155 lines
3.3 KiB
C
155 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* w1_ds2406.c - w1 family 12 (DS2406) driver
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* based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
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*
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* Copyright (c) 2014 Scott Alfter <scott@alfter.us>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/device.h>
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#include <linux/types.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/crc16.h>
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#include <linux/w1.h>
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#define W1_FAMILY_DS2406 0x12
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#define W1_F12_FUNC_READ_STATUS 0xAA
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#define W1_F12_FUNC_WRITE_STATUS 0x55
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static ssize_t w1_f12_read_state(
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struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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u16 crc=0;
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int i;
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ssize_t rtnval=1;
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if (off != 0)
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return 0;
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if (!buf)
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return -EINVAL;
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mutex_lock(&sl->master->bus_mutex);
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if (w1_reset_select_slave(sl)) {
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mutex_unlock(&sl->master->bus_mutex);
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return -EIO;
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}
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w1_write_block(sl->master, w1_buf, 3);
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w1_read_block(sl->master, w1_buf+3, 3);
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for (i=0; i<6; i++)
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crc=crc16_byte(crc, w1_buf[i]);
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if (crc==0xb001) /* good read? */
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*buf=((w1_buf[3]>>5)&3)|0x30;
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else
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rtnval=-EIO;
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mutex_unlock(&sl->master->bus_mutex);
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return rtnval;
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}
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static ssize_t w1_f12_write_output(
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struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
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u16 crc=0;
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int i;
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ssize_t rtnval=1;
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if (count != 1 || off != 0)
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return -EFAULT;
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mutex_lock(&sl->master->bus_mutex);
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if (w1_reset_select_slave(sl)) {
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mutex_unlock(&sl->master->bus_mutex);
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return -EIO;
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}
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w1_buf[3] = (((*buf)&3)<<5)|0x1F;
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w1_write_block(sl->master, w1_buf, 4);
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w1_read_block(sl->master, w1_buf+4, 2);
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for (i=0; i<6; i++)
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crc=crc16_byte(crc, w1_buf[i]);
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if (crc==0xb001) /* good read? */
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w1_write_8(sl->master, 0xFF);
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else
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rtnval=-EIO;
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mutex_unlock(&sl->master->bus_mutex);
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return rtnval;
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}
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#define NB_SYSFS_BIN_FILES 2
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static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
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{
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.attr = {
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.name = "state",
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.mode = S_IRUGO,
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},
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.size = 1,
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.read = w1_f12_read_state,
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},
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{
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.attr = {
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.name = "output",
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.mode = S_IRUGO | S_IWUSR | S_IWGRP,
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},
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.size = 1,
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.write = w1_f12_write_output,
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}
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};
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static int w1_f12_add_slave(struct w1_slave *sl)
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{
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int err = 0;
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int i;
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for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
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err = sysfs_create_bin_file(
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&sl->dev.kobj,
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&(w1_f12_sysfs_bin_files[i]));
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if (err)
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while (--i >= 0)
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sysfs_remove_bin_file(&sl->dev.kobj,
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&(w1_f12_sysfs_bin_files[i]));
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return err;
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}
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static void w1_f12_remove_slave(struct w1_slave *sl)
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{
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int i;
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for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
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sysfs_remove_bin_file(&sl->dev.kobj,
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&(w1_f12_sysfs_bin_files[i]));
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}
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static const struct w1_family_ops w1_f12_fops = {
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.add_slave = w1_f12_add_slave,
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.remove_slave = w1_f12_remove_slave,
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};
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static struct w1_family w1_family_12 = {
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.fid = W1_FAMILY_DS2406,
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.fops = &w1_f12_fops,
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};
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module_w1_family(w1_family_12);
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MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
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MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
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MODULE_LICENSE("GPL");
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