andrea.merello | 7f07ec0 | 2017-02-02 08:44:03 +0100 | [diff] [blame] | 1 | /* |
| 2 | * STTS751 sensor driver |
| 3 | * |
| 4 | * Copyright (C) 2016-2017 Istituto Italiano di Tecnologia - RBCS - EDL |
| 5 | * Robotics, Brain and Cognitive Sciences department |
| 6 | * Electronic Design Laboratory |
| 7 | * |
| 8 | * Written by Andrea Merello <andrea.merello@gmail.com> |
| 9 | * |
| 10 | * Based on LM95241 driver and LM90 driver |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/bitops.h> |
| 24 | #include <linux/err.h> |
| 25 | #include <linux/hwmon.h> |
| 26 | #include <linux/hwmon-sysfs.h> |
| 27 | #include <linux/i2c.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/interrupt.h> |
| 30 | #include <linux/jiffies.h> |
| 31 | #include <linux/module.h> |
| 32 | #include <linux/mutex.h> |
| 33 | #include <linux/property.h> |
| 34 | #include <linux/slab.h> |
| 35 | #include <linux/sysfs.h> |
| 36 | #include <linux/util_macros.h> |
| 37 | |
| 38 | #define DEVNAME "stts751" |
| 39 | |
| 40 | static const unsigned short normal_i2c[] = { |
| 41 | 0x48, 0x49, 0x38, 0x39, /* STTS751-0 */ |
| 42 | 0x4A, 0x4B, 0x3A, 0x3B, /* STTS751-1 */ |
| 43 | I2C_CLIENT_END }; |
| 44 | |
| 45 | #define STTS751_REG_TEMP_H 0x00 |
| 46 | #define STTS751_REG_STATUS 0x01 |
| 47 | #define STTS751_STATUS_TRIPT BIT(0) |
| 48 | #define STTS751_STATUS_TRIPL BIT(5) |
| 49 | #define STTS751_STATUS_TRIPH BIT(6) |
| 50 | #define STTS751_REG_TEMP_L 0x02 |
| 51 | #define STTS751_REG_CONF 0x03 |
| 52 | #define STTS751_CONF_RES_MASK 0x0C |
| 53 | #define STTS751_CONF_RES_SHIFT 2 |
| 54 | #define STTS751_CONF_EVENT_DIS BIT(7) |
| 55 | #define STTS751_CONF_STOP BIT(6) |
| 56 | #define STTS751_REG_RATE 0x04 |
| 57 | #define STTS751_REG_HLIM_H 0x05 |
| 58 | #define STTS751_REG_HLIM_L 0x06 |
| 59 | #define STTS751_REG_LLIM_H 0x07 |
| 60 | #define STTS751_REG_LLIM_L 0x08 |
| 61 | #define STTS751_REG_TLIM 0x20 |
| 62 | #define STTS751_REG_HYST 0x21 |
| 63 | #define STTS751_REG_SMBUS_TO 0x22 |
| 64 | |
| 65 | #define STTS751_REG_PROD_ID 0xFD |
| 66 | #define STTS751_REG_MAN_ID 0xFE |
| 67 | #define STTS751_REG_REV_ID 0xFF |
| 68 | |
| 69 | #define STTS751_0_PROD_ID 0x00 |
| 70 | #define STTS751_1_PROD_ID 0x01 |
| 71 | #define ST_MAN_ID 0x53 |
| 72 | |
| 73 | /* |
| 74 | * Possible update intervals are (in mS): |
| 75 | * 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, 31.25 |
| 76 | * However we are not going to complicate things too much and we stick to the |
| 77 | * approx value in mS. |
| 78 | */ |
| 79 | static const int stts751_intervals[] = { |
| 80 | 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31 |
| 81 | }; |
| 82 | |
| 83 | static const struct i2c_device_id stts751_id[] = { |
| 84 | { "stts751", 0 }, |
| 85 | { } |
| 86 | }; |
| 87 | |
Javier Martinez Canillas | 1c1a7b7 | 2017-02-24 10:13:09 -0300 | [diff] [blame] | 88 | static const struct of_device_id stts751_of_match[] = { |
| 89 | { .compatible = "stts751" }, |
| 90 | { }, |
| 91 | }; |
| 92 | MODULE_DEVICE_TABLE(of, stts751_of_match); |
| 93 | |
andrea.merello | 7f07ec0 | 2017-02-02 08:44:03 +0100 | [diff] [blame] | 94 | struct stts751_priv { |
| 95 | struct device *dev; |
| 96 | struct i2c_client *client; |
| 97 | struct mutex access_lock; |
| 98 | u8 interval; |
| 99 | int res; |
| 100 | int event_max, event_min; |
| 101 | int therm; |
| 102 | int hyst; |
| 103 | bool smbus_timeout; |
| 104 | int temp; |
| 105 | unsigned long last_update, last_alert_update; |
| 106 | u8 config; |
| 107 | bool min_alert, max_alert, therm_trip; |
| 108 | bool data_valid, alert_valid; |
| 109 | bool notify_max, notify_min; |
| 110 | }; |
