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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * lm75.c - Part of lm_sensors, Linux kernel modules for hardware4 * monitoring5 * Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>6 */7 8#include <linux/module.h>9#include <linux/init.h>10#include <linux/interrupt.h>11#include <linux/slab.h>12#include <linux/jiffies.h>13#include <linux/i2c.h>14#include <linux/hwmon.h>15#include <linux/err.h>16#include <linux/of.h>17#include <linux/regmap.h>18#include <linux/util_macros.h>19#include <linux/regulator/consumer.h>20#include "lm75.h"21 22/*23 * This driver handles the LM75 and compatible digital temperature sensors.24 */25 26enum lm75_type { /* keep sorted in alphabetical order */27 adt75,28 as6200,29 at30ts74,30 ds1775,31 ds75,32 ds7505,33 g751,34 lm75,35 lm75a,36 lm75b,37 max6625,38 max6626,39 max31725,40 mcp980x,41 pct2075,42 stds75,43 stlm75,44 tcn75,45 tmp100,46 tmp101,47 tmp105,48 tmp112,49 tmp175,50 tmp275,51 tmp75,52 tmp75b,53 tmp75c,54 tmp1075,55};56 57/**58 * struct lm75_params - lm75 configuration parameters.59 * @config_reg_16bits: Configure register size is 2 bytes.60 * @set_mask: Bits to set in configuration register when configuring61 * the chip.62 * @clr_mask: Bits to clear in configuration register when configuring63 * the chip.64 * @default_resolution: Default number of bits to represent the temperature65 * value.66 * @resolution_limits: Limit register resolution. Optional. Should be set if67 * the resolution of limit registers does not match the68 * resolution of the temperature register.69 * @resolutions: List of resolutions associated with sample times.70 * Optional. Should be set if num_sample_times is larger71 * than 1, and if the resolution changes with sample times.72 * If set, number of entries must match num_sample_times.73 * @default_sample_time:Sample time to be set by default.74 * @num_sample_times: Number of possible sample times to be set. Optional.75 * Should be set if the number of sample times is larger76 * than one.77 * @sample_times: All the possible sample times to be set. Mandatory if78 * num_sample_times is larger than 1. If set, number of79 * entries must match num_sample_times.80 * @alarm: Alarm bit is supported.81 */82 83struct lm75_params {84 bool config_reg_16bits;85 u16 set_mask;86 u16 clr_mask;87 u8 default_resolution;88 u8 resolution_limits;89 const u8 *resolutions;90 unsigned int default_sample_time;91 u8 num_sample_times;92 const unsigned int *sample_times;93 bool alarm;94};95 96/* Addresses scanned */97static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,98 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };99 100/* The LM75 registers */101#define LM75_REG_TEMP 0x00102#define LM75_REG_CONF 0x01103#define LM75_REG_HYST 0x02104#define LM75_REG_MAX 0x03105#define PCT2075_REG_IDLE 0x04106 107/* Each client has this additional data */108struct lm75_data {109 struct i2c_client *client;110 struct regmap *regmap;111 struct regulator *vs;112 u16 orig_conf;113 u16 current_conf;114 u8 resolution; /* In bits, 9 to 16 */115 unsigned int sample_time; /* In ms */116 enum lm75_type kind;117 const struct lm75_params *params;118};119 120/*-----------------------------------------------------------------------*/121 122static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };123 124#define LM75_SAMPLE_CLEAR_MASK (3 << 5)125 126/* The structure below stores the configuration values of the supported devices.127 * In case of being supported multiple configurations, the default one must128 * always be the first element of the array129 */130static const struct lm75_params device_params[] = {131 [adt75] = {132 .clr_mask = 1 << 5, /* not one-shot mode */133 .default_resolution = 12,134 .default_sample_time = MSEC_PER_SEC / 10,135 },136 [as6200] = {137 .config_reg_16bits = true,138 .set_mask = 0x94C0, /* 8 