1 /* 2 * w1_ds2413.c - w1 family 3a (DS2413) driver 3 * based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com> 4 * 5 * Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net> 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 19 #include "../w1.h" 20 #include "../w1_int.h" 21 #include "../w1_family.h" 22 23 MODULE_LICENSE("GPL"); 24 MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>"); 25 MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO"); 26 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413)); 27 28 #define W1_F3A_RETRIES 3 29 #define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5 30 #define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A 31 #define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA 32 33 static ssize_t w1_f3a_read_state( 34 struct file *filp, struct kobject *kobj, 35 struct bin_attribute *bin_attr, 36 char *buf, loff_t off, size_t count) 37 { 38 struct w1_slave *sl = kobj_to_w1_slave(kobj); 39 dev_dbg(&sl->dev, 40 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", 41 bin_attr->attr.name, kobj, (unsigned int)off, count, buf); 42 43 if (off != 0) 44 return 0; 45 if (!buf) 46 return -EINVAL; 47 48 mutex_lock(&sl->master->bus_mutex); 49 dev_dbg(&sl->dev, "mutex locked"); 50 51 if (w1_reset_select_slave(sl)) { 52 mutex_unlock(&sl->master->bus_mutex); 53 return -EIO; 54 } 55 56 w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ); 57 *buf = w1_read_8(sl->master); 58 59 mutex_unlock(&sl->master->bus_mutex); 60 dev_dbg(&sl->dev, "mutex unlocked"); 61 62 /* check for correct complement */ 63 if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F)) 64 return -EIO; 65 else 66 return 1; 67 } 68 69 static ssize_t w1_f3a_write_output( 70 struct file *filp, struct kobject *kobj, 71 struct bin_attribute *bin_attr, 72 char *buf, loff_t off, size_t count) 73 { 74 struct w1_slave *sl = kobj_to_w1_slave(kobj); 75 u8 w1_buf[3]; 76 unsigned int retries = W1_F3A_RETRIES; 77 78 if (count != 1 || off != 0) 79 return -EFAULT; 80 81 dev_dbg(&sl->dev, "locking mutex for write_output"); 82 mutex_lock(&sl->master->bus_mutex); 83 dev_dbg(&sl->dev, "mutex locked"); 84 85 if (w1_reset_select_slave(sl)) 86 goto error; 87 88 /* according to the DS2413 datasheet the most significant 6 bits 89 should be set to "1"s, so do it now */ 90 *buf = *buf | 0xFC; 91 92 while (retries--) { 93 w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE; 94 w1_buf[1] = *buf; 95 w1_buf[2] = ~(*buf); 96 w1_write_block(sl->master, w1_buf, 3); 97 98 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) { 99 mutex_unlock(&sl->master->bus_mutex); 100 dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries); 101 return 1; 102 } 103 if (w1_reset_resume_command(sl->master)) 104 goto error; 105 } 106 107 error: 108 mutex_unlock(&sl->master->bus_mutex); 109 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); 110 return -EIO; 111 } 112 113 #define NB_SYSFS_BIN_FILES 2 114 static struct bin_attribute w1_f3a_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { 115 { 116 .attr = { 117 .name = "state", 118 .mode = S_IRUGO, 119 }, 120 .size = 1, 121 .read = w1_f3a_read_state, 122 }, 123 { 124 .attr = { 125 .name = "output", 126 .mode = S_IRUGO | S_IWUSR | S_IWGRP, 127 }, 128 .size = 1, 129 .write = w1_f3a_write_output, 130 } 131 }; 132 133 static int w1_f3a_add_slave(struct w1_slave *sl) 134 { 135 int err = 0; 136 int i; 137 138 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) 139 err = sysfs_create_bin_file( 140 &sl->dev.kobj, 141 &(w1_f3a_sysfs_bin_files[i])); 142 if (err) 143 while (--i >= 0) 144 sysfs_remove_bin_file(&sl->dev.kobj, 145 &(w1_f3a_sysfs_bin_files[i])); 146 return err; 147 } 148 149 static void w1_f3a_remove_slave(struct w1_slave *sl) 150 { 151 int i; 152 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) 153 sysfs_remove_bin_file(&sl->dev.kobj, 154 &(w1_f3a_sysfs_bin_files[i])); 155 } 156 157 static struct w1_family_ops w1_f3a_fops = { 158 .add_slave = w1_f3a_add_slave, 159 .remove_slave = w1_f3a_remove_slave, 160 }; 161 162 static struct w1_family w1_family_3a = { 163 .fid = W1_FAMILY_DS2413, 164 .fops = &w1_f3a_fops, 165 }; 166 167 static int __init w1_f3a_init(void) 168 { 169 return w1_register_family(&w1_family_3a); 170 } 171 172 static void __exit w1_f3a_exit(void) 173 { 174 w1_unregister_family(&w1_family_3a); 175 } 176 177 module_init(w1_f3a_init); 178 module_exit(w1_f3a_exit); 179