drivers/hwmon/pmbus/zl6100.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Hardware monitoring driver for ZL6100 and compatibles
   4  *
   5  * Copyright (c) 2011 Ericsson AB.
   6  * Copyright (c) 2012 Guenter Roeck
   7  */
   8
   9 #include <linux/bitops.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/err.h>
  14 #include <linux/slab.h>
  15 #include <linux/i2c.h>
  16 #include <linux/ktime.h>
  17 #include <linux/delay.h>
  18 #include "pmbus.h"
  19
  20 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
  21              zl9101, zl9117 };
  22
  23 struct zl6100_data {
  24         int id;
  25         ktime_t access;         /* chip access time */
  26         int delay;              /* Delay between chip accesses in uS */
  27         struct pmbus_driver_info info;
  28 };
  29
  30 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)
  31
  32 #define ZL6100_MFR_CONFIG               0xd0
  33 #define ZL6100_DEVICE_ID                0xe4
  34
  35 #define ZL6100_MFR_XTEMP_ENABLE         BIT(7)
  36
  37 #define MFR_VMON_OV_FAULT_LIMIT         0xf5
  38 #define MFR_VMON_UV_FAULT_LIMIT         0xf6
  39 #define MFR_READ_VMON                   0xf7
  40
  41 #define VMON_UV_WARNING                 BIT(5)
  42 #define VMON_OV_WARNING                 BIT(4)
  43 #define VMON_UV_FAULT                   BIT(1)
  44 #define VMON_OV_FAULT                   BIT(0)
  45
  46 #define ZL6100_WAIT_TIME                1000    /* uS   */
  47
  48 static ushort delay = ZL6100_WAIT_TIME;
  49 module_param(delay, ushort, 0644);
  50 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
  51
  52 /* Convert linear sensor value to milli-units */
  53 static long zl6100_l2d(s16 l)
  54 {
  55         s16 exponent;
  56         s32 mantissa;
  57         long val;
  58
  59         exponent = l >> 11;
  60         mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;
  61
  62         val = mantissa;
  63
  64         /* scale result to milli-units */
  65         val = val * 1000L;
  66
  67         if (exponent >= 0)
  68                 val <<= exponent;
  69         else
  70                 val >>= -exponent;
  71
  72         return val;
  73 }
  74
  75 #define MAX_MANTISSA    (1023 * 1000)
  76 #define MIN_MANTISSA    (511 * 1000)
  77
  78 static u16 zl6100_d2l(long val)
  79 {
  80         s16 exponent = 0, mantissa;
  81         bool negative = false;
  82
  83         /* simple case */
  84         if (val == 0)
  85                 return 0;
  86
  87         if (val < 0) {
  88                 negative = true;
  89                 val = -val;
  90         }
  91
  92         /* Reduce large mantissa until it fits into 10 bit */
  93         while (val >= MAX_MANTISSA && exponent < 15) {
  94                 exponent++;
  95                 val >>= 1;
  96         }
  97         /* Increase small mantissa to improve precision */
  98         while (val < MIN_MANTISSA && exponent > -15) {
  99                 exponent--;
 100                 val <<= 1;
 101         }
 102
 103         /* Convert mantissa from milli-units to units */
 104         mantissa = DIV_ROUND_CLOSEST(val, 1000);
 105
 106         /* Ensure that resulting number is within range */
 107         if (mantissa > 0x3ff)
 108                 mantissa = 0x3ff;
 109
 110         /* restore sign */
 111         if (negative)
 112                 mantissa = -mantissa;
 113
 114         /* Convert to 5 bit exponent, 11 bit mantissa */
 115         return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
 116 }
 117
 118 /* Some chips need a delay between accesses */
 119 static inline void zl6100_wait(const struct zl6100_data *data)
 120 {
 121         if (data->delay) {
 122                 s64 delta = ktime_us_delta(ktime_get(), data->access);
 123                 if (delta < data->delay)
 124                         udelay(data->delay - delta);
 125         }
 126 }
 127
 128 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
 129 {
 130         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 131         struct zl6100_data *data = to_zl6100_data(info);
 132         int ret, vreg;
 133
 134         if (page > 0)
 135                 return -ENXIO;
 136
 137         if (data->id == zl2005) {
 138                 /*
 139                  * Limit register detection is not reliable on ZL2005.
