aboutsummaryrefslogtreecommitdiff
path: root/drivers/misc/c2port/c2port-duramar2150.c
blob: 7e370949e00eacde43a2f77cdf779b1a48cbbf24 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Silicon Labs C2 port Linux support for Eurotech Duramar 2150
 *
 *  Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it>
 *  Copyright (c) 2008 Eurotech S.p.A. <info@eurotech.it>
 */

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/c2port.h>

#define DATA_PORT	0x325
#define DIR_PORT	0x326
#define    C2D		   (1 << 0)
#define    C2CK		   (1 << 1)

static DEFINE_MUTEX(update_lock);

/*
 * C2 port operations
 */

static void duramar2150_c2port_access(struct c2port_device *dev, int status)
{
	u8 v;

	mutex_lock(&update_lock);

	v = inb(DIR_PORT);

	/* 0 = input, 1 = output */
	if (status)
		outb(v | (C2D | C2CK), DIR_PORT);
	else
		/* When access is "off" is important that both lines are set
		 * as inputs or hi-impedance */
		outb(v & ~(C2D | C2CK), DIR_PORT);

	mutex_unlock(&update_lock);
}

static void duramar2150_c2port_c2d_dir(struct c2port_device *dev, int dir)
{
	u8 v;

	mutex_lock(&update_lock);

	v = inb(DIR_PORT);

	if (dir)
		outb(v & ~C2D, DIR_PORT);
	else
		outb(v | C2D, DIR_PORT);

	mutex_unlock(&update_lock);
}

static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
{
	return inb(DATA_PORT) & C2D;
}

static void duramar2150_c2port_c2d_set(struct c2port_device *dev, int status)
{
	u8 v;

	mutex_lock(&update_lock);

	v = inb(DATA_PORT);

	if (status)
		outb(v | C2D, DATA_PORT);
	else
		outb(v & ~C2D, DATA_PORT);

	mutex_unlock(&update_lock);
}

static void duramar2150_c2port_c2ck_set(struct c2port_device *dev, int status)
{
	u8 v;

	mutex_lock(&update_lock);

	v = inb(DATA_PORT);

	if (status)
		outb(v | C2CK, DATA_PORT);
	else
		outb(v & ~C2CK, DATA_PORT);

	mutex_unlock(&update_lock);
}

static struct c2port_ops duramar2150_c2port_ops = {
	.block_size	= 512,	/* bytes */
	.blocks_num	= 30,	/* total flash size: 15360 bytes */

	.access		= duramar2150_c2port_access,
	.c2d_dir	= duramar2150_c2port_c2d_dir,
	.c2d_get	= duramar2150_c2port_c2d_get,
	.c2d_set	= duramar2150_c2port_c2d_set,
	.c2ck_set	= duramar2150_c2port_c2ck_set,
};

static struct c2port_device *duramar2150_c2port_dev;

/*
 * Module stuff
 */

static int __init duramar2150_c2port_init(void)
{
	struct resource *res;
	int ret = 0;

	res = request_region(0x325, 2, "c2port");
	if (!res)
		return -EBUSY;

	duramar2150_c2port_dev = c2port_device_register("uc",
					&duramar2150_c2port_ops, NULL);
	if (IS_ERR(duramar2150_c2port_dev)) {
		ret = PTR_ERR(duramar2150_c2port_dev);
		goto free_region;
	}

	return 0;

free_region:
	release_region(0x325, 2);
	return ret;
}

static void __exit duramar2150_c2port_exit(void)
{
	/* Setup the GPIOs as input by default (access = 0) */
	duramar2150_c2port_access(duramar2150_c2port_dev, 0);

	c2port_device_unregister(duramar2150_c2port_dev);

	release_region(0x325, 2);
}

module_init(duramar2150_c2port_init);
module_exit(duramar2150_c2port_exit);

MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150");
MODULE_LICENSE("GPL");