1 /* linux/drivers/i2c/scx200_i2c.c
3 Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
5 National Semiconductor SCx200 I2C bus on GPIO pins
7 Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl
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.
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.
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.
24 #include <linux/config.h>
25 #include <linux/module.h>
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/i2c.h>
30 #include <linux/i2c-algo-bit.h>
33 #include <linux/scx200_gpio.h>
35 #define NAME "scx200_i2c"
37 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
38 MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");
39 MODULE_LICENSE("GPL");
41 MODULE_PARM(scl, "i");
42 MODULE_PARM_DESC(scl, "GPIO line for SCL");
43 MODULE_PARM(sda, "i");
44 MODULE_PARM_DESC(sda, "GPIO line for SDA");
46 static int scl = CONFIG_SCx200_I2C_SCL;
47 static int sda = CONFIG_SCx200_I2C_SDA;
49 static void scx200_i2c_setscl(void *data, int state)
51 scx200_gpio_set(scl, state);
54 static void scx200_i2c_setsda(void *data, int state)
56 scx200_gpio_set(sda, state);
59 static int scx200_i2c_getscl(void *data)
61 return scx200_gpio_get(scl);
64 static int scx200_i2c_getsda(void *data)
66 return scx200_gpio_get(sda);
69 static int scx200_i2c_reg(struct i2c_client *client)
74 static int scx200_i2c_unreg(struct i2c_client *client)
79 static void scx200_i2c_inc_use(struct i2c_adapter *adap)
84 static void scx200_i2c_dec_use(struct i2c_adapter *adap)
89 /* ------------------------------------------------------------------------
90 * Encapsulate the above functions in the correct operations structure.
91 * This is only done when more than one hardware adapter is supported.
94 static struct i2c_algo_bit_data scx200_i2c_data = {
100 10, 10, 100, /* waits, timeout */
103 static struct i2c_adapter scx200_i2c_ops = {
104 .name = "NatSemi SCx200 I2C",
105 .id = I2C_HW_B_VELLE,
106 .algo_data = &scx200_i2c_data,
107 .inc_use = scx200_i2c_inc_use,
108 .dec_use = scx200_i2c_dec_use,
109 .client_register = scx200_i2c_reg,
110 .client_unregister = scx200_i2c_unreg,
113 int scx200_i2c_init(void)
115 printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n");
117 if (!scx200_gpio_present()) {
118 printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
122 printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n",
125 if (scl == -1 || sda == -1 || scl == sda) {
126 printk(KERN_ERR NAME ": scl and sda must be specified\n");
130 /* Configure GPIOs as open collector outputs */
131 scx200_gpio_configure(scl, ~2, 5);
132 scx200_gpio_configure(sda, ~2, 5);
134 if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {
135 printk(KERN_ERR NAME ": adapter %s registration failed\n",
136 scx200_i2c_ops.name);
143 void scx200_i2c_cleanup(void)
145 i2c_bit_del_bus(&scx200_i2c_ops);
148 module_init(scx200_i2c_init);
149 module_exit(scx200_i2c_cleanup);
153 compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"