[PATCH v2 08/10] gpio: Add gpio driver for Actions OWL S900 SoC

Andy Shevchenko andy.shevchenko at gmail.com
Wed Feb 21 11:13:53 PST 2018


On Wed, Feb 21, 2018 at 6:00 PM, Manivannan Sadhasivam
<manivannan.sadhasivam at linaro.org> wrote:
> Add gpio driver for Actions Semi OWL family S900 SoC. Set of registers
> controlling the gpio shares the same register range with pinctrl block.
>
> GPIO registers are organized as 6 banks and each bank controls the
> maximum of 32 gpios.

> +static void owl_gpio_set_reg(void __iomem *base, unsigned int pin, int flag)
> +{
> +       u32 val;
> +
> +       if (flag) {
> +               val = readl(base);
> +               val |= BIT(pin);
> +               writel(val, base);
> +       } else {
> +               val = readl(base);
> +               val &= ~BIT(pin);
> +               writel(val, base);
> +       }
> +}

Why not to use the same pattern as below?

readl()
if ()
 ...
else
...
writel()

?

> +static void owl_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
> +{
> +       struct owl_gpio *gpio = gpiochip_get_data(chip);
> +       const struct owl_gpio_port *port = gpio->port;
> +       void __iomem *gpio_base = gpio->base + port->offset;
> +       u32 val;
> +
> +       val = readl(gpio_base + GPIO_DAT);
> +
> +       if (value)
> +               val |= BIT(offset);
> +       else
> +               val &= ~BIT(offset);
> +
> +       writel(val, gpio_base + GPIO_DAT);
> +}


-- 
With Best Regards,
Andy Shevchenko



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