aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-mxc/gpio.c
blob: de5c4747453fbedaf476fd3043a857fe8a1ee6c3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
/*
 * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
 *
 * Based on code from Freescale,
 * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * 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.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <mach/hardware.h>
#include <asm-generic/bug.h>

static struct mxc_gpio_port *mxc_gpio_ports;
static int gpio_table_size;

/* Note: This driver assumes 32 GPIOs are handled in one register */

static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index)
{
	__raw_writel(1 << index, port->base + GPIO_ISR);
}

static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index,
				int enable)
{
	u32 l;

	l = __raw_readl(port->base + GPIO_IMR);
	l = (l & (~(1 << index))) | (!!enable << index);
	__raw_writel(l, port->base + GPIO_IMR);
}

static void gpio_ack_irq(u32 irq)
{
	u32 gpio = irq_to_gpio(irq);
	_clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
}

static void gpio_mask_irq(u32 irq)
{
	u32 gpio = irq_to_gpio(irq);
	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
}

static void gpio_unmask_irq(u32 irq)
{
	u32 gpio = irq_to_gpio(irq);
	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
}

static int gpio_set_irq_type(u32 irq, u32 type)
{
	u32 gpio = irq_to_gpio(irq);
	struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
	u32 bit, val;
	int edge;
	void __iomem *reg = port->base;

	switch (type) {
	case IRQ_TYPE_EDGE_RISING:
		edge = GPIO_INT_RISE_EDGE;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		edge = GPIO_INT_FALL_EDGE;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		edge = GPIO_INT_LOW_LEV;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		edge = GPIO_INT_HIGH_LEV;
		break;
	default:	/* this includes IRQ_TYPE_EDGE_BOTH */
		return -EINVAL;
	}

	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
	bit = gpio & 0xf;
	val = __raw_readl(reg) & ~(0x3 << (bit << 1));
	__raw_writel(val | (edge << (bit << 1)), reg);
	_clear_gpio_irqstatus(port, gpio & 0x1f);

	return 0;
}

/* handle n interrupts in one status register */
static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
{
	u32 gpio_irq_no;

	gpio_irq_no = port->virtual_irq_start;
	for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {

		if ((irq_stat & 1) == 0)
			continue;

		BUG_ON(!(irq_desc[gpio_irq_no].handle_irq));
		irq_desc[gpio_irq_no].handle_irq(gpio_irq_no,
				&irq_desc[gpio_irq_no]);
	}
}

#ifdef CONFIG_ARCH_MX3
/* MX3 has one interrupt *per* gpio port */
static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc)
{
	u32 irq_stat;
	struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);

	irq_stat = __raw_readl(port->base + GPIO_ISR) &
			__raw_readl(port->base + GPIO_IMR);
	BUG_ON(!irq_stat);
	mxc_gpio_irq_handler(port, irq_stat);
}
#endif

#ifdef CONFIG_ARCH_MX2
/* MX2 has one interrupt *for all* gpio ports */
static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
{
	int i;
	u32 irq_msk, irq_stat;
	struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);

	/* walk through all interrupt status registers */
	for (i = 0; i < gpio_table_size; i++) {
		irq_msk = __raw_readl(port[i].base + GPIO_IMR);
		if (!irq_msk)
			continue;

		irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk;
		if (irq_stat)
			mxc_gpio_irq_handler(&port[i], irq_stat);
	}
}
#endif

static struct irq_chip gpio_irq_chip = {
	.ack = gpio_ack_irq,
	.mask = gpio_mask_irq,
	.unmask = gpio_unmask_irq,
	.set_type = gpio_set_irq_type,
};

static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
				int dir)
{
	struct mxc_gpio_port *port =
		container_of(chip, struct mxc_gpio_port, chip);
	u32 l;

	l = __raw_readl(port->base + GPIO_GDIR);
	if (dir)
		l |= 1 << offset;
	else
		l &= ~(1 << offset);
	__raw_writel(l, port->base + GPIO_GDIR);
}

static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mxc_gpio_port *port =
		container_of(chip, struct mxc_gpio_port, chip);
	void __iomem *reg = port->base + GPIO_DR;
	u32 l;

	l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
	__raw_writel(l, reg);
}

static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct mxc_gpio_port *port =
		container_of(chip, struct mxc_gpio_port, chip);

	return (__raw_readl(port->base + GPIO_PSR) >> offset) & 1;
}

static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	_set_gpio_direction(chip, offset, 0);
	return 0;
}

static int mxc_gpio_direction_output(struct gpio_chip *chip,
				     unsigned offset, int value)
{
	_set_gpio_direction(chip, offset, 1);
	mxc_gpio_set(chip, offset, value);
	return 0;
}

int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt)
{
	int i, j;

	/* save for local usage */
	mxc_gpio_ports = port;
	gpio_table_size = cnt;

	printk(KERN_INFO "MXC GPIO hardware\n");

	for (i = 0; i < cnt; i++) {
		/* disable the interrupt and clear the status */
		__raw_writel(0, port[i].base + GPIO_IMR);
		__raw_writel(~0, port[i].base + GPIO_ISR);
		for (j = port[i].virtual_irq_start;
			j < port[i].virtual_irq_start + 32; j++) {
			set_irq_chip(j, &gpio_irq_chip);
			set_irq_handler(j, handle_edge_irq);
			set_irq_flags(j, IRQF_VALID);
		}

		/* register gpio chip */
		port[i].chip.direction_input = mxc_gpio_direction_input;
		port[i].chip.direction_output = mxc_gpio_direction_output;
		port[i].chip.get = mxc_gpio_get;
		port[i].chip.set = mxc_gpio_set;
		port[i].chip.base = i * 32;
		port[i].chip.ngpio = 32;

		/* its a serious configuration bug when it fails */
		BUG_ON( gpiochip_add(&port[i].chip) < 0 );

#ifdef CONFIG_ARCH_MX3
		/* setup one handler for each entry */
		set_irq_chained_handler(port[i].irq, mx3_gpio_irq_handler);
		set_irq_data(port[i].irq, &port[i]);
#endif
	}

#ifdef CONFIG_ARCH_MX2
	/* setup one handler for all GPIO interrupts */
	set_irq_chained_handler(port[0].irq, mx2_gpio_irq_handler);
	set_irq_data(port[0].irq, port);
#endif
	return 0;
}