1da177e4c3
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!
132 lines
3.3 KiB
C
132 lines
3.3 KiB
C
/* linux/drivers/i2c/scx200_i2c.c
|
|
|
|
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
|
|
|
|
National Semiconductor SCx200 I2C bus on GPIO pins
|
|
|
|
Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-algo-bit.h>
|
|
#include <asm/io.h>
|
|
|
|
#include <linux/scx200_gpio.h>
|
|
|
|
#define NAME "scx200_i2c"
|
|
|
|
MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
|
|
MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static int scl = CONFIG_SCx200_I2C_SCL;
|
|
static int sda = CONFIG_SCx200_I2C_SDA;
|
|
|
|
module_param(scl, int, 0);
|
|
MODULE_PARM_DESC(scl, "GPIO line for SCL");
|
|
module_param(sda, int, 0);
|
|
MODULE_PARM_DESC(sda, "GPIO line for SDA");
|
|
|
|
static void scx200_i2c_setscl(void *data, int state)
|
|
{
|
|
scx200_gpio_set(scl, state);
|
|
}
|
|
|
|
static void scx200_i2c_setsda(void *data, int state)
|
|
{
|
|
scx200_gpio_set(sda, state);
|
|
}
|
|
|
|
static int scx200_i2c_getscl(void *data)
|
|
{
|
|
return scx200_gpio_get(scl);
|
|
}
|
|
|
|
static int scx200_i2c_getsda(void *data)
|
|
{
|
|
return scx200_gpio_get(sda);
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------
|
|
* Encapsulate the above functions in the correct operations structure.
|
|
* This is only done when more than one hardware adapter is supported.
|
|
*/
|
|
|
|
static struct i2c_algo_bit_data scx200_i2c_data = {
|
|
NULL,
|
|
scx200_i2c_setsda,
|
|
scx200_i2c_setscl,
|
|
scx200_i2c_getsda,
|
|
scx200_i2c_getscl,
|
|
10, 10, 100, /* waits, timeout */
|
|
};
|
|
|
|
static struct i2c_adapter scx200_i2c_ops = {
|
|
.owner = THIS_MODULE,
|
|
.algo_data = &scx200_i2c_data,
|
|
.name = "NatSemi SCx200 I2C",
|
|
};
|
|
|
|
static int scx200_i2c_init(void)
|
|
{
|
|
pr_debug(NAME ": NatSemi SCx200 I2C Driver\n");
|
|
|
|
if (!scx200_gpio_present()) {
|
|
printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
pr_debug(NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda);
|
|
|
|
if (scl == -1 || sda == -1 || scl == sda) {
|
|
printk(KERN_ERR NAME ": scl and sda must be specified\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Configure GPIOs as open collector outputs */
|
|
scx200_gpio_configure(scl, ~2, 5);
|
|
scx200_gpio_configure(sda, ~2, 5);
|
|
|
|
if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {
|
|
printk(KERN_ERR NAME ": adapter %s registration failed\n",
|
|
scx200_i2c_ops.name);
|
|
return -ENODEV;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void scx200_i2c_cleanup(void)
|
|
{
|
|
i2c_bit_del_bus(&scx200_i2c_ops);
|
|
}
|
|
|
|
module_init(scx200_i2c_init);
|
|
module_exit(scx200_i2c_cleanup);
|
|
|
|
/*
|
|
Local variables:
|
|
compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
|
|
c-basic-offset: 8
|
|
End:
|
|
*/
|