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/driver.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 #define irq_to_gpio(x) ((x) - GPIO_IRQ_BASE)
27
28 /* GPIO registers definition */
29 #define GPIO_DATA_OUT 0x0
30 #define GPIO_DATA_IN 0x4
31 #define GPIO_DIR 0x8
32 #define GPIO_DATA_SET 0x10
33 #define GPIO_DATA_CLR 0x14
34 #define GPIO_PULL_EN 0x18
35 #define GPIO_PULL_TYPE 0x1C
36 #define GPIO_INT_EN 0x20
37 #define GPIO_INT_STAT 0x24
38 #define GPIO_INT_MASK 0x2C
39 #define GPIO_INT_CLR 0x30
40 #define GPIO_INT_TYPE 0x34
41 #define GPIO_INT_BOTH_EDGE 0x38
42 #define GPIO_INT_LEVEL 0x3C
43 #define GPIO_DEBOUNCE_EN 0x40
44 #define GPIO_DEBOUNCE_PRESCALE 0x44
45
46 #define GPIO_PORT_NUM 3
47
_set_gpio_irqenable(void __iomem * base,unsigned int index,int enable)48 static void _set_gpio_irqenable(void __iomem *base, unsigned int index,
49 int enable)
50 {
51 unsigned int reg;
52
53 reg = __raw_readl(base + GPIO_INT_EN);
54 reg = (reg & (~(1 << index))) | (!!enable << index);
55 __raw_writel(reg, base + GPIO_INT_EN);
56 }
57
gpio_ack_irq(struct irq_data * d)58 static void gpio_ack_irq(struct irq_data *d)
59 {
60 unsigned int gpio = irq_to_gpio(d->irq);
61 void __iomem *base = GPIO_BASE(gpio / 32);
62
63 __raw_writel(1 << (gpio % 32), base + GPIO_INT_CLR);
64 }
65
gpio_mask_irq(struct irq_data * d)66 static void gpio_mask_irq(struct irq_data *d)
67 {
68 unsigned int gpio = irq_to_gpio(d->irq);
69 void __iomem *base = GPIO_BASE(gpio / 32);
70
71 _set_gpio_irqenable(base, gpio % 32, 0);
72 }
73
gpio_unmask_irq(struct irq_data * d)74 static void gpio_unmask_irq(struct irq_data *d)
75 {
76 unsigned int gpio = irq_to_gpio(d->irq);
77 void __iomem *base = GPIO_BASE(gpio / 32);
78
79 _set_gpio_irqenable(base, gpio % 32, 1);
80 }
81
gpio_set_irq_type(struct irq_data * d,unsigned int type)82 static int gpio_set_irq_type(struct irq_data *d, unsigned int type)
83 {
84 unsigned int gpio = irq_to_gpio(d->irq);
85 unsigned int gpio_mask = 1 << (gpio % 32);
86 void __iomem *base = GPIO_BASE(gpio / 32);
87 unsigned int reg_both, reg_level, reg_type;
88
89 reg_type = __raw_readl(base + GPIO_INT_TYPE);
90 reg_level = __raw_readl(base + GPIO_INT_LEVEL);
91 reg_both = __raw_readl(base + GPIO_INT_BOTH_EDGE);
92
93 switch (type) {
94 case IRQ_TYPE_EDGE_BOTH:
95 reg_type &= ~gpio_mask;
96 reg_both |= gpio_mask;
97 break;
98 case IRQ_TYPE_EDGE_RISING:
99 reg_type &= ~gpio_mask;
100 reg_both &= ~gpio_mask;
101 reg_level &= ~gpio_mask;
102 break;
103 case IRQ_TYPE_EDGE_FALLING:
104 reg_type &= ~gpio_mask;
105 reg_both &= ~gpio_mask;
106 reg_level |= gpio_mask;
107 break;
108 case IRQ_TYPE_LEVEL_HIGH:
109 reg_type |= gpio_mask;
110 reg_level &= ~gpio_mask;
111 break;
112 case IRQ_TYPE_LEVEL_LOW:
113 reg_type |= gpio_mask;
114 reg_level |= gpio_mask;
115 break;
116 default:
117 return -EINVAL;
118 }
119
120 __raw_writel(reg_type, base + GPIO_INT_TYPE);
121 __raw_writel(reg_level, base + GPIO_INT_LEVEL);
122 __raw_writel(reg_both, base + GPIO_INT_BOTH_EDGE);
123
124 gpio_ack_irq(d);
125
126 return 0;
127 }
128
gpio_irq_handler(struct irq_desc * desc)129 static void gpio_irq_handler(struct irq_desc *desc)
