summaryrefslogtreecommitdiffstats
path: root/target/linux/rdc/files-2.6.30/arch/x86/mach-rdc321x/gpio.c
blob: 408a4158d6a0f976c7924aea9a6f6a64e585d926 (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
/*
 * RDC321x GPIO driver
 *
 * Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
 * Copyright (C) 2007-2010 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/gpio.h>

#include <asm/rdc321x_defs.h>

struct rdc321x_gpio {
	spinlock_t	lock;
	u32 		data_reg[2];
} rdc321x_gpio_dev;

extern int rdc321x_pci_write(int reg, u32 val);
extern int rdc321x_pci_read(int reg, u32 *val);

/* read GPIO pin */
static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
	u32 value = 0;
	int reg;

	reg = gpio < 32 ? RDC321X_GPIO_DATA_REG1 : RDC321X_GPIO_DATA_REG2;

	spin_lock(&rdc321x_gpio_dev.lock);
	rdc321x_pci_write(reg, rdc321x_gpio_dev.data_reg[gpio < 32 ? 0 : 1]);
	rdc321x_pci_read(reg, &value);
	spin_unlock(&rdc321x_gpio_dev.lock);

	return (1 << (gpio & 0x1f)) & value ? 1 : 0;
}

static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
				unsigned gpio, int value)
{
	int reg = (gpio < 32) ? 0 : 1;

	if (value)
		rdc321x_gpio_dev.data_reg[reg] |= 1 << (gpio & 0x1f);
	else
		rdc321x_gpio_dev.data_reg[reg] &= ~(1 << (gpio & 0x1f));

	rdc321x_pci_write(reg ? RDC321X_GPIO_DATA_REG2 : RDC321X_GPIO_DATA_REG1,
			       rdc321x_gpio_dev.data_reg[reg]);
}

/* set GPIO pin to value */
static void rdc_gpio_set_value(struct gpio_chip *chip,
				unsigned gpio, int value)
{
	spin_lock(&rdc321x_gpio_dev.lock);
	rdc_gpio_set_value_impl(chip, gpio, value);
	spin_unlock(&rdc321x_gpio_dev.lock);
}

static int rdc_gpio_config(struct gpio_chip *chip,
				unsigned gpio, int value)
{
	int err;
	u32 reg;

	spin_lock(&rdc321x_gpio_dev.lock);
	err = rdc321x_pci_read(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
										&reg);
	if (err)
		goto unlock;

	reg |= 1 << (gpio & 0x1f);

	err = rdc321x_pci_write(gpio < 32 ? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
										reg);
	if (err)
		goto unlock;

	rdc_gpio_set_value_impl(chip, gpio, value);

unlock:
	spin_unlock(&rdc321x_gpio_dev.lock);

	return err;
}

/* configure GPIO pin as input */
static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
	return rdc_gpio_config(chip, gpio, 1);
}

static struct gpio_chip rdc321x_gpio_chip = {
	.label			= "rdc321x-gpio",
	.direction_input	= rdc_gpio_direction_input,
	.direction_output	= rdc_gpio_config,
	.get			= rdc_gpio_get_value,
	.set			= rdc_gpio_set_value,
	.base			= 0,
	.ngpio			= RDC321X_MAX_GPIO,
};

/* initially setup the 2 copies of the gpio data registers.
   This function is called before the platform setup code. */
static int __devinit rdc321x_gpio_probe(struct platform_device *pdev)
{
	int err;

	/* this might not be, what others (BIOS, bootloader, etc.)
	   wrote to these registers before, but it's a good guess. Still
	   better than just using 0xffffffff. */
	err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG1, &rdc321x_gpio_dev.data_reg[0]);
	if (err)
		return err;

	err = rdc321x_pci_read(RDC321X_GPIO_DATA_REG2, &rdc321x_gpio_dev.data_reg[1]);
	if (err)
		return err;

	spin_lock_init(&rdc321x_gpio_dev.lock);

	printk(KERN_INFO "rdc321x: registering %d GPIOs\n", rdc321x_gpio_chip.ngpio);
	return gpiochip_add(&rdc321x_gpio_chip);
}

static int __devexit rdc321x_gpio_remove(struct platform_device *pdev)
{
	gpiochip_remove(&rdc321x_gpio_chip);
	return 0;
}

static struct platform_driver rdc321x_gpio_driver = {
	.driver.name	= "rdc321x-gpio",
	.driver.owner	= THIS_MODULE,
	.probe		= rdc321x_gpio_probe,
	.remove		= __devexit_p(rdc321x_gpio_remove),
};

static int __init rdc321x_gpio_init(void)
{
	return platform_driver_register(&rdc321x_gpio_driver);
}

static void __exit rdc321x_gpio_exit(void)
{
	platform_driver_unregister(&rdc321x_gpio_driver);
}

module_init(rdc321x_gpio_init);
module_exit(rdc321x_gpio_exit);

MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x GPIO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rdc321x-gpio");