sample/s, 4 CF, positive polarity */139 .default_resolution = 12,140 .default_sample_time = 125,141 .num_sample_times = 4,142 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },143 .alarm = true,144 },145 [at30ts74] = {146 .set_mask = 3 << 5, /* 12-bit mode*/147 .default_resolution = 12,148 .default_sample_time = 200,149 .num_sample_times = 4,150 .sample_times = (unsigned int []){ 25, 50, 100, 200 },151 .resolutions = (u8 []) {9, 10, 11, 12 },152 },153 [ds1775] = {154 .clr_mask = 3 << 5,155 .set_mask = 2 << 5, /* 11-bit mode */156 .default_resolution = 11,157 .default_sample_time = 500,158 .num_sample_times = 4,159 .sample_times = (unsigned int []){ 125, 250, 500, 1000 },160 .resolutions = (u8 []) {9, 10, 11, 12 },161 },162 [ds75] = {163 .clr_mask = 3 << 5,164 .set_mask = 2 << 5, /* 11-bit mode */165 .default_resolution = 11,166 .default_sample_time = 600,167 .num_sample_times = 4,168 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },169 .resolutions = (u8 []) {9, 10, 11, 12 },170 },171 [stds75] = {172 .clr_mask = 3 << 5,173 .set_mask = 2 << 5, /* 11-bit mode */174 .default_resolution = 11,175 .default_sample_time = 600,176 .num_sample_times = 4,177 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },178 .resolutions = (u8 []) {9, 10, 11, 12 },179 },180 [stlm75] = {181 .default_resolution = 9,182 .default_sample_time = MSEC_PER_SEC / 6,183 },184 [ds7505] = {185 .set_mask = 3 << 5, /* 12-bit mode*/186 .default_resolution = 12,187 .default_sample_time = 200,188 .num_sample_times = 4,189 .sample_times = (unsigned int []){ 25, 50, 100, 200 },190 .resolutions = (u8 []) {9, 10, 11, 12 },191 },192 [g751] = {193 .default_resolution = 9,194 .default_sample_time = MSEC_PER_SEC / 10,195 },196 [lm75] = {197 .default_resolution = 9,198 .default_sample_time = MSEC_PER_SEC / 10,199 },200 [lm75a] = {201 .default_resolution = 9,202 .default_sample_time = MSEC_PER_SEC / 10,203 },204 [lm75b] = {205 .default_resolution = 11,206 .default_sample_time = MSEC_PER_SEC / 10,207 },208 [max6625] = {209 .default_resolution = 9,210 .default_sample_time = MSEC_PER_SEC / 7,211 },212 [max6626] = {213 .default_resolution = 12,214 .default_sample_time = MSEC_PER_SEC / 7,215 .resolution_limits = 9,216 },217 [max31725] = {218 .default_resolution = 16,219 .default_sample_time = MSEC_PER_SEC / 20,220 },221 [tcn75] = {222 .default_resolution = 9,223 .default_sample_time = MSEC_PER_SEC / 18,224 },225 [pct2075] = {226 .default_resolution = 11,227 .default_sample_time = MSEC_PER_SEC / 10,228 .num_sample_times = 31,229 .sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600,230 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700,231 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700,232 2800, 2900, 3000, 3100 },233 },234 [mcp980x] = {235 .set_mask = 3 << 5, /* 12-bit mode */236 .clr_mask = 1 << 7, /* not one-shot mode */237 .default_resolution = 12,238 .resolution_limits = 9,239 .default_sample_time = 240,240 .num_sample_times = 4,241 .sample_times = (unsigned int []){ 30, 60, 120, 240 },242 .resolutions = (u8 []) {9, 10, 11, 12 },243 },244 [tmp100] = {245 .set_mask = 3 << 5, /* 12-bit mode */246 .clr_mask = 1 << 7, /* not one-shot mode */247 .default_resolution = 12,248 .default_sample_time = 320,249 .num_sample_times = 4,250 .sample_times = (unsigned int []){ 40, 80, 160, 320 },251 .resolutions = (u8 []) {9, 10, 11, 12 },252 },253 [tmp101] = {254 .set_mask = 3 << 5, /* 12-bit mode */255 .clr_mask = 1 << 7, /* not one-shot mode */256 .default_resolution = 12,257 .default_sample_time = 320,258 .num_sample_times = 4,259 .sample_times = (unsigned int []){ 40, 80, 160, 320 },260 .resolutions = (u8 []) {9, 10, 11, 12 },261 },262 [tmp105] = {263 .set_mask = 3 << 5, /* 12-bit mode */264 .clr_mask = 1 << 7, /* not one-shot mode*/265 .default_resolution = 12,266 .default_sample_time = 220,267 .num_sample_times = 4,268 .sample_times = (unsigned int []){ 28, 55, 110, 220 },269 .resolutions = (u8 []) {9, 10, 11, 12 },270 },271 [tmp112] = {272 .config_reg_16bits = true,273 .set_mask = 0x60C0, /* 12-bit mode, 8 samples / second */274 .clr_mask = 1 << 15, /* no one-shot mode*/275 .default_resolution = 12,276 .default_sample_time = 125,277 .num_sample_times = 4,278 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },279 },280 [tmp175] = {281 .set_mask = 3 << 5, /* 12-bit mode */282 .clr_mask = 1 << 7, /* not one-shot mode*/283 .default_resolution = 12,284 .default_sample_time = 220,285 .num_sample_times = 4,286 .sample_times = (unsigned int []){ 28, 55, 110, 220 },287 .resolutions = (u8 []) {9, 10, 11, 12 },288 },289 [tmp275] = {290 .set_mask = 3 << 5, /* 12-bit mode */291 .clr_mask = 1 << 7, /* not one-shot mode*/292 .default_resolution = 12,293 .default_sample_time = 220,294 .num_sample_times = 4,295 .sample_times = (unsigned int []){ 28, 55, 110, 220 },296 .resolutions = (u8 []) {9, 10, 11, 12 },297 },298 [tmp75] = {299 .set_mask = 3 << 5, /* 12-bit mode */300 .clr_mask = 1 << 7, /* not one-shot mode*/301 .default_resolution = 12,302 .default_sample_time = 220,303 .num_sample_times = 4,304 .sample_times = (unsigned int []){ 28, 55, 110, 220 },305 .resolutions = (u8 []) {9, 10, 11, 12 },306 },307 [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */308 .clr_mask = 1 << 7 | 3 << 5,309 .default_resolution = 12,310 .default_sample_time = MSEC_PER_SEC / 37,311 .sample_times = (unsigned int []){ MSEC_PER_SEC / 37,312 MSEC_PER_SEC / 18,313 MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 },314 .num_sample_times = 4,315 },316 [tmp75c] = {317 .clr_mask = 1 << 5, /*not one-shot mode*/318 .default_resolution = 12,319 .default_sample_time = MSEC_PER_SEC / 12,320 },321 [tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */322 .clr_mask = 1 << 5 | 1 << 6 | 1 << 7,323 .default_resolution = 12,324 .default_sample_time = 28,325 .num_sample_times = 4,326 .sample_times = (unsigned int []){ 28, 55, 110, 220 },327 }328};329 330static inline long lm75_reg_to_mc(s16 temp, u8 resolution)331{332 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);333}334 335static int lm75_write_config(struct lm75_data *data, u16 set_mask,336 u16 clr_mask)337{338 unsigned int value;339 340 clr_mask |= LM75_SHUTDOWN << (8 * data->params->config_reg_16bits);341 value = data->current_conf & ~clr_mask;342 value |= set_mask;343 344 if (data->current_conf != value) {345 s32 err;346 if (data->params->config_reg_16bits)347 err = regmap_write(data->regmap, LM75_REG_CONF, value);348 else349 err = i2c_smbus_write_byte_data(data->client,350 LM75_REG_CONF,351 value);352 if (err)353 return err;354 data->current_conf = value;355 }356 return 0;357}358 359static int lm75_read_config(struct lm75_data *data)360{361 int ret;362 unsigned int status;363 364 if (data->params->config_reg_16bits) {365 ret = regmap_read(data->regmap, LM75_REG_CONF, &status);366 return ret ? ret : status;367 }368 369 return i2c_smbus_read_byte_data(data->client, LM75_REG_CONF);370}371 372static irqreturn_t lm75_alarm_handler(int irq, void *private)373{374 struct device *hwmon_dev = private;375 376 hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_alarm, 0);377 return IRQ_HANDLED;378}379 380static int lm75_read(struct device *dev, enum hwmon_sensor_types type,381 u32 attr, int channel, long *val)382{383 struct lm75_data *data = dev_get_drvdata(dev);384 unsigned int regval;385 int err, reg;386 387 switch (type) {388 case hwmon_chip:389 switch (attr) {390 case hwmon_chip_update_interval:391 *val = data->sample_time;392 break;393 default:394 return -EINVAL;395 }396 break;397 case hwmon_temp:398 switch (attr) {399 case hwmon_temp_input:400 reg = LM75_REG_TEMP;401 break;402 case hwmon_temp_max:403 reg = LM75_REG_MAX;404 break;405 case hwmon_temp_max_hyst:406 reg = LM75_REG_HYST;407 break;408 