drivers/iio/temperature/ltc2983.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
   4  * driver
   5  *
   6  * Copyright 2019 Analog Devices Inc.
   7  */
   8 #include <linux/bitfield.h>
   9 #include <linux/completion.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/iio/iio.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/list.h>
  15 #include <linux/module.h>
  16 #include <linux/of_gpio.h>
  17 #include <linux/regmap.h>
  18 #include <linux/spi/spi.h>
  19
  20 /* register map */
  21 #define LTC2983_STATUS_REG                      0x0000
  22 #define LTC2983_TEMP_RES_START_REG              0x0010
  23 #define LTC2983_TEMP_RES_END_REG                0x005F
  24 #define LTC2983_GLOBAL_CONFIG_REG               0x00F0
  25 #define LTC2983_MULT_CHANNEL_START_REG          0x00F4
  26 #define LTC2983_MULT_CHANNEL_END_REG            0x00F7
  27 #define LTC2983_MUX_CONFIG_REG                  0x00FF
  28 #define LTC2983_CHAN_ASSIGN_START_REG           0x0200
  29 #define LTC2983_CHAN_ASSIGN_END_REG             0x024F
  30 #define LTC2983_CUST_SENS_TBL_START_REG         0x0250
  31 #define LTC2983_CUST_SENS_TBL_END_REG           0x03CF
  32
  33 #define LTC2983_DIFFERENTIAL_CHAN_MIN           2
  34 #define LTC2983_MAX_CHANNELS_NR                 20
  35 #define LTC2983_MIN_CHANNELS_NR                 1
  36 #define LTC2983_SLEEP                           0x97
  37 #define LTC2983_CUSTOM_STEINHART_SIZE           24
  38 #define LTC2983_CUSTOM_SENSOR_ENTRY_SZ          6
  39 #define LTC2983_CUSTOM_STEINHART_ENTRY_SZ       4
  40
  41 #define LTC2983_CHAN_START_ADDR(chan) \
  42                         (((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
  43 #define LTC2983_CHAN_RES_ADDR(chan) \
  44                         (((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG)
  45 #define LTC2983_THERMOCOUPLE_DIFF_MASK          BIT(3)
  46 #define LTC2983_THERMOCOUPLE_SGL(x) \
  47                                 FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x)
  48 #define LTC2983_THERMOCOUPLE_OC_CURR_MASK       GENMASK(1, 0)
  49 #define LTC2983_THERMOCOUPLE_OC_CURR(x) \
  50                                 FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x)
  51 #define LTC2983_THERMOCOUPLE_OC_CHECK_MASK      BIT(2)
  52 #define LTC2983_THERMOCOUPLE_OC_CHECK(x) \
  53                         FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x)
  54
  55 #define LTC2983_THERMISTOR_DIFF_MASK            BIT(2)
  56 #define LTC2983_THERMISTOR_SGL(x) \
  57                                 FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x)
  58 #define LTC2983_THERMISTOR_R_SHARE_MASK         BIT(1)
  59 #define LTC2983_THERMISTOR_R_SHARE(x) \
  60                                 FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x)
  61 #define LTC2983_THERMISTOR_C_ROTATE_MASK        BIT(0)
  62 #define LTC2983_THERMISTOR_C_ROTATE(x) \
  63                                 FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x)
  64
  65 #define LTC2983_DIODE_DIFF_MASK                 BIT(2)
  66 #define LTC2983_DIODE_SGL(x) \
  67                         FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x)
  68 #define LTC2983_DIODE_3_CONV_CYCLE_MASK         BIT(1)
  69 #define LTC2983_DIODE_3_CONV_CYCLE(x) \
  70                                 FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x)
  71 #define LTC2983_DIODE_AVERAGE_ON_MASK           BIT(0)
  72 #define LTC2983_DIODE_AVERAGE_ON(x) \
  73                                 FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x)
  74
  75 #define LTC2983_RTD_4_WIRE_MASK                 BIT(3)
  76 #define LTC2983_RTD_ROTATION_MASK               BIT(1)
  77 #define LTC2983_RTD_C_ROTATE(x) \
  78                         FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x)
  79 #define LTC2983_RTD_KELVIN_R_SENSE_MASK         GENMASK(3, 2)
  80 #define LTC2983_RTD_N_WIRES_MASK                GENMASK(3, 2)
  81 #define LTC2983_RTD_N_WIRES(x) \
  82                         FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x)
  83 #define LTC2983_RTD_R_SHARE_MASK                BIT(0)
  84 #define LTC2983_RTD_R_SHARE(x) \
  85                         FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1)
  86
  87 #define LTC2983_COMMON_HARD_FAULT_MASK  GENMASK(31, 30)
  88 #define LTC2983_COMMON_SOFT_FAULT_MASK  GENMASK(27, 25)
  89
  90 #define LTC2983_STATUS_START_MASK       BIT(7)
  91 #define LTC2983_STATUS_START(x)         FIELD_PREP(LTC2983_STATUS_START_MASK, x)
  92 #define LTC2983_STATUS_UP_MASK          GENMASK(7, 6)
  93 #define LTC2983_STATUS_UP(reg)          FIELD_GET(LTC2983_STATUS_UP_MASK, reg)
  94
  95 #define LTC2983_STATUS_CHAN_SEL_MASK    GENMASK(4, 0)
  96 #define LTC2983_STATUS_CHAN_SEL(x) \
  97                                 FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x)
  98
  99 #define LTC2983_TEMP_UNITS_MASK         BIT(2)
 100 #define LTC2983_TEMP_UNITS(x)           FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x)
 101
 102 #define LTC2983_NOTCH_FREQ_MASK         GENMASK(1, 0)
 103 #define LTC2983_NOTCH_FREQ(x)           FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x)
 104
 105 #define LTC2983_RES_VALID_MASK          BIT(24)
 106 #define LTC2983_DATA_MASK               GENMASK(23, 0)
 107 #define LTC2983_DATA_SIGN_BIT           23
 108
 109 #define LTC2983_CHAN_TYPE_MASK          GENMASK(31, 27)
 110 #define LTC2983_CHAN_TYPE(x)            FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x)
 111
 112 /* cold junction for thermocouples and rsense for rtd's and thermistor's */
 113 #define LTC2983_CHAN_ASSIGN_MASK        GENMASK(26, 22)
 114 #define LTC2983_CHAN_ASSIGN(x)          FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x)
 115
 116 #define LTC2983_CUSTOM_LEN_MASK         GENMASK(5, 0)
 117 #define LTC2983_CUSTOM_LEN(x)           FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x)
 118
 119 #define LTC2983_CUSTOM_ADDR_MASK        GENMASK(11, 6)
 120 #define LTC2983_CUSTOM_ADDR(x)          FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x)
 121
 122 #define LTC2983_THERMOCOUPLE_CFG_MASK   GENMASK(21, 18)
 123 #define LTC2983_THERMOCOUPLE_CFG(x) \
 124                                 FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x)
 125 #define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK    GENMASK(31, 29)
 126 #define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK    GENMASK(28, 25)
 127
 128 #define LTC2983_RTD_CFG_MASK            GENMASK(21, 18)
 129 #define LTC2983_RTD_CFG(x)              FIELD_PREP(LTC2983_RTD_CFG_MASK, x)
 130 #define LTC2983_RTD_EXC_CURRENT_MASK    GENMASK(17, 14)
 131 #define LTC2983_RTD_EXC_CURRENT(x) \
 132                                 FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x)
 133 #define LTC2983_RTD_CURVE_MASK          GENMASK(13, 12)
 134 #define LTC2983_RTD_CURVE(x)            FIELD_PREP(LTC2983_RTD_CURVE_MASK, x)
 135
 136 #define LTC2983_THERMISTOR_CFG_MASK     GENMASK(21, 19)
 137 #define LTC2983_THERMISTOR_CFG(x) \
 138                                 FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x)
 139 #define LTC2983_THERMISTOR_EXC_CURRENT_MASK     GENMASK(18, 15)
 140 #define LTC2983_THERMISTOR_EXC_CURRENT(x) \
 141                         FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x)
 142
