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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | /* linux/drivers/i2c/busses/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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <linux/io.h>
#include <linux/scx200_gpio.h>
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 = {
.setsda = scx200_i2c_setsda,
.setscl = scx200_i2c_setscl,
.getsda = scx200_i2c_getsda,
.getscl = scx200_i2c_getscl,
.udelay = 10,
.timeout = HZ,
};
static struct i2c_adapter scx200_i2c_ops = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo_data = &scx200_i2c_data,
.name = "NatSemi SCx200 I2C",
};
static int scx200_i2c_init(void)
{
pr_debug("NatSemi SCx200 I2C Driver\n");
if (!scx200_gpio_present()) {
pr_err("no SCx200 gpio pins available\n");
return -ENODEV;
}
pr_debug("SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda);
if (scl == -1 || sda == -1 || scl == sda) {
pr_err("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) {
pr_err("adapter %s registration failed\n", scx200_i2c_ops.name);
return -ENODEV;
}
return 0;
}
static void scx200_i2c_cleanup(void)
{
i2c_del_adapter(&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:
*/
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