drivers/iio/potentiometer/mcp4531.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Industrial I/O driver for Microchip digital potentiometers
   4  * Copyright (c) 2015  Axentia Technologies AB
   5  * Author: Peter Rosin <peda@axentia.se>
   6  *
   7  * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
   8  *
   9  * DEVID        #Wipers #Positions      Resistor Opts (kOhm)    i2c address
  10  * mcp4531      1       129             5, 10, 50, 100          010111x
  11  * mcp4532      1       129             5, 10, 50, 100          01011xx
  12  * mcp4541      1       129             5, 10, 50, 100          010111x
  13  * mcp4542      1       129             5, 10, 50, 100          01011xx
  14  * mcp4551      1       257             5, 10, 50, 100          010111x
  15  * mcp4552      1       257             5, 10, 50, 100          01011xx
  16  * mcp4561      1       257             5, 10, 50, 100          010111x
  17  * mcp4562      1       257             5, 10, 50, 100          01011xx
  18  * mcp4631      2       129             5, 10, 50, 100          0101xxx
  19  * mcp4632      2       129             5, 10, 50, 100          01011xx
  20  * mcp4641      2       129             5, 10, 50, 100          0101xxx
  21  * mcp4642      2       129             5, 10, 50, 100          01011xx
  22  * mcp4651      2       257             5, 10, 50, 100          0101xxx
  23  * mcp4652      2       257             5, 10, 50, 100          01011xx
  24  * mcp4661      2       257             5, 10, 50, 100          0101xxx
  25  * mcp4662      2       257             5, 10, 50, 100          01011xx
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/i2c.h>
  30 #include <linux/err.h>
  31 #include <linux/mod_devicetable.h>
  32 #include <linux/property.h>
  33
  34 #include <linux/iio/iio.h>
  35
  36 struct mcp4531_cfg {
  37         int wipers;
  38         int avail[3];
  39         int kohms;
  40 };
  41
  42 enum mcp4531_type {
  43         MCP453x_502,
  44         MCP453x_103,
  45         MCP453x_503,
  46         MCP453x_104,
  47         MCP454x_502,
  48         MCP454x_103,
  49         MCP454x_503,
  50         MCP454x_104,
  51         MCP455x_502,
  52         MCP455x_103,
  53         MCP455x_503,
  54         MCP455x_104,
  55         MCP456x_502,
  56         MCP456x_103,
  57         MCP456x_503,
  58         MCP456x_104,
  59         MCP463x_502,
  60         MCP463x_103,
  61         MCP463x_503,
  62         MCP463x_104,
  63         MCP464x_502,
  64         MCP464x_103,
  65         MCP464x_503,
  66         MCP464x_104,
  67         MCP465x_502,
  68         MCP465x_103,
  69         MCP465x_503,
  70         MCP465x_104,
  71         MCP466x_502,
  72         MCP466x_103,
  73         MCP466x_503,
  74         MCP466x_104,
  75 };
  76
  77 static const struct mcp4531_cfg mcp4531_cfg[] = {
  78         [MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
  79         [MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
  80         [MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
  81         [MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
  82         [MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
  83         [MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
  84         [MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
  85         [MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
  86         [MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
  87         [MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
  88         [MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
  89         [MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
  90         [MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
  91         [MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
  92         [MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
  93         [MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
  94         [MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
  95         [MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
  96         [MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
  97         [MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
  98         [MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
  99         [MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
 100         [MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
 101         [MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
 102         [MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
 103         [MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
 104         [MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
 105         [MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
 106         [MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
 107         [MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
 108         [MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
 109         [MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
 110 };
 111
 112 #define MCP4531_WRITE (0 << 2)
 113 #define MCP4531_INCR  (1 << 2)
 114 #define MCP4531_DECR  (2 << 2)
 115 #define MCP4531_READ  (3 << 2)
 116
 117 #define MCP4531_WIPER_SHIFT (4)
 118
 119 struct mcp4531_data {
 120         struct i2c_client *client;
 121         const struct mcp4531_cfg *cfg;
 122 };
 123
 124 #define MCP4531_CHANNEL(ch) {                                           \
 125         .type = IIO_RESISTANCE,                                         \
 126         .indexed = 1,                                                   \
 127         .output = 1,                                                    \
 128         .channel = (ch),                                                \
 129         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 130         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
 131         .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW),   \
 132 }
 133
 134 static const struct iio_chan_spec mcp4531_channels[] = {