 143 #define LTC2983_DIODE_CFG_MASK          GENMASK(26, 24)
 144 #define LTC2983_DIODE_CFG(x)            FIELD_PREP(LTC2983_DIODE_CFG_MASK, x)
 145 #define LTC2983_DIODE_EXC_CURRENT_MASK  GENMASK(23, 22)
 146 #define LTC2983_DIODE_EXC_CURRENT(x) \
 147                                 FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x)
 148 #define LTC2983_DIODE_IDEAL_FACTOR_MASK GENMASK(21, 0)
 149 #define LTC2983_DIODE_IDEAL_FACTOR(x) \
 150                                 FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x)
 151
 152 #define LTC2983_R_SENSE_VAL_MASK        GENMASK(26, 0)
 153 #define LTC2983_R_SENSE_VAL(x)          FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x)
 154
 155 #define LTC2983_ADC_SINGLE_ENDED_MASK   BIT(26)
 156 #define LTC2983_ADC_SINGLE_ENDED(x) \
 157                                 FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x)
 158
 159 enum {
 160         LTC2983_SENSOR_THERMOCOUPLE = 1,
 161         LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9,
 162         LTC2983_SENSOR_RTD = 10,
 163         LTC2983_SENSOR_RTD_CUSTOM = 18,
 164         LTC2983_SENSOR_THERMISTOR = 19,
 165         LTC2983_SENSOR_THERMISTOR_STEINHART = 26,
 166         LTC2983_SENSOR_THERMISTOR_CUSTOM = 27,
 167         LTC2983_SENSOR_DIODE = 28,
 168         LTC2983_SENSOR_SENSE_RESISTOR = 29,
 169         LTC2983_SENSOR_DIRECT_ADC = 30,
 170 };
 171
 172 #define to_thermocouple(_sensor) \
 173                 container_of(_sensor, struct ltc2983_thermocouple, sensor)
 174
 175 #define to_rtd(_sensor) \
 176                 container_of(_sensor, struct ltc2983_rtd, sensor)
 177
 178 #define to_thermistor(_sensor) \
 179                 container_of(_sensor, struct ltc2983_thermistor, sensor)
 180
 181 #define to_diode(_sensor) \
 182                 container_of(_sensor, struct ltc2983_diode, sensor)
 183
 184 #define to_rsense(_sensor) \
 185                 container_of(_sensor, struct ltc2983_rsense, sensor)
 186
 187 #define to_adc(_sensor) \
 188                 container_of(_sensor, struct ltc2983_adc, sensor)
 189
 190 struct ltc2983_data {
 191         struct regmap *regmap;
 192         struct spi_device *spi;
 193         struct mutex lock;
 194         struct completion completion;
 195         struct iio_chan_spec *iio_chan;
 196         struct ltc2983_sensor **sensors;
 197         u32 mux_delay_config;
 198         u32 filter_notch_freq;
 199         u16 custom_table_size;
 200         u8 num_channels;
 201         u8 iio_channels;
 202         /*
 203          * DMA (thus cache coherency maintenance) requires the
 204          * transfer buffers to live in their own cache lines.
 205          * Holds the converted temperature
 206          */
 207         __be32 temp ____cacheline_aligned;
 208 };
 209
 210 struct ltc2983_sensor {
 211         int (*fault_handler)(const struct ltc2983_data *st, const u32 result);
 212         int (*assign_chan)(struct ltc2983_data *st,
 213                            const struct ltc2983_sensor *sensor);
 214         /* specifies the sensor channel */
 215         u32 chan;
 216         /* sensor type */
 217         u32 type;
 218 };
 219
 220 struct ltc2983_custom_sensor {
 221         /* raw table sensor data */
 222         u8 *table;
 223         size_t size;
 224         /* address offset */
 225         s8 offset;
 226         bool is_steinhart;
 227 };
 228
 229 struct ltc2983_thermocouple {
 230         struct ltc2983_sensor sensor;
 231         struct ltc2983_custom_sensor *custom;
 232         u32 sensor_config;
 233         u32 cold_junction_chan;
 234 };
 235
 236 struct ltc2983_rtd {
 237         struct ltc2983_sensor sensor;
 238         struct ltc2983_custom_sensor *custom;
 239         u32 sensor_config;
 240         u32 r_sense_chan;
 241         u32 excitation_current;
 242         u32 rtd_curve;
 243 };
 244
 245 struct ltc2983_thermistor {
 246         struct ltc2983_sensor sensor;
 247         struct ltc2983_custom_sensor *custom;
 248         u32 sensor_config;
 249         u32 r_sense_chan;
 250         u32 excitation_current;
 251 };
 252
 253 struct ltc2983_diode {
 254         struct ltc2983_sensor sensor;
 255         u32 sensor_config;
 256         u32 excitation_current;
 257         u32 ideal_factor_value;
 258 };
 259
 260 struct ltc2983_rsense {
 261         struct ltc2983_sensor sensor;
 262         u32 r_sense_val;
 263 };
 264
 265 struct ltc2983_adc {
 266         struct ltc2983_sensor sensor;
 267         bool single_ended;
 268 };
 269
 270 /*
 271  * Convert to Q format numbers. These number's are integers where
 272  * the number of integer and fractional bits are specified. The resolution
 273  * is given by 1/@resolution and tell us the number of fractional bits. For
 274  * instance a resolution of 2^-10 means we have 10 fractional bits.
 275  */
 276 static u32 __convert_to_raw(const u64 val, const u32 resolution)
 277 {
 278         u64 __res = val * resolution;
 279
 280         /* all values are multiplied by 1000000 to remove the fraction */
 281         do_div(__res, 1000000);
 282
 283         return __res;
 284 }
 285
 286 static u32 __convert_to_raw_sign(const u64 val, const u32 resolution)
 287 {
 288         s64 __res = -(s32)val;
 289
 290         __res = __convert_to_raw(__res, resolution);
 291
 292         return (u32)-__res;
 293 }
 294
 295 static int __ltc2983_fault_handler(const struct ltc2983_data *st,
 296                                    const u32 result, const u32 hard_mask,
 297                                    const u32 soft_mask)
 298 {
 299         const struct device *dev = &st->spi->dev;
 300
 301         if (result & hard_mask) {
 302                 dev_err(dev, "Invalid conversion: Sensor HARD fault\n");
 303                 return -EIO;
 304         } else if (result & soft_mask) {
 305                 /* just print a warning */
 306                 dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n");
 307         }
 308
 309         return 0;
 310 }
 311
 312 static int __ltc2983_chan_assign_common(const struct ltc2983_data *st,
 313                                         const struct ltc2983_sensor *sensor,
 314                                         u32 chan_val)
 315 {
 316         u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
 317         __be32 __chan_val;
 318
 319         chan_val |= LTC2983_CHAN_TYPE(sensor->type);
 320         dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
 321                 chan_val);
 322         __chan_val = cpu_to_be32(chan_val);
 323         return regmap_bulk_write(st->regmap, reg, &__chan_val,
 324                                  sizeof(__chan_val));
 325 }
 326
 327 static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
 328                                           struct ltc2983_custom_sensor *custom,
 329                                           u32 *chan_val)
 330 {
 331         u32 reg;
 332         u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ :
 333                 LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
 334         const struct device *dev = &st->spi->dev;
 335         /*
 336          * custom->size holds the raw size of the table. However, when
 337          * configuring the sensor channel, we must write the number of
 338          * entries of the table minus 1. For steinhart sensors 0 is written
 339          * since the size is constant!
