diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/busses/i2c-parport-light.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/i2c/busses/i2c-parport-light.c')
-rw-r--r-- | drivers/i2c/busses/i2c-parport-light.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c new file mode 100644 index 000000000000..cb5e722301d8 --- /dev/null +++ b/drivers/i2c/busses/i2c-parport-light.c | |||
@@ -0,0 +1,175 @@ | |||
1 | /* ------------------------------------------------------------------------ * | ||
2 | * i2c-parport.c I2C bus over parallel port * | ||
3 | * ------------------------------------------------------------------------ * | ||
4 | Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org> | ||
5 | |||
6 | Based on older i2c-velleman.c driver | ||
7 | Copyright (C) 1995-2000 Simon G. Vogl | ||
8 | With some changes from: | ||
9 | Frodo Looijaard <frodol@dds.nl> | ||
10 | Kyösti Mälkki <kmalkki@cc.hut.fi> | ||
11 | |||
12 | This program is free software; you can redistribute it and/or modify | ||
13 | it under the terms of the GNU General Public License as published by | ||
14 | the Free Software Foundation; either version 2 of the License, or | ||
15 | (at your option) any later version. | ||
16 | |||
17 | This program is distributed in the hope that it will be useful, | ||
18 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
19 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
20 | GNU General Public License for more details. | ||
21 | |||
22 | You should have received a copy of the GNU General Public License | ||
23 | along with this program; if not, write to the Free Software | ||
24 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
25 | * ------------------------------------------------------------------------ */ | ||
26 | |||
27 | #include <linux/config.h> | ||
28 | #include <linux/kernel.h> | ||
29 | #include <linux/module.h> | ||
30 | #include <linux/init.h> | ||
31 | #include <linux/ioport.h> | ||
32 | #include <linux/i2c.h> | ||
33 | #include <linux/i2c-algo-bit.h> | ||
34 | #include <asm/io.h> | ||
35 | #include "i2c-parport.h" | ||
36 | |||
37 | #define DEFAULT_BASE 0x378 | ||
38 | |||
39 | static u16 base; | ||
40 | module_param(base, ushort, 0); | ||
41 | MODULE_PARM_DESC(base, "Base I/O address"); | ||
42 | |||
43 | /* ----- Low-level parallel port access ----------------------------------- */ | ||
44 | |||
45 | static inline void port_write(unsigned char p, unsigned char d) | ||
46 | { | ||
47 | outb(d, base+p); | ||
48 | } | ||
49 | |||
50 | static inline unsigned char port_read(unsigned char p) | ||
51 | { | ||
52 | return inb(base+p); | ||
53 | } | ||
54 | |||
55 | /* ----- Unified line operation functions --------------------------------- */ | ||
56 | |||
57 | static inline void line_set(int state, const struct lineop *op) | ||
58 | { | ||
59 | u8 oldval = port_read(op->port); | ||
60 | |||
61 | /* Touch only the bit(s) needed */ | ||
62 | if ((op->inverted && !state) || (!op->inverted && state)) | ||
63 | port_write(op->port, oldval | op->val); | ||
64 | else | ||
65 | port_write(op->port, oldval & ~op->val); | ||
66 | } | ||
67 | |||
68 | static inline int line_get(const struct lineop *op) | ||
69 | { | ||
70 | u8 oldval = port_read(op->port); | ||
71 | |||
72 | return ((op->inverted && (oldval & op->val) != op->val) | ||
73 | || (!op->inverted && (oldval & op->val) == op->val)); | ||
74 | } | ||
75 | |||