 135         MCP4531_CHANNEL(0),
 136         MCP4531_CHANNEL(1),
 137 };
 138
 139 static int mcp4531_read_raw(struct iio_dev *indio_dev,
 140                             struct iio_chan_spec const *chan,
 141                             int *val, int *val2, long mask)
 142 {
 143         struct mcp4531_data *data = iio_priv(indio_dev);
 144         int address = chan->channel << MCP4531_WIPER_SHIFT;
 145         s32 ret;
 146
 147         switch (mask) {
 148         case IIO_CHAN_INFO_RAW:
 149                 ret = i2c_smbus_read_word_swapped(data->client,
 150                                                   MCP4531_READ | address);
 151                 if (ret < 0)
 152                         return ret;
 153                 *val = ret;
 154                 return IIO_VAL_INT;
 155         case IIO_CHAN_INFO_SCALE:
 156                 *val = 1000 * data->cfg->kohms;
 157                 *val2 = data->cfg->avail[2];
 158                 return IIO_VAL_FRACTIONAL;
 159         }
 160
 161         return -EINVAL;
 162 }
 163
 164 static int mcp4531_read_avail(struct iio_dev *indio_dev,
 165                               struct iio_chan_spec const *chan,
 166                               const int **vals, int *type, int *length,
 167                               long mask)
 168 {
 169         struct mcp4531_data *data = iio_priv(indio_dev);
 170
 171         switch (mask) {
 172         case IIO_CHAN_INFO_RAW:
 173                 *length = ARRAY_SIZE(data->cfg->avail);
 174                 *vals = data->cfg->avail;
 175                 *type = IIO_VAL_INT;
 176                 return IIO_AVAIL_RANGE;
 177         }
 178
 179         return -EINVAL;
 180 }
 181
 182 static int mcp4531_write_raw(struct iio_dev *indio_dev,
 183                              struct iio_chan_spec const *chan,
 184                              int val, int val2, long mask)
 185 {
 186         struct mcp4531_data *data = iio_priv(indio_dev);
 187         int address = chan->channel << MCP4531_WIPER_SHIFT;
 188
 189         switch (mask) {
 190         case IIO_CHAN_INFO_RAW:
 191                 if (val > data->cfg->avail[2] || val < 0)
 192                         return -EINVAL;
 193                 break;
 194         default:
 195                 return -EINVAL;
 196         }
 197
 198         return i2c_smbus_write_byte_data(data->client,
 199                                          MCP4531_WRITE | address | (val >> 8),
 200                                          val & 0xff);
 201 }
 202
 203 static const struct iio_info mcp4531_info = {
 204         .read_raw = mcp4531_read_raw,
 205         .read_avail = mcp4531_read_avail,
 206         .write_raw = mcp4531_write_raw,
 207 };
 208
 209 static const struct i2c_device_id mcp4531_id[] = {
 210         { "mcp4531-502", MCP453x_502 },
 211         { "mcp4531-103", MCP453x_103 },
 212         { "mcp4531-503", MCP453x_503 },
 213         { "mcp4531-104", MCP453x_104 },
 214         { "mcp4532-502", MCP453x_502 },
 215         { "mcp4532-103", MCP453x_103 },
 216         { "mcp4532-503", MCP453x_503 },
 217         { "mcp4532-104", MCP453x_104 },
 218         { "mcp4541-502", MCP454x_502 },
 219         { "mcp4541-103", MCP454x_103 },
 220         { "mcp4541-503", MCP454x_503 },
 221         { "mcp4541-104", MCP454x_104 },
 222         { "mcp4542-502", MCP454x_502 },
 223         { "mcp4542-103", MCP454x_103 },
 224         { "mcp4542-503", MCP454x_503 },
 225         { "mcp4542-104", MCP454x_104 },
 226         { "mcp4551-502", MCP455x_502 },
 227         { "mcp4551-103", MCP455x_103 },
 228         { "mcp4551-503", MCP455x_503 },
 229         { "mcp4551-104", MCP455x_104 },
 230         { "mcp4552-502", MCP455x_502 },
 231         { "mcp4552-103", MCP455x_103 },
 232         { "mcp4552-503", MCP455x_503 },
 233         { "mcp4552-104", MCP455x_104 },
 234         { "mcp4561-502", MCP456x_502 },
 235         { "mcp4561-103", MCP456x_103 },
 236         { "mcp4561-503", MCP456x_503 },
 237         { "mcp4561-104", MCP456x_104 },
 238         { "mcp4562-502", MCP456x_502 },
 239         { "mcp4562-103", MCP456x_103 },
 240         { "mcp4562-503", MCP456x_503 },
 241         { "mcp4562-104", MCP456x_104 },
 242         { "mcp4631-502", MCP463x_502 },
 243         { "mcp4631-103", MCP463x_103 },
 244         { "mcp4631-503", MCP463x_503 },
 245         { "mcp4631-104", MCP463x_104 },
 246         { "mcp4632-502", MCP463x_502 },
 247         { "mcp4632-103", MCP463x_103 },
 248         { "mcp4632-503", MCP463x_503 },
 249         { "mcp4632-104", MCP463x_104 },
 250         { "mcp4641-502", MCP464x_502 },
 251         { "mcp4641-103", MCP464x_103 },
 252         { "mcp4641-503", MCP464x_503 },
 253         { "mcp4641-104", MCP464x_104 },
 254         { "mcp4642-502", MCP464x_502 },
 255         { "mcp4642-103", MCP464x_103 },
 256         { "mcp4642-503", MCP464x_503 },
 257         { "mcp4642-104", MCP464x_104 },
 258         { "mcp4651-502", MCP465x_502 },
 259         { "mcp4651-103", MCP465x_103 },
 260         { "mcp4651-503", MCP465x_503 },
 261         { "mcp4651-104", MCP465x_104 },
 262         { "mcp4652-502", MCP465x_502 },
 263         { "mcp4652-103", MCP465x_103 },
 264         { "mcp4652-503", MCP465x_503 },
 265         { "mcp4652-104", MCP465x_104 },
 266         { "mcp4661-502", MCP466x_502 },
 267         { "mcp4661-103", MCP466x_103 },
 268         { "mcp4661-503", MCP466x_503 },
 269         { "mcp4661-104", MCP466x_104 },
 270         { "mcp4662-502", MCP466x_502 },
 271         { "mcp4662-103", MCP466x_103 },
 272         { "mcp4662-503", MCP466x_503 },
 273         { "mcp4662-104", MCP466x_104 },
 274         {}
 275 };
 276 MODULE_DEVICE_TABLE(i2c, mcp4531_id);
 277
 278 #define MCP4531_COMPATIBLE(of_compatible, cfg) {        \
 279                         .compatible = of_compatible,    \
 280                         .data = &mcp4531_cfg[cfg],      \
 281 }
 282
 283 static const struct of_device_id mcp4531_of_match[] = {
 284         MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
