[U-Boot] [PATCH 1/3] bcm2835_gpio: Add support for pinmux

[Simon Glass]

Hi Alex,

On 16 January 2018 at 05:46, Alexander Graf <agraf at suse.de> wrote:
> On the bcm2835 the GPIO IP block is responsible to control pin muxing
> of the configurable pins on the chip.
>
> This adds a simple helper function that allows a device driver to set
> pin muxing according to device tree configuration on those devices.
>
> Signed-off-by: Alexander Graf <agraf at suse.de>
> ---
>  arch/arm/mach-bcm283x/include/mach/gpio.h |  1 +
>  drivers/gpio/bcm2835_gpio.c               | 40 +++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
>
> diff --git a/arch/arm/mach-bcm283x/include/mach/gpio.h b/arch/arm/mach-bcm283x/include/mach/gpio.h
> index daaee52f81..751594d09f 100644
> --- a/arch/arm/mach-bcm283x/include/mach/gpio.h
> +++ b/arch/arm/mach-bcm283x/include/mach/gpio.h
> @@ -62,5 +62,6 @@ struct bcm2835_gpio_platdata {
>  };
>
>  int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio);
> +void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle);
>
>  #endif /* _BCM2835_GPIO_H_ */
> diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c
> index beaa21853a..209cbed9e6 100644
> --- a/drivers/gpio/bcm2835_gpio.c
> +++ b/drivers/gpio/bcm2835_gpio.c
> @@ -83,6 +83,46 @@ int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio)
>         return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
>  }
>
> +static void bcm2835_gpio_set_func_id(struct udevice *dev, unsigned gpio, int func)
> +{
> +       struct bcm2835_gpios *gpios = dev_get_priv(dev);
> +       u32 val;
> +
> +       val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> +       val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       val |= (func << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> +}
> +
> +void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle)
> +{
> +       int node = fdt_node_offset_by_phandle(gd->fdt_blob, handle);
> +       u32 pins[16];
> +       int len;
> +       u32 func;
> +       int i;
> +
> +       if (!node)
> +               goto err;
> +
> +       func = fdtdec_get_int(gd->fdt_blob, node, "brcm,function", -1);
> +       if (func <= 0)
> +               goto err;
> +
> +       len = fdtdec_get_int_array_count(gd->fdt_blob, node, "brcm,pins", pins,
> +                                        ARRAY_SIZE(pins));
> +       if (len <= 0)
> +               goto err;
> +
> +       for (i = 0; i < len; i++)
> +               bcm2835_gpio_set_func_id(dev, pins[i], func);
> +
> +       return;
> +err:
> +       printf("Failed to pinmux phandle 0x%x\n", handle);
> +       return;
> +}

This should use livetree functions and I'm pretty sure it should go in
a pinctrl driver, not GPIO.

> +
>  static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
>  {
>         int funcid = bcm2835_gpio_get_func_id(dev, offset);
> --
> 2.12.3
>

Regards,
Simon