Re: [PATCH v5 2/3] pinctrl: add NXP S32 SoC family support

andy.shevchenko
2023-03-06T23:28:20Z

Mon, Feb 20, 2023 at 10:33:19AM +0800, Chester Lin kirjoitti:
> Add the pinctrl driver for NXP S32 SoC family. This driver is mainly based
> on NXP's downstream implementation on nxp-auto-linux repo[1].

Seems Linus already applied this, but still some comments for the future, some
for the followups. However, personally I prefer this to be dropped and redone
because too many things here and there.

> [1] https://github.com/nxp-auto-linux/linux/tree/bsp35.0-5.15.73-rt/drivers/pinctrl/freescale

This can be transformed to Link: tag.

> Signed-off-by: Matthew Nunez <matthew.nunez@nxp.com>
> Signed-off-by: Phu Luu An <phu.luuan@nxp.com>
> Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
> Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@oss.nxp.com>
> Signed-off-by: Andrei Stefanescu <andrei.stefanescu@nxp.com>
> Signed-off-by: Radu Pirea <radu-nicolae.pirea@nxp.com>
> Signed-off-by: Chester Lin <clin@suse.com>

Is it for real?!
Quite a long chain and none of Co-developed-by.

...

> + depends on ARCH_S32 && OF

Is OF necessary? Can it be

depends OF || COMPILE_TEST

?

...

> + depends on ARCH_S32 && OF

Ditto.

...

> +/**
> + * struct s32_pin_group - describes an S32 pin group
> + * @name: the name of this specific pin group
> + * @npins: the number of pins in this group array, i.e. the number of
> + * elements in pin_ids and pin_sss so we can iterate over that array
> + * @pin_ids: an array of pin IDs in this group
> + * @pin_sss: an array of source signal select configs paired with pin_ids
> + */
> +struct s32_pin_group {
> + const char *name;
> + unsigned int npins;
> + unsigned int *pin_ids;
> + unsigned int *pin_sss;

Why didn't you embed struct pingroup?

> +};
> +
> +/**
> + * struct s32_pmx_func - describes S32 pinmux functions
> + * @name: the name of this specific function
> + * @groups: corresponding pin groups
> + * @num_groups: the number of groups
> + */
> +struct s32_pmx_func {
> + const char *name;
> + const char **groups;
> + unsigned int num_groups;
> +};

struct pinfunction.

...

> +#ifdef CONFIG_PM_SLEEP
> +int __maybe_unused s32_pinctrl_resume(struct device *dev);
> +int __maybe_unused s32_pinctrl_suspend(struct device *dev);
> +#endif

Please, consider using new PM macros, like pm_ptr().

...

> +static u32 get_pin_no(u32 pinmux)
> +{
> + return (pinmux & S32_PIN_ID_MASK) >> __ffs(S32_PIN_ID_MASK);

Oh, don't you have MASK to be 2^x - 1? Why to drag this with __ffs()?
Just define a complement _SHIFT.

> +}

...

> + n_pins = of_property_count_elems_of_size(np, "pinmux", sizeof(u32));
> + if (n_pins < 0) {
> + dev_warn(dev, "Unable to find 'pinmux' property in node %s.\n",
> + np->name);

Use %pOFn instead of %s.

> + } else if (!n_pins) {
> + return -EINVAL;
> + }

...

> + for (i = 0; i < grp->npins; ++i) {

Why pre-increment?

> + if (s32_check_pin(pctldev, grp->pin_ids[i]) != 0) {
> + dev_err(info->dev, "invalid pin: %d in group: %d\n",
> + grp->pin_ids[i], group);
> + return -EINVAL;
> + }
> + }
> +
> + for (i = 0, ret = 0; i < grp->npins && !ret; ++i) {

Ditto.

> + ret = s32_regmap_update(pctldev, grp->pin_ids[i],
> + S32_MSCR_SSS_MASK, grp->pin_sss[i]);

Traditional pattern is

if (ret)
return ret;

This avoids first assignment of the ret.

> + }
> +
> + return ret;

return 0;

> +}

...

> + ret = s32_regmap_read(pctldev, offset, &config);
> + if (ret != 0)
> + return -EINVAL;

Why not

if (ret)
return ret;

...

> + list_add(&(gpio_pin->list), &(ipctl->gpio_configs));

Too many parentheses.

...

> + list_for_each_safe(pos, tmp, &ipctl->gpio_configs) {
> + gpio_pin = list_entry(pos, struct gpio_pin_config, list);

Why not list_for_each_entry_safe() ?

> + if (gpio_pin->pin_id == offset) {
> + ret = s32_regmap_write(pctldev, gpio_pin->pin_id,
> + gpio_pin->config);
> + if (ret != 0)
> + goto unlock;
> +
> + list_del(pos);
> + kfree(gpio_pin);
> + break;
> + }
> + }

...

> +static int s32_get_slew_regval(int arg)
> +{
> + int i;

unsigned int i;

+ Blank line.

> + /* Translate a real slew rate (MHz) to a register value */
> + for (i = 0; i < ARRAY_SIZE(support_slew); i++) {
> + if (arg == support_slew[i])
> + return i;
> + }
> +
> + return -EINVAL;
> +}

...

> + case PIN_CONFIG_BIAS_PULL_UP:
> + if (arg)
> + *config |= S32_MSCR_PUS;
> + else
> + *config &= ~S32_MSCR_PUS;

> + fallthrough;

It's quite easy to miss this and tell us about how is it supposed to work with PU + PD?