 140                  * Make sure registers are not erroneously detected.
 141                  */
 142                 switch (reg) {
 143                 case PMBUS_VOUT_OV_WARN_LIMIT:
 144                 case PMBUS_VOUT_UV_WARN_LIMIT:
 145                 case PMBUS_IOUT_OC_WARN_LIMIT:
 146                         return -ENXIO;
 147                 }
 148         }
 149
 150         switch (reg) {
 151         case PMBUS_VIRT_READ_VMON:
 152                 vreg = MFR_READ_VMON;
 153                 break;
 154         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 155         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 156                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 157                 break;
 158         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 159         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 160                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 161                 break;
 162         default:
 163                 if (reg >= PMBUS_VIRT_BASE)
 164                         return -ENXIO;
 165                 vreg = reg;
 166                 break;
 167         }
 168
 169         zl6100_wait(data);
 170         ret = pmbus_read_word_data(client, page, vreg);
 171         data->access = ktime_get();
 172         if (ret < 0)
 173                 return ret;
 174
 175         switch (reg) {
 176         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 177                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
 178                 break;
 179         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 180                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
 181                 break;
 182         }
 183
 184         return ret;
 185 }
 186
 187 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
 188 {
 189         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 190         struct zl6100_data *data = to_zl6100_data(info);
 191         int ret, status;
 192
 193         if (page > 0)
 194                 return -ENXIO;
 195
 196         zl6100_wait(data);
 197
 198         switch (reg) {
 199         case PMBUS_VIRT_STATUS_VMON:
 200                 ret = pmbus_read_byte_data(client, 0,
 201                                            PMBUS_STATUS_MFR_SPECIFIC);
 202                 if (ret < 0)
 203                         break;
 204
 205                 status = 0;
 206                 if (ret & VMON_UV_WARNING)
 207                         status |= PB_VOLTAGE_UV_WARNING;
 208                 if (ret & VMON_OV_WARNING)
 209                         status |= PB_VOLTAGE_OV_WARNING;
 210                 if (ret & VMON_UV_FAULT)
 211                         status |= PB_VOLTAGE_UV_FAULT;
 212                 if (ret & VMON_OV_FAULT)
 213                         status |= PB_VOLTAGE_OV_FAULT;
 214                 ret = status;
 215                 break;
 216         default:
 217                 ret = pmbus_read_byte_data(client, page, reg);
 218                 break;
 219         }
 220         data->access = ktime_get();
 221
 222         return ret;
 223 }
 224
 225 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
 226                                   u16 word)
 227 {
 228         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 229         struct zl6100_data *data = to_zl6100_data(info);
 230         int ret, vreg;
 231
 232         if (page > 0)
 233                 return -ENXIO;
 234
 235         switch (reg) {
 236         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 237                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
 238                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 239                 pmbus_clear_cache(client);
 240                 break;
 241         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 242                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 243                 pmbus_clear_cache(client);
 244                 break;
 245         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 246                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
 247                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 248                 pmbus_clear_cache(client);
 249                 break;
 250         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 251                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 252                 pmbus_clear_cache(client);
 253                 break;
 254         default:
 255                 if (reg >= PMBUS_VIRT_BASE)
 256                         return -ENXIO;
 257                 vreg = reg;
 258         }
 259
 260         zl6100_wait(data);
 261         ret = pmbus_write_word_data(client, page, vreg, word);
 262         data->access = ktime_get();
 263
 264         return ret;
 265 }
 266
 267 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
 268 {
 269         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 270         struct zl6100_data *data = to_zl6100_data(info);
