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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | // SPDX-License-Identifier: GPL-2.0-only /* * w1_ds2413.c - w1 family 3a (DS2413) driver * based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com> * * Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net> */ #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/w1.h> #define W1_FAMILY_DS2413 0x3A #define W1_F3A_RETRIES 3 #define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5 #define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A #define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA #define W1_F3A_INVALID_PIO_STATE 0xFF static ssize_t state_read(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); unsigned int retries = W1_F3A_RETRIES; ssize_t bytes_read = -EIO; u8 state; dev_dbg(&sl->dev, "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", bin_attr->attr.name, kobj, (unsigned int)off, count, buf); if (off != 0) return 0; if (!buf) return -EINVAL; mutex_lock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "mutex locked"); next: if (w1_reset_select_slave(sl)) goto out; while (retries--) { w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ); state = w1_read_8(sl->master); if ((state & 0x0F) == ((~state >> 4) & 0x0F)) { /* complement is correct */ *buf = state; bytes_read = 1; goto out; } else if (state == W1_F3A_INVALID_PIO_STATE) { /* slave didn't respond, try to select it again */ dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \ "reselecting, retries left: %d\n", retries); goto next; } if (w1_reset_resume_command(sl->master)) goto out; /* unrecoverable error */ dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries); } out: mutex_unlock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n", (bytes_read > 0) ? "succeeded" : "error", retries); return bytes_read; } static BIN_ATTR_RO(state, 1); static ssize_t output_write(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[3]; unsigned int retries = W1_F3A_RETRIES; ssize_t bytes_written = -EIO; if (count != 1 || off != 0) return -EFAULT; dev_dbg(&sl->dev, "locking mutex for write_output"); mutex_lock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "mutex locked"); if (w1_reset_select_slave(sl)) goto out; /* * according to the DS2413 datasheet the most significant 6 bits * should be set to "1"s, so do it now */ *buf = *buf | 0xFC; while (retries--) { w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE; w1_buf[1] = *buf; w1_buf[2] = ~(*buf); w1_write_block(sl->master, w1_buf, 3); if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) { bytes_written = 1; goto out; } if (w1_reset_resume_command(sl->master)) goto out; /* unrecoverable error */ dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries); } out: mutex_unlock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n", (bytes_written > 0) ? "succeeded" : "error", retries); return bytes_written; } static BIN_ATTR(output, 0664, NULL, output_write, 1); static struct bin_attribute *w1_f3a_bin_attrs[] = { &bin_attr_state, &bin_attr_output, NULL, }; static const struct attribute_group w1_f3a_group = { .bin_attrs = w1_f3a_bin_attrs, }; static const struct attribute_group *w1_f3a_groups[] = { &w1_f3a_group, NULL, }; static const struct w1_family_ops w1_f3a_fops = { .groups = w1_f3a_groups, }; static struct w1_family w1_family_3a = { .fid = W1_FAMILY_DS2413, .fops = &w1_f3a_fops, }; module_w1_family(w1_family_3a); MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>"); MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO"); MODULE_LICENSE("GPL"); MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413)); |