linux/drivers/hwmon/lm78.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * lm78.c - Part of lm_sensors, Linux kernel modules for hardware
   4 *          monitoring
   5 * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
   6 * Copyright (c) 2007, 2011  Jean Delvare <jdelvare@suse.de>
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/module.h>
  12#include <linux/init.h>
  13#include <linux/slab.h>
  14#include <linux/jiffies.h>
  15#include <linux/i2c.h>
  16#include <linux/hwmon.h>
  17#include <linux/hwmon-vid.h>
  18#include <linux/hwmon-sysfs.h>
  19#include <linux/err.h>
  20#include <linux/mutex.h>
  21
  22#ifdef CONFIG_ISA
  23#include <linux/platform_device.h>
  24#include <linux/ioport.h>
  25#include <linux/io.h>
  26#endif
  27
  28/* Addresses to scan */
  29static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
  30                                                0x2e, 0x2f, I2C_CLIENT_END };
  31enum chips { lm78, lm79 };
  32
  33/* Many LM78 constants specified below */
  34
  35/* Length of ISA address segment */
  36#define LM78_EXTENT 8
  37
  38/* Where are the ISA address/data registers relative to the base address */
  39#define LM78_ADDR_REG_OFFSET 5
  40#define LM78_DATA_REG_OFFSET 6
  41
  42/* The LM78 registers */
  43#define LM78_REG_IN_MAX(nr) (0x2b + (nr) * 2)
  44#define LM78_REG_IN_MIN(nr) (0x2c + (nr) * 2)
  45#define LM78_REG_IN(nr) (0x20 + (nr))
  46
  47#define LM78_REG_FAN_MIN(nr) (0x3b + (nr))
  48#define LM78_REG_FAN(nr) (0x28 + (nr))
  49
  50#define LM78_REG_TEMP 0x27
  51#define LM78_REG_TEMP_OVER 0x39
  52#define LM78_REG_TEMP_HYST 0x3a
  53
  54#define LM78_REG_ALARM1 0x41
  55#define LM78_REG_ALARM2 0x42
  56
  57#define LM78_REG_VID_FANDIV 0x47
  58
  59#define LM78_REG_CONFIG 0x40
  60#define LM78_REG_CHIPID 0x49
  61#define LM78_REG_I2C_ADDR 0x48
  62
  63/*
  64 * Conversions. Rounding and limit checking is only done on the TO_REG
  65 * variants.
  66 */
  67
  68/*
  69 * IN: mV (0V to 4.08V)
  70 * REG: 16mV/bit
  71 */
  72static inline u8 IN_TO_REG(unsigned long val)
  73{
  74        unsigned long nval = clamp_val(val, 0, 4080);
  75        return (nval + 8) / 16;
  76}
  77#define IN_FROM_REG(val) ((val) *  16)
  78
  79static inline u8 FAN_TO_REG(long rpm, int div)
  80{
  81        if (rpm <= 0)
  82                return 255;
  83        if (rpm > 1350000)
  84                return 1;
  85        return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
  86}
  87
  88static inline int FAN_FROM_REG(u8 val, int div)
  89{
  90        return val == 0 ? -1 : val == 255 ? 0 : 1350000 / (val * div);
  91}
  92
  93/*
  94 * TEMP: mC (-128C to +127C)
  95 * REG: 1C/bit, two's complement
  96 */
  97static inline s8 TEMP_TO_REG(long val)
  98{
  99        int nval = clamp_val(val, -128000, 127000) ;
 100        return nval < 0 ? (nval - 500) / 1000 : (nval + 500) / 1000;
 101}
 102
 103static inline int TEMP_FROM_REG(s8 val)
 104{
 105        return val * 1000;
 106}
 107
 108#define DIV_FROM_REG(val) (1 << (val))
 109
 110struct lm78_data {
 111        struct i2c_client *client;
 112        struct mutex lock;
 113        enum chips type;
 114
 115        /* For ISA device only */
 116        const char *name;
 117        int isa_addr;
 118
 119        struct mutex update_lock;
 120        char valid;             /* !=0 if following fields are valid */
 121        unsigned long last_updated;     /* In jiffies */
 122
 123        u8 in[7];               /* Register value */
 124        u8 in_max[7];           /* Register value */
 125        u8 in_min[7];           /* Register value */
 126        u8 fan[3];              /* Register value */
 127        u8 fan_min[3];          /* Register value */
 128        s8 temp;                /* Register value */
 129        s8 temp_over;           /* Register value */
 130        s8 temp_hyst;           /* Register value */
 131        u8 fan_div[3];          /* Register encoding, shifted right */
 132        u8 vid;                 /* Register encoding, combined */
 133        u16 alarms;             /* Register encoding, combined */
 134};
 135
 136static int lm78_read_value(struct lm78_data *data, u8 reg);
 137static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value);
 138static struct lm78_data *lm78_update_device(struct device *dev);