 340          */
 341         const u8 len = custom->is_steinhart ? 0 :
 342                 (custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1;
 343         /*
 344          * Check if the offset was assigned already. It should be for steinhart
 345          * sensors. When coming from sleep, it should be assigned for all.
 346          */
 347         if (custom->offset < 0) {
 348                 /*
 349                  * This needs to be done again here because, from the moment
 350                  * when this test was done (successfully) for this custom
 351                  * sensor, a steinhart sensor might have been added changing
 352                  * custom_table_size...
 353                  */
 354                 if (st->custom_table_size + custom->size >
 355                     (LTC2983_CUST_SENS_TBL_END_REG -
 356                      LTC2983_CUST_SENS_TBL_START_REG) + 1) {
 357                         dev_err(dev,
 358                                 "Not space left(%d) for new custom sensor(%zu)",
 359                                 st->custom_table_size,
 360                                 custom->size);
 361                         return -EINVAL;
 362                 }
 363
 364                 custom->offset = st->custom_table_size /
 365                                         LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
 366                 st->custom_table_size += custom->size;
 367         }
 368
 369         reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG;
 370
 371         *chan_val |= LTC2983_CUSTOM_LEN(len);
 372         *chan_val |= LTC2983_CUSTOM_ADDR(custom->offset);
 373         dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu",
 374                 reg, custom->offset,
 375                 custom->size);
 376         /* write custom sensor table */
 377         return regmap_bulk_write(st->regmap, reg, custom->table, custom->size);
 378 }
 379
 380 static struct ltc2983_custom_sensor *__ltc2983_custom_sensor_new(
 381                                                 struct ltc2983_data *st,
 382                                                 const struct device_node *np,
 383                                                 const char *propname,
 384                                                 const bool is_steinhart,
 385                                                 const u32 resolution,
 386                                                 const bool has_signed)
 387 {
 388         struct ltc2983_custom_sensor *new_custom;
 389         u8 index, n_entries, tbl = 0;
 390         struct device *dev = &st->spi->dev;
 391         /*
 392          * For custom steinhart, the full u32 is taken. For all the others
 393          * the MSB is discarded.
 394          */
 395         const u8 n_size = is_steinhart ? 4 : 3;
 396         const u8 e_size = is_steinhart ? sizeof(u32) : sizeof(u64);
 397
 398         n_entries = of_property_count_elems_of_size(np, propname, e_size);
 399         /* n_entries must be an even number */
 400         if (!n_entries || (n_entries % 2) != 0) {
 401                 dev_err(dev, "Number of entries either 0 or not even\n");
 402                 return ERR_PTR(-EINVAL);
 403         }
 404
 405         new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
 406         if (!new_custom)
 407                 return ERR_PTR(-ENOMEM);
 408
 409         new_custom->size = n_entries * n_size;
 410         /* check Steinhart size */
 411         if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
 412                 dev_err(dev, "Steinhart sensors size(%zu) must be 24",
 413                                                         new_custom->size);
 414                 return ERR_PTR(-EINVAL);
 415         }
 416         /* Check space on the table. */
 417         if (st->custom_table_size + new_custom->size >
 418             (LTC2983_CUST_SENS_TBL_END_REG -
 419              LTC2983_CUST_SENS_TBL_START_REG) + 1) {
 420                 dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
 421                                 st->custom_table_size, new_custom->size);
 422                 return ERR_PTR(-EINVAL);
 423         }
 424
 425         /* allocate the table */
 426         new_custom->table = devm_kzalloc(dev, new_custom->size, GFP_KERNEL);
 427         if (!new_custom->table)
 428                 return ERR_PTR(-ENOMEM);
 429
 430         for (index = 0; index < n_entries; index++) {
 431                 u64 temp = 0, j;
 432                 /*
 433                  * Steinhart sensors are configured with raw values in the
 434                  * devicetree. For the other sensors we must convert the
 435                  * value to raw. The odd index's correspond to temperarures
 436                  * and always have 1/1024 of resolution. Temperatures also
 437                  * come in kelvin, so signed values is not possible
 438                  */
 439                 if (!is_steinhart) {
 440                         of_property_read_u64_index(np, propname, index, &temp);
 441
 442                         if ((index % 2) != 0)
 443                                 temp = __convert_to_raw(temp, 1024);
 444                         else if (has_signed && (s64)temp < 0)
 445                                 temp = __convert_to_raw_sign(temp, resolution);
 446                         else
 447                                 temp = __convert_to_raw(temp, resolution);
 448                 } else {
 449                         u32 t32;
 450
 451                         of_property_read_u32_index(np, propname, index, &t32);
 452                         temp = t32;
 453                 }
 454
 455                 for (j = 0; j < n_size; j++)
 456                         new_custom->table[tbl++] =
 457                                 temp >> (8 * (n_size - j - 1));
 458         }
 459
 460         new_custom->is_steinhart = is_steinhart;
 461         /*
 462          * This is done to first add all the steinhart sensors to the table,
 463          * in order to maximize the table usage. If we mix adding steinhart
 464          * with the other sensors, we might have to do some roundup to make
 465          * sure that sensor_addr - 0x250(start address) is a multiple of 4
 466          * (for steinhart), and a multiple of 6 for all the other sensors.
 467          * Since we have const 24 bytes for steinhart sensors and 24 is
 468          * also a multiple of 6, we guarantee that the first non-steinhart
 469          * sensor will sit in a correct address without the need of filling
 470          * addresses.
