[linux-2.6-block.git] / arch / powerpc / sysdev / simple_gpio.c

/*
 * Simple Memory-Mapped GPIOs
 *
 * Copyright (c) MontaVista Software, Inc. 2008.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <asm/prom.h>
#include "simple_gpio.h"

struct u8_gpio_chip {
	struct of_mm_gpio_chip mm_gc;
	spinlock_t lock;

	/* shadowed data register to clear/set bits safely */
	u8 data;
};

static struct u8_gpio_chip *to_u8_gpio_chip(struct of_mm_gpio_chip *mm_gc)
{
	return container_of(mm_gc, struct u8_gpio_chip, mm_gc);
}

static u8 u8_pin2mask(unsigned int pin)
{
	return 1 << (8 - 1 - pin);
}

static int u8_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	return in_8(mm_gc->regs) & u8_pin2mask(gpio);
}

static void u8_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);
	unsigned long flags;

	spin_lock_irqsave(&u8_gc->lock, flags);

	if (val)
		u8_gc->data |= u8_pin2mask(gpio);
	else
		u8_gc->data &= ~u8_pin2mask(gpio);

	out_8(mm_gc->regs, u8_gc->data);

	spin_unlock_irqrestore(&u8_gc->lock, flags);
}

static int u8_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
	return 0;
}

static int u8_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
	u8_gpio_set(gc, gpio, val);
	return 0;
}

static void u8_gpio_save_regs(struct of_mm_gpio_chip *mm_gc)
{
	struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);

	u8_gc->data = in_8(mm_gc->regs);
}

static int __init u8_simple_gpiochip_add(struct device_node *np)
{
	int ret;
	struct u8_gpio_chip *u8_gc;
	struct of_mm_gpio_chip *mm_gc;
	struct gpio_chip *gc;

	u8_gc = kzalloc(sizeof(*u8_gc), GFP_KERNEL);
	if (!u8_gc)
		return -ENOMEM;

	spin_lock_init(&u8_gc->lock);

	mm_gc = &u8_gc->mm_gc;
	gc = &mm_gc->gc;

	mm_gc->save_regs = u8_gpio_save_regs;
	gc->ngpio = 8;
	gc->direction_input = u8_gpio_dir_in;
	gc->direction_output = u8_gpio_dir_out;
	gc->get = u8_gpio_get;
	gc->set = u8_gpio_set;

	ret = of_mm_gpiochip_add(np, mm_gc);
	if (ret)
		goto err;
	return 0;
err:
	kfree(u8_gc);
	return ret;
}

void __init simple_gpiochip_init(const char *compatible)
{
	struct device_node *np;

	for_each_compatible_node(np, NULL, compatible) {
		int ret;
		struct resource r;

		ret = of_address_to_resource(np, 0, &r);
		if (ret)
			goto err;