| 111 | |
| 112 | /* |
| 113 | * These functions converts temperature from HW format to integer format and |
| 114 | * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC. |
| 115 | */ |
| 116 | static int stts751_to_deg(s16 hw_val) |
| 117 | { |
| 118 | return hw_val * 125 / 32; |
| 119 | } |
| 120 | |
| 121 | static s32 stts751_to_hw(int val) |
| 122 | { |
| 123 | return DIV_ROUND_CLOSEST(val, 125) * 32; |
| 124 | } |
| 125 | |
| 126 | static int stts751_adjust_resolution(struct stts751_priv *priv) |
| 127 | { |
| 128 | u8 res; |
| 129 | |
| 130 | switch (priv->interval) { |
| 131 | case 9: |
| 132 | /* 10 bits */ |
| 133 | res = 0; |
| 134 | break; |
| 135 | case 8: |
| 136 | /* 11 bits */ |
| 137 | res = 1; |
| 138 | break; |
| 139 | default: |
| 140 | /* 12 bits */ |
| 141 | res = 3; |
| 142 | break; |
| 143 | } |
| 144 | |
| 145 | if (priv->res == res) |
| 146 | return 0; |
| 147 | |
| 148 | priv->config &= ~STTS751_CONF_RES_MASK; |
| 149 | priv->config |= res << STTS751_CONF_RES_SHIFT; |
| 150 | dev_dbg(&priv->client->dev, "setting res %d. config %x", |
| 151 | res, priv->config); |
| 152 | priv->res = res; |
| 153 | |
| 154 | return i2c_smbus_write_byte_data(priv->client, |
| 155 | STTS751_REG_CONF, priv->config); |
| 156 | } |
| 157 | |
| 158 | static int stts751_update_temp(struct stts751_priv *priv) |
| 159 | { |
| 160 | s32 integer1, integer2, frac; |
| 161 | |
| 162 | /* |
| 163 | * There is a trick here, like in the lm90 driver. We have to read two |
| 164 | * registers to get the sensor temperature, but we have to beware a |
| 165 | * conversion could occur between the readings. We could use the |
| 166 | * one-shot conversion register, but we don't want to do this (disables |
| 167 | * hardware monitoring). So the solution used here is to read the high |
| 168 | * byte once, then the low byte, then the high byte again. If the new |
| 169 | * high byte matches the old one, then we have a valid reading. Else we |
| 170 | * have to read the low byte again, and now we believe we have a correct |
| 171 | * reading. |
| 172 | */ |
| 173 | integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); |
| 174 | if (integer1 < 0) { |
| 175 | dev_dbg(&priv->client->dev, |
| 176 | "I2C read failed (temp H). ret: %x\n", integer1); |
| 177 | return integer1; |
| 178 | } |
| 179 | |
| 180 | frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L); |
| 181 | if (frac < 0) { |
| 182 | dev_dbg(&priv->client->dev, |
| 183 | "I2C read failed (temp L). ret: %x\n", frac); |
| 184 | return frac; |
| 185 | } |
| 186 | |
| 187 | integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); |
| 188 | if (integer2 < 0) { |
| 189 | dev_dbg(&priv->client->dev, |
| 190 | "I2C 2nd read failed (temp H). ret: %x\n", integer2); |
| 191 | return integer2; |
| 192 | } |
| 193 | |
| 194 | if (integer1 != integer2) { |
| 195 | frac = i2c_smbus_read_byte_data(priv->client, |
| 196 | STTS751_REG_TEMP_L); |
| 197 | if (frac < 0) { |
| 198 | dev_dbg(&priv->client->dev, |
| 199 | "I2C 2nd read failed (temp L). ret: %x\n", |
| 200 | frac); |
| 201 | return frac; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | priv->temp = stts751_to_deg((integer1 << 8) | frac); |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp, |
| 210 | u8 hreg, u8 lreg) |
| 211 | { |
| 212 | s32 hwval; |
| 213 | int ret; |
| 214 | |
| 215 | hwval = stts751_to_hw(temp); |
| 216 | |
| 217 | ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8); |
| 218 | if (ret) |
| 219 | return ret; |
| 220 | |
| 221 | return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff); |
| 222 | } |
| 223 | |
