aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-mxc91231/iomux.c
blob: 405d9b19d891ee636c7591ea827a0f1def0da0d4 (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
/*
 * 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/kernel.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
#include <mach/iomux-mxc91231.h>

/*
 * IOMUX register (base) addresses
 */
#define IOMUX_AP_BASE		MXC91231_IO_ADDRESS(MXC91231_IOMUX_AP_BASE_ADDR)
#define IOMUX_COM_BASE		MXC91231_IO_ADDRESS(MXC91231_IOMUX_COM_BASE_ADDR)
#define IOMUXSW_AP_MUX_CTL	(IOMUX_AP_BASE + 0x000)
#define IOMUXSW_SP_MUX_CTL	(IOMUX_COM_BASE + 0x000)
#define IOMUXSW_PAD_CTL		(IOMUX_COM_BASE + 0x200)

#define IOMUXINT_OBS1		(IOMUX_AP_BASE + 0x600)
#define IOMUXINT_OBS2		(IOMUX_AP_BASE + 0x004)

static DEFINE_SPINLOCK(gpio_mux_lock);

#define NB_PORTS			((PIN_MAX + 32) / 32)
#define PIN_GLOBAL_NUM(pin) \
	(((pin & MUX_SIDE_MASK) >> MUX_SIDE_SHIFT)*PIN_AP_MAX +	\
	 ((pin & MUX_REG_MASK) >> MUX_REG_SHIFT)*4 +		\
	 ((pin & MUX_FIELD_MASK) >> MUX_FIELD_SHIFT))

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

	side = (pin_mode & MUX_SIDE_MASK) >> MUX_SIDE_SHIFT;
	switch (side) {
	case MUX_SIDE_AP:
		reg = IOMUXSW_AP_MUX_CTL;
		break;
	case MUX_SIDE_SP:
		reg = IOMUXSW_SP_MUX_CTL;
		break;
	default:
		return -EINVAL;
	}
	reg += ((pin_mode & MUX_REG_MASK) >> MUX_REG_SHIFT) * 4;
	field = (pin_mode & MUX_FIELD_MASK) >> MUX_FIELD_SHIFT;
	mode = (pin_mode & MUX_MODE_MASK) >> MUX_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 padgrp, field, l;
	void __iomem *reg;

	padgrp = (pin & MUX_PADGRP_MASK) >> MUX_PADGRP_SHIFT;
	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);

/*
 * allocs a single pin:
 * 	- reserves the pin so that it is not claimed by another driver
 * 	- setups the iomux according to the configuration
 */
int mxc_iomux_alloc_pin(const unsigned int pin_mode, const char *label)
{
	unsigned pad = PIN_GLOBAL_NUM(pin_mode);
	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 -EBUSY;
	}
	mxc_iomux_mode(pin_mode);

	return 0;
}
EXPORT_SYMBOL(mxc_iomux_alloc_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++) {
		ret = mxc_iomux_alloc_pin(*p, label);
		if (ret)
			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_mode)
{
	unsigned pad = PIN_GLOBAL_NUM(pin_mode);

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