1/*
2 *  Silicon Labs C2 port Linux support for Eurotech Duramar 2150
3 *
4 *  Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it>
5 *  Copyright (c) 2008 Eurotech S.p.A. <info@eurotech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation
10 */
11
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/delay.h>
17#include <linux/io.h>
18#include <linux/ioport.h>
19#include <linux/c2port.h>
20
21#define DATA_PORT	0x325
22#define DIR_PORT	0x326
23#define    C2D		   (1 << 0)
24#define    C2CK		   (1 << 1)
25
26static DEFINE_MUTEX(update_lock);
27
28/*
29 * C2 port operations
30 */
31
32static void duramar2150_c2port_access(struct c2port_device *dev, int status)
33{
34	u8 v;
35
36	mutex_lock(&update_lock);
37
38	v = inb(DIR_PORT);
39
40	/* 0 = input, 1 = output */
41	if (status)
42		outb(v | (C2D | C2CK), DIR_PORT);
43	else
44		/* When access is "off" is important that both lines are set
45		 * as inputs or hi-impedance */
46		outb(v & ~(C2D | C2CK), DIR_PORT);
47
48	mutex_unlock(&update_lock);
49}
50
51static void duramar2150_c2port_c2d_dir(struct c2port_device *dev, int dir)
52{
53	u8 v;
54
55	mutex_lock(&update_lock);
56
57	v = inb(DIR_PORT);
58
59	if (dir)
60		outb(v & ~C2D, DIR_PORT);
61	else
62		outb(v | C2D, DIR_PORT);
63
64	mutex_unlock(&update_lock);
65}
66
67static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
68{
69	return inb(DATA_PORT) & C2D;
70}
71
72static void duramar2150_c2port_c2d_set(struct c2port_device *dev, int status)
73{
74	u8 v;
75
76	mutex_lock(&update_lock);
77
78	v = inb(DATA_PORT);
79
80	if (status)
81		outb(v | C2D, DATA_PORT);
82	else
83		outb(v & ~C2D, DATA_PORT);
84
85	mutex_unlock(&update_lock);
86}
87
88static void duramar2150_c2port_c2ck_set(struct c2port_device *dev, int status)
89{
90	u8 v;
91
92	mutex_lock(&update_lock);
93
94	v = inb(DATA_PORT);
95
96	if (status)
97		outb(v | C2CK, DATA_PORT);
98	else
99		outb(v & ~C2CK, DATA_PORT);
100
101	mutex_unlock(&update_lock);
102}
103
104static struct c2port_ops duramar2150_c2port_ops = {
105	.block_size	= 512,	/* bytes */
106	.blocks_num	= 30,	/* total flash size: 15360 bytes */
107
108	.access		= duramar2150_c2port_access,
109	.c2d_dir	= duramar2150_c2port_c2d_dir,
110	.c2d_get	= duramar2150_c2port_c2d_get,
111	.c2d_set	= duramar2150_c2port_c2d_set,
112	.c2ck_set	= duramar2150_c2port_c2ck_set,
113};
114
115static struct c2port_device *duramar2150_c2port_dev;
116
117/*
118 * Module stuff
119 */
120
121static int __init duramar2150_c2port_init(void)
122{
123	struct resource *res;
124	int ret = 0;
125
126	res = request_region(0x325, 2, "c2port");
127	if (!res)
128		return -EBUSY;
129
130	duramar2150_c2port_dev = c2port_device_register("uc",
131					&duramar2150_c2port_ops, NULL);
132	if (!duramar2150_c2port_dev) {
133		ret = -ENODEV;
134		goto free_region;
135	}
136
137	return 0;
138
139free_region:
140	release_region(0x325, 2);
141	return ret;
142}
143
144static void __exit duramar2150_c2port_exit(void)
145{
146	/* Setup the GPIOs as input by default (access = 0) */
147	duramar2150_c2port_access(duramar2150_c2port_dev, 0);
148
149	c2port_device_unregister(duramar2150_c2port_dev);
150
151	release_region(0x325, 2);
152}
153
154module_init(duramar2150_c2port_init);
155module_exit(duramar2150_c2port_exit);
156
157MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
158MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150");
159MODULE_LICENSE("GPL");
160