76 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | ||
77 | |||
78 | static void parport_setscl(void *data, int state) | ||
79 | { | ||
80 | line_set(state, &adapter_parm[type].setscl); | ||
81 | } | ||
82 | |||
83 | static void parport_setsda(void *data, int state) | ||
84 | { | ||
85 | line_set(state, &adapter_parm[type].setsda); | ||
86 | } | ||
87 | |||
88 | static int parport_getscl(void *data) | ||
89 | { | ||
90 | return line_get(&adapter_parm[type].getscl); | ||
91 | } | ||
92 | |||
93 | static int parport_getsda(void *data) | ||
94 | { | ||
95 | return line_get(&adapter_parm[type].getsda); | ||
96 | } | ||
97 | |||
98 | /* Encapsulate the functions above in the correct structure | ||
99 | Note that getscl will be set to NULL by the attaching code for adapters | ||
100 | that cannot read SCL back */ | ||
101 | static struct i2c_algo_bit_data parport_algo_data = { | ||
102 | .setsda = parport_setsda, | ||
103 | .setscl = parport_setscl, | ||
104 | .getsda = parport_getsda, | ||
105 | .getscl = parport_getscl, | ||
106 | .udelay = 50, | ||
107 | .mdelay = 50, | ||
108 | .timeout = HZ, | ||
109 | }; | ||
110 | |||
111 | /* ----- I2c structure ---------------------------------------------------- */ | ||
112 | |||
113 | static struct i2c_adapter parport_adapter = { | ||
114 | .owner = THIS_MODULE, | ||
115 | .class = I2C_CLASS_HWMON, | ||
116 | .id = I2C_HW_B_LP, | ||
117 | .algo_data = &parport_algo_data, | ||
118 | .name = "Parallel port adapter (light)", | ||
119 | }; | ||
120 | |||
121 | /* ----- Module loading, unloading and information ------------------------ */ | ||
122 | |||
123 | static int __init i2c_parport_init(void) | ||
124 | { | ||
125 | int type_count; | ||
126 | |||
127 | type_count = sizeof(adapter_parm)/sizeof(struct adapter_parm); | ||
128 | if (type < 0 || type >= type_count) { | ||
129 | printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type); | ||
130 | type = 0; | ||
131 | } | ||
132 | |||
133 | if (base == 0) { | ||
134 | printk(KERN_INFO "i2c-parport: using default base 0x%x\n", DEFAULT_BASE); | ||
135 | base = DEFAULT_BASE; | ||
136 | } | ||
137 | |||
138 | if (!request_region(base, 3, "i2c-parport")) | ||
139 | return -ENODEV; | ||
140 | |||
141 | if (!adapter_parm[type].getscl.val) | ||
142 | parport_algo_data.getscl = NULL; | ||
143 | |||
144 | /* Reset hardware to a sane state (SCL and SDA high) */ | ||
145 | parport_setsda(NULL, 1); | ||
146 | parport_setscl(NULL, 1); | ||
147 | /* Other init if needed (power on...) */ | ||
148 | if (adapter_parm[type].init.val) | ||
149 | line_set(1, &adapter_parm[type].init); | ||
150 | |||
151 | if (i2c_bit_add_bus(&parport_adapter) < 0) { | ||
152 | printk(KERN_ERR "i2c-parport: Unable to register with I2C\n"); | ||
153 | release_region(base, 3); | ||
154 | return -ENODEV; | ||
155 | } | ||
156 | |||
157 | return 0; | ||
158 | } | ||
159 | |||
160 | static void __exit i2c_parport_exit(void) | ||
161 | { | ||
162 | /* Un-init if needed (power off...) */ | ||
163 | if (adapter_parm[type].init.val) | ||
164 | line_set(0, &adapter_parm[type].init); | ||
165 | |||
166 | i2c_bit_del_bus(&parport_adapter); | ||
167 | release_region(base, 3); | ||
168 | } | ||
169 | |||
170 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | ||
171 | MODULE_DESCRIPTION("I2C bus over parallel port (light)"); | ||
172 | MODULE_LICENSE("GPL"); | ||
173 | |||
174 | module_init(i2c_parport_init); | ||
175 | module_exit(i2c_parport_exit); | ||