Re: [RFC v7 4/6] gpio: mpfs: add polarfire soc gpio support
From: Linus Walleij
Date: Mon Aug 05 2024 - 04:07:53 EST
On Tue, Jul 23, 2024 at 1:28 PM Conor Dooley <conor.dooley@xxxxxxxxxxxxx> wrote:
> From: Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
>
> Add a driver to support the Polarfire SoC gpio controller
>
> Signed-off-by: Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Just a comment on second thought:
> +config GPIO_POLARFIRE_SOC
> + bool "Microchip FPGA GPIO support"
> + depends on OF_GPIO
> + select GPIOLIB_IRQCHIP
select GPIO_GENERIC?
> +static int mpfs_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio_index)
> +{
> + struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
> + u32 gpio_cfg;
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&mpfs_gpio->lock, flags);
> +
> + gpio_cfg = readl(mpfs_gpio->base + MPFS_GPIO_CTRL(gpio_index));
> + gpio_cfg |= MPFS_GPIO_EN_IN;
> + gpio_cfg &= ~(MPFS_GPIO_EN_OUT | MPFS_GPIO_EN_OUT_BUF);
OK this part is unique...
> +static int mpfs_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio_index, int value)
> +{
> + struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
> + u32 gpio_cfg;
> + unsigned long flags;
> +
> + raw_spin_lock_irqsave(&mpfs_gpio->lock, flags);
> +
> + gpio_cfg = readl(mpfs_gpio->base + MPFS_GPIO_CTRL(gpio_index));
> + gpio_cfg |= MPFS_GPIO_EN_OUT | MPFS_GPIO_EN_OUT_BUF;
Also here
> +static int mpfs_gpio_get_direction(struct gpio_chip *gc,
> + unsigned int gpio_index)
> +static int mpfs_gpio_get(struct gpio_chip *gc,
> + unsigned int gpio_index)
> +static void mpfs_gpio_set(struct gpio_chip *gc, unsigned int gpio_index, int value)
But these are just MMIO functions.
Is it possible to use augmented generic MMIO, i.e just override these
two functions that
need special handling?
Yours,
Linus Walleij