 139static void lm78_init_device(struct lm78_data *data);
 140
 141/* 7 Voltages */
 142static ssize_t in_show(struct device *dev, struct device_attribute *da,
 143                       char *buf)
 144{
 145        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 146        struct lm78_data *data = lm78_update_device(dev);
 147        return sprintf(buf, "%d\n", IN_FROM_REG(data->in[attr->index]));
 148}
 149
 150static ssize_t in_min_show(struct device *dev, struct device_attribute *da,
 151                           char *buf)
 152{
 153        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 154        struct lm78_data *data = lm78_update_device(dev);
 155        return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[attr->index]));
 156}
 157
 158static ssize_t in_max_show(struct device *dev, struct device_attribute *da,
 159                           char *buf)
 160{
 161        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 162        struct lm78_data *data = lm78_update_device(dev);
 163        return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[attr->index]));
 164}
 165
 166static ssize_t in_min_store(struct device *dev, struct device_attribute *da,
 167                            const char *buf, size_t count)
 168{
 169        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 170        struct lm78_data *data = dev_get_drvdata(dev);
 171        int nr = attr->index;
 172        unsigned long val;
 173        int err;
 174
 175        err = kstrtoul(buf, 10, &val);
 176        if (err)
 177                return err;
 178
 179        mutex_lock(&data->update_lock);
 180        data->in_min[nr] = IN_TO_REG(val);
 181        lm78_write_value(data, LM78_REG_IN_MIN(nr), data->in_min[nr]);
 182        mutex_unlock(&data->update_lock);
 183        return count;
 184}
 185
 186static ssize_t in_max_store(struct device *dev, struct device_attribute *da,
 187                            const char *buf, size_t count)
 188{
 189        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 190        struct lm78_data *data = dev_get_drvdata(dev);
 191        int nr = attr->index;
 192        unsigned long val;
 193        int err;
 194
 195        err = kstrtoul(buf, 10, &val);
 196        if (err)
 197                return err;
 198
 199        mutex_lock(&data->update_lock);
 200        data->in_max[nr] = IN_TO_REG(val);
 201        lm78_write_value(data, LM78_REG_IN_MAX(nr), data->in_max[nr]);
 202        mutex_unlock(&data->update_lock);
 203        return count;
 204}
 205
 206static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
 207static SENSOR_DEVICE_ATTR_RW(in0_min, in_min, 0);
 208static SENSOR_DEVICE_ATTR_RW(in0_max, in_max, 0);
 209static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
 210static SENSOR_DEVICE_ATTR_RW(in1_min, in_min, 1);
 211static SENSOR_DEVICE_ATTR_RW(in1_max, in_max, 1);
 212static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
 213static SENSOR_DEVICE_ATTR_RW(in2_min, in_min, 2);
 214static SENSOR_DEVICE_ATTR_RW(in2_max, in_max, 2);
 215static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
 216static SENSOR_DEVICE_ATTR_RW(in3_min, in_min, 3);
 217static SENSOR_DEVICE_ATTR_RW(in3_max, in_max, 3);
 218static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
 219static SENSOR_DEVICE_ATTR_RW(in4_min, in_min, 4);
 220static SENSOR_DEVICE_ATTR_RW(in4_max, in_max, 4);
 221static SENSOR_DEVICE_ATTR_RO(in5_input, in, 5);
 222static SENSOR_DEVICE_ATTR_RW(in5_min, in_min, 5);
 223static SENSOR_DEVICE_ATTR_RW(in5_max, in_max, 5);
 224static SENSOR_DEVICE_ATTR_RO(in6_input, in, 6);
 225static SENSOR_DEVICE_ATTR_RW(in6_min, in_min, 6);
 226static SENSOR_DEVICE_ATTR_RW(in6_max, in_max, 6);
 227
 228/* Temperature */
 229static ssize_t temp1_input_show(struct device *dev,
 230                                struct device_attribute *da, char *buf)
 231{
 232        struct lm78_data *data = lm78_update_device(dev);
 233        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
 234}
 235
 236static ssize_t temp1_max_show(struct device *dev, struct device_attribute *da,
 237                              char *buf)
 238{
 239        struct lm78_data *data = lm78_update_device(dev);
 240        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
 241}
 242
 243static ssize_t temp1_max_store(struct device *dev,