130 {
131 unsigned int port = (unsigned int)irq_desc_get_handler_data(desc);
132 unsigned int gpio_irq_no, irq_stat;
133
134 irq_stat = __raw_readl(GPIO_BASE(port) + GPIO_INT_STAT);
135
136 gpio_irq_no = GPIO_IRQ_BASE + port * 32;
137 for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
138
139 if ((irq_stat & 1) == 0)
140 continue;
141
142 generic_handle_irq(gpio_irq_no);
143 }
144 }
145
146 static struct irq_chip gpio_irq_chip = {
147 .name = "GPIO",
148 .irq_ack = gpio_ack_irq,
149 .irq_mask = gpio_mask_irq,
150 .irq_unmask = gpio_unmask_irq,
151 .irq_set_type = gpio_set_irq_type,
152 };
153
_set_gpio_direction(struct gpio_chip * chip,unsigned offset,int dir)154 static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
155 int dir)
156 {
157 void __iomem *base = GPIO_BASE(offset / 32);
158 unsigned int reg;
159
160 reg = __raw_readl(base + GPIO_DIR);
161 if (dir)
162 reg |= 1 << (offset % 32);
163 else
164 reg &= ~(1 << (offset % 32));
165 __raw_writel(reg, base + GPIO_DIR);
166 }
167
gemini_gpio_set(struct gpio_chip * chip,unsigned offset,int value)168 static void gemini_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
169 {
170 void __iomem *base = GPIO_BASE(offset / 32);
171
172 if (value)
173 __raw_writel(1 << (offset % 32), base + GPIO_DATA_SET);
174 else
175 __raw_writel(1 << (offset % 32), base + GPIO_DATA_CLR);
176 }
177
gemini_gpio_get(struct gpio_chip * chip,unsigned offset)178 static int gemini_gpio_get(struct gpio_chip *chip, unsigned offset)
179 {
180 void __iomem *base = GPIO_BASE(offset / 32);
181
182 return (__raw_readl(base + GPIO_DATA_IN) >> (offset % 32)) & 1;
183 }
184
gemini_gpio_direction_input(struct gpio_chip * chip,unsigned offset)185 static int gemini_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
186 {
187 _set_gpio_direction(chip, offset, 0);
188 return 0;
189 }
190
gemini_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)191 static int gemini_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
192 int value)
193 {
194 _set_gpio_direction(chip, offset, 1);
195 gemini_gpio_set(chip, offset, value);
196 return 0;
197 }
198
199 static struct gpio_chip gemini_gpio_chip = {
200 .label = "Gemini",
201 .direction_input = gemini_gpio_direction_input,
202 .get = gemini_gpio_get,
203 .direction_output = gemini_gpio_direction_output,
204 .set = gemini_gpio_set,
205 .base = 0,
206 .ngpio = GPIO_PORT_NUM * 32,
207 };
208
gemini_gpio_init(void)209 void __init gemini_gpio_init(void)
210 {
211 int i, j;
212
213 for (i = 0; i < GPIO_PORT_NUM; i++) {
214 /* disable, unmask and clear all interrupts */
215 __raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_EN);
216 __raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_MASK);
217 __raw_writel(~0x0, GPIO_BASE(i) + GPIO_INT_CLR);
218
219 for (j = GPIO_IRQ_BASE + i * 32;
220 j < GPIO_IRQ_BASE + (i + 1) * 32; j++) {
221 irq_set_chip_and_handler(j, &gpio_irq_chip,
222 handle_edge_irq);
223 irq_clear_status_flags(j, IRQ_NOREQUEST);
224 }
225
226 irq_set_chained_handler_and_data(IRQ_GPIO(i), gpio_irq_handler,
227 (void *)i);
228 }
229
230 BUG_ON(gpiochip_add_data(&gemini_gpio_chip, NULL));
231 }
232