case hwmon_temp_alarm:409 reg = LM75_REG_CONF;410 break;411 default:412 return -EINVAL;413 }414 err = regmap_read(data->regmap, reg, ®val);415 if (err < 0)416 return err;417 418 if (attr == hwmon_temp_alarm) {419 switch (data->kind) {420 case as6200:421 *val = (regval >> 5) & 0x1;422 break;423 default:424 return -EINVAL;425 }426 } else {427 *val = lm75_reg_to_mc(regval, data->resolution);428 }429 break;430 default:431 return -EINVAL;432 }433 return 0;434}435 436static int lm75_write_temp(struct device *dev, u32 attr, long temp)437{438 struct lm75_data *data = dev_get_drvdata(dev);439 u8 resolution;440 int reg;441 442 switch (attr) {443 case hwmon_temp_max:444 reg = LM75_REG_MAX;445 break;446 case hwmon_temp_max_hyst:447 reg = LM75_REG_HYST;448 break;449 default:450 return -EINVAL;451 }452 453 /*454 * Resolution of limit registers is assumed to be the same as the455 * temperature input register resolution unless given explicitly.456 */457 if (data->params->resolution_limits)458 resolution = data->params->resolution_limits;459 else460 resolution = data->resolution;461 462 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);463 temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),464 1000) << (16 - resolution);465 466 return regmap_write(data->regmap, reg, (u16)temp);467}468 469static int lm75_update_interval(struct device *dev, long val)470{471 struct lm75_data *data = dev_get_drvdata(dev);472 unsigned int reg;473 u8 index;474 s32 err;475 476 index = find_closest(val, data->params->sample_times,477 (int)data->params->num_sample_times);478 479 switch (data->kind) {480 default:481 err = lm75_write_config(data, lm75_sample_set_masks[index],482 LM75_SAMPLE_CLEAR_MASK);483 if (err)484 return err;485 486 data->sample_time = data->params->sample_times[index];487 if (data->params->resolutions)488 data->resolution = data->params->resolutions[index];489 break;490 case tmp112:491 case as6200:492 err = regmap_read(data->regmap, LM75_REG_CONF, ®);493 if (err < 0)494 return err;495 reg &= ~0x00c0;496 reg |= (3 - index) << 6;497 err = regmap_write(data->regmap, LM75_REG_CONF, reg);498 if (err < 0)499 return err;500 data->sample_time = data->params->sample_times[index];501 break;502 case pct2075:503 err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE,504 index + 1);505 if (err)506 return err;507 data->sample_time = data->params->sample_times[index];508 break;509 }510 return 0;511}512 513static int lm75_write_chip(struct device *dev, u32 attr, long val)514{515 switch (attr) {516 case hwmon_chip_update_interval:517 return lm75_update_interval(dev, val);518 default:519 return -EINVAL;520 }521 return 0;522}523 524static int lm75_write(struct device *dev, enum hwmon_sensor_types type,525 u32 attr, int channel, long val)526{527 switch (type) {528 case hwmon_chip:529 return lm75_write_chip(dev, attr, val);530 case hwmon_temp:531 return lm75_write_temp(dev, attr, val);532 default:533 return -EINVAL;534 }535 return 0;536}537 538static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,539 u32 attr, int channel)540{541 const struct lm75_data *config_data = data;542 543 switch (type) {544 case hwmon_chip:545 switch (attr) {546 case hwmon_chip_update_interval:547 if (config_data->params->num_sample_times > 1)548 return 0644;549 return 0444;550 }551 break;552 case hwmon_temp:553 switch (attr) {554 case hwmon_temp_input:555 return 0444;556 case hwmon_temp_max:557 case hwmon_temp_max_hyst:558 return 0644;559 case hwmon_temp_alarm:560 if (config_data->params->alarm)561 return 0444;562 break;563 }564 break;565 default:566 break;567 }568 return 0;569}570 571static const struct hwmon_channel_info * const lm75_info[] = {572 HWMON_CHANNEL_INFO(chip,573 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),574 HWMON_CHANNEL_INFO(temp,575 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |576 HWMON_T_ALARM),577 NULL578};579 