summaryrefslogtreecommitdiff
path: root/arch/mips/rb532/gpio.c
blob: 29c21b9d42dabf55aadf7f57f2ced10b84a6d746 (plain)
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
/*
 *  Miscellaneous functions for IDT EB434 board
 *
 *  Copyright 2004 IDT Inc. (rischelp@idt.com)
 *  Copyright 2006 Phil Sutter <n0-1@freewrt.org>
 *  Copyright 2007 Florian Fainelli <florian@openwrt.org>
 *
 *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>

#include <asm/mach-rc32434/rb.h>
#include <asm/mach-rc32434/gpio.h>

#define GPIOBASE	0x050000
/* Offsets relative to GPIOBASE */
#define GPIOFUNC	0x00
#define GPIOCFG		0x04
#define GPIOD		0x08
#define GPIOILEVEL	0x0C
#define GPIOISTAT	0x10
#define GPIONMIEN	0x14
#define IMASK6		0x38

struct rb532_gpio_chip {
	struct gpio_chip chip;
	void __iomem	 *regbase;
};

static struct resource rb532_gpio_reg0_res[] = {
	{
		.name	= "gpio_reg0",
		.start	= REGBASE + GPIOBASE,
		.end	= REGBASE + GPIOBASE + sizeof(struct rb532_gpio_reg) - 1,
		.flags	= IORESOURCE_MEM,
	}
};

/* rb532_set_bit - sanely set a bit
 *
 * bitval: new value for the bit
 * offset: bit index in the 4 byte address range
 * ioaddr: 4 byte aligned address being altered
 */
static inline void rb532_set_bit(unsigned bitval,
		unsigned offset, void __iomem *ioaddr)
{
	unsigned long flags;
	u32 val;

	local_irq_save(flags);

	val = readl(ioaddr);
	val &= ~(!bitval << offset);   /* unset bit if bitval == 0 */
	val |= (!!bitval << offset);   /* set bit if bitval == 1 */
	writel(val, ioaddr);

	local_irq_restore(flags);
}

/* rb532_get_bit - read a bit
 *
 * returns the boolean state of the bit, which may be > 1
 */
static inline int rb532_get_bit(unsigned offset, void __iomem *ioaddr)
{
	return readl(ioaddr) & (1 << offset);
}

/*
 * Return GPIO level */
static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct rb532_gpio_chip	*gpch;

	gpch = gpiochip_get_data(chip);
	return !!rb532_get_bit(offset, gpch->regbase + GPIOD);
}

/*
 * Set output GPIO level
 */
static void rb532_gpio_set(struct gpio_chip *chip,
				unsigned offset, int value)
{
	struct rb532_gpio_chip	*gpch;

	gpch = gpiochip_get_data(chip);
	rb532_set_bit(value, offset, gpch->regbase + GPIOD);
}

/*
 * Set GPIO direction to input
 */
static int rb532_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct rb532_gpio_chip	*gpch;

	gpch = gpiochip_get_data(chip);

	/* disable alternate function in case it's set */
	rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);

	rb532_set_bit(0, offset, gpch->regbase + GPIOCFG);
	return 0;
}

/*
 * Set GPIO direction to output
 */
static int rb532_gpio_direction_output(struct gpio_chip *chip,
					unsigned offset, int value)
{
	struct rb532_gpio_chip	*gpch;

	gpch = gpiochip_get_data(chip);

	/* disable alternate function in case it's set */
	rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);

	/* set the initial output value */
	rb532_set_bit(value, offset, gpch->regbase + GPIOD);

	rb532_set_bit(1, offset, gpch->regbase + GPIOCFG);
	return 0;
}

static int rb532_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
{
	return 8 + 4 * 32 + gpio;
}

static struct rb532_gpio_chip rb532_gpio_chip[] = {
	[0] = {
		.chip = {
			.label			= "gpio0",
			.direction_input	= rb532_gpio_direction_input,
			.direction_output	= rb532_gpio_direction_output,
			.get			= rb532_gpio_get,
			.set			= rb532_gpio_set,
			.to_irq			= rb532_gpio_to_irq,
			.base			= 0,
			.ngpio			= 32,
		},
	},
};

/*
 * Set GPIO interrupt level
 */
void rb532_gpio_set_ilevel(int bit, unsigned gpio)
{
	rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOILEVEL);
}
EXPORT_SYMBOL(rb532_gpio_set_ilevel);

/*
 * Set GPIO interrupt status
 */
void rb532_gpio_set_istat(int bit, unsigned gpio)
{
	rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOISTAT);
}
EXPORT_SYMBOL(rb532_gpio_set_istat);

/*
 * Configure GPIO alternate function
 */
void rb532_gpio_set_func(unsigned gpio)
{
       rb532_set_bit(1, gpio, rb532_gpio_chip->regbase + GPIOFUNC);
}
EXPORT_SYMBOL(rb532_gpio_set_func);

int __init rb532_gpio_init(void)
{
	struct resource *r;

	r = rb532_gpio_reg0_res;
	rb532_gpio_chip->regbase = ioremap(r->start, resource_size(r));

	if (!rb532_gpio_chip->regbase) {
		printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
		return -ENXIO;
	}

	/* Register our GPIO chip */
	gpiochip_add_data(&rb532_gpio_chip->chip, rb532_gpio_chip);

	return 0;
}
arch_initcall(rb532_gpio_init);