Re: [PATCH 2/3] gpio/lpc32xx: Add device tree support

[Grant Likely]

On Thu, May 17, 2012 at 2:04 PM, Grant Likely <grant.likely@xxxxxxxxxxxx> wrote:
> From: Roland Stigge <stigge@xxxxxxxxx>
>
> This patch adds device tree support for gpio-lpc32xx.c.
>
> To register the various GPIO banks as (struct) gpio_chips via the same DT
> gpio-controller, we utilize the adjusted of_xlate API to manipulate the
> actually used struct gpio_chip.
>
> Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>
> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxxxx>

Hi Roland,

This is only a repost of your patch unchanged.  I've separated my
changes out into patch three so you can review them.

g.

> ---
>  .../devicetree/bindings/gpio/gpio_lpc32xx.txt      |   43 +++++++++++++++
>  arch/arm/mach-lpc32xx/include/mach/gpio.h          |    9 +++-
>  drivers/gpio/gpio-lpc32xx.c                        |   55 +++++++++++++++++++-
>  3 files changed, 105 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt b/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
> new file mode 100644
> index 0000000..4981936
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
> @@ -0,0 +1,43 @@
> +NXP LPC32xx SoC GPIO controller
> +
> +Required properties:
> +- compatible: must be "nxp,lpc3220-gpio"
> +- reg: Physical base address and length of the controller's registers.
> +- gpio-controller: Marks the device node as a GPIO controller.
> +- #gpio-cells: Should be 3:
> +   1) bank:
> +      0: GPIO P0
> +      1: GPIO P1
> +      2: GPIO P2
> +      3: GPIO P3
> +      4: GPI P3
> +      5: GPO P3
> +   2) pin number
> +   3) optional parameters:
> +      - bit 0 specifies polarity (0 for normal, 1 for inverted)
> +- reg: Index of the GPIO group
> +
> +Example:
> +
> +       gpio: gpio@40028000 {
> +               compatible = "nxp,lpc3220-gpio";
> +               reg = <0x40028000 0x1000>;
> +               gpio-controller;
> +               #gpio-cells = <3>; /* bank, pin, flags */
> +       };
> +
> +       leds {
> +               compatible = "gpio-leds";
> +
> +               led0 {
> +                       gpios = <&gpio 5 1 1>; /* GPO_P3 1, active low */
> +                       linux,default-trigger = "heartbeat";
> +                       default-state = "off";
> +               };
> +
> +               led1 {
> +                       gpios = <&gpio 5 14 1>; /* GPO_P3 14, active low */
> +                       linux,default-trigger = "timer";
> +                       default-state = "off";
> +               };
> +       };
> diff --git a/arch/arm/mach-lpc32xx/include/mach/gpio.h b/arch/arm/mach-lpc32xx/include/mach/gpio.h
> index 40a8c17..2ba6ca4 100644
> --- a/arch/arm/mach-lpc32xx/include/mach/gpio.h
> +++ b/arch/arm/mach-lpc32xx/include/mach/gpio.h
> @@ -1 +1,8 @@
> -/* empty */
> +#ifndef __MACH_GPIO_H
> +#define __MACH_GPIO_H
> +
> +#include "gpio-lpc32xx.h"
> +
> +#define ARCH_NR_GPIOS (LPC32XX_GPO_P3_GRP + LPC32XX_GPO_P3_MAX)
> +
> +#endif /* __MACH_GPIO_H */
> diff --git a/drivers/gpio/gpio-lpc32xx.c b/drivers/gpio/gpio-lpc32xx.c
> index 61c2d08..d42bf6c 100644
> --- a/drivers/gpio/gpio-lpc32xx.c
> +++ b/drivers/gpio/gpio-lpc32xx.c
> @@ -21,6 +21,9 @@
>  #include <linux/io.h>
>  #include <linux/errno.h>
>  #include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/module.h>
>
>  #include <mach/hardware.h>
>  #include <mach/platform.h>
> @@ -454,10 +457,60 @@ static struct lpc32xx_gpio_chip lpc32xx_gpiochip[] = {
>        },
>  };
>
> +/* Empty now, can be removed later when mach-lpc32xx is finally switched over
> + * to DT support
> + */
>  void __init lpc32xx_gpio_init(void)
>  {
> +}
> +
> +static int lpc32xx_of_xlate(struct gpio_chip **gc,
> +                           const struct of_phandle_args *gpiospec, u32 *flags)
> +{
> +       u32 bank;
> +       if (WARN_ON(gpiospec->args_count < 3))
> +               return -EINVAL;
> +
> +       bank = gpiospec->args[0];
> +       if (WARN_ON(bank > 5))
> +               return -EINVAL;
> +
> +       *gc = &lpc32xx_gpiochip[bank].chip;
> +       if (flags)
> +               *flags = gpiospec->args[2];
> +       return gpiospec->args[1];
> +}
> +
> +static int __devinit lpc32xx_gpio_probe(struct platform_device *pdev)
> +{
>        int i;
>
> -       for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
> +       for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++) {
> +               if (pdev->dev.of_node) {
> +                       lpc32xx_gpiochip[i].chip.of_xlate = lpc32xx_of_xlate;
> +                       lpc32xx_gpiochip[i].chip.of_gpio_n_cells = 3;
> +                       lpc32xx_gpiochip[i].chip.of_node = pdev->dev.of_node;
> +               }
>                gpiochip_add(&lpc32xx_gpiochip[i].chip);
> +       }
> +
> +       return 0;
>  }
> +
> +#ifdef CONFIG_OF
> +static struct of_device_id lpc32xx_gpio_of_match[] __devinitdata = {
> +       { .compatible = "nxp,lpc3220-gpio", },
> +       { },
> +};
> +#endif
> +
> +static struct platform_driver lpc32xx_gpio_driver = {
> +       .driver         = {
> +               .name   = "lpc32xx-gpio",
> +               .owner  = THIS_MODULE,
> +               .of_match_table = of_match_ptr(lpc32xx_gpio_of_match),
> +       },
> +       .probe          = lpc32xx_gpio_probe,
> +};
> +
> +module_platform_driver(lpc32xx_gpio_driver);
> --
> 1.7.9.5
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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