580static const struct hwmon_ops lm75_hwmon_ops = {581 .is_visible = lm75_is_visible,582 .read = lm75_read,583 .write = lm75_write,584};585 586static const struct hwmon_chip_info lm75_chip_info = {587 .ops = &lm75_hwmon_ops,588 .info = lm75_info,589};590 591static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)592{593 return reg != LM75_REG_TEMP;594}595 596static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)597{598 return reg == LM75_REG_TEMP || reg == LM75_REG_CONF;599}600 601static const struct regmap_config lm75_regmap_config = {602 .reg_bits = 8,603 .val_bits = 16,604 .max_register = PCT2075_REG_IDLE,605 .writeable_reg = lm75_is_writeable_reg,606 .volatile_reg = lm75_is_volatile_reg,607 .val_format_endian = REGMAP_ENDIAN_BIG,608 .cache_type = REGCACHE_MAPLE,609 .use_single_read = true,610 .use_single_write = true,611};612 613static void lm75_disable_regulator(void *data)614{615 struct lm75_data *lm75 = data;616 617 regulator_disable(lm75->vs);618}619 620static void lm75_remove(void *data)621{622 struct lm75_data *lm75 = data;623 struct i2c_client *client = lm75->client;624 625 i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);626}627 628static int lm75_probe(struct i2c_client *client)629{630 struct device *dev = &client->dev;631 struct device *hwmon_dev;632 struct lm75_data *data;633 int status, err;634 635 if (!i2c_check_functionality(client->adapter,636 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))637 return -EIO;638 639 data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);640 if (!data)641 return -ENOMEM;642 643 data->client = client;644 data->kind = (uintptr_t)i2c_get_match_data(client);645 646 data->vs = devm_regulator_get(dev, "vs");647 if (IS_ERR(data->vs))648 return PTR_ERR(data->vs);649 650 data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);651 if (IS_ERR(data->regmap))652 return PTR_ERR(data->regmap);653 654 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.655 * Then tweak to be more precise when appropriate.656 */657 658 data->params = &device_params[data->kind];659 660 /* Save default sample time and resolution*/661 data->sample_time = data->params->default_sample_time;662 data->resolution = data->params->default_resolution;663 664 /* Enable the power */665 err = regulator_enable(data->vs);666 if (err) {667 dev_err(dev, "failed to enable regulator: %d\n", err);668 return err;669 }670 671 err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);672 if (err)673 return err;674 675 /* Cache original configuration */676 status = lm75_read_config(data);677 if (status < 0) {678 dev_dbg(dev, "Can't read config? %d\n", status);679 return status;680 }681 data->orig_conf = status;682 data->current_conf = status;683 684 err = lm75_write_config(data, data->params->set_mask,685 data->params->clr_mask);686 if (err)687 return err;688 689 err = devm_add_action_or_reset(dev, lm75_remove, data);690 if (err)691 return err;692 693 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,694 data, &lm75_chip_info,695 NULL);696 if (IS_ERR(hwmon_dev))697 return PTR_ERR(hwmon_dev);698 699 if (client->irq) {700 if (data->params->alarm) {701 err = devm_request_threaded_irq(dev,702 client->irq,703 NULL,704 &lm75_alarm_handler,705 IRQF_ONESHOT,706 client->name,707 hwmon_dev);708 if (err)709 return err;710 } else {711 /* alarm is only supported for chips with alarm bit */712 dev_err(dev, "alarm interrupt is not supported\n");713 }714 }715 716 dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);717 718 return 0;719}720 721static const struct i2c_device_id lm75_ids[] = {722 { "adt75", adt75, },723 { "as6200", as6200, },724 { "at30ts74", at30ts74, },725 { "ds1775", ds1775, },726 { "ds75", ds75, },727 { "ds7505", ds7505, },728 { "g751", g751, },729 { "lm75", lm75, },730 { "lm75a", lm75a, },731 { "lm75b", lm75b, },732 { "max6625", max6625, },733 { "max6626", max6626, },734 { "max31725", max31725, },735 { "max31726", max31725, },736 { "mcp980x", mcp980x, },737 { "pct2075", pct2075, },738 { "stds75", stds75, },739 { "stlm75", stlm75, },740 { "tcn75", tcn75, },741 { "tmp100", tmp100, },742 { "tmp101", tmp101, },743 { "tmp105", tmp105, },744 { "tmp112", tmp112, },745 { "tmp175", tmp175, },746 { "tmp275", tmp275, },747 { "tmp75", tmp75, },748 { "tmp75b", tmp75b, },749 { "tmp75c", tmp75c, },750 { "tmp1075", tmp1075, },751 { /* LIST END */ }752};753MODULE_DEVICE_TABLE(i2c, lm75_ids);754 755static const struct of_device_id __maybe_unused lm75_of_match[] = {756 {757 .compatible = "adi,adt75",758 .data = (void *)adt75759 },760 {761 .compatible = "ams,as6200",762 .data = (void *)as6200763 },764 {765 .compatible = "atmel,at30ts74",766 .data = (void *)at30ts74767 },768 {769 .compatible = "dallas,ds1775",770 .data = (void *)ds1775771 },772 {773 .compatible = "dallas,ds75",774 .data = (void *)ds75775 },776 {777 .compatible = "dallas,ds7505",778 .data = (void *)ds7505779 },780 {781 .compatible = "gmt,g751",782 .data = (void *)g751783 },784 {785 .compatible = "national,lm75",786 .data = (void *)lm75787 },788 {789 .compatible = "national,lm75a",790 .data = (void *)lm75a791 },792 {793 .compatible = "national,lm75b",794 .data = (void *)lm75b795 },796 {797 .compatible = "maxim,max6625",798 .data = (void *)max6625799 },800 {801 .compatible = "maxim,max6626",802 .data = (void *)max6626803 },804 {805 .compatible = "maxim,max31725",806 .data = (void *)max31725807 },808 {809 .compatible = "maxim,max31726",810 .data = (void *)max31725811 },812 {813 .compatible = "maxim,mcp980x",814 .data = (void *)mcp980x815 },816 {817 .compatible = "nxp,pct2075",818 .data = (void *)pct2075819 },820 {821 .compatible = "st,stds75",822 .data = (void *)stds75823 },824 {825 .compatible = "st,stlm75",826 .data = (void *)stlm75827 },828 {829 .compatible = "microchip,tcn75",830 .data = (void *)tcn75831 },832 {833 .compatible = "ti,tmp100",834 .data = (void *)tmp100835 },836 {837 .compatible = "ti,tmp101",838 .data = (void *)tmp101839 },840 {841 .compatible = "ti,tmp105",842 .data = (void *)tmp105843 },844 {845 .compatible = "ti,tmp112",846 .data = (void *)tmp112847 },848 {849 .compatible = "ti,tmp175",850 .data = (void *)tmp175851 },852 {853 .compatible = "ti,tmp275",854 .data = (void *)tmp275855 },856 {857 .compatible = "ti,tmp75",858 .data = (void *)tmp75859 },860 {861 .compatible = "ti,tmp75b",862 .data = (void *)tmp75b863 },864 {865 .compatible = "ti,tmp75c",866 .data = (void *)tmp75c867 },868 {869 .compatible = "ti,tmp1075",870 .data = (void *)tmp1075871 },872 { },873};874MODULE_DEVICE_TABLE(of, lm75_of_match);875 876#define LM75A_ID 0xA1877 878/* Return 0 if detection is successful, -ENODEV otherwise */879static int lm75_detect(struct i2c_client *new_client,880 struct i2c_board_info *info)881{882 struct i2c_adapter *adapter = new_client->adapter;883 int i;884 int conf, hyst, os;885 bool is_lm75a = 0;886 887 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |888 I2C_FUNC_SMBUS_WORD_DATA))889 return -ENODEV;890 891 /*892 * Now, we do the remaining detection. There is no identification-893 * dedicated register so we have to rely on several tricks:894 * unused bits, registers cycling over 8-address boundaries,895 * addresses 0x04-0x07 returning the last read value.896 * The cycling+unused addresses combination is not tested,897 * since it would significantly slow the detection down and would898 * hardly add any value.899 *900 * The National Semiconductor LM75A is different than earlier901 * LM75s. It has an ID byte of 0xaX (where X is the chip902 * revision, with 1 being the only revision in existence) in903 * register 7, and unused registers return 0xff rather than the904 * last read value.905 *906 * Note that this function only detects the original National907 * Semiconductor LM75 and the LM75A. Clones