 471          */
 472         if (is_steinhart) {
 473                 new_custom->offset = st->custom_table_size /
 474                                         LTC2983_CUSTOM_STEINHART_ENTRY_SZ;
 475                 st->custom_table_size += new_custom->size;
 476         } else {
 477                 /* mark as unset. This is checked later on the assign phase */
 478                 new_custom->offset = -1;
 479         }
 480
 481         return new_custom;
 482 }
 483
 484 static int ltc2983_thermocouple_fault_handler(const struct ltc2983_data *st,
 485                                               const u32 result)
 486 {
 487         return __ltc2983_fault_handler(st, result,
 488                                        LTC2983_THERMOCOUPLE_HARD_FAULT_MASK,
 489                                        LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK);
 490 }
 491
 492 static int ltc2983_common_fault_handler(const struct ltc2983_data *st,
 493                                         const u32 result)
 494 {
 495         return __ltc2983_fault_handler(st, result,
 496                                        LTC2983_COMMON_HARD_FAULT_MASK,
 497                                        LTC2983_COMMON_SOFT_FAULT_MASK);
 498 }
 499
 500 static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st,
 501                                 const struct ltc2983_sensor *sensor)
 502 {
 503         struct ltc2983_thermocouple *thermo = to_thermocouple(sensor);
 504         u32 chan_val;
 505
 506         chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan);
 507         chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config);
 508
 509         if (thermo->custom) {
 510                 int ret;
 511
 512                 ret = __ltc2983_chan_custom_sensor_assign(st, thermo->custom,
 513                                                           &chan_val);
 514                 if (ret)
 515                         return ret;
 516         }
 517         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 518 }
 519
 520 static int ltc2983_rtd_assign_chan(struct ltc2983_data *st,
 521                                    const struct ltc2983_sensor *sensor)
 522 {
 523         struct ltc2983_rtd *rtd = to_rtd(sensor);
 524         u32 chan_val;
 525
 526         chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan);
 527         chan_val |= LTC2983_RTD_CFG(rtd->sensor_config);
 528         chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current);
 529         chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve);
 530
 531         if (rtd->custom) {
 532                 int ret;
 533
 534                 ret = __ltc2983_chan_custom_sensor_assign(st, rtd->custom,
 535                                                           &chan_val);
 536                 if (ret)
 537                         return ret;
 538         }
 539         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 540 }
 541
 542 static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st,
 543                                           const struct ltc2983_sensor *sensor)
 544 {
 545         struct ltc2983_thermistor *thermistor = to_thermistor(sensor);
 546         u32 chan_val;
 547
 548         chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan);
 549         chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config);
 550         chan_val |=
 551                 LTC2983_THERMISTOR_EXC_CURRENT(thermistor->excitation_current);
 552
 553         if (thermistor->custom) {
 554                 int ret;
 555
 556                 ret = __ltc2983_chan_custom_sensor_assign(st,
 557                                                           thermistor->custom,
 558                                                           &chan_val);
 559                 if (ret)
 560                         return ret;
 561         }
 562         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 563 }
 564
 565 static int ltc2983_diode_assign_chan(struct ltc2983_data *st,
 566                                      const struct ltc2983_sensor *sensor)
 567 {
 568         struct ltc2983_diode *diode = to_diode(sensor);
 569         u32 chan_val;
 570
 571         chan_val = LTC2983_DIODE_CFG(diode->sensor_config);
 572         chan_val |= LTC2983_DIODE_EXC_CURRENT(diode->excitation_current);
 573         chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode->ideal_factor_value);
 574
 575         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 576 }
 577
 578 static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st,
 579                                        const struct ltc2983_sensor *sensor)
 580 {
 581         struct ltc2983_rsense *rsense = to_rsense(sensor);
 582         u32 chan_val;
 583
 584         chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val);
 585
 586         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 587 }
 588
 589 static int ltc2983_adc_assign_chan(struct ltc2983_data *st,
 590                                    const struct ltc2983_sensor *sensor)
 591 {
 592         struct ltc2983_adc *adc = to_adc(sensor);
 593         u32 chan_val;
 594
 595         chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended);
 596
 597         return __ltc2983_chan_assign_common(st, sensor, chan_val);
 598 }
 599
 600 static struct ltc2983_sensor *ltc2983_thermocouple_new(
 601                                         const struct device_node *child,
 602                                         struct ltc2983_data *st,
 603                                         const struct ltc2983_sensor *sensor)
 604 {
 605         struct ltc2983_thermocouple *thermo;
 606         struct device_node *phandle;
 607         u32 oc_current;
 608         int ret;
 609
 610         thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
 611         if (!thermo)
 612                 return ERR_PTR(-ENOMEM);
 613
 614         if (of_property_read_bool(child, "adi,single-ended"))
 615                 thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1);
 616
 617         ret = of_property_read_u32(child, "adi,sensor-oc-current-microamp",
 618                                    &oc_current);
 619         if (!ret) {
 620                 switch (oc_current) {
 621                 case 10:
 622                         thermo->sensor_config |=
 623                                         LTC2983_THERMOCOUPLE_OC_CURR(0);
 624                         break;
 625                 case 100:
 626                         thermo->sensor_config |=
 627                                         LTC2983_THERMOCOUPLE_OC_CURR(1);
 628                         break;
 629                 case 500:
 630                         thermo->sensor_config |=
 631                                         LTC2983_THERMOCOUPLE_OC_CURR(2);
 632                         break;
 633                 case 1000:
 634                         thermo->sensor_config |=
 635                                         LTC2983_THERMOCOUPLE_OC_CURR(3);
 636                         break;
 637                 default:
 638                         dev_err(&st->spi->dev,
 639                                 "Invalid open circuit current:%u", oc_current);
 640                         return ERR_PTR(-EINVAL);
 641                 }
 642
 643                 thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
 644         }
 645         /* validate channel index */
 646         if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
 647             sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
 648                 dev_err(&st->spi->dev,
 649                         "Invalid chann:%d for differential thermocouple",
 650                         sensor->chan);
 651                 return ERR_PTR(-EINVAL);
 652         }
 653
 654         phandle = of_parse_phandle(child, "adi,cold-junction-handle", 0);
 655         if (phandle) {
 656                 int ret;
 657
 658                 ret = of_property_read_u32(phandle, "reg",
 659                                            &thermo->cold_junction_chan);
 660                 if (ret) {
 661                         /*
 662                          * This would be catched later but we can just return
 663                          * the error right away.
 664                          */
 665                         dev_err(&st->spi->dev, "Property reg must be given\n");
 666                         of_node_put(phandle);
 667                         return ERR_PTR(-EINVAL);
 668                 }
 669         }
 670
 671         /* check custom sensor */
 672         if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
 673                 const char *propname = "adi,custom-thermocouple";
 674
 675                 thermo->custom = __ltc2983_custom_sensor_new(st, child,
 676                                                              propname, false,
 677                                                              16384, true);
 678                 if (IS_ERR(thermo->custom)) {
 679                         of_node_put(phandle);
 680                         return ERR_CAST(thermo->custom);
 681                 }
 682         }
 683
 684         /* set common parameters */
 685         thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
 686         thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
 687
 688         of_node_put(phandle);
 689         return &thermo->sensor;
 690 }
 691
 692 static struct ltc2983_sensor *ltc2983_rtd_new(const struct device_node *child,
 693                                           struct ltc2983_data *st,
 694                                           const struct ltc2983_sensor *sensor)
 695 {
 696         struct ltc2983_rtd *rtd;
 697         int ret = 0;
 698         struct device *dev = &st->spi->dev;
 699         struct device_node *phandle;
 700         u32 excitation_current = 0, n_wires = 0;
 701
 702         rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
 703         if (!rtd)
 704                 return ERR_PTR(-ENOMEM);
 705
 706         phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
 707         if (!phandle) {
 708                 dev_err(dev, "Property adi,rsense-handle missing or invalid");
 709                 return ERR_PTR(-EINVAL);
 710         }
 711
 712         ret = of_property_read_u32(phandle, "reg", &rtd->r_sense_chan);
 713         if (ret) {
 714                 dev_err(dev, "Property reg must be given\n");
 715                 goto fail;
 716         }
 717
 718         ret = of_property_read_u32(child, "adi,number-of-wires", &n_wires);
 719         if (!ret) {
 720                 switch (n_wires) {
 721                 case 2:
 722                         rtd->sensor_config = LTC2983_RTD_N_WIRES(0);
 723                         break;
 724                 case 3:
 725                         rtd->sensor_config = LTC2983_RTD_N_WIRES(1);
 726                         break;
 727                 case 4:
 728                         rtd->sensor_config = LTC2983_RTD_N_WIRES(2);
 729                         break;
 730                 case 5:
 731                         /* 4 wires, Kelvin Rsense */
 732                         rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
 733                         break;
 734                 default:
 735                         dev_err(dev, "Invalid number of wires:%u\n", n_wires);
 736                         ret = -EINVAL;
 737                         goto fail;
 738                 }
 739         }
 740
 741         if (of_property_read_bool(child, "adi,rsense-share")) {
 742                 /* Current rotation is only available with rsense sharing */
 743                 if (of_property_read_bool(child, "adi,current-rotate")) {
 744                         if (n_wires == 2 || n_wires == 3) {
 745                                 dev_err(dev,
 746                                         "Rotation not allowed for 2/3 Wire RTDs");
 747                                 ret = -EINVAL;
 748                                 goto fail;
 749                         }
 750                         rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
 751                 } else {
 752                         rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
 753                 }
 754         }
 755         /*
 756          * rtd channel indexes are a bit more complicated to validate.
