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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | // SPDX-License-Identifier: GPL-2.0-only /* * w1_ds2406.c - w1 family 12 (DS2406) driver * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net> * * Copyright (c) 2014 Scott Alfter <scott@alfter.us> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/device.h> #include <linux/types.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/crc16.h> #include <linux/w1.h> #define W1_FAMILY_DS2406 0x12 #define W1_F12_FUNC_READ_STATUS 0xAA #define W1_F12_FUNC_WRITE_STATUS 0x55 static ssize_t w1_f12_read_state( struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { u8 w1_buf[6] = {W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0}; struct w1_slave *sl = kobj_to_w1_slave(kobj); u16 crc = 0; int i; ssize_t rtnval = 1; if (off != 0) return 0; if (!buf) return -EINVAL; mutex_lock(&sl->master->bus_mutex); if (w1_reset_select_slave(sl)) { mutex_unlock(&sl->master->bus_mutex); return -EIO; } w1_write_block(sl->master, w1_buf, 3); w1_read_block(sl->master, w1_buf+3, 3); for (i = 0; i < 6; i++) crc = crc16_byte(crc, w1_buf[i]); if (crc == 0xb001) /* good read? */ *buf = ((w1_buf[3]>>5)&3)|0x30; else rtnval = -EIO; mutex_unlock(&sl->master->bus_mutex); return rtnval; } static ssize_t w1_f12_write_output( struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); u8 w1_buf[6] = {W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0}; u16 crc = 0; int i; ssize_t rtnval = 1; if (count != 1 || off != 0) return -EFAULT; mutex_lock(&sl->master->bus_mutex); if (w1_reset_select_slave(sl)) { mutex_unlock(&sl->master->bus_mutex); return -EIO; } w1_buf[3] = (((*buf)&3)<<5)|0x1F; w1_write_block(sl->master, w1_buf, 4); w1_read_block(sl->master, w1_buf+4, 2); for (i = 0; i < 6; i++) crc = crc16_byte(crc, w1_buf[i]); if (crc == 0xb001) /* good read? */ w1_write_8(sl->master, 0xFF); else rtnval = -EIO; mutex_unlock(&sl->master->bus_mutex); return rtnval; } #define NB_SYSFS_BIN_FILES 2 static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { { .attr = { .name = "state", .mode = 0444, }, .size = 1, .read = w1_f12_read_state, }, { .attr = { .name = "output", .mode = 0664, }, .size = 1, .write = w1_f12_write_output, } }; static int w1_f12_add_slave(struct w1_slave *sl) { int err = 0; int i; for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) err = sysfs_create_bin_file( &sl->dev.kobj, &(w1_f12_sysfs_bin_files[i])); if (err) while (--i >= 0) sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f12_sysfs_bin_files[i])); return err; } static void w1_f12_remove_slave(struct w1_slave *sl) { int i; for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f12_sysfs_bin_files[i])); } static const struct w1_family_ops w1_f12_fops = { .add_slave = w1_f12_add_slave, .remove_slave = w1_f12_remove_slave, }; static struct w1_family w1_family_12 = { .fid = W1_FAMILY_DS2406, .fops = &w1_f12_fops, }; module_w1_family(w1_family_12); MODULE_AUTHOR("Scott Alfter <scott@alfter.us>"); MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO"); MODULE_LICENSE("GPL"); |