 271         int ret;
 272
 273         if (page > 0)
 274                 return -ENXIO;
 275
 276         zl6100_wait(data);
 277         ret = pmbus_write_byte(client, page, value);
 278         data->access = ktime_get();
 279
 280         return ret;
 281 }
 282
 283 static const struct i2c_device_id zl6100_id[] = {
 284         {"bmr450", zl2005},
 285         {"bmr451", zl2005},
 286         {"bmr462", zl2008},
 287         {"bmr463", zl2008},
 288         {"bmr464", zl2008},
 289         {"zl2004", zl2004},
 290         {"zl2005", zl2005},
 291         {"zl2006", zl2006},
 292         {"zl2008", zl2008},
 293         {"zl2105", zl2105},
 294         {"zl2106", zl2106},
 295         {"zl6100", zl6100},
 296         {"zl6105", zl6105},
 297         {"zl9101", zl9101},
 298         {"zl9117", zl9117},
 299         { }
 300 };
 301 MODULE_DEVICE_TABLE(i2c, zl6100_id);
 302
 303 static int zl6100_probe(struct i2c_client *client,
 304                         const struct i2c_device_id *id)
 305 {
 306         int ret;
 307         struct zl6100_data *data;
 308         struct pmbus_driver_info *info;
 309         u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
 310         const struct i2c_device_id *mid;
 311
 312         if (!i2c_check_functionality(client->adapter,
 313                                      I2C_FUNC_SMBUS_READ_WORD_DATA
 314                                      | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 315                 return -ENODEV;
 316
 317         ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
 318                                         device_id);
 319         if (ret < 0) {
 320                 dev_err(&client->dev, "Failed to read device ID\n");
 321                 return ret;
 322         }
 323         device_id[ret] = '\0';
 324         dev_info(&client->dev, "Device ID %s\n", device_id);
 325
 326         mid = NULL;
 327         for (mid = zl6100_id; mid->name[0]; mid++) {
 328                 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
 329                         break;
 330         }
 331         if (!mid->name[0]) {
 332                 dev_err(&client->dev, "Unsupported device\n");
 333                 return -ENODEV;
 334         }
 335         if (id->driver_data != mid->driver_data)
 336                 dev_notice(&client->dev,
 337                            "Device mismatch: Configured %s, detected %s\n",
 338                            id->name, mid->name);
 339
 340         data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
 341                             GFP_KERNEL);
 342         if (!data)
 343                 return -ENOMEM;
 344
 345         data->id = mid->driver_data;
 346
 347         /*
 348          * According to information from the chip vendor, all currently
 349          * supported chips are known to require a wait time between I2C
 350          * accesses.
 351          */
 352         data->delay = delay;
 353
 354         /*
 355          * Since there was a direct I2C device access above, wait before
 356          * accessing the chip again.
 357          */
 358         data->access = ktime_get();
 359         zl6100_wait(data);
 360
 361         info = &data->info;
 362
 363         info->pages = 1;
 364         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 365           | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 366           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 367           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 368
 369         /*
 370          * ZL2004, ZL9101M, and ZL9117M support monitoring an extra voltage
 371          * (VMON for ZL2004, VDRV for ZL9101M and ZL9117M). Report it as vmon.
 372          */
 373         if (data->id == zl2004 || data->id == zl9101 || data->id == zl9117)
 374                 info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
 375
 376         ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
 377         if (ret < 0)
 378                 return ret;
 379
 380         if (ret & ZL6100_MFR_XTEMP_ENABLE)
 381                 info->func[0] |= PMBUS_HAVE_TEMP2;
 382
 383         data->access = ktime_get();
 384         zl6100_wait(data);
 385
 386         info->read_word_data = zl6100_read_word_data;
 387         info->read_byte_data = zl6100_read_byte_data;
 388         info->write_word_data = zl6100_write_word_data;
 389         info->write_byte = zl6100_write_byte;
 390
 391         return pmbus_do_probe(client, mid, info);
 392 }
 393
 394 static struct i2c_driver zl6100_driver = {
 395         .driver = {
 396                    .name = "zl6100",
 397                    },
 398         .probe = zl6100_probe,
 399         .remove = pmbus_do_remove,
 400         .id_table = zl6100_id,
 401 };
 402
 403 module_i2c_driver(zl6100_driver);
 404
 405 MODULE_AUTHOR("Guenter Roeck");
 406 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
 407 MODULE_LICENSE("GPL");