 757          * For 4wire RTD with rotation, the channel selection cannot be
 758          * >=19 since the chann + 1 is used in this configuration.
 759          * For 4wire RTDs with kelvin rsense, the rsense channel cannot be
 760          * <=1 since chanel - 1 and channel - 2 are used.
 761          */
 762         if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
 763                 /* 4-wire */
 764                 u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
 765                         max = LTC2983_MAX_CHANNELS_NR;
 766
 767                 if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
 768                         max = LTC2983_MAX_CHANNELS_NR - 1;
 769
 770                 if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
 771                      == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
 772                     (rtd->r_sense_chan <=  min)) {
 773                         /* kelvin rsense*/
 774                         dev_err(dev,
 775                                 "Invalid rsense chann:%d to use in kelvin rsense",
 776                                 rtd->r_sense_chan);
 777
 778                         ret = -EINVAL;
 779                         goto fail;
 780                 }
 781
 782                 if (sensor->chan < min || sensor->chan > max) {
 783                         dev_err(dev, "Invalid chann:%d for the rtd config",
 784                                 sensor->chan);
 785
 786                         ret = -EINVAL;
 787                         goto fail;
 788                 }
 789         } else {
 790                 /* same as differential case */
 791                 if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
 792                         dev_err(&st->spi->dev,
 793                                 "Invalid chann:%d for RTD", sensor->chan);
 794
 795                         ret = -EINVAL;
 796                         goto fail;
 797                 }
 798         }
 799
 800         /* check custom sensor */
 801         if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) {
 802                 rtd->custom = __ltc2983_custom_sensor_new(st, child,
 803                                                           "adi,custom-rtd",
 804                                                           false, 2048, false);
 805                 if (IS_ERR(rtd->custom)) {
 806                         of_node_put(phandle);
 807                         return ERR_CAST(rtd->custom);
 808                 }
 809         }
 810
 811         /* set common parameters */
 812         rtd->sensor.fault_handler = ltc2983_common_fault_handler;
 813         rtd->sensor.assign_chan = ltc2983_rtd_assign_chan;
 814
 815         ret = of_property_read_u32(child, "adi,excitation-current-microamp",
 816                                    &excitation_current);
 817         if (ret) {
 818                 /* default to 5uA */
 819                 rtd->excitation_current = 1;
 820         } else {
 821                 switch (excitation_current) {
 822                 case 5:
 823                         rtd->excitation_current = 0x01;
 824                         break;
 825                 case 10:
 826                         rtd->excitation_current = 0x02;
 827                         break;
 828                 case 25:
 829                         rtd->excitation_current = 0x03;
 830                         break;
 831                 case 50:
 832                         rtd->excitation_current = 0x04;
 833                         break;
 834                 case 100:
 835                         rtd->excitation_current = 0x05;
 836                         break;
 837                 case 250:
 838                         rtd->excitation_current = 0x06;
 839                         break;
 840                 case 500:
 841                         rtd->excitation_current = 0x07;
 842                         break;
 843                 case 1000:
 844                         rtd->excitation_current = 0x08;
 845                         break;
 846                 default:
 847                         dev_err(&st->spi->dev,
 848                                 "Invalid value for excitation current(%u)",
 849                                 excitation_current);
 850                         ret = -EINVAL;
 851                         goto fail;
 852                 }
 853         }
 854
 855         of_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
 856
 857         of_node_put(phandle);
 858         return &rtd->sensor;
 859 fail:
 860         of_node_put(phandle);
 861         return ERR_PTR(ret);
 862 }
 863
 864 static struct ltc2983_sensor *ltc2983_thermistor_new(
 865                                         const struct device_node *child,
 866                                         struct ltc2983_data *st,
 867                                         const struct ltc2983_sensor *sensor)
 868 {
 869         struct ltc2983_thermistor *thermistor;
 870         struct device *dev = &st->spi->dev;
 871         struct device_node *phandle;
 872         u32 excitation_current = 0;
 873         int ret = 0;
 874
 875         thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL);
 876         if (!thermistor)
 877                 return ERR_PTR(-ENOMEM);
 878
 879         phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
 880         if (!phandle) {
 881                 dev_err(dev, "Property adi,rsense-handle missing or invalid");
 882                 return ERR_PTR(-EINVAL);
 883         }
 884
 885         ret = of_property_read_u32(phandle, "reg", &thermistor->r_sense_chan);
 886         if (ret) {
 887                 dev_err(dev, "rsense channel must be configured...\n");
 888                 goto fail;
 889         }
 890
 891         if (of_property_read_bool(child, "adi,single-ended")) {
 892                 thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
 893         } else if (of_property_read_bool(child, "adi,rsense-share")) {
 894                 /* rotation is only possible if sharing rsense */
 895                 if (of_property_read_bool(child, "adi,current-rotate"))
 896                         thermistor->sensor_config =
 897                                                 LTC2983_THERMISTOR_C_ROTATE(1);
 898                 else
 899                         thermistor->sensor_config =
 900                                                 LTC2983_THERMISTOR_R_SHARE(1);
 901         }
 902         /* validate channel index */
 903         if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
 904             sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
 905                 dev_err(&st->spi->dev,
 906                         "Invalid chann:%d for differential thermistor",
 907                         sensor->chan);
 908                 ret = -EINVAL;
 909                 goto fail;
 910         }
 911
 912         /* check custom sensor */
 913         if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
 914                 bool steinhart = false;
 915                 const char *propname;
 916
 917                 if (sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART) {
 918                         steinhart = true;
 919                         propname = "adi,custom-steinhart";
 920                 } else {
 921                         propname = "adi,custom-thermistor";
 922                 }
 923
 924                 thermistor->custom = __ltc2983_custom_sensor_new(st, child,
 925                                                                  propname,
 926                                                                  steinhart,
 927                                                                  64, false);
 928                 if (IS_ERR(thermistor->custom)) {
 929                         of_node_put(phandle);
 930                         return ERR_CAST(thermistor->custom);
 931                 }
 932         }
 933         /* set common parameters */
 934         thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
 935         thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan;
 936
 937         ret = of_property_read_u32(child, "adi,excitation-current-nanoamp",
 938                                    &excitation_current);
 939         if (ret) {
 940                 /* Auto range is not allowed for custom sensors */
 941                 if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
 942                         /* default to 1uA */
 943                         thermistor->excitation_current = 0x03;
 944                 else
 945                         /* default to auto-range */
 946                         thermistor->excitation_current = 0x0c;
 947         } else {
 948                 switch (excitation_current) {
