linux/drivers/w1/slaves/w1_ds2406.c
Thomas Gleixner 40b0b3f8fb treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230
Based on 2 normalized pattern(s):

  this source code is licensed under the gnu general public license
  version 2 see the file copying for more details

  this source code is licensed under general public license version 2
  see

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 52 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.449021192@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:06 +02:00

155 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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 <linux/w1.h>
#define W1_FAMILY_DS2406 0x12
#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,
};
module_w1_family(w1_family_12);
MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
MODULE_LICENSE("GPL");