drivers/iio/adc/sc27xx_adc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Spreadtrum Communications Inc.
   3
   4 #include <linux/hwspinlock.h>
   5 #include <linux/iio/iio.h>
   6 #include <linux/module.h>
   7 #include <linux/mutex.h>
   8 #include <linux/nvmem-consumer.h>
   9 #include <linux/of.h>
  10 #include <linux/of_device.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.h>
  13 #include <linux/regulator/consumer.h>
  14 #include <linux/slab.h>
  15
  16 /* PMIC global registers definition */
  17 #define SC2730_MODULE_EN                0x1808
  18 #define SC2731_MODULE_EN                0xc08
  19 #define SC27XX_MODULE_ADC_EN            BIT(5)
  20 #define SC2721_ARM_CLK_EN               0xc0c
  21 #define SC2730_ARM_CLK_EN               0x180c
  22 #define SC2731_ARM_CLK_EN               0xc10
  23 #define SC27XX_CLK_ADC_EN               BIT(5)
  24 #define SC27XX_CLK_ADC_CLK_EN           BIT(6)
  25
  26 /* ADC controller registers definition */
  27 #define SC27XX_ADC_CTL                  0x0
  28 #define SC27XX_ADC_CH_CFG               0x4
  29 #define SC27XX_ADC_DATA                 0x4c
  30 #define SC27XX_ADC_INT_EN               0x50
  31 #define SC27XX_ADC_INT_CLR              0x54
  32 #define SC27XX_ADC_INT_STS              0x58
  33 #define SC27XX_ADC_INT_RAW              0x5c
  34
  35 /* Bits and mask definition for SC27XX_ADC_CTL register */
  36 #define SC27XX_ADC_EN                   BIT(0)
  37 #define SC27XX_ADC_CHN_RUN              BIT(1)
  38 #define SC27XX_ADC_12BIT_MODE           BIT(2)
  39 #define SC27XX_ADC_RUN_NUM_MASK         GENMASK(7, 4)
  40 #define SC27XX_ADC_RUN_NUM_SHIFT        4
  41
  42 /* Bits and mask definition for SC27XX_ADC_CH_CFG register */
  43 #define SC27XX_ADC_CHN_ID_MASK          GENMASK(4, 0)
  44 #define SC27XX_ADC_SCALE_MASK           GENMASK(10, 9)
  45 #define SC2721_ADC_SCALE_MASK           BIT(5)
  46 #define SC27XX_ADC_SCALE_SHIFT          9
  47 #define SC2721_ADC_SCALE_SHIFT          5
  48
  49 /* Bits definitions for SC27XX_ADC_INT_EN registers */
  50 #define SC27XX_ADC_IRQ_EN               BIT(0)
  51
  52 /* Bits definitions for SC27XX_ADC_INT_CLR registers */
  53 #define SC27XX_ADC_IRQ_CLR              BIT(0)
  54
  55 /* Bits definitions for SC27XX_ADC_INT_RAW registers */
  56 #define SC27XX_ADC_IRQ_RAW              BIT(0)
  57
  58 /* Mask definition for SC27XX_ADC_DATA register */
  59 #define SC27XX_ADC_DATA_MASK            GENMASK(11, 0)
  60
  61 /* Timeout (ms) for the trylock of hardware spinlocks */
  62 #define SC27XX_ADC_HWLOCK_TIMEOUT       5000
  63
  64 /* Timeout (us) for ADC data conversion according to ADC datasheet */
  65 #define SC27XX_ADC_RDY_TIMEOUT          1000000
  66 #define SC27XX_ADC_POLL_RAW_STATUS      500
  67
  68 /* Maximum ADC channel number */
  69 #define SC27XX_ADC_CHANNEL_MAX          32
  70
  71 /* ADC voltage ratio definition */
  72 #define SC27XX_VOLT_RATIO(n, d)         \
  73         (((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d))
  74 #define SC27XX_RATIO_NUMERATOR_OFFSET   16
  75 #define SC27XX_RATIO_DENOMINATOR_MASK   GENMASK(15, 0)
  76
  77 /* ADC specific channel reference voltage 3.5V */
  78 #define SC27XX_ADC_REFVOL_VDD35         3500000
  79
  80 /* ADC default channel reference voltage is 2.8V */
  81 #define SC27XX_ADC_REFVOL_VDD28         2800000
  82
  83 struct sc27xx_adc_data {
  84         struct device *dev;
  85         struct regulator *volref;
  86         struct regmap *regmap;
  87         /* lock to protect against multiple access to the device */
  88         struct mutex lock;
  89         /*
  90          * One hardware spinlock to synchronize between the multiple
  91          * subsystems which will access the unique ADC controller.