 949                 case 0:
 950                         /* auto range */
 951                         if (sensor->type >=
 952                             LTC2983_SENSOR_THERMISTOR_STEINHART) {
 953                                 dev_err(&st->spi->dev,
 954                                         "Auto Range not allowed for custom sensors\n");
 955                                 ret = -EINVAL;
 956                                 goto fail;
 957                         }
 958                         thermistor->excitation_current = 0x0c;
 959                         break;
 960                 case 250:
 961                         thermistor->excitation_current = 0x01;
 962                         break;
 963                 case 500:
 964                         thermistor->excitation_current = 0x02;
 965                         break;
 966                 case 1000:
 967                         thermistor->excitation_current = 0x03;
 968                         break;
 969                 case 5000:
 970                         thermistor->excitation_current = 0x04;
 971                         break;
 972                 case 10000:
 973                         thermistor->excitation_current = 0x05;
 974                         break;
 975                 case 25000:
 976                         thermistor->excitation_current = 0x06;
 977                         break;
 978                 case 50000:
 979                         thermistor->excitation_current = 0x07;
 980                         break;
 981                 case 100000:
 982                         thermistor->excitation_current = 0x08;
 983                         break;
 984                 case 250000:
 985                         thermistor->excitation_current = 0x09;
 986                         break;
 987                 case 500000:
 988                         thermistor->excitation_current = 0x0a;
 989                         break;
 990                 case 1000000:
 991                         thermistor->excitation_current = 0x0b;
 992                         break;
 993                 default:
 994                         dev_err(&st->spi->dev,
 995                                 "Invalid value for excitation current(%u)",
 996                                 excitation_current);
 997                         ret = -EINVAL;
 998                         goto fail;
 999                 }
1000         }
1001
1002         of_node_put(phandle);
1003         return &thermistor->sensor;
1004 fail:
1005         of_node_put(phandle);
1006         return ERR_PTR(ret);
1007 }
1008
1009 static struct ltc2983_sensor *ltc2983_diode_new(
1010                                         const struct device_node *child,
1011                                         const struct ltc2983_data *st,
1012                                         const struct ltc2983_sensor *sensor)
1013 {
1014         struct ltc2983_diode *diode;
1015         u32 temp = 0, excitation_current = 0;
1016         int ret;
1017
1018         diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
1019         if (!diode)
1020                 return ERR_PTR(-ENOMEM);
1021
1022         if (of_property_read_bool(child, "adi,single-ended"))
1023                 diode->sensor_config = LTC2983_DIODE_SGL(1);
1024
1025         if (of_property_read_bool(child, "adi,three-conversion-cycles"))
1026                 diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1);
1027
1028         if (of_property_read_bool(child, "adi,average-on"))
1029                 diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1);
1030
1031         /* validate channel index */
1032         if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
1033             sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1034                 dev_err(&st->spi->dev,
1035                         "Invalid chann:%d for differential thermistor",
1036                         sensor->chan);
1037                 return ERR_PTR(-EINVAL);
1038         }
1039         /* set common parameters */
1040         diode->sensor.fault_handler = ltc2983_common_fault_handler;
1041         diode->sensor.assign_chan = ltc2983_diode_assign_chan;
1042
1043         ret = of_property_read_u32(child, "adi,excitation-current-microamp",
1044                                    &excitation_current);
1045         if (!ret) {
1046                 switch (excitation_current) {
1047                 case 10:
1048                         diode->excitation_current = 0x00;
1049                         break;
1050                 case 20:
1051                         diode->excitation_current = 0x01;
1052                         break;
1053                 case 40:
1054                         diode->excitation_current = 0x02;
1055                         break;
1056                 case 80:
1057                         diode->excitation_current = 0x03;
1058                         break;
1059                 default:
1060                         dev_err(&st->spi->dev,
1061                                 "Invalid value for excitation current(%u)",
1062                                 excitation_current);
1063                         return ERR_PTR(-EINVAL);
1064                 }
1065         }
1066
1067         of_property_read_u32(child, "adi,ideal-factor-value", &temp);
1068
1069         /* 2^20 resolution */
1070         diode->ideal_factor_value = __convert_to_raw(temp, 1048576);
1071
1072         return &diode->sensor;
1073 }
1074
1075 static struct ltc2983_sensor *ltc2983_r_sense_new(struct device_node *child,
1076                                         struct ltc2983_data *st,
1077                                         const struct ltc2983_sensor *sensor)
1078 {
1079         struct ltc2983_rsense *rsense;
1080         int ret;
1081         u32 temp;
1082
1083         rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
1084         if (!rsense)
1085                 return ERR_PTR(-ENOMEM);
1086
1087         /* validate channel index */
1088         if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1089                 dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
1090                         sensor->chan);
1091                 return ERR_PTR(-EINVAL);
1092         }
1093
1094         ret = of_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
1095         if (ret) {
1096                 dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
1097                 return ERR_PTR(-EINVAL);
1098         }
1099         /*
1100          * Times 1000 because we have milli-ohms and __convert_to_raw
1101          * expects scales of 1000000 which are used for all other
1102          * properties.
1103          * 2^10 resolution
1104          */
1105         rsense->r_sense_val = __convert_to_raw((u64)temp * 1000, 1024);
1106
1107         /* set common parameters */
1108         rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan;
1109
1110         return &rsense->sensor;
1111 }
1112
1113 static struct ltc2983_sensor *ltc2983_adc_new(struct device_node *child,
1114                                          struct ltc2983_data *st,
1115                                          const struct ltc2983_sensor *sensor)
1116 {
1117         struct ltc2983_adc *adc;
1118
1119         adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
1120         if (!adc)
1121                 return ERR_PTR(-ENOMEM);
1122
1123         if (of_property_read_bool(child, "adi,single-ended"))
1124                 adc->single_ended = true;
1125
1126         if (!adc->single_ended &&
1127             sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1128                 dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
1129                         sensor->chan);
1130                 return ERR_PTR(-EINVAL);
1131         }
1132         /* set common parameters */
1133         adc->sensor.assign_chan = ltc2983_adc_assign_chan;
1134         adc->sensor.fault_handler = ltc2983_common_fault_handler;
1135
1136         return &adc->sensor;
1137 }
1138
1139 static int ltc2983_chan_read(struct ltc2983_data *st,
1140                         const struct ltc2983_sensor *sensor, int *val)
1141 {
1142         u32 start_conversion = 0;
1143         int ret;
1144         unsigned long time;
1145
1146         start_conversion = LTC2983_STATUS_START(true);
1147         start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan);
1148         dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n",
1149                 sensor->chan, start_conversion);
1150         /* start conversion */
1151         ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion);
1152         if (ret)
1153                 return ret;
1154
1155         reinit_completion(&st->completion);
1156         /*
1157          * wait for conversion to complete.
