Re: [PATCH v6 3/3] pinctrl: nuvoton: Add ma35d1 pinctrl and GPIO driver

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Dear Linus,

Thanks for your review.


On 2024/3/28 下午 05:10, Linus Walleij wrote:
Hi Jacky,

overall this looks very good.

On Wed, Mar 13, 2024 at 4:57 AM Jacky Huang <ychuang570808@xxxxxxxxx> wrote:


From: Jacky Huang <ychuang3@xxxxxxxxxxx>

Add common pinctrl and GPIO driver for Nuvoton MA35 series SoC, and
add support for ma35d1 pinctrl.

Signed-off-by: Jacky Huang <ychuang3@xxxxxxxxxxx>
(...)
+static int ma35_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int selector,
+                              unsigned int group)
+{
+       struct ma35_pinctrl *npctl = pinctrl_dev_get_drvdata(pctldev);
+       struct ma35_pin_group *grp = &npctl->groups[group];
+       struct ma35_pin_setting *setting = grp->settings;
+       u32 i, regval;
+
+       dev_dbg(npctl->dev, "enable function %s group %s\n",
+               npctl->functions[selector].name, npctl->groups[group].name);
+
+       for (i = 0; i < grp->npins; i++) {
+               regmap_read(npctl->regmap, setting->offset, &regval);
+               regval &= ~GENMASK(setting->shift + 3, setting->shift);
Add a comment explaining why you add +3

The pinmux selection is 4 bits. I will use a constant for the bitmask width instead.


+static int ma35_gpio_core_direction_in(struct gpio_chip *gc, unsigned int gpio)
+{
+       struct ma35_pin_bank *bank = gpiochip_get_data(gc);
+       void __iomem *reg_mode = bank->reg_base + MA35_GP_REG_MODE;
+       unsigned long flags;
+       unsigned int regval;
+
+       spin_lock_irqsave(&bank->lock, flags);
+
+       regval = readl(reg_mode);
+       regval &= ~GENMASK(gpio * 2 + 1, gpio * 2);
+       regval |= MA35_GP_MODE_INPUT << gpio * 2;
Here the first time you do this magic explain in a comment why you
use *2+1 and *2 overall (I guess two bits per line).

Yes, it is two bits per pin. I will add a comment to explain this.

+static int ma35_gpio_core_get(struct gpio_chip *gc, unsigned int gpio)
+{
+       struct ma35_pin_bank *bank = gpiochip_get_data(gc);
+
+       return readl(bank->reg_base + MA35_PIN_MAP_BASE + gpio * 4);
Here add a comment explaining the *4
I guess one 32-bit register per pin?

Yes, it maps one 32-bit register to a gpio pin.
I will add a comment to explain this.

+static int ma35_irq_irqtype(struct irq_data *d, unsigned int type)
+{
+       struct ma35_pin_bank *bank = gpiochip_get_data(irq_data_get_irq_chip_data(d));
+       void __iomem *reg_itype = bank->reg_base + MA35_GP_REG_INTTYPE;
+       void __iomem *reg_ien = bank->reg_base + MA35_GP_REG_INTEN;
+       unsigned int num = (d->hwirq);
+
+       if (type == IRQ_TYPE_PROBE) {
+               writel(readl(reg_itype) & ~BIT(num), reg_itype);
+               writel(readl(reg_ien) | BIT(num) | BIT(num + 16), reg_ien);
+               bank->irqtype &= ~BIT(num);
+               bank->irqinten |= BIT(num) | BIT(num + 16);
+               return 0;
+       }
+
+       if (type & IRQ_TYPE_LEVEL_MASK) {
+               writel(readl(reg_itype) | BIT(num), reg_itype);
+               writel(readl(reg_ien) & ~(BIT(num) | BIT(num + 16)), reg_ien);
+               bank->irqtype |= BIT(num);
+               bank->irqinten &= ~(BIT(num) | BIT(num + 16));
+               if (type == IRQ_TYPE_LEVEL_HIGH) {
+                       writel(readl(reg_ien) | BIT(num + 16), reg_ien);
+                       bank->irqinten |= BIT(num + 16);
+                       return 0;
+               }
+
+               if (type == IRQ_TYPE_LEVEL_LOW) {
+                       writel(readl(reg_ien) | BIT(num), reg_ien);
+                       bank->irqinten |= BIT(num);
+                       return 0;
+               }
+
+       } else {
+               writel(readl(reg_itype) & ~BIT(num), reg_itype);
+               bank->irqtype &= ~BIT(num);
+
+               if (type & IRQ_TYPE_EDGE_RISING) {
+                       writel(readl(reg_ien) | BIT(num + 16), reg_ien);
+                       bank->irqinten |= BIT(num + 16);
+
+               } else {
+                       writel(readl(reg_ien) & ~BIT(num + 16), reg_ien);
+                       bank->irqinten &= ~BIT(num + 16);
+               }
+
+               if (type & IRQ_TYPE_EDGE_FALLING) {
+                       writel(readl(reg_ien) | BIT(num), reg_ien);
+                       bank->irqinten |= BIT(num);
+
+               } else {
+                       writel(readl(reg_ien) & ~BIT(num), reg_ien);
+                       bank->irqinten &= ~BIT(num);
+               }
+       }
+       return 0;
+}
I don't understand why you don't set the irq_handler:
irq_set_handler_locked(d, handle_edge_irq);
irq_set_handler_locked(d, handle_level_irq);