 244                               struct device_attribute *da, const char *buf,
 245                               size_t count)
 246{
 247        struct lm78_data *data = dev_get_drvdata(dev);
 248        long val;
 249        int err;
 250
 251        err = kstrtol(buf, 10, &val);
 252        if (err)
 253                return err;
 254
 255        mutex_lock(&data->update_lock);
 256        data->temp_over = TEMP_TO_REG(val);
 257        lm78_write_value(data, LM78_REG_TEMP_OVER, data->temp_over);
 258        mutex_unlock(&data->update_lock);
 259        return count;
 260}
 261
 262static ssize_t temp1_max_hyst_show(struct device *dev,
 263                                   struct device_attribute *da, char *buf)
 264{
 265        struct lm78_data *data = lm78_update_device(dev);
 266        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
 267}
 268
 269static ssize_t temp1_max_hyst_store(struct device *dev,
 270                                    struct device_attribute *da,
 271                                    const char *buf, size_t count)
 272{
 273        struct lm78_data *data = dev_get_drvdata(dev);
 274        long val;
 275        int err;
 276
 277        err = kstrtol(buf, 10, &val);
 278        if (err)
 279                return err;
 280
 281        mutex_lock(&data->update_lock);
 282        data->temp_hyst = TEMP_TO_REG(val);
 283        lm78_write_value(data, LM78_REG_TEMP_HYST, data->temp_hyst);
 284        mutex_unlock(&data->update_lock);
 285        return count;
 286}
 287
 288static DEVICE_ATTR_RO(temp1_input);
 289static DEVICE_ATTR_RW(temp1_max);
 290static DEVICE_ATTR_RW(temp1_max_hyst);
 291
 292/* 3 Fans */
 293static ssize_t fan_show(struct device *dev, struct device_attribute *da,
 294                        char *buf)
 295{
 296        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 297        struct lm78_data *data = lm78_update_device(dev);
 298        int nr = attr->index;
 299        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
 300                DIV_FROM_REG(data->fan_div[nr])));
 301}
 302
 303static ssize_t fan_min_show(struct device *dev, struct device_attribute *da,
 304                            char *buf)
 305{
 306        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 307        struct lm78_data *data = lm78_update_device(dev);
 308        int nr = attr->index;
 309        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
 310                DIV_FROM_REG(data->fan_div[nr])));
 311}
 312
 313static ssize_t fan_min_store(struct device *dev, struct device_attribute *da,
 314                             const char *buf, size_t count)
 315{
 316        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 317        struct lm78_data *data = dev_get_drvdata(dev);
 318        int nr = attr->index;
 319        unsigned long val;
 320        int err;
 321
 322        err = kstrtoul(buf, 10, &val);
 323        if (err)
 324                return err;
 325
 326        mutex_lock(&data->update_lock);
 327        data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
 328        lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
 329        mutex_unlock(&data->update_lock);
 330        return count;
 331}
 332
 333static ssize_t fan_div_show(struct device *dev, struct device_attribute *da,
 334                            char *buf)
 335{
 336        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 337        struct lm78_data *data = lm78_update_device(dev);
 338        return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
 339}
 340
 341/*
 342 * Note: we save and restore the fan minimum here, because its value is
 343 * determined in part by the fan divisor.  This follows the principle of
 344 * least surprise; the user doesn't expect the fan minimum to change just
 345 * because the divisor changed.
 346 */
 347static ssize_t fan_div_store(struct device *dev, struct device_attribute *da,
 348                             const char *buf, size_t count)
 349{
 350        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 351        struct lm78_data *data = dev_get_drvdata(dev);
 352        int nr = attr->index;
 353        unsigned long min;
 354        u8 reg;
 355        unsigned long val;
 356        int err;
 357
 358        err = kstrtoul(buf, 10, &val);
 359        if (err)
 360                return err;
 361
