1/*
  2 * Gemini gpiochip and interrupt routines
  3 *
  4 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
  5 *
  6 * Based on plat-mxc/gpio.c:
  7 *  MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
  8 *  Copyright 2008 Juergen Beisert, kernel@pengutronix.de
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License as published by
 12 * the Free Software Foundation; either version 2 of the License, or
 13 * (at your option) any later version.
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/init.h>
 18#include <linux/io.h>
 19#include <linux/irq.h>
 20#include <linux/gpio.h>
 21
 22#include <mach/hardware.h>
 23#include <mach/irqs.h>
 24
 25#define GPIO_BASE(x)		IO_ADDRESS(GEMINI_GPIO_BASE(x))
 26
 27/* GPIO registers definition */
 28#define GPIO_DATA_OUT		0x0
 29#define GPIO_DATA_IN		0x4
 30#define GPIO_DIR		0x8
 31#define GPIO_DATA_SET		0x10
 32#define GPIO_DATA_CLR		0x14
 33#define GPIO_PULL_EN		0x18
 34#define GPIO_PULL_TYPE		0x1C
 35#define GPIO_INT_EN		0x20
 36#define GPIO_INT_STAT		0x24
 37#define GPIO_INT_MASK		0x2C
 38#define GPIO_INT_CLR		0x30
 39#define GPIO_INT_TYPE		0x34
 40#define GPIO_INT_BOTH_EDGE	0x38
 41#define GPIO_INT_LEVEL		0x3C
 42#define GPIO_DEBOUNCE_EN	0x40
 43#define GPIO_DEBOUNCE_PRESCALE	0x44
 44
 45#define GPIO_PORT_NUM		3
 46
 47static void _set_gpio_irqenable(unsigned int base, unsigned int index,
 48				int enable)
 49{
 50	unsigned int reg;
 51
 52	reg = __raw_readl(base + GPIO_INT_EN);
 53	reg = (reg & (~(1 << index))) | (!!enable << index);
 54	__raw_writel(reg, base + GPIO_INT_EN);
 55}
 56
 57static void gpio_ack_irq(struct irq_data *d)
 58{
 59	unsigned int gpio = irq_to_gpio(d->irq);
 60	unsigned int base = GPIO_BASE(gpio / 32);
 61
 62	__raw_writel(1 << (gpio % 32), base + GPIO_INT_CLR);
 63}
 64
 65static void gpio_mask_irq(struct irq_data *d)
 66{
 67	unsigned int gpio = irq_to_gpio(d->irq);
 68	unsigned int base = GPIO_BASE(gpio / 32);
 69
 70	_set_gpio_irqenable(base, gpio % 32, 0);
 71}
 72
 73static void gpio_unmask_irq(struct irq_data *d)
 74{
 75	unsigned int gpio = irq_to_gpio(d->irq);
 76	unsigned int base = GPIO_BASE(gpio / 32);
 77
 78	_set_gpio_irqenable(base, gpio % 32, 1);
 79}
 80
 81static int gpio_set_irq_type(struct irq_data *d, unsigned int type)
 82{
 83	unsigned int gpio = irq_to_gpio(d->irq);
 84	unsigned int gpio_mask = 1 << (gpio % 32);
 85	unsigned int base = GPIO_BASE(gpio / 32);
 86	unsigned int reg_both, reg_level, reg_type;
 87
 88	reg_type = __raw_readl(base + GPIO_INT_TYPE);
 89	reg_level = __raw_readl(base + GPIO_INT_LEVEL);
 90	reg_both = __raw_readl(base + GPIO_INT_BOTH_EDGE);
 91
 92	switch (type) {
 93	case IRQ_TYPE_EDGE_BOTH:
 94		reg_type &= ~gpio_mask;
 95		reg_both |= gpio_mask;
 96		break;
 97	case IRQ_TYPE_EDGE_RISING:
 98		reg_type &= ~gpio_mask;
 99		reg_both &= ~gpio_mask;
100		reg_level &= ~gpio_mask;
101		break;
102	case IRQ_TYPE_EDGE_FALLING:
103		reg_type &= ~gpio_mask;
104		reg_both &= ~gpio_mask;
105		reg_level |= gpio_mask;
106		break;
107	case IRQ_TYPE_LEVEL_HIGH:
108		reg_type |= gpio_mask;
109		reg_level &= ~gpio_mask;
110		break;
111	case IRQ_TYPE_LEVEL_LOW:
112		reg_type |= gpio_mask;
113		reg_level |= gpio_mask;
