1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Silicon Labs C2 port Linux support for Eurotech Duramar 2150
4 *
5 * Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it>
6 * Copyright (c) 2008 Eurotech S.p.A. <info@eurotech.it>
7 */
8
9 #include <linux/errno.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/c2port.h>
17
18 #define DATA_PORT 0x325
19 #define DIR_PORT 0x326
20 #define C2D (1 << 0)
21 #define C2CK (1 << 1)
22
23 static DEFINE_MUTEX(update_lock);
24
25 /*
26 * C2 port operations
27 */
28
duramar2150_c2port_access(struct c2port_device * dev,int status)29 static void duramar2150_c2port_access(struct c2port_device *dev, int status)
30 {
31 u8 v;
32
33 mutex_lock(&update_lock);
34
35 v = inb(DIR_PORT);
36
37 /* 0 = input, 1 = output */
38 if (status)
39 outb(v | (C2D | C2CK), DIR_PORT);
40 else
41 /* When access is "off" is important that both lines are set
42 * as inputs or hi-impedance */
43 outb(v & ~(C2D | C2CK), DIR_PORT);
44
45 mutex_unlock(&update_lock);
46 }
47
duramar2150_c2port_c2d_dir(struct c2port_device * dev,int dir)48 static void duramar2150_c2port_c2d_dir(struct c2port_device *dev, int dir)
49 {
50 u8 v;
51
52 mutex_lock(&update_lock);
53
54 v = inb(DIR_PORT);
55
56 if (dir)
57 outb(v & ~C2D, DIR_PORT);
58 else
59 outb(v | C2D, DIR_PORT);
60
61 mutex_unlock(&update_lock);
62 }
63
duramar2150_c2port_c2d_get(struct c2port_device * dev)64 static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
65 {
66 return inb(DATA_PORT) & C2D;
67 }
68
duramar2150_c2port_c2d_set(struct c2port_device * dev,int status)69 static void duramar2150_c2port_c2d_set(struct c2port_device *dev, int status)
70 {
71 u8 v;
72
73 mutex_lock(&update_lock);
74
75 v = inb(DATA_PORT);
76
77 if (status)
78 outb(v | C2D, DATA_PORT);
79 else
80 outb(v & ~C2D, DATA_PORT);
81
82 mutex_unlock(&update_lock);
83 }
84
duramar2150_c2port_c2ck_set(struct c2port_device * dev,int status)85 static void duramar2150_c2port_c2ck_set(struct c2port_device *dev, int status)
86 {
87 u8 v;
88
89 mutex_lock(&update_lock);
90
91 v = inb(DATA_PORT);
92
93 if (status)
94 outb(v | C2CK, DATA_PORT);
95 else
96 outb(v & ~C2CK, DATA_PORT);
97
98 mutex_unlock(&update_lock);
99 }
100
101 static struct c2port_ops duramar2150_c2port_ops = {
102 .block_size = 512, /* bytes */
103 .blocks_num = 30, /* total flash size: 15360 bytes */
104
105 .access = duramar2150_c2port_access,
106 .c2d_dir = duramar2150_c2port_c2d_dir,
107 .c2d_get = duramar2150_c2port_c2d_get,
108 .c2d_set = duramar2150_c2port_c2d_set,
109 .c2ck_set = duramar2150_c2port_c2ck_set,
110 };
111
112 static struct c2port_device *duramar2150_c2port_dev;
113
114 /*
115 * Module stuff
116 */
117
duramar2150_c2port_init(void)118 static int __init duramar2150_c2port_init(void)
119 {
120 struct resource *res;
121 int ret = 0;
122
123 res = request_region(0x325, 2, "c2port");
124 if (!res)
125 return -EBUSY;
126
127 duramar2150_c2port_dev = c2port_device_register("uc",
128 &duramar2150_c2port_ops, NULL);
129 if (IS_ERR(duramar2150_c2port_dev)) {
130 ret = PTR_ERR(duramar2150_c2port_dev);
131 goto free_region;
132 }
133
134 return 0;
135
136 free_region:
137 release_region(0x325, 2);
138 return ret;
139 }
140
duramar2150_c2port_exit(void)141 static void __exit duramar2150_c2port_exit(void)
142 {
143 /* Setup the GPIOs as input by default (access = 0) */
144 duramar2150_c2port_access(duramar2150_c2port_dev, 0);
145
146 c2port_device_unregister(duramar2150_c2port_dev);
147
148 release_region(0x325, 2);
149 }
150
151 module_init(duramar2150_c2port_init);
152 module_exit(duramar2150_c2port_exit);
153
154 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
155 MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150");
156 MODULE_LICENSE("GPL");
157