/*
* w1_ds2406.c - w1 family 12 (DS2406) driver
* based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
*
* Copyright (c) 2014 Scott Alfter <scott@alfter.us>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/crc16.h>
#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
#define W1_F12_FUNC_READ_STATUS 0xAA
#define W1_F12_FUNC_WRITE_STATUS 0x55
static ssize_t w1_f12_read_state(
struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u16 crc=0;
int i;
ssize_t rtnval=1;
if (off != 0)
return 0;
if (!buf)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (w1_reset_select_slave(sl)) {
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
w1_write_block(sl->master, w1_buf, 3);
w1_read_block(sl->master, w1_buf+3, 3);
for (i=0; i<6; i++)
crc=crc16_byte(crc, w1_buf[i]);
if (crc==0xb001) /* good read? */
*buf=((w1_buf[3]>>5)&3)|0x30;
else
rtnval=-EIO;
mutex_unlock(&sl->master->bus_mutex);
return rtnval;
}
static ssize_t w1_f12_write_output(
struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
u16 crc=0;
int i;
ssize_t rtnval=1;
if (count != 1 || off != 0)
return -EFAULT;
mutex_lock(&sl->master->bus_mutex);
if (w1_reset_select_slave(sl)) {
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
w1_buf[3] = (((*buf)&3)<<5)|0x1F;
w1_write_block(sl->master, w1_buf, 4);
w1_read_block(sl->master, w1_buf+4, 2);
for (i=0; i<6; i++)
crc=crc16_byte(crc, w1_buf[i]);
if (crc==0xb001) /* good read? */
w1_write_8(sl->master, 0xFF);
else
rtnval=-EIO;
mutex_unlock(&sl->master->bus_mutex);
return rtnval;
}
#define NB_SYSFS_BIN_FILES 2
static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
{
.attr = {
.name = "state",
.mode = S_IRUGO,
},
.size = 1,
.read = w1_f12_read_state,
},
{
.attr = {
.name = "output",
.mode = S_IRUGO | S_IWUSR | S_IWGRP,
},
.size = 1,
.write = w1_f12_write_output,
}
};
static int w1_f12_add_slave(struct w1_slave *sl)
{
int err = 0;
int i;
for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
err = sysfs_create_bin_file(
&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
if (err)
while (--i >= 0)
sysfs_remove_bin_file(&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
return err;
}
static void w1_f12_remove_slave(struct w1_slave *sl)
{
int i;
for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
sysfs_remove_bin_file(&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
}
static struct w1_family_ops w1_f12_fops = {
.add_slave = w1_f12_add_slave,
.remove_slave = w1_f12_remove_slave,
};
static struct w1_family w1_family_12 = {
.fid = W1_FAMILY_DS2406,
.fops = &w1_f12_fops,
};
static int __init w1_f12_init(void)
{
return w1_register_family(&w1_family_12);
}
static void __exit w1_f12_exit(void)
{
w1_unregister_family(&w1_family_12);
}
module_init(w1_f12_init);
module_exit(w1_f12_exit);
