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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 | // SPDX-License-Identifier: GPL-2.0-only /* * w1_ds2408.c - w1 family 29 (DS2408) driver * * Copyright (c) 2010 Jean-Francois Dagenais <dagenaisj@sonatest.com> */ #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_DS2408 0x29 #define W1_F29_RETRIES 3 #define W1_F29_REG_LOGIG_STATE 0x88 /* R */ #define W1_F29_REG_OUTPUT_LATCH_STATE 0x89 /* R */ #define W1_F29_REG_ACTIVITY_LATCH_STATE 0x8A /* R */ #define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */ #define W1_F29_REG_COND_SEARCH_POL_SELECT 0x8C /* RW */ #define W1_F29_REG_CONTROL_AND_STATUS 0x8D /* RW */ #define W1_F29_FUNC_READ_PIO_REGS 0xF0 #define W1_F29_FUNC_CHANN_ACCESS_READ 0xF5 #define W1_F29_FUNC_CHANN_ACCESS_WRITE 0x5A /* also used to write the control/status reg (0x8D): */ #define W1_F29_FUNC_WRITE_COND_SEARCH_REG 0xCC #define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3 #define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf) { u8 wrbuf[3]; dev_dbg(&sl->dev, "Reading with slave: %p, reg addr: %0#4x, buff addr: %p", sl, (unsigned int)address, buf); if (!buf) return -EINVAL; mutex_lock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "mutex locked"); if (w1_reset_select_slave(sl)) { mutex_unlock(&sl->master->bus_mutex); return -EIO; } wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS; wrbuf[1] = address; wrbuf[2] = 0; w1_write_block(sl->master, wrbuf, 3); *buf = w1_read_8(sl->master); mutex_unlock(&sl->master->bus_mutex); dev_dbg(&sl->dev, "mutex unlocked"); return 1; } static ssize_t state_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { dev_dbg(&kobj_to_w1_slave(kobj)->dev, "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", bin_attr->attr.name, kobj, (unsigned int)off, count, buf); if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf); } static ssize_t output_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { dev_dbg(&kobj_to_w1_slave(kobj)->dev, "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", bin_attr->attr.name, kobj, (unsigned int)off, count, buf); if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_OUTPUT_LATCH_STATE, buf); } static ssize_t activity_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { dev_dbg(&kobj_to_w1_slave(kobj)->dev, "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", bin_attr->attr.name, kobj, (unsigned int)off, count, buf); if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_ACTIVITY_LATCH_STATE, buf); } static ssize_t cond_search_mask_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { dev_dbg(&kobj_to_w1_slave(kobj)->dev, "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", bin_attr->attr.name, kobj, (unsigned int)off, count, buf); if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_COND_SEARCH_SELECT_MASK, buf); } static ssize_t cond_search_polarity_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_COND_SEARCH_POL_SELECT, buf); } static ssize_t status_control_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { if (count != 1 || off != 0) return -EFAULT; return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_CONTROL_AND_STATUS, buf); } #ifdef CONFIG_W1_SLAVE_DS2408_READBACK static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) { u8 w1_buf[3]; if (w1_reset_resume_command(sl->master)) return false; w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; w1_buf[2] = 0; w1_write_block(sl->master, w1_buf, 3); return (w1_read_8(sl->master) == expected); } #else static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) { return true; } #endif 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_F29_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; do { w1_buf[0] = W1_F29_FUNC_CHANN_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_F29_SUCCESS_CONFIRM_BYTE && optional_read_back_valid(sl, *buf)) { bytes_written = 1; goto out; } if (w1_reset_resume_command(sl->master)) goto out; /* unrecoverable error */ /* try again, the slave is ready for a command */ } while (--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; } /** * Writing to the activity file resets the activity latches. */ static ssize_t activity_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); unsigned int retries = W1_F29_RETRIES; if (count != 1 || off != 0) return -EFAULT; mutex_lock(&sl->master->bus_mutex); if (w1_reset_select_slave(sl)) goto error; while (retries--) { w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES); if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) { mutex_unlock(&sl->master->bus_mutex); return 1; } if (w1_reset_resume_command(sl->master)) goto error; } error: mutex_unlock(&sl->master->bus_mutex); return -EIO; } static ssize_t status_control_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[4]; unsigned int retries = W1_F29_RETRIES; if (count != 1 || off != 0) return -EFAULT; mutex_lock(&sl->master->bus_mutex); if (w1_reset_select_slave(sl)) goto error; while (retries--) { w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG; w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; w1_buf[2] = 0; w1_buf[3] = *buf; w1_write_block(sl->master, w1_buf, 4); if (w1_reset_resume_command(sl->master)) goto error; w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; w1_buf[2] = 0; w1_write_block(sl->master, w1_buf, 3); if (w1_read_8(sl->master) == *buf) { /* success! */ mutex_unlock(&sl->master->bus_mutex); return 1; } } error: mutex_unlock(&sl->master->bus_mutex); return -EIO; } /* * This is a special sequence we must do to ensure the P0 output is not stuck * in test mode. This is described in rev 2 of the ds2408's datasheet * (http://datasheets.maximintegrated.com/en/ds/DS2408.pdf) under * "APPLICATION INFORMATION/Power-up timing". */ static int w1_f29_disable_test_mode(struct w1_slave *sl) { int res; u8 magic[10] = {0x96, }; u64 rn = le64_to_cpu(*((u64*)&sl->reg_num)); memcpy(&magic[1], &rn, 8); magic[9] = 0x3C; mutex_lock(&sl->master->bus_mutex); res = w1_reset_bus(sl->master); if (res) goto out; w1_write_block(sl->master, magic, ARRAY_SIZE(magic)); res = w1_reset_bus(sl->master); out: mutex_unlock(&sl->master->bus_mutex); return res; } static BIN_ATTR_RO(state, 1); static BIN_ATTR_RW(output, 1); static BIN_ATTR_RW(activity, 1); static BIN_ATTR_RO(cond_search_mask, 1); static BIN_ATTR_RO(cond_search_polarity, 1); static BIN_ATTR_RW(status_control, 1); static struct bin_attribute *w1_f29_bin_attrs[] = { &bin_attr_state, &bin_attr_output, &bin_attr_activity, &bin_attr_cond_search_mask, &bin_attr_cond_search_polarity, &bin_attr_status_control, NULL, }; static const struct attribute_group w1_f29_group = { .bin_attrs = w1_f29_bin_attrs, }; static const struct attribute_group *w1_f29_groups[] = { &w1_f29_group, NULL, }; static const struct w1_family_ops w1_f29_fops = { .add_slave = w1_f29_disable_test_mode, .groups = w1_f29_groups, }; static struct w1_family w1_family_29 = { .fid = W1_FAMILY_DS2408, .fops = &w1_f29_fops, }; module_w1_family(w1_family_29); MODULE_AUTHOR("Jean-Francois Dagenais <dagenaisj@sonatest.com>"); MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO"); MODULE_LICENSE("GPL"); MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2408)); |