 362        mutex_lock(&data->update_lock);
 363        min = FAN_FROM_REG(data->fan_min[nr],
 364                           DIV_FROM_REG(data->fan_div[nr]));
 365
 366        switch (val) {
 367        case 1:
 368                data->fan_div[nr] = 0;
 369                break;
 370        case 2:
 371                data->fan_div[nr] = 1;
 372                break;
 373        case 4:
 374                data->fan_div[nr] = 2;
 375                break;
 376        case 8:
 377                data->fan_div[nr] = 3;
 378                break;
 379        default:
 380                dev_err(dev,
 381                        "fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
 382                        val);
 383                mutex_unlock(&data->update_lock);
 384                return -EINVAL;
 385        }
 386
 387        reg = lm78_read_value(data, LM78_REG_VID_FANDIV);
 388        switch (nr) {
 389        case 0:
 390                reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
 391                break;
 392        case 1:
 393                reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
 394                break;
 395        }
 396        lm78_write_value(data, LM78_REG_VID_FANDIV, reg);
 397
 398        data->fan_min[nr] =
 399                FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
 400        lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
 401        mutex_unlock(&data->update_lock);
 402
 403        return count;
 404}
 405
 406static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
 407static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
 408static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
 409static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
 410static SENSOR_DEVICE_ATTR_RO(fan3_input, fan, 2);
 411static SENSOR_DEVICE_ATTR_RW(fan3_min, fan_min, 2);
 412
 413/* Fan 3 divisor is locked in H/W */
 414static SENSOR_DEVICE_ATTR_RW(fan1_div, fan_div, 0);
 415static SENSOR_DEVICE_ATTR_RW(fan2_div, fan_div, 1);
 416static SENSOR_DEVICE_ATTR_RO(fan3_div, fan_div, 2);
 417
 418/* VID */
 419static ssize_t cpu0_vid_show(struct device *dev, struct device_attribute *da,
 420                             char *buf)
 421{
 422        struct lm78_data *data = lm78_update_device(dev);
 423        return sprintf(buf, "%d\n", vid_from_reg(data->vid, 82));
 424}
 425static DEVICE_ATTR_RO(cpu0_vid);
 426
 427/* Alarms */
 428static ssize_t alarms_show(struct device *dev, struct device_attribute *da,
 429                           char *buf)
 430{
 431        struct lm78_data *data = lm78_update_device(dev);
 432        return sprintf(buf, "%u\n", data->alarms);
 433}
 434static DEVICE_ATTR_RO(alarms);
 435
 436static ssize_t alarm_show(struct device *dev, struct device_attribute *da,
 437                          char *buf)
 438{
 439        struct lm78_data *data = lm78_update_device(dev);
 440        int nr = to_sensor_dev_attr(da)->index;
 441        return sprintf(buf, "%u\n", (data->alarms >> nr) & 1);
 442}
 443static SENSOR_DEVICE_ATTR_RO(in0_alarm, alarm, 0);
 444static SENSOR_DEVICE_ATTR_RO(in1_alarm, alarm, 1);
 445static SENSOR_DEVICE_ATTR_RO(in2_alarm, alarm, 2);
 446static SENSOR_DEVICE_ATTR_RO(in3_alarm, alarm, 3);
 447static SENSOR_DEVICE_ATTR_RO(in4_alarm, alarm, 8);
 448static SENSOR_DEVICE_ATTR_RO(in5_alarm, alarm, 9);
 449static SENSOR_DEVICE_ATTR_RO(in6_alarm, alarm, 10);
 450static SENSOR_DEVICE_ATTR_RO(fan1_alarm, alarm, 6);
 451static SENSOR_DEVICE_ATTR_RO(fan2_alarm, alarm, 7);
 452static SENSOR_DEVICE_ATTR_RO(fan3_alarm, alarm, 11);
 453static SENSOR_DEVICE_ATTR_RO(temp1_alarm, alarm, 4);
 454
 455static struct attribute *lm78_attrs[] = {
 456        &sensor_dev_attr_in0_input.dev_attr.attr,
 457        &sensor_dev_attr_in0_min.dev_attr.attr,
 458        &sensor_dev_attr_in0_max.dev_attr.attr,
 459        &sensor_dev_attr_in0_alarm.dev_attr.attr,
 460        &sensor_dev_attr_in1_input.dev_attr.attr,
 461        &sensor_dev_attr_in1_min.dev_attr.attr,
 462        &sensor_dev_attr_in1_max.dev_attr.attr,
 463        &sensor_dev_attr_in1_alarm.dev_attr.attr,
 464        &sensor_dev_attr_in2_input.dev_attr.attr,
 465        &sensor_dev_attr_in2_min.dev_attr.attr,
 466        &sensor_dev_attr_in2_max.dev_attr.attr,
 467        &sensor_dev_attr_in2_alarm.dev_attr.attr,
 468        &sensor_dev_attr_in3_input.dev_attr.attr,