> + case PIN_CONFIG_BIAS_PULL_DOWN:
> + if (arg)
> + *config |= S32_MSCR_PUE;
> + else
> + *config &= ~S32_MSCR_PUE;
> + *mask |= S32_MSCR_PUE | S32_MSCR_PUS;
> + break;
> + case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
> + *config &= ~(S32_MSCR_ODE | S32_MSCR_OBE | S32_MSCR_IBE);
> + *mask |= S32_MSCR_ODE | S32_MSCR_OBE | S32_MSCR_IBE;
> + fallthrough;

Ditto.

> + case PIN_CONFIG_BIAS_DISABLE:
> + *config &= ~(S32_MSCR_PUS | S32_MSCR_PUE);
> + *mask |= S32_MSCR_PUS | S32_MSCR_PUE;
> + break;

...

> + if (s32_check_pin(pctldev, pin_id) != 0)

Shadowing an error?

> + return -EINVAL;

...

> + ret = s32_regmap_update(pctldev, pin_id, mask, config);
> +
> + dev_dbg(ipctl->dev, "update: pin %d cfg 0x%x\n", pin_id, config);
> +
> + return ret;

You are not using ret in between, hence

return _regmap_update(...);

...

> +static void s32_pinconf_dbg_show(struct pinctrl_dev *pctldev,
> + struct seq_file *s, unsigned int pin_id)
> +{
> + unsigned int config;
> + int ret = s32_regmap_read(pctldev, pin_id, &config);
> +
> + if (!ret)
> + seq_printf(s, "0x%x", config);

int ret;

ret = s32_regmap_read(pctldev, pin_id, &config);
if (ret)
return;

seq_printf(s, "0x%x", config);

> +}

...

> + npins = of_property_count_elems_of_size(np, "pinmux", sizeof(u32));

> +

Unneccessary blank line.

> + if (npins < 0) {
> + dev_err(dev, "Failed to read 'pinmux' property in node %s.\n",
> + np->name);
> + return;
> + }
> + if (!npins) {
> + dev_err(dev, "The group %s has no pins.\n", np->name);
> + return;
> + }

...

> + grp->pin_ids = devm_kcalloc(info->dev, grp->npins,
> + sizeof(unsigned int), GFP_KERNEL);
> + grp->pin_sss = devm_kcalloc(info->dev, grp->npins,
> + sizeof(unsigned int), GFP_KERNEL);

> +

Ditto.

> + if (!grp->pin_ids || !grp->pin_sss) {

> + dev_err(dev, "Failed to allocate memory for the group %s.\n",
> + np->name);

We do not print ENOMEM error messages.

> + return;
> + }

...

> + func->groups = devm_kzalloc(info->dev,
> + func->num_groups * sizeof(char *), GFP_KERNEL);

First of all, this is devm_kcalloc().
Second, where is the error check?

> + for_each_child_of_node(np, child) {
> + func->groups[i] = child->name;
> + grp = &info->groups[info->grp_index++];
> + s32_pinctrl_parse_groups(child, grp, info);
> + i++;
> + }

...

> + ipctl->regions = devm_kzalloc(&pdev->dev,
> + mem_regions * sizeof(*(ipctl->regions)),
> + GFP_KERNEL);

devm_kcalloc()

> + if (!ipctl->regions)
> + return -ENOMEM;

...

> + info->functions = devm_kzalloc(&pdev->dev,
> + nfuncs * sizeof(struct s32_pmx_func),
> + GFP_KERNEL);

Ditto.

> + if (!info->functions)
> + return -ENOMEM;

...

> + info->groups = devm_kzalloc(&pdev->dev,
> + info->ngroups * sizeof(struct s32_pin_group),
> + GFP_KERNEL);

Ditto.

> + if (!info->groups)
> + return -ENOMEM;

...

> + ipctl->pctl = devm_pinctrl_register(&pdev->dev, s32_pinctrl_desc,
> + ipctl);

> +

Unneeded blank line.

> + if (IS_ERR(ipctl->pctl)) {

> + dev_err(&pdev->dev, "could not register s32 pinctrl driver\n");
> + return PTR_ERR(ipctl->pctl);

return dev_err_probe(...);

> + }

...

> diff --git a/drivers/pinctrl/nxp/pinctrl-s32g2.c b/drivers/pinctrl/nxp/pinctrl-s32g2.c

Similar issues has to be addressed, if any.

...

> + return s32_pinctrl_probe
> + (pdev, (struct s32_pinctrl_soc_info *) of_id->data);

Broken indentation.

...

> +static const struct dev_pm_ops s32g_pinctrl_pm_ops = {
> + SET_LATE_SYSTEM_SLEEP_PM_OPS(s32_pinctrl_suspend,
> + s32_pinctrl_resume)
> +};

Consider using DEFINE_* PM macros.

...

> +static struct platform_driver s32g_pinctrl_driver = {
> + .driver = {
> + .name = "s32g-siul2-pinctrl",

> + .owner = THIS_MODULE,

Duplicate assignment.

> + .of_match_table = s32_pinctrl_of_match,
> + .pm = &s32g_pinctrl_pm_ops,
> + .suppress_bind_attrs = true,
> + },
> + .probe = s32g_pinctrl_probe,
> +};

> +

Unnecessary blank line.

> +builtin_platform_driver(s32g_pinctrl_driver);

--
With Best Regards,
Andy Shevchenko