1 /* 2 * w1_ds2406.c - w1 family 12 (DS2406) driver 3 * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net> 4 * 5 * Copyright (c) 2014 Scott Alfter <scott@alfter.us> 6 * 7 * This source code is licensed under the GNU General Public License, 8 * Version 2. See the file COPYING for more details. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/moduleparam.h> 14 #include <linux/device.h> 15 #include <linux/types.h> 16 #include <linux/delay.h> 17 #include <linux/slab.h> 18 #include <linux/crc16.h> 19 20 #include "../w1.h" 21 #include "../w1_int.h" 22 #include "../w1_family.h" 23 24 MODULE_LICENSE("GPL"); 25 MODULE_AUTHOR("Scott Alfter <scott@alfter.us>"); 26 MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO"); 27 28 #define W1_F12_FUNC_READ_STATUS 0xAA 29 #define W1_F12_FUNC_WRITE_STATUS 0x55 30 31 static ssize_t w1_f12_read_state( 32 struct file *filp, struct kobject *kobj, 33 struct bin_attribute *bin_attr, 34 char *buf, loff_t off, size_t count) 35 { 36 u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0}; 37 struct w1_slave *sl = kobj_to_w1_slave(kobj); 38 u16 crc=0; 39 int i; 40 ssize_t rtnval=1; 41 42 if (off != 0) 43 return 0; 44 if (!buf) 45 return -EINVAL; 46 47 mutex_lock(&sl->master->bus_mutex); 48 49 if (w1_reset_select_slave(sl)) { 50 mutex_unlock(&sl->master->bus_mutex); 51 return -EIO; 52 } 53 54 w1_write_block(sl->master, w1_buf, 3); 55 w1_read_block(sl->master, w1_buf+3, 3); 56 for (i=0; i<6; i++) 57 crc=crc16_byte(crc, w1_buf[i]); 58 if (crc==0xb001) /* good read? */ 59 *buf=((w1_buf[3]>>5)&3)|0x30; 60 else 61 rtnval=-EIO; 62 63 mutex_unlock(&sl->master->bus_mutex); 64 65 return rtnval; 66 } 67 68 static ssize_t w1_f12_write_output( 69 struct file *filp, struct kobject *kobj, 70 struct bin_attribute *bin_attr, 71 char *buf, loff_t off, size_t count) 72 { 73 struct w1_slave *sl = kobj_to_w1_slave(kobj); 74 u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0}; 75 u16 crc=0; 76 int i; 77 ssize_t rtnval=1; 78 79 if (count != 1 || off != 0) 80 return -EFAULT; 81 82 mutex_lock(&sl->master->bus_mutex); 83 84 if (w1_reset_select_slave(sl)) { 85 mutex_unlock(&sl->master->bus_mutex); 86 return -EIO; 87 } 88 89 w1_buf[3] = (((*buf)&3)<<5)|0x1F; 90 w1_write_block(sl->master, w1_buf, 4); 91 w1_read_block(sl->master, w1_buf+4, 2); 92 for (i=0; i<6; i++) 93 crc=crc16_byte(crc, w1_buf[i]); 94 if (crc==0xb001) /* good read? */ 95 w1_write_8(sl->master, 0xFF); 96 else 97 rtnval=-EIO; 98 99 mutex_unlock(&sl->master->bus_mutex); 100 return rtnval; 101 } 102 103 #define NB_SYSFS_BIN_FILES 2 104 static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { 105 { 106 .attr = { 107 .name = "state", 108 .mode = S_IRUGO, 109 }, 110 .size = 1, 111 .read = w1_f12_read_state, 112 }, 113 { 114 .attr = { 115 .name = "output", 116 .mode = S_IRUGO | S_IWUSR | S_IWGRP, 117 }, 118 .size = 1, 119 .write = w1_f12_write_output, 120 } 121 }; 122 123 static int w1_f12_add_slave(struct w1_slave *sl) 124 { 125 int err = 0; 126 int i; 127 128 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) 129 err = sysfs_create_bin_file( 130 &sl->dev.kobj, 131 &(w1_f12_sysfs_bin_files[i])); 132 if (err) 133 while (--i >= 0) 134 sysfs_remove_bin_file(&sl->dev.kobj, 135 &(w1_f12_sysfs_bin_files[i])); 136 return err; 137 } 138 139 static void w1_f12_remove_slave(struct w1_slave *sl) 140 { 141 int i; 142 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) 143 sysfs_remove_bin_file(&sl->dev.kobj, 144 &(w1_f12_sysfs_bin_files[i])); 145 } 146 147 static struct w1_family_ops w1_f12_fops = { 148 .add_slave = w1_f12_add_slave, 149 .remove_slave = w1_f12_remove_slave, 150 }; 151 152 static struct w1_family w1_family_12 = { 153 .fid = W1_FAMILY_DS2406, 154 .fops = &w1_f12_fops, 155 }; 156 157 static int __init w1_f12_init(void) 158 { 159 return w1_register_family(&w1_family_12); 160 } 161 162 static void __exit w1_f12_exit(void) 163 { 164 w1_unregister_family(&w1_family_12); 165 } 166 167 module_init(w1_f12_init); 168 module_exit(w1_f12_exit); 169