  92          */
  93         struct hwspinlock *hwlock;
  94         int channel_scale[SC27XX_ADC_CHANNEL_MAX];
  95         u32 base;
  96         int irq;
  97         const struct sc27xx_adc_variant_data *var_data;
  98 };
  99
 100 /*
 101  * Since different PMICs of SC27xx series can have different
 102  * address and ratio, we should save ratio config and base
 103  * in the device data structure.
 104  */
 105 struct sc27xx_adc_variant_data {
 106         u32 module_en;
 107         u32 clk_en;
 108         u32 scale_shift;
 109         u32 scale_mask;
 110         const struct sc27xx_adc_linear_graph *bscale_cal;
 111         const struct sc27xx_adc_linear_graph *sscale_cal;
 112         void (*init_scale)(struct sc27xx_adc_data *data);
 113         int (*get_ratio)(int channel, int scale);
 114         bool set_volref;
 115 };
 116
 117 struct sc27xx_adc_linear_graph {
 118         int volt0;
 119         int adc0;
 120         int volt1;
 121         int adc1;
 122 };
 123
 124 /*
 125  * According to the datasheet, we can convert one ADC value to one voltage value
 126  * through 2 points in the linear graph. If the voltage is less than 1.2v, we
 127  * should use the small-scale graph, and if more than 1.2v, we should use the
 128  * big-scale graph.
 129  */
 130 static struct sc27xx_adc_linear_graph big_scale_graph = {
 131         4200, 3310,
 132         3600, 2832,
 133 };
 134
 135 static struct sc27xx_adc_linear_graph small_scale_graph = {
 136         1000, 3413,
 137         100, 341,
 138 };
 139
 140 static const struct sc27xx_adc_linear_graph sc2731_big_scale_graph_calib = {
 141         4200, 850,
 142         3600, 728,
 143 };
 144
 145 static const struct sc27xx_adc_linear_graph sc2731_small_scale_graph_calib = {
 146         1000, 838,
 147         100, 84,
 148 };
 149
 150 static const struct sc27xx_adc_linear_graph big_scale_graph_calib = {
 151         4200, 856,
 152         3600, 733,
 153 };
 154
 155 static const struct sc27xx_adc_linear_graph small_scale_graph_calib = {
 156         1000, 833,
 157         100, 80,
 158 };
 159
 160 static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc)
 161 {
 162         return ((calib_data & 0xff) + calib_adc - 128) * 4;
 163 }
 164
 165 /* get the adc nvmem cell calibration data */
 166 static int adc_nvmem_cell_calib_data(struct sc27xx_adc_data *data, const char *cell_name)
 167 {
 168         struct nvmem_cell *cell;
 169         void *buf;
 170         u32 origin_calib_data = 0;
 171         size_t len;
 172
 173         if (!data)
 174                 return -EINVAL;
 175
 176         cell = nvmem_cell_get(data->dev, cell_name);
 177         if (IS_ERR(cell))
 178                 return PTR_ERR(cell);
 179
 180         buf = nvmem_cell_read(cell, &len);
 181         if (IS_ERR(buf)) {
 182                 nvmem_cell_put(cell);
 183                 return PTR_ERR(buf);
 184         }
 185
 186         memcpy(&origin_calib_data, buf, min(len, sizeof(u32)));
 187
 188         kfree(buf);
 189         nvmem_cell_put(cell);
 190         return origin_calib_data;
 191 }
 192
 193 static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data,
 194                                         bool big_scale)
 195 {
 196         const struct sc27xx_adc_linear_graph *calib_graph;
 197         struct sc27xx_adc_linear_graph *graph;
 198         const char *cell_name;
 199         u32 calib_data = 0;
 200
 201         if (big_scale) {
 202                 calib_graph = data->var_data->bscale_cal;
 203                 graph = &big_scale_graph;
 204                 cell_name = "big_scale_calib";
 205         } else {
 206                 calib_graph = data->var_data->sscale_cal;
 207                 graph = &small_scale_graph;
 208                 cell_name = "small_scale_calib";
 209         }
 210
 211         calib_data = adc_nvmem_cell_calib_data(data, cell_name);
 212
 213         /* Only need to calibrate the adc values in the linear graph. */
 214         graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0);
 215         graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8,
 216                                                 calib_graph->adc1);
 217