 469        &sensor_dev_attr_in3_min.dev_attr.attr,
 470        &sensor_dev_attr_in3_max.dev_attr.attr,
 471        &sensor_dev_attr_in3_alarm.dev_attr.attr,
 472        &sensor_dev_attr_in4_input.dev_attr.attr,
 473        &sensor_dev_attr_in4_min.dev_attr.attr,
 474        &sensor_dev_attr_in4_max.dev_attr.attr,
 475        &sensor_dev_attr_in4_alarm.dev_attr.attr,
 476        &sensor_dev_attr_in5_input.dev_attr.attr,
 477        &sensor_dev_attr_in5_min.dev_attr.attr,
 478        &sensor_dev_attr_in5_max.dev_attr.attr,
 479        &sensor_dev_attr_in5_alarm.dev_attr.attr,
 480        &sensor_dev_attr_in6_input.dev_attr.attr,
 481        &sensor_dev_attr_in6_min.dev_attr.attr,
 482        &sensor_dev_attr_in6_max.dev_attr.attr,
 483        &sensor_dev_attr_in6_alarm.dev_attr.attr,
 484        &dev_attr_temp1_input.attr,
 485        &dev_attr_temp1_max.attr,
 486        &dev_attr_temp1_max_hyst.attr,
 487        &sensor_dev_attr_temp1_alarm.dev_attr.attr,
 488        &sensor_dev_attr_fan1_input.dev_attr.attr,
 489        &sensor_dev_attr_fan1_min.dev_attr.attr,
 490        &sensor_dev_attr_fan1_div.dev_attr.attr,
 491        &sensor_dev_attr_fan1_alarm.dev_attr.attr,
 492        &sensor_dev_attr_fan2_input.dev_attr.attr,
 493        &sensor_dev_attr_fan2_min.dev_attr.attr,
 494        &sensor_dev_attr_fan2_div.dev_attr.attr,
 495        &sensor_dev_attr_fan2_alarm.dev_attr.attr,
 496        &sensor_dev_attr_fan3_input.dev_attr.attr,
 497        &sensor_dev_attr_fan3_min.dev_attr.attr,
 498        &sensor_dev_attr_fan3_div.dev_attr.attr,
 499        &sensor_dev_attr_fan3_alarm.dev_attr.attr,
 500        &dev_attr_alarms.attr,
 501        &dev_attr_cpu0_vid.attr,
 502
 503        NULL
 504};
 505
 506ATTRIBUTE_GROUPS(lm78);
 507
 508/*
 509 * ISA related code
 510 */
 511#ifdef CONFIG_ISA
 512
 513/* ISA device, if found */
 514static struct platform_device *pdev;
 515
 516static unsigned short isa_address = 0x290;
 517
 518static struct lm78_data *lm78_data_if_isa(void)
 519{
 520        return pdev ? platform_get_drvdata(pdev) : NULL;
 521}
 522
 523/* Returns 1 if the I2C chip appears to be an alias of the ISA chip */
 524static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
 525{
 526        struct lm78_data *isa;
 527        int i;
 528
 529        if (!pdev)      /* No ISA chip */
 530                return 0;
 531        isa = platform_get_drvdata(pdev);
 532
 533        if (lm78_read_value(isa, LM78_REG_I2C_ADDR) != client->addr)
 534                return 0;       /* Address doesn't match */
 535        if ((lm78_read_value(isa, LM78_REG_CHIPID) & 0xfe) != (chipid & 0xfe))
 536                return 0;       /* Chip type doesn't match */
 537
 538        /*
 539         * We compare all the limit registers, the config register and the
 540         * interrupt mask registers
 541         */
 542        for (i = 0x2b; i <= 0x3d; i++) {
 543                if (lm78_read_value(isa, i) !=
 544                    i2c_smbus_read_byte_data(client, i))
 545                        return 0;
 546        }
 547        if (lm78_read_value(isa, LM78_REG_CONFIG) !=
 548            i2c_smbus_read_byte_data(client, LM78_REG_CONFIG))
 549                return 0;
 550        for (i = 0x43; i <= 0x46; i++) {
 551                if (lm78_read_value(isa, i) !=
 552                    i2c_smbus_read_byte_data(client, i))
 553                        return 0;
 554        }
 555
 556        return 1;
 557}
 558#else /* !CONFIG_ISA */
 559
 560static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
 561{
 562        return 0;
 563}
 564
 565static struct lm78_data *lm78_data_if_isa(void)
 566{
 567        return NULL;
 568}
 569#endif /* CONFIG_ISA */
 570
 571static int lm78_i2c_detect(struct i2c_client *client,
 572                           struct i2c_board_info *info)
 573{
 574        int i;
 575        struct lm78_data *isa = lm78_data_if_isa();
 576        const char *client_name;
 577        struct i2c_adapter *adapter = client->adapter;
 578        int address = client->addr;
 579
 580        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 581                return -ENODEV;
 582
 583        /*
 584         * We block updates of the ISA device to minimize the risk of
 585         * concurrent access to the same LM78 chip through different
 586         * interfaces.