		switch (resource_size(&r)) {
		case 1:
			ret = u8_simple_gpiochip_add(np);
			if (ret)
				goto err;
			break;
		default:
			/*
			 * Whenever you need support for GPIO bank width > 1,
			 * please just turn u8_ code into huge macros, and
			 * construct needed uX_ code with it.
			 */
			ret = -ENOSYS;
			goto err;
		}
		continue;
err:
		pr_err("%s: registration failed, status %d\n",
		       np->full_name, ret);
	}
}
Commit	Line	Data
3d64de9c AV	1	/*
	2	* Simple Memory-Mapped GPIOs
	3	*
	4	* Copyright (c) MontaVista Software, Inc. 2008.
	5	*
	6	* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*/
	13
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
3d64de9c AV	16	#include <linux/spinlock.h>
	17	#include <linux/types.h>
	18	#include <linux/ioport.h>
	19	#include <linux/io.h>
	20	#include <linux/of.h>
	21	#include <linux/of_gpio.h>
	22	#include <linux/gpio.h>
5a0e3ad6	23	#include <linux/slab.h>
3d64de9c AV	24	#include <asm/prom.h>
	25	#include "simple_gpio.h"
	26
	27	struct u8_gpio_chip {
	28	struct of_mm_gpio_chip mm_gc;
	29	spinlock_t lock;
	30
	31	/* shadowed data register to clear/set bits safely */
	32	u8 data;
	33	};
	34
	35	static struct u8_gpio_chip to_u8_gpio_chip(struct of_mm_gpio_chip mm_gc)
	36	{
	37	return container_of(mm_gc, struct u8_gpio_chip, mm_gc);
	38	}
	39
	40	static u8 u8_pin2mask(unsigned int pin)
	41	{
	42	return 1 << (8 - 1 - pin);
	43	}
	44
	45	static int u8_gpio_get(struct gpio_chip *gc, unsigned int gpio)
	46	{
	47	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	48
	49	return in_8(mm_gc->regs) & u8_pin2mask(gpio);
	50	}
	51
	52	static void u8_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	53	{
	54	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	55	struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);
	56	unsigned long flags;
	57
	58	spin_lock_irqsave(&u8_gc->lock, flags);
	59
	60	if (val)
	61	u8_gc->data \|= u8_pin2mask(gpio);
	62	else
	63	u8_gc->data &= ~u8_pin2mask(gpio);
	64
	65	out_8(mm_gc->regs, u8_gc->data);
	66
	67	spin_unlock_irqrestore(&u8_gc->lock, flags);
	68	}
	69
	70	static int u8_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
	71	{
	72	return 0;
	73	}
	74
	75	static int u8_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	76	{
	77	u8_gpio_set(gc, gpio, val);
	78	return 0;
	79	}
	80
	81	static void u8_gpio_save_regs(struct of_mm_gpio_chip *mm_gc)
	82	{
	83	struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc);
	84
	85	u8_gc->data = in_8(mm_gc->regs);
	86	}
	87
88	static int __init u8_simple_gpiochip_add(struct device_node *np)
89	{
90	int ret;
91	struct u8_gpio_chip *u8_gc;
92	struct of_mm_gpio_chip *mm_gc;
3d64de9c AV	93	struct gpio_chip *gc;
	94
	95	u8_gc = kzalloc(sizeof(*u8_gc), GFP_KERNEL);
	96	if (!u8_gc)
	97	return -ENOMEM;
	98
	99	spin_lock_init(&u8_gc->lock);
	100
	101	mm_gc = &u8_gc->mm_gc;
a19e3da5	102	gc = &mm_gc->gc;
3d64de9c AV	103
3d64de9c AV	104	mm_gc->save_regs = u8_gpio_save_regs;
3d64de9c AV	105	gc->ngpio = 8;
	106	gc->direction_input = u8_gpio_dir_in;
	107	gc->direction_output = u8_gpio_dir_out;
	108	gc->get = u8_gpio_get;
	109	gc->set = u8_gpio_set;
	110
	111	ret = of_mm_gpiochip_add(np, mm_gc);
	112	if (ret)
	113	goto err;
	114	return 0;
	115	err:
	116	kfree(u8_gc);
	117	return ret;
	118	}
	119
	120	void __init simple_gpiochip_init(const char *compatible)
	121	{
	122	struct device_node *np;
	123
	124	for_each_compatible_node(np, NULL, compatible) {
	125	int ret;
	126	struct resource r;
	127
	128	ret = of_address_to_resource(np, 0, &r);
	129	if (ret)
	130	goto err;
	131
	132	switch (resource_size(&r)) {
	133	case 1:
	134	ret = u8_simple_gpiochip_add(np);
	135	if (ret)
	136	goto err;
	137	break;
	138	default:
	139	/*
	140	* Whenever you need support for GPIO bank width > 1,
	141	* please just turn u8_ code into huge macros, and
	142	* construct needed uX_ code with it.
	143	*/
	144	ret = -ENOSYS;
	145	goto err;
	146	}
	147	continue;
	148	err:
	149	pr_err("%s: registration failed, status %d\n",
	150	np->full_name, ret);
	151	}
	152	}