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