1158          * 300 ms should be more than enough to complete the conversion.
1159          * Depending on the sensor configuration, there are 2/3 conversions
1160          * cycles of 82ms.
1161          */
1162         time = wait_for_completion_timeout(&st->completion,
1163                                            msecs_to_jiffies(300));
1164         if (!time) {
1165                 dev_warn(&st->spi->dev, "Conversion timed out\n");
1166                 return -ETIMEDOUT;
1167         }
1168
1169         /* read the converted data */
1170         ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan),
1171                                &st->temp, sizeof(st->temp));
1172         if (ret)
1173                 return ret;
1174
1175         *val = __be32_to_cpu(st->temp);
1176
1177         if (!(LTC2983_RES_VALID_MASK & *val)) {
1178                 dev_err(&st->spi->dev, "Invalid conversion detected\n");
1179                 return -EIO;
1180         }
1181
1182         ret = sensor->fault_handler(st, *val);
1183         if (ret)
1184                 return ret;
1185
1186         *val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT);
1187         return 0;
1188 }
1189
1190 static int ltc2983_read_raw(struct iio_dev *indio_dev,
1191                             struct iio_chan_spec const *chan,
1192                             int *val, int *val2, long mask)
1193 {
1194         struct ltc2983_data *st = iio_priv(indio_dev);
1195         int ret;
1196
1197         /* sanity check */
1198         if (chan->address >= st->num_channels) {
1199                 dev_err(&st->spi->dev, "Invalid chan address:%ld",
1200                         chan->address);
1201                 return -EINVAL;
1202         }
1203
1204         switch (mask) {
1205         case IIO_CHAN_INFO_RAW:
1206                 mutex_lock(&st->lock);
1207                 ret = ltc2983_chan_read(st, st->sensors[chan->address], val);
1208                 mutex_unlock(&st->lock);
1209                 return ret ?: IIO_VAL_INT;
1210         case IIO_CHAN_INFO_SCALE:
1211                 switch (chan->type) {
1212                 case IIO_TEMP:
1213                         /* value in milli degrees */
1214                         *val = 1000;
1215                         /* 2^10 */
1216                         *val2 = 1024;
1217                         return IIO_VAL_FRACTIONAL;
1218                 case IIO_VOLTAGE:
1219                         /* value in millivolt */
1220                         *val = 1000;
1221                         /* 2^21 */
1222                         *val2 = 2097152;
1223                         return IIO_VAL_FRACTIONAL;
1224                 default:
1225                         return -EINVAL;
1226                 }
1227         }
1228
1229         return -EINVAL;
1230 }
1231
1232 static int ltc2983_reg_access(struct iio_dev *indio_dev,
1233                               unsigned int reg,
1234                               unsigned int writeval,
1235                               unsigned int *readval)
1236 {
1237         struct ltc2983_data *st = iio_priv(indio_dev);
1238
1239         if (readval)
1240                 return regmap_read(st->regmap, reg, readval);
1241         else
1242                 return regmap_write(st->regmap, reg, writeval);
1243 }
1244
1245 static irqreturn_t ltc2983_irq_handler(int irq, void *data)
1246 {
1247         struct ltc2983_data *st = data;
1248
1249         complete(&st->completion);
1250         return IRQ_HANDLED;
1251 }
1252
1253 #define LTC2983_CHAN(__type, index, __address) ({ \
1254         struct iio_chan_spec __chan = { \
1255                 .type = __type, \
1256                 .indexed = 1, \
1257                 .channel = index, \
1258                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
1259                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
1260                 .address = __address, \
1261         }; \
1262         __chan; \
1263 })
1264
1265 static int ltc2983_parse_dt(struct ltc2983_data *st)
1266 {
1267         struct device_node *child;
1268         struct device *dev = &st->spi->dev;
1269         int ret = 0, chan = 0, channel_avail_mask = 0;
1270
1271         of_property_read_u32(dev->of_node, "adi,mux-delay-config-us",
1272                              &st->mux_delay_config);
1273
1274         of_property_read_u32(dev->of_node, "adi,filter-notch-freq",
1275                              &st->filter_notch_freq);
1276
1277         st->num_channels = of_get_available_child_count(dev->of_node);
1278         if (!st->num_channels) {
1279                 dev_err(&st->spi->dev, "At least one channel must be given!");
1280                 return -EINVAL;
1281         }
1282
1283         st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
1284                                    GFP_KERNEL);
1285         if (!st->sensors)
1286                 return -ENOMEM;
1287
1288         st->iio_channels = st->num_channels;
1289         for_each_available_child_of_node(dev->of_node, child) {
1290                 struct ltc2983_sensor sensor;
1291
1292                 ret = of_property_read_u32(child, "reg", &sensor.chan);
1293                 if (ret) {
1294                         dev_err(dev, "reg property must given for child nodes\n");
1295                         goto put_child;
1296                 }
1297
1298                 /* check if we have a valid channel */
1299                 if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
1300                     sensor.chan > LTC2983_MAX_CHANNELS_NR) {
1301                         ret = -EINVAL;
1302                         dev_err(dev,
1303                                 "chan:%d must be from 1 to 20\n", sensor.chan);
1304                         goto put_child;
1305                 } else if (channel_avail_mask & BIT(sensor.chan)) {
1306                         ret = -EINVAL;
1307                         dev_err(dev, "chan:%d already in use\n", sensor.chan);
1308                         goto put_child;
1309                 }
1310
1311                 ret = of_property_read_u32(child, "adi,sensor-type",
1312                                                &sensor.type);
1313                 if (ret) {
1314                         dev_err(dev,
1315                                 "adi,sensor-type property must given for child nodes\n");
1316                         goto put_child;
1317                 }
1318
1319                 dev_dbg(dev, "Create new sensor, type %u, chann %u",
1320                                                                 sensor.type,
1321                                                                 sensor.chan);
1322
1323                 if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
1324                     sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
1325                         st->sensors[chan] = ltc2983_thermocouple_new(child, st,
1326                                                                      &sensor);
1327                 } else if (sensor.type >= LTC2983_SENSOR_RTD &&
1328                            sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) {
1329                         st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor);
1330                 } else if (sensor.type >= LTC2983_SENSOR_THERMISTOR &&
1331                            sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) {
1332                         st->sensors[chan] = ltc2983_thermistor_new(child, st,
1333                                                                    &sensor);
1334                 } else if (sensor.type == LTC2983_SENSOR_DIODE) {
1335                         st->sensors[chan] = ltc2983_diode_new(child, st,
1336                                                               &sensor);
1337                 } else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) {
1338                         st->sensors[chan] = ltc2983_r_sense_new(child, st,
1339                                                                 &sensor);
1340                         /* don't add rsense to iio */
1341                         st->iio_channels--;
1342                 } else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
1343                         st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
1344                 } else {
1345                         dev_err(dev, "Unknown sensor type %d\n", sensor.type);
1346                         ret = -EINVAL;
1347                         goto put_child;
1348                 }
1349
1350                 if (IS_ERR(st->sensors[chan])) {
1351                         dev_err(dev, "Failed to create sensor %ld",
1352                                 PTR_ERR(st->sensors[chan]));
1353                         ret = PTR_ERR(st->sensors[chan]);
1354                         goto put_child;
1355                 }
1356                 /* set generic sensor parameters */
1357                 st->sensors[chan]->chan = sensor.chan;
1358                 st->sensors[chan]->type = sensor.type;
1359
1360                 channel_avail_mask |= BIT(sensor.chan);
1361                 chan++;
1362         }
1363
1364         return 0;
1365 put_child:
1366         of_node_put(child);
1367         return ret;
1368 }
1369
1370 static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
1371 {
1372         u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
1373         int ret;
1374
1375         /* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */
1376         ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status,
1377                                        LTC2983_STATUS_UP(status) == 1, 25000,
1378                                        25000 * 10);
1379         if (ret) {
1380                 dev_err(&st->spi->dev, "Device startup timed out\n");
1381                 return ret;
1382         }
1383
1384         st->iio_chan = devm_kzalloc(&st->spi->dev,
1385                                     st->iio_channels * sizeof(*st->iio_chan),
1386                                     GFP_KERNEL);
1387
1388         if (!st->iio_chan)
1389                 return -ENOMEM;
1390
1391         ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
1392                                  LTC2983_NOTCH_FREQ_MASK,
1393                                  LTC2983_NOTCH_FREQ(st->filter_notch_freq));
1394         if (ret)
1395                 return ret;
1396
1397         ret = regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG,
1398                            st->mux_delay_config);
1399         if (ret)
1400                 return ret;
1401
1402         for (chan = 0; chan < st->num_channels; chan++) {
1403                 u32 chan_type = 0, *iio_chan;
1404
1405                 ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]);
1406                 if (ret)
1407                         return ret;
1408                 /*
1409                  * The assign_iio flag is necessary for when the device is
1410                  * coming out of sleep. In that case, we just need to
1411                  * re-configure the device channels.