 218         return 0;
 219 }
 220
 221 static int sc2720_adc_get_ratio(int channel, int scale)
 222 {
 223         switch (channel) {
 224         case 14:
 225                 switch (scale) {
 226                 case 0:
 227                         return SC27XX_VOLT_RATIO(68, 900);
 228                 case 1:
 229                         return SC27XX_VOLT_RATIO(68, 1760);
 230                 case 2:
 231                         return SC27XX_VOLT_RATIO(68, 2327);
 232                 case 3:
 233                         return SC27XX_VOLT_RATIO(68, 3654);
 234                 default:
 235                         return SC27XX_VOLT_RATIO(1, 1);
 236                 }
 237         case 16:
 238                 switch (scale) {
 239                 case 0:
 240                         return SC27XX_VOLT_RATIO(48, 100);
 241                 case 1:
 242                         return SC27XX_VOLT_RATIO(480, 1955);
 243                 case 2:
 244                         return SC27XX_VOLT_RATIO(480, 2586);
 245                 case 3:
 246                         return SC27XX_VOLT_RATIO(48, 406);
 247                 default:
 248                         return SC27XX_VOLT_RATIO(1, 1);
 249                 }
 250         case 21:
 251         case 22:
 252         case 23:
 253                 switch (scale) {
 254                 case 0:
 255                         return SC27XX_VOLT_RATIO(3, 8);
 256                 case 1:
 257                         return SC27XX_VOLT_RATIO(375, 1955);
 258                 case 2:
 259                         return SC27XX_VOLT_RATIO(375, 2586);
 260                 case 3:
 261                         return SC27XX_VOLT_RATIO(300, 3248);
 262                 default:
 263                         return SC27XX_VOLT_RATIO(1, 1);
 264                 }
 265         default:
 266                 switch (scale) {
 267                 case 0:
 268                         return SC27XX_VOLT_RATIO(1, 1);
 269                 case 1:
 270                         return SC27XX_VOLT_RATIO(1000, 1955);
 271                 case 2:
 272                         return SC27XX_VOLT_RATIO(1000, 2586);
 273                 case 3:
 274                         return SC27XX_VOLT_RATIO(100, 406);
 275                 default:
 276                         return SC27XX_VOLT_RATIO(1, 1);
 277                 }
 278         }
 279         return SC27XX_VOLT_RATIO(1, 1);
 280 }
 281
 282 static int sc2721_adc_get_ratio(int channel, int scale)
 283 {
 284         switch (channel) {
 285         case 1:
 286         case 2:
 287         case 3:
 288         case 4:
 289                 return scale ? SC27XX_VOLT_RATIO(400, 1025) :
 290                         SC27XX_VOLT_RATIO(1, 1);
 291         case 5:
 292                 return SC27XX_VOLT_RATIO(7, 29);
 293         case 7:
 294         case 9:
 295                 return scale ? SC27XX_VOLT_RATIO(100, 125) :
 296                         SC27XX_VOLT_RATIO(1, 1);
 297         case 14:
 298                 return SC27XX_VOLT_RATIO(68, 900);
 299         case 16:
 300                 return SC27XX_VOLT_RATIO(48, 100);
 301         case 19:
 302                 return SC27XX_VOLT_RATIO(1, 3);
 303         default:
 304                 return SC27XX_VOLT_RATIO(1, 1);
 305         }
 306         return SC27XX_VOLT_RATIO(1, 1);
 307 }
 308
 309 static int sc2730_adc_get_ratio(int channel, int scale)
 310 {
 311         switch (channel) {
 312         case 14:
 313                 switch (scale) {
 314                 case 0:
 315                         return SC27XX_VOLT_RATIO(68, 900);
 316                 case 1:
 317                         return SC27XX_VOLT_RATIO(68, 1760);
 318                 case 2:
 319                         return SC27XX_VOLT_RATIO(68, 2327);
 320                 case 3:
 321                         return SC27XX_VOLT_RATIO(68, 3654);
 322                 default:
 323                         return SC27XX_VOLT_RATIO(1, 1);
 324                 }
 325         case 15:
 326                 switch (scale) {
 327                 case 0:
 328                         return SC27XX_VOLT_RATIO(1, 3);
 329                 case 1:
 330                         return SC27XX_VOLT_RATIO(1000, 5865);
