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    Subject[PATCH v2] gpio: Device tree support for LPC32xx
    Date
    This patch adds device tree support for gpio-lpc32xx.c

    Signed-off-by: Roland Stigge <stigge@antcom.de>

    ---

    Applies to v3.4-rc1

    Changes since last version:
    * Documented property #address-cells (always 1)
    * Documented property status="disabled"
    * Removed gpio-lines property
    * Removed #gpio-cells from the parent node
    * Support both DT and non-DT to make patch less disruptive and independent
    from DT switch of mach-lpc32xx
    * Use module_platform_driver()

    Thanks to Arnd Bergmann and Grant Likely for reviewing!

    Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt | 65 ++++++++++++++++
    arch/arm/mach-lpc32xx/include/mach/gpio.h | 9 +-
    drivers/gpio/gpio-lpc32xx.c | 52 ++++++++++++
    3 files changed, 123 insertions(+), 3 deletions(-)

    --- /dev/null
    +++ linux-2.6/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
    @@ -0,0 +1,65 @@
    +NXP LPC32xx SoC GPIO controller
    +
    +Required properties:
    +- compatible: "nxp,lpc32xx-gpio"
    +- reg: Physical base address and length of the controller's registers.
    +- #address-cells: Always 1, for indexing of the subnodes (GPIO groups of the
    + SoC)
    +- #size-cells: Always 0
    +
    +Required properties of sub-nodes which describe the GPIO groups of LPC32xx:
    +- gpio-controller: Marks the device node as a GPIO controller.
    +- #gpio-cells: Should be two. The first cell is the pin number and the
    + second cell is used to specify optional parameters:
    + - bit 0 specifies polarity (0 for normal, 1 for inverted)
    +- reg: Index of the GPIO group
    +
    +Optional properties of sub-nodes which describe the GPIO groups of LPC32xx:
    +- status: Set to "disabled" if you don't use the respective GPIO group
    + of the LPC32 SoC
    +
    +Example:
    +
    + gpio: gpio@40028000 {
    + compatible = "nxp,lpc32xx-gpio";
    + reg = <0x40028000 0x1000>;
    + /* create a private address space for enumeration */
    + #address-cells = <1>;
    + #size-cells = <0>;
    +
    + gpio_p0: gpio-bank@0 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <0>;
    + };
    +
    + gpio_p1: gpio-bank@1 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <1>;
    + };
    +
    + gpio_p2: gpio-bank@2 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <2>;
    + };
    +
    + gpio_p3: gpio-bank@3 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <3>;
    + };
    +
    + gpi_p3: gpio-bank@4 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <4>;
    + };
    +
    + gpo_p3: gpio-bank@5 {
    + gpio-controller;
    + #gpio-cells = <2>;
    + reg = <5>;
    + };
    + };
    --- linux-2.6.orig/arch/arm/mach-lpc32xx/include/mach/gpio.h
    +++ linux-2.6/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 */
    --- linux-2.6.orig/drivers/gpio/gpio-lpc32xx.c
    +++ linux-2.6/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 +457,55 @@ static struct lpc32xx_gpio_chip lpc32xx_
    },
    };

    +/* Empty now, can be removed later when mach-lpc32xx is finally switched over
    + * to DT support
    + */
    void __init lpc32xx_gpio_init(void)
    {
    +}
    +
    +static int __devinit lpc32xx_gpio_probe(struct platform_device *pdev)
    +{
    + struct device_node *node;
    int i;

    - for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
    - gpiochip_add(&lpc32xx_gpiochip[i].chip);
    + if (pdev->dev.of_node) {
    + for_each_child_of_node(pdev->dev.of_node, node) {
    + if (of_device_is_available(node)) {
    + u32 index;
    + struct gpio_chip *chip;
    + if (of_property_read_u32(node,
    + "reg", &index) < 0)
    + continue;
    + if (index >= ARRAY_SIZE(lpc32xx_gpiochip))
    + continue;
    + chip = &lpc32xx_gpiochip[index].chip;
    + chip->of_node = of_node_get(node);
    + gpiochip_add(chip);
    + }
    + }
    + } else {
    + for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
    + gpiochip_add(&lpc32xx_gpiochip[i].chip);
    + }
    +
    + return 0;
    }
    +
    +#ifdef CONFIG_OF
    +static struct of_device_id lpc32xx_gpio_of_match[] __devinitdata = {
    + { .compatible = "nxp,lpc32xx-gpio", },
    + { },
    +};
    +#endif
    +
    +static struct platform_driver lpc32xx_gpio_driver = {
    + .driver = {
    + .name = "lpc32xx-gpio",
    + .owner = THIS_MODULE,
    + .of_match_table = lpc32xx_gpio_of_match,
    + },
    + .probe = lpc32xx_gpio_probe,
    +};
    +
    +module_platform_driver(lpc32xx_gpio_driver);

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