I will add the irq_set_handler_locked().
It seems you are not handling IRQ_TYPE_EDGE_BOTH?
What happens if both rising and falling is specified simultaneously?

The if/else nesting is hard to read.
switch (type) {
         case IRQ_TYPE_EDGE_BOTH:
(...)
         case IRQ_TYPE_EDGE_RISING:
(...)

See drivers/gpio/gpio-ftgpio010.c for an example.

We'll refer to this driver to modify our code.

Have you checked that handling edge and level IRQs really work
as expected?

This driver works with edge or level IRQs in linux-5.10, and some modifications
have been made for upstream. We'll verify if it also works in linux-6.9.

+static int ma35_gpiolib_register(struct platform_device *pdev, struct ma35_pinctrl *npctl)
+{
+       struct ma35_pin_ctrl *ctrl = npctl->ctrl;
+       struct ma35_pin_bank *bank = ctrl->pin_banks;
+       int ret;
+       int i;
+
+       for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
+               if (!bank->valid) {
+                       dev_warn(&pdev->dev, "bank %s is not valid\n",
+                                bank->np->name);
+                       continue;
+               }
+               bank->irqtype = 0;
+               bank->irqinten = 0;
+               bank->chip.label = bank->name;
+               bank->chip.of_gpio_n_cells = 2;
+               bank->chip.parent = &pdev->dev;
+               bank->chip.request = ma35_gpio_core_to_request;
+               bank->chip.direction_input = ma35_gpio_core_direction_in;
+               bank->chip.direction_output = ma35_gpio_core_direction_out;
+               bank->chip.get = ma35_gpio_core_get;
+               bank->chip.set = ma35_gpio_core_set;
+               bank->chip.base = -1;
+               bank->chip.ngpio = bank->nr_pins;
+               bank->chip.can_sleep = false;
+               spin_lock_init(&bank->lock);
+
+               if (bank->irq > 0) {
+                       struct gpio_irq_chip *girq;
+
+                       girq = &bank->chip.irq;
+                       gpio_irq_chip_set_chip(girq, &ma35_gpio_irqchip);
+                       girq->parent_handler = ma35_irq_demux_intgroup;
+                       girq->num_parents = 1;
+
+                       girq->parents = devm_kcalloc(&pdev->dev, 1, sizeof(*girq->parents),
+                                                    GFP_KERNEL);
+                       if (!girq->parents)
+                               return -ENOMEM;
+
+                       girq->parents[0] = bank->irq;
+                       girq->default_type = IRQ_TYPE_NONE;
+                       girq->handler = handle_level_irq;
Does this really work for the edge IRQs?

I recommend setting this to handle_bad_irq and assign the right
handler in .set_type().

Yours,
Linus Walleij

OK, I will fix it.


Best Regards,
Jacky Huang








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