 285         MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
 286         MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
 287         MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
 288         MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
 289         MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
 290         MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
 291         MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
 292         MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
 293         MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
 294         MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
 295         MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
 296         MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
 297         MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
 298         MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
 299         MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
 300         MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
 301         MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
 302         MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
 303         MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
 304         MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
 305         MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
 306         MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
 307         MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
 308         MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
 309         MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
 310         MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
 311         MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
 312         MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
 313         MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
 314         MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
 315         MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
 316         MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
 317         MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
 318         MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
 319         MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
 320         MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
 321         MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
 322         MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
 323         MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
 324         MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
 325         MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
 326         MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
 327         MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
 328         MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
 329         MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
 330         MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
 331         MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
 332         MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
 333         MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
 334         MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
 335         MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
 336         MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
 337         MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
 338         MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
 339         MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
 340         MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
 341         MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
 342         MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
 343         MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
 344         MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
 345         MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
 346         MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
 347         MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
 348         { /* sentinel */ }
 349 };
 350 MODULE_DEVICE_TABLE(of, mcp4531_of_match);
 351
 352 static int mcp4531_probe(struct i2c_client *client)
 353 {
 354         struct device *dev = &client->dev;
 355         struct mcp4531_data *data;
 356         struct iio_dev *indio_dev;
 357
 358         if (!i2c_check_functionality(client->adapter,
 359                                      I2C_FUNC_SMBUS_WORD_DATA)) {
 360                 dev_err(dev, "SMBUS Word Data not supported\n");
 361                 return -EOPNOTSUPP;
 362         }
 363
 364         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 365         if (!indio_dev)
 366                 return -ENOMEM;
 367         data = iio_priv(indio_dev);
 368         i2c_set_clientdata(client, indio_dev);
 369         data->client = client;
 370
 371         data->cfg = device_get_match_data(dev);
 372         if (!data->cfg)
 373                 data->cfg = &mcp4531_cfg[i2c_match_id(mcp4531_id, client)->driver_data];
 374
 375         indio_dev->info = &mcp4531_info;
 376         indio_dev->channels = mcp4531_channels;
 377         indio_dev->num_channels = data->cfg->wipers;
 378         indio_dev->name = client->name;
 379
 380         return devm_iio_device_register(dev, indio_dev);
 381 }
 382
 383 static struct i2c_driver mcp4531_driver = {
 384         .driver = {
 385                 .name   = "mcp4531",
 386                 .of_match_table = mcp4531_of_match,
 387         },
 388         .probe_new      = mcp4531_probe,
 389         .id_table       = mcp4531_id,
 390 };
 391
 392 module_i2c_driver(mcp4531_driver);
 393
 394 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
 395 MODULE_DESCRIPTION("MCP4531 digital potentiometer");
 396 MODULE_LICENSE("GPL v2");