 587         */
 588        if (isa)
 589                mutex_lock(&isa->update_lock);
 590
 591        if ((i2c_smbus_read_byte_data(client, LM78_REG_CONFIG) & 0x80)
 592         || i2c_smbus_read_byte_data(client, LM78_REG_I2C_ADDR) != address)
 593                goto err_nodev;
 594
 595        /* Explicitly prevent the misdetection of Winbond chips */
 596        i = i2c_smbus_read_byte_data(client, 0x4f);
 597        if (i == 0xa3 || i == 0x5c)
 598                goto err_nodev;
 599
 600        /* Determine the chip type. */
 601        i = i2c_smbus_read_byte_data(client, LM78_REG_CHIPID);
 602        if (i == 0x00 || i == 0x20      /* LM78 */
 603         || i == 0x40)                  /* LM78-J */
 604                client_name = "lm78";
 605        else if ((i & 0xfe) == 0xc0)
 606                client_name = "lm79";
 607        else
 608                goto err_nodev;
 609
 610        if (lm78_alias_detect(client, i)) {
 611                dev_dbg(&adapter->dev,
 612                        "Device at 0x%02x appears to be the same as ISA device\n",
 613                        address);
 614                goto err_nodev;
 615        }
 616
 617        if (isa)
 618                mutex_unlock(&isa->update_lock);
 619
 620        strlcpy(info->type, client_name, I2C_NAME_SIZE);
 621
 622        return 0;
 623
 624 err_nodev:
 625        if (isa)
 626                mutex_unlock(&isa->update_lock);
 627        return -ENODEV;
 628}
 629
 630static int lm78_i2c_probe(struct i2c_client *client,
 631                          const struct i2c_device_id *id)
 632{
 633        struct device *dev = &client->dev;
 634        struct device *hwmon_dev;
 635        struct lm78_data *data;
 636
 637        data = devm_kzalloc(dev, sizeof(struct lm78_data), GFP_KERNEL);
 638        if (!data)
 639                return -ENOMEM;
 640
 641        data->client = client;
 642        data->type = id->driver_data;
 643
 644        /* Initialize the LM78 chip */
 645        lm78_init_device(data);
 646
 647        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 648                                                           data, lm78_groups);
 649        return PTR_ERR_OR_ZERO(hwmon_dev);
 650}
 651
 652static const struct i2c_device_id lm78_i2c_id[] = {
 653        { "lm78", lm78 },
 654        { "lm79", lm79 },
 655        { }
 656};
 657MODULE_DEVICE_TABLE(i2c, lm78_i2c_id);
 658
 659static struct i2c_driver lm78_driver = {
 660        .class          = I2C_CLASS_HWMON,
 661        .driver = {
 662                .name   = "lm78",
 663        },
 664        .probe          = lm78_i2c_probe,
 665        .id_table       = lm78_i2c_id,
 666        .detect         = lm78_i2c_detect,
 667        .address_list   = normal_i2c,
 668};
 669
 670/*
 671 * The SMBus locks itself, but ISA access must be locked explicitly!
 672 * We don't want to lock the whole ISA bus, so we lock each client
 673 * separately.
 674 * We ignore the LM78 BUSY flag at this moment - it could lead to deadlocks,
 675 * would slow down the LM78 access and should not be necessary.
 676 */
 677static int lm78_read_value(struct lm78_data *data, u8 reg)
 678{
 679        struct i2c_client *client = data->client;
 680
 681#ifdef CONFIG_ISA
 682        if (!client) { /* ISA device */
 683                int res;
 684                mutex_lock(&data->lock);
 685                outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
 686                res = inb_p(data->isa_addr + LM78_DATA_REG_OFFSET);
 687                mutex_unlock(&data->lock);
 688                return res;
 689        } else
 690#endif
 691                return i2c_smbus_read_byte_data(client, reg);
 692}
 693
 694static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value)
 695{
 696        struct i2c_client *client = data->client;
 697
 698#ifdef CONFIG_ISA
 699        if (!client) { /* ISA device */
 700                mutex_lock(&data->lock);
 701                outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
 702                outb_p(value, data->isa_addr + LM78_DATA_REG_OFFSET);
 703                mutex_unlock(&data->lock);
 704                return 0;
 705        } else
 706#endif
 707                return i2c_smbus_write_byte_data(client, reg, value);
 708}
 709
 710static void lm78_init_device(struct lm78_data *data)
 711{
 712        u8 config;
 713        int i;
 714
 715        /* Start monitoring */
 716        config = lm78_read_value(data, LM78_REG_CONFIG);
 717        if ((config & 0x09) != 0x01)
 718                lm78_write_value(data, LM78_REG_CONFIG,
 719                                 (config & 0xf7) | 0x01);
 720
 721        /* A few vars need to be filled upon startup */
 722        for (i = 0; i < 3; i++) {
 723                data->fan_min[i] = lm78_read_value(data,
 724                                        LM78_REG_FAN_MIN(i));
 725        }
 726
 727        mutex_init(&data->update_lock);
 728}
 729
 730static struct lm78_data *lm78_update_device(struct device *dev)
 731{