| 224 | static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg) |
| 225 | { |
| 226 | s32 hwval; |
| 227 | |
| 228 | hwval = stts751_to_hw(temp); |
| 229 | return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8); |
| 230 | } |
| 231 | |
| 232 | static int stts751_read_reg16(struct stts751_priv *priv, int *temp, |
| 233 | u8 hreg, u8 lreg) |
| 234 | { |
| 235 | int integer, frac; |
| 236 | |
| 237 | integer = i2c_smbus_read_byte_data(priv->client, hreg); |
| 238 | if (integer < 0) |
| 239 | return integer; |
| 240 | |
| 241 | frac = i2c_smbus_read_byte_data(priv->client, lreg); |
| 242 | if (frac < 0) |
| 243 | return frac; |
| 244 | |
| 245 | *temp = stts751_to_deg((integer << 8) | frac); |
| 246 | |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg) |
| 251 | { |
| 252 | int integer; |
| 253 | |
| 254 | integer = i2c_smbus_read_byte_data(priv->client, reg); |
| 255 | if (integer < 0) |
| 256 | return integer; |
| 257 | |
| 258 | *temp = stts751_to_deg(integer << 8); |
| 259 | |
| 260 | return 0; |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * Update alert flags without waiting for cache to expire. We detects alerts |
| 265 | * immediately for the sake of the alert handler; we still need to deal with |
| 266 | * caching to workaround the fact that alarm flags int the status register, |
| 267 | * despite what the datasheet claims, gets always cleared on read. |
| 268 | */ |
| 269 | static int stts751_update_alert(struct stts751_priv *priv) |
| 270 | { |
| 271 | int ret; |
| 272 | bool conv_done; |
| 273 | int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); |
| 274 | |
| 275 | /* |
| 276 | * Add another 10% because if we run faster than the HW conversion |
| 277 | * rate we will end up in reporting incorrectly alarms. |
| 278 | */ |
| 279 | cache_time += cache_time / 10; |
| 280 | |
| 281 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS); |
| 282 | if (ret < 0) |
| 283 | return ret; |
| 284 | |
| 285 | dev_dbg(&priv->client->dev, "status reg %x\n", ret); |
| 286 | conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL); |
| 287 | /* |
| 288 | * Reset the cache if the cache time expired, or if we are sure |
| 289 | * we have valid data from a device conversion, or if we know |
| 290 | * our cache has been never written. |
| 291 | * |
| 292 | * Note that when the cache has been never written the point is |
| 293 | * to correctly initialize the timestamp, rather than clearing |
| 294 | * the cache values. |
| 295 | * |
| 296 | * Note that updating the cache timestamp when we get an alarm flag |
| 297 | * is required, otherwise we could incorrectly report alarms to be zero. |
| 298 | */ |
| 299 | if (time_after(jiffies, priv->last_alert_update + cache_time) || |
| 300 | conv_done || !priv->alert_valid) { |
| 301 | priv->max_alert = false; |
| 302 | priv->min_alert = false; |
| 303 | priv->alert_valid = true; |
| 304 | priv->last_alert_update = jiffies; |
| 305 | dev_dbg(&priv->client->dev, "invalidating alert cache\n"); |
| 306 | } |
| 307 | |
| 308 | priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH); |
| 309 | priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL); |
| 310 | priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT); |
| 311 | |
| 312 | dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n", |
| 313 | priv->max_alert, priv->min_alert, priv->therm_trip); |
| 314 | |
| 315 | return 0; |
| 316 | } |
| 317 | |
| 318 | static void stts751_alert(struct i2c_client *client, |
| 319 | enum i2c_alert_protocol type, unsigned int data) |
| 320 | { |
| 321 | int ret; |
| 322 | struct stts751_priv *priv = i2c_get_clientdata(client); |
