path: root/arch/arm/mach-at91/gpio.c

/*
 * linux/arch/arm/mach-at91/gpio.c
 *
 * Copyright (C) 2005 HP Labs
 *
 * 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/clk.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>

#include <mach/hardware.h>
#include <mach/at91_pio.h>

#include "generic.h"

struct at91_gpio_chip {
	struct gpio_chip	chip;
	struct at91_gpio_chip	*next;		/* Bank sharing same clock */
	int			pioc_hwirq;	/* PIO bank interrupt identifier on AIC */
	int			pioc_virq;	/* PIO bank Linux virtual interrupt */
	int			pioc_idx;	/* PIO bank index */
	void __iomem		*regbase;	/* PIO bank virtual address */
	struct clk		*clock;		/* associated clock */
	struct irq_domain	*domain;	/* associated irq domain */
};

#define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)

static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
static int at91_gpiolib_direction_output(struct gpio_chip *chip,
					 unsigned offset, int val);
static int at91_gpiolib_direction_input(struct gpio_chip *chip,
					unsigned offset);
static int at91_gpiolib_to_irq(struct gpio_chip *chip, unsigned offset);

#define AT91_GPIO_CHIP(name, nr_gpio)					\
	{								\
		.chip = {						\
			.label		  = name,			\
			.direction_input  = at91_gpiolib_direction_input, \
			.direction_output = at91_gpiolib_direction_output, \
			.get		  = at91_gpiolib_get,		\
			.set		  = at91_gpiolib_set,		\
			.dbg_show	  = at91_gpiolib_dbg_show,	\
			.to_irq		  = at91_gpiolib_to_irq,	\
			.ngpio		  = nr_gpio,			\
		},							\
	}

static struct at91_gpio_chip gpio_chip[] = {
	AT91_GPIO_CHIP("pioA", 32),
	AT91_GPIO_CHIP("pioB", 32),
	AT91_GPIO_CHIP("pioC", 32),
	AT91_GPIO_CHIP("pioD", 32),
	AT91_GPIO_CHIP("pioE", 32),
};

static int gpio_banks;
static unsigned long at91_gpio_caps;

/* All PIO controllers support PIO3 features */
#define AT91_GPIO_CAP_PIO3	(1 <<  0)

#define has_pio3()	(at91_gpio_caps & AT91_GPIO_CAP_PIO3)

/*--------------------------------------------------------------------------*/

static inline void __iomem *pin_to_controller(unsigned pin)
{
	pin /= 32;
	if (likely(pin < gpio_banks))
		return gpio_chip[pin].regbase;

	return NULL;
}

static inline unsigned pin_to_mask(unsigned pin)
{
	return 1 << (pin % 32);
}


static char peripheral_function(void __iomem *pio, unsigned mask)
{
	char	ret = 'X';
	u8	select;

	if (pio) {
		if (has_pio3()) {
			select = !!(__raw_readl(pio + PIO_ABCDSR1) & mask);
			select |= (!!(__raw_readl(pio + PIO_ABCDSR2) & mask) << 1);
			ret = 'A' + select;
		} else {
			ret = __raw_readl(pio + PIO_ABSR) & mask ?
							'B' : 'A';
		}
	}

	return ret;
}

/*--------------------------------------------------------------------------*/

/* Not all hardware capabilities are exposed through these calls; they
 * only encapsulate the most common features and modes.  (So if you
 * want to change signals in groups, do it directly.)
 *
 * Bootloaders will usually handle some of the pin multiplexing setup.
 * The intent is certainly that by the time Linux is fully booted, all
 * pins should have been fully initialized.  These setup calls should
 * only be used by board setup routines, or possibly in driver probe().
 *
 * For bootloaders doing all that setup, these calls could be inlined
 * as NOPs so Linux won't duplicate any setup code
 */


/*
 * mux the pin to the "GPIO" peripheral role.
 */
int __init_or_module at91_set_GPIO_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -