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
26 static DEFINE_MUTEX(update_lock);
27
28 /*
29 * C2 port operations
30 */
31
duramar2150_c2port_access(struct c2port_device * dev,int status)32 static 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
duramar2150_c2port_c2d_dir(struct c2port_device * dev,int dir)51 static 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
duramar2150_c2port_c2d_get(struct c2port_device * dev)67 static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
68 {
69 return inb(DATA_PORT) & C2D;
70 }
71
duramar2150_c2port_c2d_set(struct c2port_device * dev,int status)72 static 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
duramar2150_c2port_c2ck_set(struct c2port_device * dev,int status)88 static 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
104 static 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
115 static struct c2port_device *duramar2150_c2port_dev;
116
117 /*
118 * Module stuff
119 */
120
duramar2150_c2port_init(void)121 static 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
139 free_region:
140 release_region(0x325, 2);
141 return ret;
142 }
143
duramar2150_c2port_exit(void)144 static 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
154 module_init(duramar2150_c2port_init);
155 module_exit(duramar2150_c2port_exit);
156
157 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
158 MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150");
159 MODULE_LICENSE("GPL");
160