114		break;
115	default:
116		return -EINVAL;
117	}
118
119	__raw_writel(reg_type, base + GPIO_INT_TYPE);
120	__raw_writel(reg_level, base + GPIO_INT_LEVEL);
121	__raw_writel(reg_both, base + GPIO_INT_BOTH_EDGE);
122
123	gpio_ack_irq(d->irq);
124
125	return 0;
126}
127
128static void gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
129{
130	unsigned int port = (unsigned int)irq_desc_get_handler_data(desc);
131	unsigned int gpio_irq_no, irq_stat;
132
133	irq_stat = __raw_readl(GPIO_BASE(port) + GPIO_INT_STAT);
134
135	gpio_irq_no = GPIO_IRQ_BASE + port * 32;
136	for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
137
138		if ((irq_stat & 1) == 0)
139			continue;
140
141		generic_handle_irq(gpio_irq_no);
142	}
143}
144
145static struct irq_chip gpio_irq_chip = {
146	.name = "GPIO",
147	.irq_ack = gpio_ack_irq,
148	.irq_mask = gpio_mask_irq,
149	.irq_unmask = gpio_unmask_irq,
150	.irq_set_type = gpio_set_irq_type,
151};
152
153static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
154				int dir)
155{
156	unsigned int base = GPIO_BASE(offset / 32);
157	unsigned int reg;
158
159	reg = __raw_readl(base + GPIO_DIR);
160	if (dir)
161		reg |= 1 << (offset % 32);
162	else
163		reg &= ~(1 << (offset % 32));
164	__raw_writel(reg, base + GPIO_DIR);
165}
166
167static void gemini_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
168{
169	unsigned int base = GPIO_BASE(offset / 32);
170
171	if (value)
172		__raw_writel(1 << (offset % 32), base + GPIO_DATA_SET);
173	else
174		__raw_writel(1 << (offset % 32), base + GPIO_DATA_CLR);
175}
176
177static int gemini_gpio_get(struct gpio_chip *chip, unsigned offset)
178{
179	unsigned int base = GPIO_BASE(offset / 32);
180
181	return (__raw_readl(base + GPIO_DATA_IN) >> (offset % 32)) & 1;
182}
183
184static int gemini_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
185{
186	_set_gpio_direction(chip, offset, 0);
187	return 0;
188}
189
190static int gemini_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
191					int value)
192{
193	_set_gpio_direction(chip, offset, 1);
194	gemini_gpio_set(chip, offset, value);
195	return 0;
196}
197
198static struct gpio_chip gemini_gpio_chip = {
199	.label			= "Gemini",
200	.direction_input	= gemini_gpio_direction_input,
201	.get			= gemini_gpio_get,
202	.direction_output	= gemini_gpio_direction_output,
203	.set			= gemini_gpio_set,
204	.base			= 0,
205	.ngpio			= GPIO_PORT_NUM * 32,
206};
207
208void __init gemini_gpio_init(void)
209{
210	int i, j;
211
212	for (i = 0; i < GPIO_PORT_NUM; i++) {
213		/* disable, unmask and clear all interrupts */
214		__raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_EN);
215		__raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_MASK);
216		__raw_writel(~0x0, GPIO_BASE(i) + GPIO_INT_CLR);
217
218		for (j = GPIO_IRQ_BASE + i * 32;
219		     j < GPIO_IRQ_BASE + (i + 1) * 32; j++) {
220			irq_set_chip_and_handler(j, &gpio_irq_chip,
221						 handle_edge_irq);
222			set_irq_flags(j, IRQF_VALID);
223		}
224
225		irq_set_chained_handler(IRQ_GPIO(i), gpio_irq_handler);
226		irq_set_handler_data(IRQ_GPIO(i), (void *)i);
227	}
228
229	BUG_ON(gpiochip_add(&gemini_gpio_chip));
230}