u32 nfuncs = 0;
> > +       u32 i = 0;
> 
> Why not plain unsigned int, for both?

Thanks for your review and comments, you are right in all of them.
I'll fix them and re-post.

Thanks
Phil

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds