drivers/hwmon/pmbus/zl6100.c

   1 /*
   2  * Hardware monitoring driver for ZL6100 and compatibles
   3  *
   4  * Copyright (c) 2011 Ericsson AB.
   5  * Copyright (c) 2012 Guenter Roeck
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/err.h>
  26 #include <linux/slab.h>
  27 #include <linux/i2c.h>
  28 #include <linux/ktime.h>
  29 #include <linux/delay.h>
  30 #include "pmbus.h"
  31
  32 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
  33              zl9101, zl9117 };
  34
  35 struct zl6100_data {
  36         int id;
  37         ktime_t access;         /* chip access time */
  38         int delay;              /* Delay between chip accesses in uS */
  39         struct pmbus_driver_info info;
  40 };
  41
  42 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)
  43
  44 #define ZL6100_MFR_CONFIG               0xd0
  45 #define ZL6100_DEVICE_ID                0xe4
  46
  47 #define ZL6100_MFR_XTEMP_ENABLE         (1 << 7)
  48
  49 #define MFR_VMON_OV_FAULT_LIMIT         0xf5
  50 #define MFR_VMON_UV_FAULT_LIMIT         0xf6
  51 #define MFR_READ_VMON                   0xf7
  52
  53 #define VMON_UV_WARNING                 (1 << 5)
  54 #define VMON_OV_WARNING                 (1 << 4)
  55 #define VMON_UV_FAULT                   (1 << 1)
  56 #define VMON_OV_FAULT                   (1 << 0)
  57
  58 #define ZL6100_WAIT_TIME                1000    /* uS   */
  59
  60 static ushort delay = ZL6100_WAIT_TIME;
  61 module_param(delay, ushort, 0644);
  62 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
  63
  64 /* Convert linear sensor value to milli-units */
  65 static long zl6100_l2d(s16 l)
  66 {
  67         s16 exponent;
  68         s32 mantissa;
  69         long val;
  70
  71         exponent = l >> 11;
  72         mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;
  73
  74         val = mantissa;
  75
  76         /* scale result to milli-units */
  77         val = val * 1000L;
  78
  79         if (exponent >= 0)
  80                 val <<= exponent;
  81         else
  82                 val >>= -exponent;
  83
  84         return val;
  85 }
  86
  87 #define MAX_MANTISSA    (1023 * 1000)
  88 #define MIN_MANTISSA    (511 * 1000)
  89
  90 static u16 zl6100_d2l(long val)
  91 {
  92         s16 exponent = 0, mantissa;
  93         bool negative = false;
  94
  95         /* simple case */
  96         if (val == 0)
  97                 return 0;
  98
  99         if (val < 0) {
 100                 negative = true;
 101                 val = -val;
 102         }
 103
 104         /* Reduce large mantissa until it fits into 10 bit */
 105         while (val >= MAX_MANTISSA && exponent < 15) {
 106                 exponent++;
 107                 val >>= 1;
 108         }
 109         /* Increase small mantissa to improve precision */
 110         while (val < MIN_MANTISSA && exponent > -15) {
 111                 exponent--;
 112                 val <<= 1;
 113         }
 114
 115         /* Convert mantissa from milli-units to units */
 116         mantissa = DIV_ROUND_CLOSEST(val, 1000);
 117
 118         /* Ensure that resulting number is within range */
 119         if (mantissa > 0x3ff)
 120                 mantissa = 0x3ff;
 121
 122         /* restore sign */
 123         if (negative)
 124                 mantissa = -mantissa;
 125
 126         /* Convert to 5 bit exponent, 11 bit mantissa */
 127         return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
 128 }
 129
 130 /* Some chips need a delay between accesses */
 131 static inline void zl6100_wait(const struct zl6100_data *data)
 132 {
 133         if (data->delay) {
 134                 s64 delta = ktime_us_delta(ktime_get(), data->access);
 135                 if (delta < data->delay)
 136                         udelay(data->delay - delta);
 137         }
 138 }
 139
 140 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
 141 {
 142         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 143         struct zl6100_data *data = to_zl6100_data(info);
 144         int ret, vreg;
 145
 146         if (page > 0)
 147                 return -ENXIO;
 148
 149         if (data->id == zl2005) {
 150                 /*
 151                  * Limit register detection is not reliable on ZL2005.