from other vendors908 * aren't detected, on purpose, because they are typically never909 * found on PC hardware. They are found on embedded designs where910 * they can be instantiated explicitly so detection is not needed.911 * The absence of identification registers on all these clones912 * would make their exhaustive detection very difficult and weak,913 * and odds are that the driver would bind to unsupported devices.914 */915 916 /* Unused bits */917 conf = i2c_smbus_read_byte_data(new_client, 1);918 if (conf & 0xe0)919 return -ENODEV;920 921 /* First check for LM75A */922 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {923 /*924 * LM75A returns 0xff on unused registers so925 * just to be sure we check for that too.926 */927 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff928 || i2c_smbus_read_byte_data(new_client, 5) != 0xff929 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)930 return -ENODEV;931 is_lm75a = 1;932 hyst = i2c_smbus_read_byte_data(new_client, 2);933 os = i2c_smbus_read_byte_data(new_client, 3);934 } else { /* Traditional style LM75 detection */935 /* Unused addresses */936 hyst = i2c_smbus_read_byte_data(new_client, 2);937 if (i2c_smbus_read_byte_data(new_client, 4) != hyst938 || i2c_smbus_read_byte_data(new_client, 5) != hyst939 || i2c_smbus_read_byte_data(new_client, 6) != hyst940 || i2c_smbus_read_byte_data(new_client, 7) != hyst)941 return -ENODEV;942 os = i2c_smbus_read_byte_data(new_client, 3);943 if (i2c_smbus_read_byte_data(new_client, 4) != os944 || i2c_smbus_read_byte_data(new_client, 5) != os945 || i2c_smbus_read_byte_data(new_client, 6) != os946 || i2c_smbus_read_byte_data(new_client, 7) != os)947 return -ENODEV;948 }949 /*950 * It is very unlikely that this is a LM75 if both951 * hysteresis and temperature limit registers are 0.952 */953 if (hyst == 0 && os == 0)954 return -ENODEV;955 956 /* Addresses cycling */957 for (i = 8; i <= 248; i += 40) {958 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf959 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst960 || i2c_smbus_read_byte_data(new_client, i + 3) != os)961 return -ENODEV;962 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)963 != LM75A_ID)964 return -ENODEV;965 }966 967 strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);968 969 return 0;970}971 972#ifdef CONFIG_PM973static int lm75_suspend(struct device *dev)974{975 int status;976 struct i2c_client *client = to_i2c_client(dev);977 978 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);979 if (status < 0) {980 dev_dbg(&client->dev, "Can't read config? %d\n", status);981 return status;982 }983 status = status | LM75_SHUTDOWN;984 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);985 return 0;986}987 988static int lm75_resume(struct device *dev)989{990 int status;991 struct i2c_client *client = to_i2c_client(dev);992 993 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);994 if (status < 0) {995 dev_dbg(&client->dev, "Can't read config? %d\n", status);996 return status;997 }998 status = status & ~LM75_SHUTDOWN;999 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);1000 return 0;1001}1002 1003static const struct dev_pm_ops lm75_dev_pm_ops = {1004 .suspend = lm75_suspend,1005 .resume = lm75_resume,1006};1007#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)1008#else1009#define LM75_DEV_PM_OPS NULL1010#endif /* CONFIG_PM */1011 1012static struct i2c_driver lm75_driver = {1013 .class = I2C_CLASS_HWMON,1014 .driver = {1015 .name = "lm75",1016 .of_match_table = of_match_ptr(lm75_of_match),1017 .pm = LM75_DEV_PM_OPS,1018 },1019 .probe = lm75_probe,1020 .id_table = lm75_ids,1021 .detect = lm75_detect,1022 .address_list = normal_i2c,1023};1024 1025module_i2c_driver(lm75_driver);1026 1027MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");1028MODULE_DESCRIPTION("LM75 driver");1029MODULE_LICENSE("GPL");1030