Commit | Line | Data |
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f30c2269 | 1 | /* linux/drivers/i2c/busses/scx200_i2c.c |
1da177e4 LT |
2 | |
3 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> | |
4 | ||
5 | National Semiconductor SCx200 I2C bus on GPIO pins | |
6 | ||
7 | Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
22 | */ | |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | #include <linux/errno.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/i2c.h> | |
29 | #include <linux/i2c-algo-bit.h> | |
30 | #include <asm/io.h> | |
31 | ||
32 | #include <linux/scx200_gpio.h> | |
33 | ||
34 | #define NAME "scx200_i2c" | |
35 | ||
36 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); | |
37 | MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver"); | |
38 | MODULE_LICENSE("GPL"); | |
39 | ||
40 | static int scl = CONFIG_SCx200_I2C_SCL; | |
41 | static int sda = CONFIG_SCx200_I2C_SDA; | |
42 | ||
43 | module_param(scl, int, 0); | |
44 | MODULE_PARM_DESC(scl, "GPIO line for SCL"); | |
45 | module_param(sda, int, 0); | |
46 | MODULE_PARM_DESC(sda, "GPIO line for SDA"); | |
47 | ||
48 | static void scx200_i2c_setscl(void *data, int state) | |
49 | { | |
50 | scx200_gpio_set(scl, state); | |
51 | } | |
52 | ||
53 | static void scx200_i2c_setsda(void *data, int state) | |
54 | { | |
55 | scx200_gpio_set(sda, state); | |
56 | } | |
57 | ||
58 | static int scx200_i2c_getscl(void *data) | |
59 | { | |
60 | return scx200_gpio_get(scl); | |
61 | } | |
62 | ||
63 | static int scx200_i2c_getsda(void *data) | |
64 | { | |
65 | return scx200_gpio_get(sda); | |
66 | } | |
67 | ||
68 | /* ------------------------------------------------------------------------ | |
69 | * Encapsulate the above functions in the correct operations structure. | |
70 | * This is only done when more than one hardware adapter is supported. | |
71 | */ | |
72 | ||
73 | static struct i2c_algo_bit_data scx200_i2c_data = { | |
a0d9c63d JD |
74 | .setsda = scx200_i2c_setsda, |
75 | .setscl = scx200_i2c_setscl, | |
76 | .getsda = scx200_i2c_getsda, | |
77 | .getscl = scx200_i2c_getscl, | |
78 | .udelay = 10, | |
79 | .timeout = 100, | |
1da177e4 LT |
80 | }; |
81 | ||
82 | static struct i2c_adapter scx200_i2c_ops = { | |
83 | .owner = THIS_MODULE, | |
9ace555d | 84 | .id = I2C_HW_B_SCX200, |
1da177e4 LT |
85 | .algo_data = &scx200_i2c_data, |
86 | .name = "NatSemi SCx200 I2C", | |
87 | }; | |
88 | ||
89 | static int scx200_i2c_init(void) | |
90 | { | |
91 | pr_debug(NAME ": NatSemi SCx200 I2C Driver\n"); | |
92 | ||
93 | if (!scx200_gpio_present()) { | |
94 | printk(KERN_ERR NAME ": no SCx200 gpio pins available\n"); | |
95 | return -ENODEV; | |
96 | } | |
97 | ||
98 | pr_debug(NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda); | |
99 | ||
100 | if (scl == -1 || sda == -1 || scl == sda) { | |
101 | printk(KERN_ERR NAME ": scl and sda must be specified\n"); | |
102 | return -EINVAL; | |
103 | } | |
104 | ||
105 | /* Configure GPIOs as open collector outputs */ | |
106 | scx200_gpio_configure(scl, ~2, 5); | |
107 | scx200_gpio_configure(sda, ~2, 5); | |
108 | ||
109 | if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) { | |
110 | printk(KERN_ERR NAME ": adapter %s registration failed\n", | |
111 | scx200_i2c_ops.name); | |
112 | return -ENODEV; | |
113 | } | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static void scx200_i2c_cleanup(void) | |
119 | { | |
3269711b | 120 | i2c_del_adapter(&scx200_i2c_ops); |
1da177e4 LT |
121 | } |
122 | ||
123 | module_init(scx200_i2c_init); | |
124 | module_exit(scx200_i2c_cleanup); | |
125 | ||
126 | /* | |
127 | Local variables: | |
128 | compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules" | |
129 | c-basic-offset: 8 | |
130 | End: | |
131 | */ |