 152                  * Make sure registers are not erroneously detected.
 153                  */
 154                 switch (reg) {
 155                 case PMBUS_VOUT_OV_WARN_LIMIT:
 156                 case PMBUS_VOUT_UV_WARN_LIMIT:
 157                 case PMBUS_IOUT_OC_WARN_LIMIT:
 158                         return -ENXIO;
 159                 }
 160         }
 161
 162         switch (reg) {
 163         case PMBUS_VIRT_READ_VMON:
 164                 vreg = MFR_READ_VMON;
 165                 break;
 166         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 167         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 168                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 169                 break;
 170         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 171         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 172                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 173                 break;
 174         default:
 175                 if (reg >= PMBUS_VIRT_BASE)
 176                         return -ENXIO;
 177                 vreg = reg;
 178                 break;
 179         }
 180
 181         zl6100_wait(data);
 182         ret = pmbus_read_word_data(client, page, vreg);
 183         data->access = ktime_get();
 184         if (ret < 0)
 185                 return ret;
 186
 187         switch (reg) {
 188         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 189                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
 190                 break;
 191         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 192                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
 193                 break;
 194         }
 195
 196         return ret;
 197 }
 198
 199 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
 200 {
 201         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 202         struct zl6100_data *data = to_zl6100_data(info);
 203         int ret, status;
 204
 205         if (page > 0)
 206                 return -ENXIO;
 207
 208         zl6100_wait(data);
 209
 210         switch (reg) {
 211         case PMBUS_VIRT_STATUS_VMON:
 212                 ret = pmbus_read_byte_data(client, 0,
 213                                            PMBUS_STATUS_MFR_SPECIFIC);
 214                 if (ret < 0)
 215                         break;
 216
 217                 status = 0;
 218                 if (ret & VMON_UV_WARNING)
 219                         status |= PB_VOLTAGE_UV_WARNING;
 220                 if (ret & VMON_OV_WARNING)
 221                         status |= PB_VOLTAGE_OV_WARNING;
 222                 if (ret & VMON_UV_FAULT)
 223                         status |= PB_VOLTAGE_UV_FAULT;
 224                 if (ret & VMON_OV_FAULT)
 225                         status |= PB_VOLTAGE_OV_FAULT;
 226                 ret = status;
 227                 break;
 228         default:
 229                 ret = pmbus_read_byte_data(client, page, reg);
 230                 break;
 231         }
 232         data->access = ktime_get();
 233
 234         return ret;
 235 }
 236
 237 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
 238                                   u16 word)
 239 {
 240         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 241         struct zl6100_data *data = to_zl6100_data(info);
 242         int ret, vreg;
 243
 244         if (page > 0)
 245                 return -ENXIO;
 246
 247         switch (reg) {
 248         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 249                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
 250                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 251                 pmbus_clear_cache(client);
 252                 break;
 253         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 254                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 255                 pmbus_clear_cache(client);
 256                 break;
 257         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 258                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
 259                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 260                 pmbus_clear_cache(client);
 261                 break;
 262         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 263                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 264                 pmbus_clear_cache(client);
 265                 break;
 266         default:
 267                 if (reg >= PMBUS_VIRT_BASE)
 268                         return -ENXIO;
 269                 vreg = reg;
 270         }
 271
 272         zl6100_wait(data);
 273         ret = pmbus_write_word_data(client, page, vreg, word);
 274         data->access = ktime_get();
 275
 276         return ret;
 277 }
 278
 279 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
 280 {
 281         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 282         struct zl6100_data *data = to_zl6100_data(info);
