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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * w1_ds2406.c - w1 family 12 (DS2406) driver4 * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>5 *6 * Copyright (c) 2014 Scott Alfter <scott@alfter.us>7 */8 9#include <linux/kernel.h>10#include <linux/module.h>11#include <linux/moduleparam.h>12#include <linux/device.h>13#include <linux/types.h>14#include <linux/delay.h>15#include <linux/slab.h>16#include <linux/crc16.h>17 18#include <linux/w1.h>19 20#define W1_FAMILY_DS2406 0x1221 22#define W1_F12_FUNC_READ_STATUS 0xAA23#define W1_F12_FUNC_WRITE_STATUS 0x5524 25static ssize_t w1_f12_read_state(26 struct file *filp, struct kobject *kobj,27 struct bin_attribute *bin_attr,28 char *buf, loff_t off, size_t count)29{30 u8 w1_buf[6] = {W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};31 struct w1_slave *sl = kobj_to_w1_slave(kobj);32 u16 crc = 0;33 int i;34 ssize_t rtnval = 1;35 36 if (off != 0)37 return 0;38 if (!buf)39 return -EINVAL;40 41 mutex_lock(&sl->master->bus_mutex);42 43 if (w1_reset_select_slave(sl)) {44 mutex_unlock(&sl->master->bus_mutex);45 return -EIO;46 }47 48 w1_write_block(sl->master, w1_buf, 3);49 w1_read_block(sl->master, w1_buf+3, 3);50 for (i = 0; i < 6; i++)51 crc = crc16_byte(crc, w1_buf[i]);52 if (crc == 0xb001) /* good read? */53 *buf = ((w1_buf[3]>>5)&3)|0x30;54 else55 rtnval = -EIO;56 57 mutex_unlock(&sl->master->bus_mutex);58 59 return rtnval;60}61 62static ssize_t w1_f12_write_output(63 struct file *filp, struct kobject *kobj,64 struct bin_attribute *bin_attr,65 char *buf, loff_t off, size_t count)66{67 struct w1_slave *sl = kobj_to_w1_slave(kobj);68 u8 w1_buf[6] = {W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};69 u16 crc = 0;70 int i;71 ssize_t rtnval = 1;72 73 if (count != 1 || off != 0)74 return -EFAULT;75 76 mutex_lock(&sl->master->bus_mutex);77 78 if (w1_reset_select_slave(sl)) {79 mutex_unlock(&sl->master->bus_mutex);80 return -EIO;81 }82 83 w1_buf[3] = (((*buf)&3)<<5)|0x1F;84 w1_write_block(sl->master, w1_buf, 4);85 w1_read_block(sl->master, w1_buf+4, 2);86 for (i = 0; i < 6; i++)87 crc = crc16_byte(crc, w1_buf[i]);88 if (crc == 0xb001) /* good read? */89 w1_write_8(sl->master, 0xFF);90 else91 rtnval = -EIO;92 93 mutex_unlock(&sl->master->bus_mutex);94 return rtnval;95}96 97#define NB_SYSFS_BIN_FILES 298static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {99 {100 .attr = {101 .name = "state",102 .mode = 0444,103 },104 .size = 1,105 .read = w1_f12_read_state,106 },107 {108 .attr = {109 .name = "output",110 .mode = 0664,111 },112 .size = 1,113 .write = w1_f12_write_output,114 }115};116 117static int w1_f12_add_slave(struct w1_slave *sl)118{119 int err = 0;120 int i;121 122 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)123 err = sysfs_create_bin_file(124 &sl->dev.kobj,125 &(w1_f12_sysfs_bin_files[i]));126 if (err)127 while (--i >= 0)128 sysfs_remove_bin_file(&sl->dev.kobj,129 &(w1_f12_sysfs_bin_files[i]));130 return err;131}132 133static void w1_f12_remove_slave(struct w1_slave *sl)134{135 int i;136 137 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)138 sysfs_remove_bin_file(&sl->dev.kobj,139 &(w1_f12_sysfs_bin_files[i]));140}141 142static const struct w1_family_ops w1_f12_fops = {143 .add_slave = w1_f12_add_slave,144 .remove_slave = w1_f12_remove_slave,145};146 147static struct w1_family w1_family_12 = {148 .fid = W1_FAMILY_DS2406,149 .fops = &w1_f12_fops,150};151module_w1_family(w1_family_12);152 153MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");154MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");155MODULE_LICENSE("GPL");156