| 323 | |
| 324 | if (type != I2C_PROTOCOL_SMBUS_ALERT) |
| 325 | return; |
| 326 | |
| 327 | dev_dbg(&client->dev, "alert!"); |
| 328 | |
| 329 | mutex_lock(&priv->access_lock); |
| 330 | ret = stts751_update_alert(priv); |
| 331 | if (ret < 0) { |
| 332 | /* default to worst case */ |
| 333 | priv->max_alert = true; |
| 334 | priv->min_alert = true; |
| 335 | |
| 336 | dev_warn(priv->dev, |
| 337 | "Alert received, but can't communicate to the device. Triggering all alarms!"); |
| 338 | } |
| 339 | |
| 340 | if (priv->max_alert) { |
| 341 | if (priv->notify_max) |
| 342 | dev_notice(priv->dev, "got alert for HIGH temperature"); |
| 343 | priv->notify_max = false; |
| 344 | |
| 345 | /* unblock alert poll */ |
| 346 | sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm"); |
| 347 | } |
| 348 | |
| 349 | if (priv->min_alert) { |
| 350 | if (priv->notify_min) |
| 351 | dev_notice(priv->dev, "got alert for LOW temperature"); |
| 352 | priv->notify_min = false; |
| 353 | |
| 354 | /* unblock alert poll */ |
| 355 | sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm"); |
| 356 | } |
| 357 | |
| 358 | if (priv->min_alert || priv->max_alert) |
| 359 | kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE); |
| 360 | |
| 361 | mutex_unlock(&priv->access_lock); |
| 362 | } |
| 363 | |
| 364 | static int stts751_update(struct stts751_priv *priv) |
| 365 | { |
| 366 | int ret; |
| 367 | int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); |
| 368 | |
| 369 | if (time_after(jiffies, priv->last_update + cache_time) || |
| 370 | !priv->data_valid) { |
| 371 | ret = stts751_update_temp(priv); |
| 372 | if (ret) |
| 373 | return ret; |
| 374 | |
| 375 | ret = stts751_update_alert(priv); |
| 376 | if (ret) |
| 377 | return ret; |
| 378 | priv->data_valid = true; |
| 379 | priv->last_update = jiffies; |
| 380 | } |
| 381 | |
| 382 | return 0; |
| 383 | } |
| 384 | |
| 385 | static ssize_t show_max_alarm(struct device *dev, struct device_attribute *attr, |
| 386 | char *buf) |
| 387 | { |
| 388 | int ret; |
| 389 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 390 | |
| 391 | mutex_lock(&priv->access_lock); |
| 392 | ret = stts751_update(priv); |
| 393 | if (!ret) |
| 394 | priv->notify_max = true; |
| 395 | mutex_unlock(&priv->access_lock); |
| 396 | if (ret < 0) |
| 397 | return ret; |
| 398 | |
| 399 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->max_alert); |
| 400 | } |
| 401 | |
| 402 | static ssize_t show_min_alarm(struct device *dev, struct device_attribute *attr, |
| 403 | char *buf) |
| 404 | { |
| 405 | int ret; |
| 406 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 407 | |
| 408 | mutex_lock(&priv->access_lock); |
| 409 | ret = stts751_update(priv); |
| 410 | if (!ret) |
| 411 | priv->notify_min = true; |
| 412 | mutex_unlock(&priv->access_lock); |
| 413 | if (ret < 0) |
| 414 | return ret; |
| 415 | |
| 416 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->min_alert); |
| 417 | } |
| 418 | |
| 419 | static ssize_t show_input(struct device *dev, struct device_attribute *attr, |
| 420 | char *buf) |
| 421 | { |
| 422 | int ret; |
| 423 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 424 | |
| 425 | mutex_lock(&priv->access_lock); |
| 426 | ret = stts751_update(priv); |
| 427 | mutex_unlock(&priv->access_lock); |
| 428 | if (ret < 0) |
| 429 | return ret; |
| 430 | |
| 431 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->temp); |
| 432 | } |
| 433 | |
| 434 | static ssize_t show_therm(struct device *dev, struct device_attribute *attr, |
| 435 | char *buf) |
| 436 | { |
