summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-mx3/iomux.c
blob: 40ffc5a664d93231c176956f0a3c927a6631a787 (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
/*
 * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright (C) 2008 by Sascha Hauer <kernel@pengutronix.de>
 * Copyright (C) 2009 by Valentin Longchamp <valentin.longchamp@epfl.ch>
 *
 * 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/module.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
#include <mach/iomux-mx3.h>

/*
 * IOMUX register (base) addresses
 */
#define IOMUX_BASE	IO_ADDRESS(IOMUXC_BASE_ADDR)
#define IOMUXINT_OBS1	(IOMUX_BASE + 0x000)
#define IOMUXINT_OBS2	(IOMUX_BASE + 0x004)
#define IOMUXGPR	(IOMUX_BASE + 0x008)
#define IOMUXSW_MUX_CTL	(IOMUX_BASE + 0x00C)
#define IOMUXSW_PAD_CTL	(IOMUX_BASE + 0x154)

static DEFINE_SPINLOCK(gpio_mux_lock);

#define IOMUX_REG_MASK (IOMUX_PADNUM_MASK & ~0x3)

unsigned long mxc_pin_alloc_map[NB_PORTS * 32 / BITS_PER_LONG];
/*
 * set the mode for a IOMUX pin.
 */
int mxc_iomux_mode(unsigned int pin_mode)
{
	u32 field, l, mode, ret = 0;
	void __iomem *reg;

	reg = IOMUXSW_MUX_CTL + (pin_mode & IOMUX_REG_MASK);
	field = pin_mode & 0x3;
	mode = (pin_mode & IOMUX_MODE_MASK) >> IOMUX_MODE_SHIFT;

	spin_lock(&gpio_mux_lock);

	l = __raw_readl(reg);
	l &= ~(0xff << (field * 8));
	l |= mode << (field * 8);
	__raw_writel(l, reg);

	spin_unlock(&gpio_mux_lock);

	return ret;
}
EXPORT_SYMBOL(mxc_iomux_mode);

/*
 * This function configures the pad value for a IOMUX pin.
 */
void mxc_iomux_set_pad(enum iomux_pins pin, u32 config)
{
	u32 field, l;
	void __iomem *reg;

	pin &= IOMUX_PADNUM_MASK;
	reg = IOMUXSW_PAD_CTL + (pin + 2) / 3 * 4;
	field = (pin + 2) % 3;

	pr_debug("%s: reg offset = 0x%x, field = %d\n",
			__func__, (pin + 2) / 3, field);

	spin_lock(&gpio_mux_lock);

	l = __raw_readl(reg);
	l &= ~(0x1ff << (field * 10));
	l |= config << (field * 10);
	__raw_writel(l, reg);

	spin_unlock(&gpio_mux_lock);
}
EXPORT_SYMBOL(mxc_iomux_set_pad);

/*
 * setups a single pin:
 * 	- reserves the pin so that it is not claimed by another driver
 * 	- setups the iomux according to the configuration
 * 	- if the pin is configured as a GPIO, we claim it through kernel gpiolib
 */
int mxc_iomux_setup_pin(const unsigned int pin, const char *label)
{
	unsigned pad = pin & IOMUX_PADNUM_MASK;
	unsigned gpio;

	if (pad >= (PIN_MAX + 1)) {
		printk(KERN_ERR "mxc_iomux: Attempt to request nonexistant pin %u for \"%s\"\n",
			pad, label ? label : "?");
		return -EINVAL;
	}

	if (test_and_set_bit(pad, mxc_pin_alloc_map)) {
		printk(KERN_ERR "mxc_iomux: pin %u already used. Allocation for \"%s\" failed\n",
			pad, label ? label : "?");
		return -EINVAL;
	}
	mxc_iomux_mode(pin);

	/* if we have a gpio, we can allocate it */
	gpio = (pin & IOMUX_GPIONUM_MASK) >> IOMUX_GPIONUM_SHIFT;
	if (gpio < (GPIO_PORT_MAX + 1) * 32)
		if (gpio_request(gpio, label))
			return -EINVAL;

	return 0;
}
EXPORT_SYMBOL(mxc_iomux_setup_pin);

int mxc_iomux_setup_multiple_pins(unsigned int *pin_list, unsigned count,
		const char *label)
{
	unsigned int *p = pin_list;
	int i;
	int ret = -EINVAL;

	for (i = 0; i < count; i++) {
		if (mxc_iomux_setup_pin(*p, label))
			goto setup_error;
		p++;
	}
	return 0;

setup_error:
	mxc_iomux_release_multiple_pins(pin_list, i);
	return ret;
}
EXPORT_SYMBOL(mxc_iomux_setup_multiple_pins);

void mxc_iomux_release_pin(const unsigned int pin)
{
	unsigned pad = pin & IOMUX_PADNUM_MASK;
	unsigned gpio;

	if (pad < (PIN_MAX + 1))
		clear_bit(pad, mxc_pin_alloc_map);

	gpio = (pin & IOMUX_GPIONUM_MASK) >> IOMUX_GPIONUM_SHIFT;
	if (gpio < (GPIO_PORT_MAX + 1) * 32)
		gpio_free(gpio);
}
EXPORT_SYMBOL(mxc_iomux_release_pin);

void mxc_iomux_release_multiple_pins(unsigned int *pin_list, int count)
{
	unsigned int *p = pin_list;
	int i;

	for (i = 0; i < count; i++) {
		mxc_iomux_release_pin(*p);
		p++;
	}
}
EXPORT_SYMBOL(mxc_iomux_release_multiple_pins);

/*
 * This function enables/disables the general purpose function for a particular
 * signal.
 */
void mxc_iomux_set_gpr(enum iomux_gp_func gp, bool en)
{
	u32 l;

	spin_lock(&gpio_mux_lock);
	l = __raw_readl(IOMUXGPR);
	if (en)
		l |= gp;
	else
		l &= ~gp;

	__raw_writel(l, IOMUXGPR);
	spin_unlock(&gpio_mux_lock);
}
EXPORT_SYMBOL(mxc_iomux_set_gpr);