drivers/iio/potentiometer/mcp4531.c

   1 /*
   2  * Industrial I/O driver for Microchip digital potentiometers
   3  * Copyright (c) 2015  Axentia Technologies AB
   4  * Author: Peter Rosin <peda@axentia.se>
   5  *
   6  * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
   7  *
   8  * DEVID        #Wipers #Positions      Resistor Opts (kOhm)    i2c address
   9  * mcp4531      1       129             5, 10, 50, 100          010111x
  10  * mcp4532      1       129             5, 10, 50, 100          01011xx
  11  * mcp4541      1       129             5, 10, 50, 100          010111x
  12  * mcp4542      1       129             5, 10, 50, 100          01011xx
  13  * mcp4551      1       257             5, 10, 50, 100          010111x
  14  * mcp4552      1       257             5, 10, 50, 100          01011xx
  15  * mcp4561      1       257             5, 10, 50, 100          010111x
  16  * mcp4562      1       257             5, 10, 50, 100          01011xx
  17  * mcp4631      2       129             5, 10, 50, 100          0101xxx
  18  * mcp4632      2       129             5, 10, 50, 100          01011xx
  19  * mcp4641      2       129             5, 10, 50, 100          0101xxx
  20  * mcp4642      2       129             5, 10, 50, 100          01011xx
  21  * mcp4651      2       257             5, 10, 50, 100          0101xxx
  22  * mcp4652      2       257             5, 10, 50, 100          01011xx
  23  * mcp4661      2       257             5, 10, 50, 100          0101xxx
  24  * mcp4662      2       257             5, 10, 50, 100          01011xx
  25  *
  26  * This program is free software; you can redistribute it and/or modify it
  27  * under the terms of the GNU General Public License version 2 as published by
  28  * the Free Software Foundation.
  29  */
  30
  31 #include <linux/module.h>
  32 #include <linux/i2c.h>
  33 #include <linux/err.h>
  34 #include <linux/of.h>
  35 #include <linux/of_device.h>
  36
  37 #include <linux/iio/iio.h>
  38
  39 struct mcp4531_cfg {
  40         int wipers;
  41         int avail[3];
  42         int kohms;
  43 };
  44
  45 enum mcp4531_type {
  46         MCP453x_502,
  47         MCP453x_103,
  48         MCP453x_503,
  49         MCP453x_104,
  50         MCP454x_502,
  51         MCP454x_103,
  52         MCP454x_503,
  53         MCP454x_104,
  54         MCP455x_502,
  55         MCP455x_103,
  56         MCP455x_503,
  57         MCP455x_104,
  58         MCP456x_502,
  59         MCP456x_103,
  60         MCP456x_503,
  61         MCP456x_104,
  62         MCP463x_502,
  63         MCP463x_103,
  64         MCP463x_503,
  65         MCP463x_104,
  66         MCP464x_502,
  67         MCP464x_103,
  68         MCP464x_503,
  69         MCP464x_104,
  70         MCP465x_502,
  71         MCP465x_103,
  72         MCP465x_503,
  73         MCP465x_104,
  74         MCP466x_502,
  75         MCP466x_103,
  76         MCP466x_503,
  77         MCP466x_104,
  78 };
  79
  80 static const struct mcp4531_cfg mcp4531_cfg[] = {
  81         [MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
  82         [MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
  83         [MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
  84         [MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
  85         [MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
  86         [MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
  87         [MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
  88         [MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
  89         [MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
  90         [MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
  91         [MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
  92         [MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
  93         [MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
  94         [MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
  95         [MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
  96         [MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
  97         [MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
  98         [MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
  99         [MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
 100         [MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
 101         [MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
 102         [MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
 103         [MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
 104         [MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
 105         [MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
 106         [MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
 107         [MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
 108         [MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
 109         [MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
 110         [MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
 111         [MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
 112         [MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
 113 };
 114
 115 #define MCP4531_WRITE (0 << 2)
 116 #define MCP4531_INCR  (1 << 2)
 117 #define MCP4531_DECR  (2 << 2)
 118 #define MCP4531_READ  (3 << 2)
 119
 120 #define MCP4531_WIPER_SHIFT (4)
 121
 122 struct mcp4531_data {
 123         struct i2c_client *client;
 124         const struct mcp4531_cfg *cfg;
 125 };
 126
 127 #define MCP4531_CHANNEL(ch) {                                           \
 128         .type = IIO_RESISTANCE,                                         \
 129         .indexed = 1,                                                   \
 130         .output = 1,                                                    \
 131         .channel = (ch),                                                \
 132         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 133         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
 134         .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW),   \
 135 }
 136
 137 static const struct iio_chan_spec mcp4531_channels[] = {
 138         MCP4531_CHANNEL(0),
 139         MCP4531_CHANNEL(1),
 140 };
 141
 142 static int mcp4531_read_raw(struct iio_dev *indio_dev,
 143                             struct iio_chan_spec const *chan,
 144                             int *val, int *val2, long mask)
 145 {
 146         struct mcp4531_data *data = iio_priv(indio_dev);
 147         int address = chan->channel << MCP4531_WIPER_SHIFT;
 148         s32 ret;
 149
 150         switch (mask) {
 151         case IIO_CHAN_INFO_RAW:
 152                 ret = i2c_smbus_read_word_swapped(data->client,
 153                                                   MCP4531_READ | address);
 154                 if (ret < 0)
 155                         return ret;
 156                 *val = ret;
 157                 return IIO_VAL_INT;
 158         case IIO_CHAN_INFO_SCALE:
 159                 *val = 1000 * data->cfg->kohms;
 160                 *val2 = data->cfg->avail[2];
 161                 return IIO_VAL_FRACTIONAL;
 162         }
 163
 164         return -EINVAL;
 165 }
 166
 167 static int mcp4531_read_avail(struct iio_dev *indio_dev,
 168                               struct iio_chan_spec const *chan,
 169                               const int **vals, int *type, int *length,
 170                               long mask)
 171 {
 172         struct mcp4531_data *data = iio_priv(indio_dev);
 173
 174         switch (mask) {
 175         case IIO_CHAN_INFO_RAW:
 176                 *length = ARRAY_SIZE(data->cfg->avail);
 177                 *vals = data->cfg->avail;
 178                 *type = IIO_VAL_INT;
 179                 return IIO_AVAIL_RANGE;
 180         }
 181
 182         return -EINVAL;
 183 }
 184
 185 static int mcp4531_write_raw(struct iio_dev *indio_dev,
 186                              struct iio_chan_spec const *chan,
 187                              int val, int val2, long mask)
 188 {
 189         struct mcp4531_data *data = iio_priv(indio_dev);
 190         int address = chan->channel << MCP4531_WIPER_SHIFT;
 191
 192         switch (mask) {
 193         case IIO_CHAN_INFO_RAW:
 194                 if (val > data->cfg->avail[2] || val < 0)
 195                         return -EINVAL;
 196                 break;
 197         default:
 198                 return -EINVAL;
 199         }
 200
 201         return i2c_smbus_write_byte_data(data->client,
 202                                          MCP4531_WRITE | address | (val >> 8),
 203                                          val & 0xff);
 204 }
 205
 206 static const struct iio_info mcp4531_info = {
 207         .read_raw = mcp4531_read_raw,
 208         .read_avail = mcp4531_read_avail,
 209         .write_raw = mcp4531_write_raw,
 210         .driver_module = THIS_MODULE,
 211 };
 212
 213 #ifdef CONFIG_OF
 214
 215 #define MCP4531_COMPATIBLE(of_compatible, cfg) {        \
 216                         .compatible = of_compatible,    \
 217                         .data = &mcp4531_cfg[cfg],      \
 218 }
 219
 220 static const struct of_device_id mcp4531_of_match[] = {
 221         MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
 222         MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
 223         MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
 224         MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
 225         MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
 226         MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
 227         MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
 228         MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
 229         MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
 230         MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
 231         MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
 232         MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
 233         MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
 234         MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
 235         MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
 236         MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
 237         MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
 238         MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
 239         MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
 240         MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
 241         MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
 242         MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
 243         MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
 244         MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
 245         MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
 246         MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
 247         MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
 248         MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
 249         MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
 250         MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
 251         MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
 252         MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
 253         MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
 254         MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
 255         MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
 256         MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
 257         MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
 258         MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
 259         MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
 260         MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
 261         MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
 262         MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
 263         MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
 264         MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
 265         MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
 266         MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