1412                  * We also don't assign iio channels for rsense.
1413                  */
1414                 if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR ||
1415                     !assign_iio)
1416                         continue;
1417
1418                 /* assign iio channel */
1419                 if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) {
1420                         chan_type = IIO_TEMP;
1421                         iio_chan = &iio_chan_t;
1422                 } else {
1423                         chan_type = IIO_VOLTAGE;
1424                         iio_chan = &iio_chan_v;
1425                 }
1426
1427                 /*
1428                  * add chan as the iio .address so that, we can directly
1429                  * reference the sensor given the iio_chan_spec
1430                  */
1431                 st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++,
1432                                                        chan);
1433         }
1434
1435         return 0;
1436 }
1437
1438 static const struct regmap_range ltc2983_reg_ranges[] = {
1439         regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
1440         regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
1441         regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
1442         regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
1443                          LTC2983_MULT_CHANNEL_END_REG),
1444         regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
1445         regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
1446                          LTC2983_CHAN_ASSIGN_END_REG),
1447         regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG,
1448                          LTC2983_CUST_SENS_TBL_END_REG),
1449 };
1450
1451 static const struct regmap_access_table ltc2983_reg_table = {
1452         .yes_ranges = ltc2983_reg_ranges,
1453         .n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges),
1454 };
1455
1456 /*
1457  *  The reg_bits are actually 12 but the device needs the first *complete*
1458  *  byte for the command (R/W).
1459  */
1460 static const struct regmap_config ltc2983_regmap_config = {
1461         .reg_bits = 24,
1462         .val_bits = 8,
1463         .wr_table = &ltc2983_reg_table,
1464         .rd_table = &ltc2983_reg_table,
1465         .read_flag_mask = GENMASK(1, 0),
1466         .write_flag_mask = BIT(1),
1467 };
1468
1469 static const struct  iio_info ltc2983_iio_info = {
1470         .read_raw = ltc2983_read_raw,
1471         .debugfs_reg_access = ltc2983_reg_access,
1472 };
1473
1474 static int ltc2983_probe(struct spi_device *spi)
1475 {
1476         struct ltc2983_data *st;
1477         struct iio_dev *indio_dev;
1478         struct gpio_desc *gpio;
1479         const char *name = spi_get_device_id(spi)->name;
1480         int ret;
1481
1482         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1483         if (!indio_dev)
1484                 return -ENOMEM;
1485
1486         st = iio_priv(indio_dev);
1487
1488         st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
1489         if (IS_ERR(st->regmap)) {
1490                 dev_err(&spi->dev, "Failed to initialize regmap\n");
1491                 return PTR_ERR(st->regmap);
1492         }
1493
1494         mutex_init(&st->lock);
1495         init_completion(&st->completion);
1496         st->spi = spi;
1497         spi_set_drvdata(spi, st);
1498
1499         ret = ltc2983_parse_dt(st);
1500         if (ret)
1501                 return ret;
1502
1503         gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
1504         if (IS_ERR(gpio))
1505                 return PTR_ERR(gpio);
1506
1507         if (gpio) {
1508                 /* bring the device out of reset */
1509                 usleep_range(1000, 1200);
1510                 gpiod_set_value_cansleep(gpio, 0);
1511         }
1512
1513         ret = ltc2983_setup(st, true);
1514         if (ret)
1515                 return ret;
1516
1517         ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
1518                                IRQF_TRIGGER_RISING, name, st);
1519         if (ret) {
1520                 dev_err(&spi->dev, "failed to request an irq, %d", ret);
1521                 return ret;
1522         }
1523
1524         indio_dev->name = name;
1525         indio_dev->num_channels = st->iio_channels;
1526         indio_dev->channels = st->iio_chan;
1527         indio_dev->modes = INDIO_DIRECT_MODE;
1528         indio_dev->info = &ltc2983_iio_info;
1529
1530         return devm_iio_device_register(&spi->dev, indio_dev);
1531 }
1532
1533 static int __maybe_unused ltc2983_resume(struct device *dev)
1534 {
1535         struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1536         int dummy;
1537
1538         /* dummy read to bring the device out of sleep */
1539         regmap_read(st->regmap, LTC2983_STATUS_REG, &dummy);
1540         /* we need to re-assign the channels */
1541         return ltc2983_setup(st, false);
1542 }
1543
1544 static int __maybe_unused ltc2983_suspend(struct device *dev)
1545 {
1546         struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1547
1548         return regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP);
1549 }
1550
1551 static SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend, ltc2983_resume);
1552
1553 static const struct spi_device_id ltc2983_id_table[] = {
1554         { "ltc2983" },
1555         {},
1556 };
1557 MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
1558
1559 static const struct of_device_id ltc2983_of_match[] = {
1560         { .compatible = "adi,ltc2983" },
1561         {},
1562 };
1563 MODULE_DEVICE_TABLE(of, ltc2983_of_match);
1564
1565 static struct spi_driver ltc2983_driver = {
1566         .driver = {
1567                 .name = "ltc2983",
1568                 .of_match_table = ltc2983_of_match,
1569                 .pm = &ltc2983_pm_ops,
1570         },
1571         .probe = ltc2983_probe,
1572         .id_table = ltc2983_id_table,
1573 };
1574
1575 module_spi_driver(ltc2983_driver);
1576
1577 MODULE_AUTHOR("Nuno Sa <[email protected]>");
1578 MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
1579 MODULE_LICENSE("GPL");