| 437 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 438 | |
| 439 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm); |
| 440 | } |
| 441 | |
| 442 | static ssize_t set_therm(struct device *dev, struct device_attribute *attr, |
| 443 | const char *buf, size_t count) |
| 444 | { |
| 445 | int ret; |
| 446 | long temp; |
| 447 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 448 | |
| 449 | if (kstrtol(buf, 10, &temp) < 0) |
| 450 | return -EINVAL; |
| 451 | |
| 452 | /* HW works in range -64C to +127.937C */ |
| 453 | temp = clamp_val(temp, -64000, 127937); |
| 454 | mutex_lock(&priv->access_lock); |
| 455 | ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM); |
| 456 | if (ret) |
| 457 | goto exit; |
| 458 | |
| 459 | dev_dbg(&priv->client->dev, "setting therm %ld", temp); |
| 460 | |
| 461 | /* |
| 462 | * hysteresis reg is relative to therm, so the HW does not need to be |
| 463 | * adjusted, we need to update our local copy only. |
| 464 | */ |
| 465 | priv->hyst = temp - (priv->therm - priv->hyst); |
| 466 | priv->therm = temp; |
| 467 | |
| 468 | exit: |
| 469 | mutex_unlock(&priv->access_lock); |
| 470 | if (ret) |
| 471 | return ret; |
| 472 | |
| 473 | return count; |
| 474 | } |
| 475 | |
| 476 | static ssize_t show_hyst(struct device *dev, struct device_attribute *attr, |
| 477 | char *buf) |
| 478 | { |
| 479 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 480 | |
| 481 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->hyst); |
| 482 | } |
| 483 | |
| 484 | static ssize_t set_hyst(struct device *dev, struct device_attribute *attr, |
| 485 | const char *buf, size_t count) |
| 486 | { |
| 487 | int ret; |
| 488 | long temp; |
| 489 | |
| 490 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 491 | |
| 492 | if (kstrtol(buf, 10, &temp) < 0) |
| 493 | return -EINVAL; |
| 494 | |
| 495 | mutex_lock(&priv->access_lock); |
| 496 | /* HW works in range -64C to +127.937C */ |
| 497 | temp = clamp_val(temp, -64000, priv->therm); |
| 498 | priv->hyst = temp; |
| 499 | dev_dbg(&priv->client->dev, "setting hyst %ld", temp); |
| 500 | temp = priv->therm - temp; |
| 501 | ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST); |
| 502 | mutex_unlock(&priv->access_lock); |
| 503 | if (ret) |
| 504 | return ret; |
| 505 | |
| 506 | return count; |
| 507 | } |
| 508 | |
| 509 | static ssize_t show_therm_trip(struct device *dev, |
| 510 | struct device_attribute *attr, char *buf) |
| 511 | { |
| 512 | int ret; |
| 513 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 514 | |
| 515 | mutex_lock(&priv->access_lock); |
| 516 | ret = stts751_update(priv); |
| 517 | mutex_unlock(&priv->access_lock); |
| 518 | if (ret < 0) |
| 519 | return ret; |
| 520 | |
| 521 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm_trip); |
| 522 | } |
| 523 | |
| 524 | static ssize_t show_max(struct device *dev, struct device_attribute *attr, |
| 525 | char *buf) |
| 526 | { |
| 527 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 528 | |
| 529 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_max); |
| 530 | } |
| 531 | |
| 532 | static ssize_t set_max(struct device *dev, struct device_attribute *attr, |
| 533 | const char *buf, size_t count) |
| 534 | { |
| 535 | int ret; |
| 536 | long temp; |
| 537 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 538 | |
| 539 | if (kstrtol(buf, 10, &temp) < 0) |
| 540 | return -EINVAL; |
| 541 | |
| 542 | mutex_lock(&priv->access_lock); |
| 543 | /* HW works in range -64C to +127.937C */ |
| 544 | temp = clamp_val(temp, priv->event_min, 127937); |
| 545 | ret = stts751_set_temp_reg16(priv, temp, |