 283         int ret;
 284
 285         if (page > 0)
 286                 return -ENXIO;
 287
 288         zl6100_wait(data);
 289         ret = pmbus_write_byte(client, page, value);
 290         data->access = ktime_get();
 291
 292         return ret;
 293 }
 294
 295 static const struct i2c_device_id zl6100_id[] = {
 296         {"bmr450", zl2005},
 297         {"bmr451", zl2005},
 298         {"bmr462", zl2008},
 299         {"bmr463", zl2008},
 300         {"bmr464", zl2008},
 301         {"zl2004", zl2004},
 302         {"zl2005", zl2005},
 303         {"zl2006", zl2006},
 304         {"zl2008", zl2008},
 305         {"zl2105", zl2105},
 306         {"zl2106", zl2106},
 307         {"zl6100", zl6100},
 308         {"zl6105", zl6105},
 309         {"zl9101", zl9101},
 310         {"zl9117", zl9117},
 311         { }
 312 };
 313 MODULE_DEVICE_TABLE(i2c, zl6100_id);
 314
 315 static int zl6100_probe(struct i2c_client *client,
 316                         const struct i2c_device_id *id)
 317 {
 318         int ret;
 319         struct zl6100_data *data;
 320         struct pmbus_driver_info *info;
 321         u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
 322         const struct i2c_device_id *mid;
 323
 324         if (!i2c_check_functionality(client->adapter,
 325                                      I2C_FUNC_SMBUS_READ_WORD_DATA
 326                                      | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 327                 return -ENODEV;
 328
 329         ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
 330                                         device_id);
 331         if (ret < 0) {
 332                 dev_err(&client->dev, "Failed to read device ID\n");
 333                 return ret;
 334         }
 335         device_id[ret] = '\0';
 336         dev_info(&client->dev, "Device ID %s\n", device_id);
 337
 338         mid = NULL;
 339         for (mid = zl6100_id; mid->name[0]; mid++) {
 340                 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
 341                         break;
 342         }
 343         if (!mid->name[0]) {
 344                 dev_err(&client->dev, "Unsupported device\n");
 345                 return -ENODEV;
 346         }
 347         if (id->driver_data != mid->driver_data)
 348                 dev_notice(&client->dev,
 349                            "Device mismatch: Configured %s, detected %s\n",
 350                            id->name, mid->name);
 351
 352         data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
 353                             GFP_KERNEL);
 354         if (!data)
 355                 return -ENOMEM;
 356
 357         data->id = mid->driver_data;
 358
 359         /*
 360          * According to information from the chip vendor, all currently
 361          * supported chips are known to require a wait time between I2C
 362          * accesses.
 363          */
 364         data->delay = delay;
 365
 366         /*
 367          * Since there was a direct I2C device access above, wait before
 368          * accessing the chip again.
 369          */
 370         data->access = ktime_get();
 371         zl6100_wait(data);
 372
 373         info = &data->info;
 374
 375         info->pages = 1;
 376         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 377           | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 378           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 379           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 380
 381         /*
 382          * ZL2004, ZL9101M, and ZL9117M support monitoring an extra voltage
 383          * (VMON for ZL2004, VDRV for ZL9101M and ZL9117M). Report it as vmon.
 384          */
 385         if (data->id == zl2004 || data->id == zl9101 || data->id == zl9117)
 386                 info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
 387
 388         ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
 389         if (ret < 0)
 390                 return ret;
 391
 392         if (ret & ZL6100_MFR_XTEMP_ENABLE)
 393                 info->func[0] |= PMBUS_HAVE_TEMP2;
 394
 395         data->access = ktime_get();
 396         zl6100_wait(data);
 397
 398         info->read_word_data = zl6100_read_word_data;
 399         info->read_byte_data = zl6100_read_byte_data;
 400         info->write_word_data = zl6100_write_word_data;
 401         info->write_byte = zl6100_write_byte;
 402
 403         return pmbus_do_probe(client, mid, info);
 404 }
 405
 406 static struct i2c_driver zl6100_driver = {
 407         .driver = {
 408                    .name = "zl6100",
 409                    },
 410         .probe = zl6100_probe,
 411         .remove = pmbus_do_remove,
 412         .id_table = zl6100_id,
 413 };
 414
 415 module_i2c_driver(zl6100_driver);
 416
 417 MODULE_AUTHOR("Guenter Roeck");
 418 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
 419 MODULE_LICENSE("GPL");