 267         MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
 268         MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
 269         MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
 270         MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
 271         MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
 272         MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
 273         MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
 274         MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
 275         MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
 276         MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
 277         MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
 278         MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
 279         MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
 280         MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
 281         MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
 282         MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
 283         MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
 284         MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
 285         { /* sentinel */ }
 286 };
 287 MODULE_DEVICE_TABLE(of, mcp4531_of_match);
 288 #endif
 289
 290 static int mcp4531_probe(struct i2c_client *client,
 291                          const struct i2c_device_id *id)
 292 {
 293         struct device *dev = &client->dev;
 294         struct mcp4531_data *data;
 295         struct iio_dev *indio_dev;
 296         const struct of_device_id *match;
 297
 298         if (!i2c_check_functionality(client->adapter,
 299                                      I2C_FUNC_SMBUS_WORD_DATA)) {
 300                 dev_err(dev, "SMBUS Word Data not supported\n");
 301                 return -EOPNOTSUPP;
 302         }
 303
 304         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 305         if (!indio_dev)
 306                 return -ENOMEM;
 307         data = iio_priv(indio_dev);
 308         i2c_set_clientdata(client, indio_dev);
 309         data->client = client;
 310
 311         match = of_match_device(of_match_ptr(mcp4531_of_match), dev);
 312         if (match)
 313                 data->cfg = of_device_get_match_data(dev);
 314         else
 315                 data->cfg = &mcp4531_cfg[id->driver_data];
 316
 317         indio_dev->dev.parent = dev;
 318         indio_dev->info = &mcp4531_info;
 319         indio_dev->channels = mcp4531_channels;
 320         indio_dev->num_channels = data->cfg->wipers;
 321         indio_dev->name = client->name;
 322
 323         return devm_iio_device_register(dev, indio_dev);
 324 }
 325
 326 static const struct i2c_device_id mcp4531_id[] = {
 327         { "mcp4531-502", MCP453x_502 },
 328         { "mcp4531-103", MCP453x_103 },
 329         { "mcp4531-503", MCP453x_503 },
 330         { "mcp4531-104", MCP453x_104 },
 331         { "mcp4532-502", MCP453x_502 },
 332         { "mcp4532-103", MCP453x_103 },
 333         { "mcp4532-503", MCP453x_503 },
 334         { "mcp4532-104", MCP453x_104 },
 335         { "mcp4541-502", MCP454x_502 },
 336         { "mcp4541-103", MCP454x_103 },
 337         { "mcp4541-503", MCP454x_503 },
 338         { "mcp4541-104", MCP454x_104 },
 339         { "mcp4542-502", MCP454x_502 },
 340         { "mcp4542-103", MCP454x_103 },
 341         { "mcp4542-503", MCP454x_503 },
 342         { "mcp4542-104", MCP454x_104 },
 343         { "mcp4551-502", MCP455x_502 },
 344         { "mcp4551-103", MCP455x_103 },
 345         { "mcp4551-503", MCP455x_503 },
 346         { "mcp4551-104", MCP455x_104 },
 347         { "mcp4552-502", MCP455x_502 },
 348         { "mcp4552-103", MCP455x_103 },
 349         { "mcp4552-503", MCP455x_503 },
 350         { "mcp4552-104", MCP455x_104 },
 351         { "mcp4561-502", MCP456x_502 },
 352         { "mcp4561-103", MCP456x_103 },
 353         { "mcp4561-503", MCP456x_503 },
 354         { "mcp4561-104", MCP456x_104 },
 355         { "mcp4562-502", MCP456x_502 },
 356         { "mcp4562-103", MCP456x_103 },
 357         { "mcp4562-503", MCP456x_503 },
 358         { "mcp4562-104", MCP456x_104 },
 359         { "mcp4631-502", MCP463x_502 },
 360         { "mcp4631-103", MCP463x_103 },
 361         { "mcp4631-503", MCP463x_503 },
 362         { "mcp4631-104", MCP463x_104 },
 363         { "mcp4632-502", MCP463x_502 },
 364         { "mcp4632-103", MCP463x_103 },
 365         { "mcp4632-503", MCP463x_503 },
 366         { "mcp4632-104", MCP463x_104 },
 367         { "mcp4641-502", MCP464x_502 },
 368         { "mcp4641-103", MCP464x_103 },
 369         { "mcp4641-503", MCP464x_503 },
 370         { "mcp4641-104", MCP464x_104 },
 371         { "mcp4642-502", MCP464x_502 },
 372         { "mcp4642-103", MCP464x_103 },
 373         { "mcp4642-503", MCP464x_503 },
 374         { "mcp4642-104", MCP464x_104 },
 375         { "mcp4651-502", MCP465x_502 },
 376         { "mcp4651-103", MCP465x_103 },
 377         { "mcp4651-503", MCP465x_503 },
 378         { "mcp4651-104", MCP465x_104 },
 379         { "mcp4652-502", MCP465x_502 },
 380         { "mcp4652-103", MCP465x_103 },
 381         { "mcp4652-503", MCP465x_503 },
 382         { "mcp4652-104", MCP465x_104 },
 383         { "mcp4661-502", MCP466x_502 },
 384         { "mcp4661-103", MCP466x_103 },
 385         { "mcp4661-503", MCP466x_503 },
 386         { "mcp4661-104", MCP466x_104 },
 387         { "mcp4662-502", MCP466x_502 },
 388         { "mcp4662-103", MCP466x_103 },
 389         { "mcp4662-503", MCP466x_503 },
 390         { "mcp4662-104", MCP466x_104 },
 391         {}
 392 };
 393 MODULE_DEVICE_TABLE(i2c, mcp4531_id);
 394
 395 static struct i2c_driver mcp4531_driver = {
 396         .driver = {
 397                 .name   = "mcp4531",
 398                 .of_match_table = of_match_ptr(mcp4531_of_match),
 399         },
 400         .probe          = mcp4531_probe,
 401         .id_table       = mcp4531_id,
 402 };
 403
 404 module_i2c_driver(mcp4531_driver);
 405
 406 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
 407 MODULE_DESCRIPTION("MCP4531 digital potentiometer");
 408 MODULE_LICENSE("GPL");