| 546 | STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); |
| 547 | if (ret) |
| 548 | goto exit; |
| 549 | |
| 550 | dev_dbg(&priv->client->dev, "setting event max %ld", temp); |
| 551 | priv->event_max = temp; |
| 552 | ret = count; |
| 553 | exit: |
| 554 | mutex_unlock(&priv->access_lock); |
| 555 | return ret; |
| 556 | } |
| 557 | |
| 558 | static ssize_t show_min(struct device *dev, struct device_attribute *attr, |
| 559 | char *buf) |
| 560 | { |
| 561 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 562 | |
| 563 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_min); |
| 564 | } |
| 565 | |
| 566 | static ssize_t set_min(struct device *dev, struct device_attribute *attr, |
| 567 | const char *buf, size_t count) |
| 568 | { |
| 569 | int ret; |
| 570 | long temp; |
| 571 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 572 | |
| 573 | if (kstrtol(buf, 10, &temp) < 0) |
| 574 | return -EINVAL; |
| 575 | |
| 576 | mutex_lock(&priv->access_lock); |
| 577 | /* HW works in range -64C to +127.937C */ |
| 578 | temp = clamp_val(temp, -64000, priv->event_max); |
| 579 | ret = stts751_set_temp_reg16(priv, temp, |
| 580 | STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); |
| 581 | if (ret) |
| 582 | goto exit; |
| 583 | |
| 584 | dev_dbg(&priv->client->dev, "setting event min %ld", temp); |
| 585 | priv->event_min = temp; |
| 586 | ret = count; |
| 587 | exit: |
| 588 | mutex_unlock(&priv->access_lock); |
| 589 | return ret; |
| 590 | } |
| 591 | |
| 592 | static ssize_t show_interval(struct device *dev, struct device_attribute *attr, |
| 593 | char *buf) |
| 594 | { |
| 595 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 596 | |
| 597 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", |
| 598 | stts751_intervals[priv->interval]); |
| 599 | } |
| 600 | |
| 601 | static ssize_t set_interval(struct device *dev, struct device_attribute *attr, |
| 602 | const char *buf, size_t count) |
| 603 | { |
| 604 | unsigned long val; |
| 605 | int idx; |
| 606 | int ret = count; |
| 607 | struct stts751_priv *priv = dev_get_drvdata(dev); |
| 608 | |
| 609 | if (kstrtoul(buf, 10, &val) < 0) |
| 610 | return -EINVAL; |
| 611 | |
| 612 | idx = find_closest_descending(val, stts751_intervals, |
| 613 | ARRAY_SIZE(stts751_intervals)); |
| 614 | |
| 615 | dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d", |
| 616 | val, idx, stts751_intervals[idx]); |
| 617 | |
| 618 | mutex_lock(&priv->access_lock); |
| 619 | if (priv->interval == idx) |
| 620 | goto exit; |
| 621 | |
| 622 | /* |
| 623 | * In early development stages I've become suspicious about the chip |
| 624 | * starting to misbehave if I ever set, even briefly, an invalid |
| 625 | * configuration. While I'm not sure this is really needed, be |
| 626 | * conservative and set rate/resolution in such an order that avoids |
| 627 | * passing through an invalid configuration. |
| 628 | */ |
| 629 | |
| 630 | /* speed up: lower the resolution, then modify convrate */ |
| 631 | if (priv->interval < idx) { |
| 632 | dev_dbg(&priv->client->dev, "lower resolution, then modify convrate"); |
| 633 | priv->interval = idx; |
| 634 | ret = stts751_adjust_resolution(priv); |
| 635 | if (ret) |
| 636 | goto exit; |
| 637 | } |
| 638 | |
| 639 | ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx); |
| 640 | if (ret) |
| 641 | goto exit; |
| 642 | /* slow down: modify convrate, then raise resolution */ |
| 643 | if (priv->interval != idx) { |
| 644 | dev_dbg(&priv->client->dev, "modify convrate, then raise resolution"); |
| 645 | priv->interval = idx; |
| 646 | ret = stts751_adjust_resolution(priv); |
