RE: [PATCH 2/2] pinctrl: ocelot: Extend support for lan966x

[Kavyasree.Kotagiri]

> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@xxxxxxxxxxx]
> Sent: Thursday, November 18, 2021 4:30 AM
> To: Kavyasree Kotagiri - I30978 <Kavyasree.Kotagiri@xxxxxxxxxxxxx>
> Cc: robh+dt@xxxxxxxxxx; linus.walleij@xxxxxxxxxx; linux-
> gpio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; UNGLinuxDriver <UNGLinuxDriver@xxxxxxxxxxxxx>
> Subject: Re: [PATCH 2/2] pinctrl: ocelot: Extend support for lan966x
> 
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> 
> Hello Kavya,
> 
> On 29/10/2021 14:57:03+0530, Kavyasree Kotagiri wrote:
> > +     LAN966X_PIN(76),
> > +     LAN966X_PIN(77),
> > +};
> > +
> > +
> 
> One blank line should be removed
> 
This is older patch series. Blank lines are already fixed in v3 patch series.

> >  static int ocelot_get_functions_count(struct pinctrl_dev *pctldev)
> >  {
> >       return ARRAY_SIZE(ocelot_function_names);
> > @@ -709,6 +1056,9 @@ static int ocelot_pin_function_idx(struct
> ocelot_pinctrl *info,
> >       for (i = 0; i < OCELOT_FUNC_PER_PIN; i++) {
> >               if (function == p->functions[i])
> >                       return i;
> > +
> > +             if (function == p->a_functions[i])
> > +                     return i + OCELOT_FUNC_PER_PIN;
> >       }
> >
> >       return -1;
> > @@ -744,6 +1094,36 @@ static int ocelot_pinmux_set_mux(struct
> pinctrl_dev *pctldev,
> >       return 0;
> >  }
> >
> > +static int lan966x_pinmux_set_mux(struct pinctrl_dev *pctldev,
> > +                               unsigned int selector, unsigned int group)
> > +{
> > +     struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
> > +     struct ocelot_pin_caps *pin = info->desc->pins[group].drv_data;
> > +     unsigned int p = pin->pin % 32;
> > +     int f;
> > +
> > +     f = ocelot_pin_function_idx(info, group, selector);
> > +     if (f < 0)
> > +             return -EINVAL;
> > +
> > +     /*
> > +      * f is encoded on three bits.
> > +      * bit 0 of f goes in BIT(pin) of ALT[0], bit 1 of f goes in BIT(pin) of
> > +      * ALT[1], bit 2 of f goes in BIT(pin) of ALT[2]
> > +      * This is racy because both registers can't be updated at the same time
> 
> That's three registers, not two so I guess this sentence should be
> reworked.
> 
I agree. I will change it.

> > +      * but it doesn't matter much for now.
> > +      * Note: ALT0/ALT1/ALT2 are organized specially for 78 gpio targets
> > +      */
> > +     regmap_update_bits(info->map, REG_ALT(0, info, pin->pin),
> > +                        BIT(p), f << p);
> > +     regmap_update_bits(info->map, REG_ALT(1, info, pin->pin),
> > +                        BIT(p), (f >> 1) << p);
> > +     regmap_update_bits(info->map, REG_ALT(2, info, pin->pin),
> > +                        BIT(p), (f >> 2) << p);
> > +
> 
> I would have thought the hardware would be fixed because you now have 78
> pins and this probably will get worse over time. This is really a poor
> choice of interface as now you will get two transient states instead of
> one.
> 
Sorry, I couldn't get you. please elaborate what you meant by this comment?

> > +     return 0;
> > +}
> > +
> >  #define REG(r, info, p) ((r) * (info)->stride + (4 * ((p) / 32)))
> >
> >  static int ocelot_gpio_set_direction(struct pinctrl_dev *pctldev,
> > @@ -774,6 +1154,23 @@ static int ocelot_gpio_request_enable(struct
> pinctrl_dev *pctldev,
> >       return 0;
> >  }
> >
> > +static int lan966x_gpio_request_enable(struct pinctrl_dev *pctldev,
> > +                                    struct pinctrl_gpio_range *range,
> > +                                    unsigned int offset)
> > +{
> > +     struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
> > +     unsigned int p = offset % 32;
> > +
> > +     regmap_update_bits(info->map, REG_ALT(0, info, offset),
> > +                        BIT(p), 0);
> > +     regmap_update_bits(info->map, REG_ALT(1, info, offset),
> > +                        BIT(p), 0);
> > +     regmap_update_bits(info->map, REG_ALT(2, info, offset),
> > +                        BIT(p), 0);
> > +
> > +     return 0;
> > +}
> > +
> >  static const struct pinmux_ops ocelot_pmx_ops = {
> >       .get_functions_count = ocelot_get_functions_count,
> >       .get_function_name = ocelot_get_function_name,
> > @@ -783,6 +1180,15 @@ static const struct pinmux_ops ocelot_pmx_ops =
> {
> >       .gpio_request_enable = ocelot_gpio_request_enable,
> >  };
> >
> > +static const struct pinmux_ops lan966x_pmx_ops = {
> > +     .get_functions_count = ocelot_get_functions_count,
> > +     .get_function_name = ocelot_get_function_name,
> > +     .get_function_groups = ocelot_get_function_groups,
> > +     .set_mux = lan966x_pinmux_set_mux,
> > +     .gpio_set_direction = ocelot_gpio_set_direction,
> > +     .gpio_request_enable = lan966x_gpio_request_enable,
> > +};
> > +
> >  static int ocelot_pctl_get_groups_count(struct pinctrl_dev *pctldev)
> >  {
> >       struct ocelot_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
> > @@ -1074,6 +1480,14 @@ static struct pinctrl_desc sparx5_desc = {
> >       .npins = ARRAY_SIZE(sparx5_pins),
> >       .pctlops = &ocelot_pctl_ops,
> >       .pmxops = &ocelot_pmx_ops,
> > +};
> > +
> > +static struct pinctrl_desc lan966x_desc = {
> > +     .name = "lan966x-pinctrl",
> > +     .pins = lan966x_pins,
> > +     .npins = ARRAY_SIZE(lan966x_pins),
> > +     .pctlops = &ocelot_pctl_ops,
> > +     .pmxops = &lan966x_pmx_ops,
> >       .confops = &ocelot_confops,
> >       .owner = THIS_MODULE,
> >  };
> > @@ -1114,6 +1528,7 @@ static int ocelot_create_group_func_map(struct
> device *dev,
> >       return 0;
> >  }
> >
> > +
> 
> Useless blank line
> 
Already fixed in v3 patch series.

> >  static int ocelot_pinctrl_register(struct platform_device *pdev,
> >                                  struct ocelot_pinctrl *info)
> >  {
> > @@ -1337,6 +1752,7 @@ static const struct of_device_id
> ocelot_pinctrl_of_match[] = {
> >       { .compatible = "mscc,ocelot-pinctrl", .data = &ocelot_desc },
> >       { .compatible = "mscc,jaguar2-pinctrl", .data = &jaguar2_desc },
> >       { .compatible = "microchip,sparx5-pinctrl", .data = &sparx5_desc },
> > +     { .compatible = "microchip,lan966x-pinctrl", .data = &lan966x_desc },
> >       {},
> >  };
> >
> > --
> > 2.17.1
> >
> 
> --
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com