/*
 * linux/arch/arm/mach-ep93xx/gpio.c
 *
 * Generic EP93xx GPIO handling
 *
 * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
 *
 * Based on code originally from:
 *  linux/arch/arm/mach-ep93xx/core.c
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/irq.h>

#include <mach/hardware.h>

struct ep93xx_gpio_chip {
	struct gpio_chip	chip;

	void __iomem		*data_reg;
	void __iomem		*data_dir_reg;
};

#define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)

/* From core.c */
extern void ep93xx_gpio_int_mask(unsigned line);
extern void ep93xx_gpio_update_int_params(unsigned port);

static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
	unsigned long flags;
	u8 v;

	local_irq_save(flags);
	v = __raw_readb(ep93xx_chip->data_dir_reg);
	v &= ~(1 << offset);
	__raw_writeb(v, ep93xx_chip->data_dir_reg);
	local_irq_restore(flags);

	return 0;
}

static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
					unsigned offset, int val)
{
	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
	unsigned long flags;
	int line;
	u8 v;

	local_irq_save(flags);

	/* Set the value */
	v = __raw_readb(ep93xx_chip->data_reg);
	if (val)
		v |= (1 << offset);
	else
		v &= ~(1 << offset);
	__raw_writeb(v, ep93xx_chip->data_reg);

	/* Drive as an output */
	line = chip->base + offset;
	if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
		/* Ports A/B/F */
		ep93xx_gpio_int_mask(line);
		ep93xx_gpio_update_int_params(line >> 3);
	}

	v = __raw_readb(ep93xx_chip->data_dir_reg);
	v |= (1 << offset);
	__raw_writeb(v, ep93xx_chip->data_dir_reg);

	local_irq_restore(flags);

	return 0;
}

static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);

	return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
}

static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
	unsigned long flags;
	u8 v;

	local_irq_save(flags);
	v = __raw_readb(ep93xx_chip->data_reg);
	if (val)
		v |= (1 << offset);
	else
		v &= ~(1 << offset);
	__raw_writeb(v, ep93xx_chip->data_reg);
	local_irq_restore(flags);
}

static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
	u8 data_reg, data_dir_reg;
	int gpio, i;

	data_reg = __raw_readb(ep93xx_chip->data_reg);
	data_dir_reg = __raw_readb(ep93xx_chip->data_dir_reg);

	gpio = ep93xx_chip->chip.base;
	for (i = 0; i < chip->ngpio; i++, gpio++) {
		int is_out = data_dir_reg & (1 << i);

		seq_printf(s, " %s%d gpio-%-3d (%-12s) %s %s",
				chip->label, i, gpio,
				gpiochip_is_requested(chip, i) ? : "",
				is_out ? "out" : "in ",
				(data_reg & (1 << i)) ? "hi" : "lo");

		if (!is_out) {
			int irq = gpio_to_irq(gpio);
			struct irq_desc *desc = irq_desc + irq;

			if (irq >= 0 && desc->action) {
				char *trigger;

				switch (desc->status & IRQ_TYPE_SENSE_MASK) {
				case IRQ_TYPE_NONE:
					trigger = "(default)";
					break;
				case IRQ_TYPE_EDGE_FALLING:
					trigger = "edge-falling";
					break;
				case IRQ_TYPE_EDGE_RISING:
					trigger = "edge-rising";
					break;
				case IRQ_TYPE_EDGE_BOTH:
					trigger = "edge-both";
					break;
				case IRQ_TYPE_LEVEL_HIGH:
					trigger = "level-high";
					break;
				case IRQ_TYPE_LEVEL_LOW:
					trigger = "level-low";
					break;
				default:
					trigger = "?trigger?";
					break;
				}

				seq_printf(s, " irq-%d %s%s",
						irq, trigger,
						(desc->status & IRQ_WAKEUP)
							? " wakeup" : "");
			}
		}

		seq_printf(s, "\n");
	}
}

#define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio)			\
	{								\
		.chip = {						\
			.label		  = name,			\
			.direction_input  = ep93xx_gpio_direction_input, \
			.direction_output = ep93xx_gpio_direction_output, \
			.get		  = ep93xx_gpio_get,		\
			.set		  = ep93xx_gpio_set,		\
			.dbg_show	  = ep93xx_gpio_dbg_show,	\
			.base		  = base_gpio,			\
			.ngpio		  = 8,				\
		},							\
		.data_reg	= EP93XX_GPIO_REG(dr),			\
		.data_dir_reg	= EP93XX_GPIO_REG(ddr),			\
	}

static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
	EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
	EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
	EP93XX_GPIO_BANK("C", 0x08, 0x18, 40),
	EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
	EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
	EP93XX_GPIO_BANK("F", 0x30, 0x34, 16),
	EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
	EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
};

void __init ep93xx_gpio_init(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
		gpiochip_add(&ep93xx_gpio_banks[i].chip);
}