| 647 | if (ret) |
| 648 | goto exit; |
| 649 | } |
| 650 | ret = count; |
| 651 | exit: |
| 652 | mutex_unlock(&priv->access_lock); |
| 653 | |
| 654 | return ret; |
| 655 | } |
| 656 | |
| 657 | static int stts751_detect(struct i2c_client *new_client, |
| 658 | struct i2c_board_info *info) |
| 659 | { |
| 660 | struct i2c_adapter *adapter = new_client->adapter; |
| 661 | const char *name; |
| 662 | int tmp; |
| 663 | |
| 664 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
| 665 | return -ENODEV; |
| 666 | |
| 667 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID); |
| 668 | if (tmp != ST_MAN_ID) |
| 669 | return -ENODEV; |
| 670 | |
| 671 | /* lower temperaure registers always have bits 0-3 set to zero */ |
| 672 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L); |
| 673 | if (tmp & 0xf) |
| 674 | return -ENODEV; |
| 675 | |
| 676 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L); |
| 677 | if (tmp & 0xf) |
| 678 | return -ENODEV; |
| 679 | |
| 680 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L); |
| 681 | if (tmp & 0xf) |
| 682 | return -ENODEV; |
| 683 | |
| 684 | /* smbus timeout register always have bits 0-7 set to zero */ |
| 685 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO); |
| 686 | if (tmp & 0x7f) |
| 687 | return -ENODEV; |
| 688 | |
| 689 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID); |
| 690 | |
| 691 | switch (tmp) { |
| 692 | case STTS751_0_PROD_ID: |
| 693 | name = "STTS751-0"; |
| 694 | break; |
| 695 | case STTS751_1_PROD_ID: |
| 696 | name = "STTS751-1"; |
| 697 | break; |
| 698 | default: |
| 699 | return -ENODEV; |
| 700 | } |
| 701 | dev_dbg(&new_client->dev, "Chip %s detected", name); |
| 702 | |
| 703 | strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE); |
| 704 | return 0; |
| 705 | } |
| 706 | |
| 707 | static int stts751_read_chip_config(struct stts751_priv *priv) |
| 708 | { |
| 709 | int ret; |
| 710 | int tmp; |
| 711 | |
| 712 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF); |
| 713 | if (ret < 0) |
| 714 | return ret; |
| 715 | priv->config = ret; |
| 716 | priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT; |
| 717 | |
| 718 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); |
| 719 | if (ret < 0) |
| 720 | return ret; |
Anton Vasilyev | 3be6bd6 | 2017-08-10 19:46:32 +0300 | [diff] [blame] | 721 | if (ret >= ARRAY_SIZE(stts751_intervals)) { |
| 722 | dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret); |
| 723 | return -ENODEV; |
| 724 | } |
andrea.merello | 7f07ec0 | 2017-02-02 08:44:03 +0100 | [diff] [blame] | 725 | priv->interval = ret; |
| 726 | |
| 727 | ret = stts751_read_reg16(priv, &priv->event_max, |
| 728 | STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); |
| 729 | if (ret) |
| 730 | return ret; |
| 731 | |
| 732 | ret = stts751_read_reg16(priv, &priv->event_min, |
| 733 | STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); |
| 734 | if (ret) |
| 735 | return ret; |
| 736 | |
| 737 | ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM); |
| 738 | if (ret) |
| 739 | return ret; |
| 740 | |
| 741 | ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST); |
| 742 | if (ret) |
| 743 | return ret; |
| 744 | priv->hyst = priv->therm - tmp; |
| 745 | |
| 746 | return 0; |
| 747 | } |
| 748 | |
| 749 | static SENSOR_DEVICE_ATTR(temp1_input, 0444, show_input, NULL, 0); |
| 750 | static SENSOR_DEVICE_ATTR(temp1_min, 0644, show_min, set_min, 0); |
| 751 | static SENSOR_DEVICE_ATTR(temp1_max, 0644, show_max, set_max, 0); |
| 752 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, 0444, show_min_alarm, NULL, 0); |
