Re: [PATCH 10/10] pinctrl: Add AXP192 pin control driver
From: Andy Shevchenko
Date: Wed Jun 15 2022 - 10:52:45 EST
On Fri, Jun 3, 2022 at 6:29 PM Aidan MacDonald
<aidanmacdonald.0x0@xxxxxxxxx> wrote:
>
> The AXP192 PMIC's GPIO registers are much different from the GPIO
> registers of the AXP20x and AXP813 PMICs supported by the existing
> pinctrl-axp209 driver. It makes more sense to add a new driver for
> the AXP192, rather than add support in the existing axp20x driver.
>
> The pinctrl-axp192 driver is considerably more flexible in terms of
> register layout and should be able to support other X-Powers PMICs.
> Interrupts and pull down resistor configuration are supported too.
Thank you for contribution, overall looks good, below some not very
critical comments.
...
> +static const struct axp192_pctl_reg_info axp192_pin_ctrl_regs[] = {
> + { .reg = AXP192_GPIO0_CTRL, .mask = 0x07 },
> + { .reg = AXP192_GPIO1_CTRL, .mask = 0x07 },
> + { .reg = AXP192_GPIO2_CTRL, .mask = 0x07 },
> + { .reg = AXP192_GPIO4_3_CTRL, .mask = 0x03 },
> + { .reg = AXP192_GPIO4_3_CTRL, .mask = 0x0c },
> + { .reg = AXP192_N_RSTO_CTRL, .mask = 0xc0 },
> +};
GENMASK()
...
> + if ((val & reginfo->mask) == (input_muxvals[offset] << (ffs(reginfo->mask) - 1)))
> + return GPIO_LINE_DIRECTION_IN;
> + else
Redundant.
Also applies for the other similar cases in your code. Note, this is
also redundant for 'continue' and 'break' in case of loops.
> + return GPIO_LINE_DIRECTION_OUT;
...
> + if (!reginfo->mask)
> + return -EOPNOTSUPP;
Please, double check that this is used by the pin control subsystem
and not ENOTSUP in your case here.
...
> + default:
> + return -EOPNOTSUPP;
Ditto.
...
> + default:
> + return -EOPNOTSUPP;
Ditto.
...
> + default:
> + /* unreachable */
> + break;
return 0?! Perhaps you need to return an error?
> + }
> + }
> +
> + return 0;
...
> + if (muxvals[group] == (u8)-1)
limits.h and U8_MAX? Or GENMASK()? Choose one which suits you.
> + return -EINVAL;
...
> + if (!of_device_is_available(pdev->dev.of_node))
> + return -ENODEV;
Dead code.
> + if (!axp20x) {
> + dev_err(&pdev->dev, "Parent drvdata not set\n");
> + return -EINVAL;
> + }
Another useless piece of code.
...
> + pctl->desc = of_device_get_match_data(&pdev->dev);
device_get_match_data()
...
> + pctl->chip.to_irq = axp192_gpio_to_irq;
Why a custom method?
...
> + pctl->pctl_dev = devm_pinctrl_register(&pdev->dev, pctrl_desc, pctl);
> + if (IS_ERR(pctl->pctl_dev)) {
> + dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
> + return PTR_ERR(pctl->pctl_dev);
Here and everywhere else in ->probe() and Co, use
return dev_err_probe(...);
pattern.
> + }
...
> + ret = gpiochip_add_pin_range(&pctl->chip, dev_name(&pdev->dev),
> + pctl->desc->pins->number,
> + pctl->desc->pins->number,
> + pctl->desc->npins);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to add pin range\n");
> + return ret;
> + }
We have a specific callback where you may put this, otherwise on some
systems it may not work as expected.
...
> + dev_info(&pdev->dev, "AXP192 pinctrl and GPIO driver loaded\n");
Useless.
...
> +static struct platform_driver axp192_pctl_driver = {
> + .probe = axp192_pctl_probe,
> + .driver = {
> + .name = "axp192-gpio",
> + .of_match_table = axp192_pctl_match,
> + },
> +};
> +
Redundant blank line.
> +module_platform_driver(axp192_pctl_driver);
...
Globally two comments:
1) I also believe that you may utilize gpio-regmap API;
2) try to get rid of OFisms, make it property provider agnostic.
--
With Best Regards,
Andy Shevchenko