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 
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 
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 
67 static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
68 {
69 	return inb(DATA_PORT) & C2D;
70 }
71 
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 
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 
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 
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