| 753 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, 0444, show_max_alarm, NULL, 0); |
| 754 | static SENSOR_DEVICE_ATTR(temp1_crit, 0644, show_therm, set_therm, 0); |
| 755 | static SENSOR_DEVICE_ATTR(temp1_crit_hyst, 0644, show_hyst, set_hyst, 0); |
| 756 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, 0444, show_therm_trip, NULL, 0); |
| 757 | static SENSOR_DEVICE_ATTR(update_interval, 0644, |
| 758 | show_interval, set_interval, 0); |
| 759 | |
| 760 | static struct attribute *stts751_attrs[] = { |
| 761 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
| 762 | &sensor_dev_attr_temp1_min.dev_attr.attr, |
| 763 | &sensor_dev_attr_temp1_max.dev_attr.attr, |
| 764 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, |
| 765 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, |
| 766 | &sensor_dev_attr_temp1_crit.dev_attr.attr, |
| 767 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, |
| 768 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
| 769 | &sensor_dev_attr_update_interval.dev_attr.attr, |
| 770 | NULL |
| 771 | }; |
| 772 | ATTRIBUTE_GROUPS(stts751); |
| 773 | |
| 774 | static int stts751_probe(struct i2c_client *client, |
| 775 | const struct i2c_device_id *id) |
| 776 | { |
| 777 | struct stts751_priv *priv; |
| 778 | int ret; |
| 779 | bool smbus_nto; |
| 780 | int rev_id; |
| 781 | |
| 782 | priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); |
| 783 | if (!priv) |
| 784 | return -ENOMEM; |
| 785 | |
| 786 | priv->client = client; |
| 787 | priv->notify_max = true; |
| 788 | priv->notify_min = true; |
| 789 | i2c_set_clientdata(client, priv); |
| 790 | mutex_init(&priv->access_lock); |
| 791 | |
| 792 | if (device_property_present(&client->dev, |
| 793 | "smbus-timeout-disable")) { |
| 794 | smbus_nto = device_property_read_bool(&client->dev, |
| 795 | "smbus-timeout-disable"); |
| 796 | |
| 797 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO, |
| 798 | smbus_nto ? 0 : 0x80); |
| 799 | if (ret) |
| 800 | return ret; |
| 801 | } |
| 802 | |
| 803 | rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID); |
| 804 | if (rev_id < 0) |
| 805 | return -ENODEV; |
| 806 | if (rev_id != 0x1) { |
| 807 | dev_dbg(&client->dev, "Chip revision 0x%x is untested\n", |
| 808 | rev_id); |
| 809 | } |
| 810 | |
| 811 | ret = stts751_read_chip_config(priv); |
| 812 | if (ret) |
| 813 | return ret; |
| 814 | |
| 815 | priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS); |
| 816 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config); |
| 817 | if (ret) |
| 818 | return ret; |
| 819 | |
| 820 | priv->dev = devm_hwmon_device_register_with_groups(&client->dev, |
| 821 | client->name, priv, |
| 822 | stts751_groups); |
| 823 | return PTR_ERR_OR_ZERO(priv->dev); |
| 824 | } |
| 825 | |
| 826 | MODULE_DEVICE_TABLE(i2c, stts751_id); |
| 827 | |
| 828 | static struct i2c_driver stts751_driver = { |
| 829 | .class = I2C_CLASS_HWMON, |
| 830 | .driver = { |
| 831 | .name = DEVNAME, |
Javier Martinez Canillas | 1c1a7b7 | 2017-02-24 10:13:09 -0300 | [diff] [blame] | 832 | .of_match_table = of_match_ptr(stts751_of_match), |
andrea.merello | 7f07ec0 | 2017-02-02 08:44:03 +0100 | [diff] [blame] | 833 | }, |
| 834 | .probe = stts751_probe, |
| 835 | .id_table = stts751_id, |
| 836 | .detect = stts751_detect, |
| 837 | .alert = stts751_alert, |
| 838 | .address_list = normal_i2c, |
| 839 | }; |
| 840 | |
| 841 | module_i2c_driver(stts751_driver); |
| 842 | |
| 843 | MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>"); |
| 844 | MODULE_DESCRIPTION("STTS751 sensor driver"); |
| 845 | MODULE_LICENSE("GPL"); |