 732        struct lm78_data *data = dev_get_drvdata(dev);
 733        int i;
 734
 735        mutex_lock(&data->update_lock);
 736
 737        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 738            || !data->valid) {
 739
 740                dev_dbg(dev, "Starting lm78 update\n");
 741
 742                for (i = 0; i <= 6; i++) {
 743                        data->in[i] =
 744                            lm78_read_value(data, LM78_REG_IN(i));
 745                        data->in_min[i] =
 746                            lm78_read_value(data, LM78_REG_IN_MIN(i));
 747                        data->in_max[i] =
 748                            lm78_read_value(data, LM78_REG_IN_MAX(i));
 749                }
 750                for (i = 0; i < 3; i++) {
 751                        data->fan[i] =
 752                            lm78_read_value(data, LM78_REG_FAN(i));
 753                        data->fan_min[i] =
 754                            lm78_read_value(data, LM78_REG_FAN_MIN(i));
 755                }
 756                data->temp = lm78_read_value(data, LM78_REG_TEMP);
 757                data->temp_over =
 758                    lm78_read_value(data, LM78_REG_TEMP_OVER);
 759                data->temp_hyst =
 760                    lm78_read_value(data, LM78_REG_TEMP_HYST);
 761                i = lm78_read_value(data, LM78_REG_VID_FANDIV);
 762                data->vid = i & 0x0f;
 763                if (data->type == lm79)
 764                        data->vid |=
 765                            (lm78_read_value(data, LM78_REG_CHIPID) &
 766                             0x01) << 4;
 767                else
 768                        data->vid |= 0x10;
 769                data->fan_div[0] = (i >> 4) & 0x03;
 770                data->fan_div[1] = i >> 6;
 771                data->alarms = lm78_read_value(data, LM78_REG_ALARM1) +
 772                    (lm78_read_value(data, LM78_REG_ALARM2) << 8);
 773                data->last_updated = jiffies;
 774                data->valid = 1;
 775
 776                data->fan_div[2] = 1;
 777        }
 778
 779        mutex_unlock(&data->update_lock);
 780
 781        return data;
 782}
 783
 784#ifdef CONFIG_ISA
 785static int lm78_isa_probe(struct platform_device *pdev)
 786{
 787        struct device *dev = &pdev->dev;
 788        struct device *hwmon_dev;
 789        struct lm78_data *data;
 790        struct resource *res;
 791
 792        /* Reserve the ISA region */
 793        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 794        if (!devm_request_region(dev, res->start + LM78_ADDR_REG_OFFSET,
 795                                 2, "lm78"))
 796                return -EBUSY;
 797
 798        data = devm_kzalloc(dev, sizeof(struct lm78_data), GFP_KERNEL);
 799        if (!data)
 800                return -ENOMEM;
 801
 802        mutex_init(&data->lock);
 803        data->isa_addr = res->start;
 804        platform_set_drvdata(pdev, data);
 805
 806        if (lm78_read_value(data, LM78_REG_CHIPID) & 0x80) {
 807                data->type = lm79;
 808                data->name = "lm79";
 809        } else {
 810                data->type = lm78;
 811                data->name = "lm78";
 812        }
 813
 814        /* Initialize the LM78 chip */
 815        lm78_init_device(data);
 816
 817        hwmon_dev = devm_hwmon_device_register_with_groups(dev, data->name,
 818                                                           data, lm78_groups);
 819        return PTR_ERR_OR_ZERO(hwmon_dev);
 820}
 821
 822static struct platform_driver lm78_isa_driver = {
 823        .driver = {
 824                .name   = "lm78",
 825        },
 826        .probe          = lm78_isa_probe,
 827};
 828
 829/* return 1 if a supported chip is found, 0 otherwise */
 830static int __init lm78_isa_found(unsigned short address)
 831{
 832        int val, save, found = 0;
 833        int port;
 834
 835        /*
 836         * Some boards declare base+0 to base+7 as a PNP device, some base+4
 837         * to base+7 and some base+5 to base+6. So we better request each port
 838         * individually for the probing phase.
 839         */
 840        for (port = address; port < address + LM78_EXTENT; port++) {
 841                if (!request_region(port, 1, "lm78")) {
 842                        pr_debug("Failed to request port 0x%x\n", port);
 843                        goto release;
 844                }
 845        }
 846
 847#define REALLY_SLOW_IO
 848        /*
 849         * We need the timeouts for at least some LM78-like
 850         * chips. But only if we read 'undefined' registers.
 851         */
 852        val = inb_p(address + 1);
 853        if (inb_p(address + 2) != val
 854         || inb_p(address + 3) != val
 855         || inb_p(address + 7) != val)
 856                goto release;
 857#undef REALLY_SLOW_IO
 858
 859        /*
 860         * We should be able to change the 7 LSB of the address port. The
 861         * MSB (busy flag) should be clear initially, set after the write.
