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 27 #define W1_F3A_RETRIES 3 28 #define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5 29 #define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A 30 #define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA 31 32 static ssize_t w1_f3a_read_state( 33 struct file *filp, struct kobject *kobj, 34 struct bin_attribute *bin_attr, 35 char *buf, loff_t off, size_t count) 36 { 37 struct w1_slave *sl = kobj_to_w1_slave(kobj); 38 dev_dbg(&sl->dev, 39 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", 40 bin_attr->attr.name, kobj, (unsigned int)off, count, buf); 41 42 if (off != 0) 43 return 0; 44 if (!buf) 45 return -EINVAL; 46 47 mutex_lock(&sl->master->bus_mutex); 48 dev_dbg(&sl->dev, "mutex locked"); 49 50 if (w1_reset_select_slave(sl)) { 51 mutex_unlock(&sl->master->bus_mutex); 52 return -EIO; 53 } 54 55 w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ); 56 *buf = w1_read_8(sl->master); 57 58 mutex_unlock(&sl->master->bus_mutex); 59 dev_dbg(&sl->dev, "mutex unlocked"); 60 61 /* check for correct complement */ 62 if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F)) 63 return -EIO; 64 else 65 return 1; 66 } 67 68 static ssize_t w1_f3a_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[3]; 75 unsigned int retries = W1_F3A_RETRIES; 76 77 if (count != 1 || off != 0) 78 return -EFAULT; 79 80 dev_dbg(&sl->dev, "locking mutex for write_output"); 81 mutex_lock(&sl->master->bus_mutex); 82 dev_dbg(&sl->dev, "mutex locked"); 83 84 if (w1_reset_select_slave(sl)) 85 goto error; 86 87 /* according to the DS2413 datasheet the most significant 6 bits 88 should be set to "1"s, so do it now */ 89 *buf = *buf | 0xFC; 90 91 while (retries--) { 92 w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE; 93 w1_buf[1] = *buf; 94 w1_buf[2] = ~(*buf); 95 w1_write_block(sl->master, w1_buf, 3); 96 97 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) { 98 mutex_unlock(&sl->master->bus_mutex); 99 dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries); 100 return 1; 101 } 102 if (w1_reset_resume_command(sl->master)) 103 goto error; 104 } 105 106 error: 107 mutex_unlock(&sl->master->bus_mutex); 108 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); 109 return -EIO; 110 } 111 112 #define NB_SYSFS_BIN_FILES 2 113 static struct bin_attribute w1_f3a_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { 114 { 115 .attr = { 116 .name = "state", 117 .mode = S_IRUGO, 118 }, 119 .size = 1, 120 .read = w1_f3a_read_state, 121 }, 122 { 123 .attr = { 124 .name = "output", 125 .mode = S_IRUGO | S_IWUSR | S_IWGRP, 126 }, 127 .size = 1, 128 .write = w1_f3a_write_output, 129 } 130 }; 131 132 static int w1_f3a_add_slave(struct w1_slave *sl) 133 { 134 int err = 0; 135 int i; 136 137 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) 138 err = sysfs_create_bin_file( 139 &sl->dev.kobj, 140 &(w1_f3a_sysfs_bin_files[i])); 141 if (err) 142 while (--i >= 0) 143 sysfs_remove_bin_file(&sl->dev.kobj, 144 &(w1_f3a_sysfs_bin_files[i])); 145 return err; 146 } 147 148 static void w1_f3a_remove_slave(struct w1_slave *sl) 149 { 150 int i; 151 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) 152 sysfs_remove_bin_file(&sl->dev.kobj, 153 &(w1_f3a_sysfs_bin_files[i])); 154 } 155 156 static struct w1_family_ops w1_f3a_fops = { 157 .add_slave = w1_f3a_add_slave, 158 .remove_slave = w1_f3a_remove_slave, 159 }; 160 161 static struct w1_family w1_family_3a = { 162 .fid = W1_FAMILY_DS2413, 163 .fops = &w1_f3a_fops, 164 }; 165 166 static int __init w1_f3a_init(void) 167 { 168 return w1_register_family(&w1_family_3a); 169 } 170 171 static void __exit w1_f3a_exit(void) 172 { 173 w1_unregister_family(&w1_family_3a); 174 } 175 176 module_init(w1_f3a_init); 177 module_exit(w1_f3a_exit); 178