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Commit e92935e1 authored by Roland Stigge's avatar Roland Stigge Committed by Grant Likely
Browse files

gpio/lpc32xx: Add device tree support 



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: default avatarRoland Stigge <stigge@antcom.de>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 3d0f7cf0

Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt

0 → 100644
+43 −0
Original line number Diff line number Diff line 
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";

		};

	};

arch/arm/mach-lpc32xx/include/mach/gpio.h

+8 −1
Original line number Diff line number Diff line 
/* 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 */

drivers/gpio/gpio-lpc32xx.c

+51 −1
Original line number Diff line number Diff line
@@ -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 +457,57 @@ 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)

{

	/* Is this the correct bank? */

	u32 bank = gpiospec->args[0];

	if ((bank > ARRAY_SIZE(lpc32xx_gpiochip) ||

	    (gc != &lpc32xx_gpiochip[bank].chip)))

		return -EINVAL;



	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);