 862         */
 863        save = inb_p(address + LM78_ADDR_REG_OFFSET);
 864        if (save & 0x80)
 865                goto release;
 866        val = ~save & 0x7f;
 867        outb_p(val, address + LM78_ADDR_REG_OFFSET);
 868        if (inb_p(address + LM78_ADDR_REG_OFFSET) != (val | 0x80)) {
 869                outb_p(save, address + LM78_ADDR_REG_OFFSET);
 870                goto release;
 871        }
 872
 873        /* We found a device, now see if it could be an LM78 */
 874        outb_p(LM78_REG_CONFIG, address + LM78_ADDR_REG_OFFSET);
 875        val = inb_p(address + LM78_DATA_REG_OFFSET);
 876        if (val & 0x80)
 877                goto release;
 878        outb_p(LM78_REG_I2C_ADDR, address + LM78_ADDR_REG_OFFSET);
 879        val = inb_p(address + LM78_DATA_REG_OFFSET);
 880        if (val < 0x03 || val > 0x77)   /* Not a valid I2C address */
 881                goto release;
 882
 883        /* The busy flag should be clear again */
 884        if (inb_p(address + LM78_ADDR_REG_OFFSET) & 0x80)
 885                goto release;
 886
 887        /* Explicitly prevent the misdetection of Winbond chips */
 888        outb_p(0x4f, address + LM78_ADDR_REG_OFFSET);
 889        val = inb_p(address + LM78_DATA_REG_OFFSET);
 890        if (val == 0xa3 || val == 0x5c)
 891                goto release;
 892
 893        /* Explicitly prevent the misdetection of ITE chips */
 894        outb_p(0x58, address + LM78_ADDR_REG_OFFSET);
 895        val = inb_p(address + LM78_DATA_REG_OFFSET);
 896        if (val == 0x90)
 897                goto release;
 898
 899        /* Determine the chip type */
 900        outb_p(LM78_REG_CHIPID, address + LM78_ADDR_REG_OFFSET);
 901        val = inb_p(address + LM78_DATA_REG_OFFSET);
 902        if (val == 0x00 || val == 0x20  /* LM78 */
 903         || val == 0x40                 /* LM78-J */
 904         || (val & 0xfe) == 0xc0)       /* LM79 */
 905                found = 1;
 906
 907        if (found)
 908                pr_info("Found an %s chip at %#x\n",
 909                        val & 0x80 ? "LM79" : "LM78", (int)address);
 910
 911 release:
 912        for (port--; port >= address; port--)
 913                release_region(port, 1);
 914        return found;
 915}
 916
 917static int __init lm78_isa_device_add(unsigned short address)
 918{
 919        struct resource res = {
 920                .start  = address,
 921                .end    = address + LM78_EXTENT - 1,
 922                .name   = "lm78",
 923                .flags  = IORESOURCE_IO,
 924        };
 925        int err;
 926
 927        pdev = platform_device_alloc("lm78", address);
 928        if (!pdev) {
 929                err = -ENOMEM;
 930                pr_err("Device allocation failed\n");
 931                goto exit;
 932        }
 933
 934        err = platform_device_add_resources(pdev, &res, 1);
 935        if (err) {
 936                pr_err("Device resource addition failed (%d)\n", err);
 937                goto exit_device_put;
 938        }
 939
 940        err = platform_device_add(pdev);
 941        if (err) {
 942                pr_err("Device addition failed (%d)\n", err);
 943                goto exit_device_put;
 944        }
 945
 946        return 0;
 947
 948 exit_device_put:
 949        platform_device_put(pdev);
 950 exit:
 951        pdev = NULL;
 952        return err;
 953}
 954
 955static int __init lm78_isa_register(void)
 956{
 957        int res;
 958
 959        if (lm78_isa_found(isa_address)) {
 960                res = platform_driver_register(&lm78_isa_driver);
 961                if (res)
 962                        goto exit;
 963
 964                /* Sets global pdev as a side effect */
 965                res = lm78_isa_device_add(isa_address);
 966                if (res)
 967                        goto exit_unreg_isa_driver;
 968        }
 969
 970        return 0;
 971
 972 exit_unreg_isa_driver:
 973        platform_driver_unregister(&lm78_isa_driver);
 974 exit:
 975        return res;
 976}
 977
 978static void lm78_isa_unregister(void)
 979{
 980        if (pdev) {
 981                platform_device_unregister(pdev);
 982                platform_driver_unregister(&lm78_isa_driver);
 983        }
 984}
 985#else /* !CONFIG_ISA */
 986
 987static int __init lm78_isa_register(void)
 988{
 989        return 0;
 990}
 991
 992static void lm78_isa_unregister(void)
 993{
 994}
 995#endif /* CONFIG_ISA */
 996
 997static int __init sm_lm78_init(void)
 998{
 999        int res;
1000
1001        /*
1002         * We register the ISA device first, so that we can skip the
1003         * registration of an I2C interface to the same device.
1004         */
1005        res = lm78_isa_register();
1006        if (res)
1007                goto exit;
1008
1009        res = i2c_add_driver(&lm78_driver);
1010        if (res)
1011                goto exit_unreg_isa_device;
1012
1013        return 0;
1014
1015 exit_unreg_isa_device:
1016        lm78_isa_unregister();
1017 exit:
1018        return res;
1019}
1020
1021static void __exit sm_lm78_exit(void)
1022{
1023        lm78_isa_unregister();
1024        i2c_del_driver(&lm78_driver);
1025}
1026
1027MODULE_AUTHOR("Frodo Looijaard, Jean Delvare <jdelvare@suse.de>");
1028MODULE_DESCRIPTION("LM78/LM79 driver");
1029MODULE_LICENSE("GPL");
1030
1031module_init(sm_lm78_init);
1032module_exit(sm_lm78_exit);
1033