 331                 case 2:
 332                         return SC27XX_VOLT_RATIO(500, 3879);
 333                 case 3:
 334                         return SC27XX_VOLT_RATIO(500, 6090);
 335                 default:
 336                         return SC27XX_VOLT_RATIO(1, 1);
 337                 }
 338         case 16:
 339                 switch (scale) {
 340                 case 0:
 341                         return SC27XX_VOLT_RATIO(48, 100);
 342                 case 1:
 343                         return SC27XX_VOLT_RATIO(480, 1955);
 344                 case 2:
 345                         return SC27XX_VOLT_RATIO(480, 2586);
 346                 case 3:
 347                         return SC27XX_VOLT_RATIO(48, 406);
 348                 default:
 349                         return SC27XX_VOLT_RATIO(1, 1);
 350                 }
 351         case 21:
 352         case 22:
 353         case 23:
 354                 switch (scale) {
 355                 case 0:
 356                         return SC27XX_VOLT_RATIO(3, 8);
 357                 case 1:
 358                         return SC27XX_VOLT_RATIO(375, 1955);
 359                 case 2:
 360                         return SC27XX_VOLT_RATIO(375, 2586);
 361                 case 3:
 362                         return SC27XX_VOLT_RATIO(300, 3248);
 363                 default:
 364                         return SC27XX_VOLT_RATIO(1, 1);
 365                 }
 366         default:
 367                 switch (scale) {
 368                 case 0:
 369                         return SC27XX_VOLT_RATIO(1, 1);
 370                 case 1:
 371                         return SC27XX_VOLT_RATIO(1000, 1955);
 372                 case 2:
 373                         return SC27XX_VOLT_RATIO(1000, 2586);
 374                 case 3:
 375                         return SC27XX_VOLT_RATIO(1000, 4060);
 376                 default:
 377                         return SC27XX_VOLT_RATIO(1, 1);
 378                 }
 379         }
 380         return SC27XX_VOLT_RATIO(1, 1);
 381 }
 382
 383 static int sc2731_adc_get_ratio(int channel, int scale)
 384 {
 385         switch (channel) {
 386         case 1:
 387         case 2:
 388         case 3:
 389         case 4:
 390                 return scale ? SC27XX_VOLT_RATIO(400, 1025) :
 391                         SC27XX_VOLT_RATIO(1, 1);
 392         case 5:
 393                 return SC27XX_VOLT_RATIO(7, 29);
 394         case 6:
 395                 return SC27XX_VOLT_RATIO(375, 9000);
 396         case 7:
 397         case 8:
 398                 return scale ? SC27XX_VOLT_RATIO(100, 125) :
 399                         SC27XX_VOLT_RATIO(1, 1);
 400         case 19:
 401                 return SC27XX_VOLT_RATIO(1, 3);
 402         default:
 403                 return SC27XX_VOLT_RATIO(1, 1);
 404         }
 405         return SC27XX_VOLT_RATIO(1, 1);
 406 }
 407
 408 /*
 409  * According to the datasheet set specific value on some channel.
 410  */
 411 static void sc2720_adc_scale_init(struct sc27xx_adc_data *data)
 412 {
 413         int i;
 414
 415         for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
 416                 switch (i) {
 417                 case 5:
 418                         data->channel_scale[i] = 3;
 419                         break;
 420                 case 7:
 421                 case 9:
 422                         data->channel_scale[i] = 2;
 423                         break;
 424                 case 13:
 425                         data->channel_scale[i] = 1;
 426                         break;
 427                 case 19:
 428                 case 30:
 429                 case 31:
 430                         data->channel_scale[i] = 3;
 431                         break;
 432                 default:
 433                         data->channel_scale[i] = 0;
 434                         break;
 435                 }
 436         }
 437 }
 438
 439 static void sc2730_adc_scale_init(struct sc27xx_adc_data *data)
 440 {
 441         int i;
 442
 443         for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
 444                 switch (i) {
 445                 case 5:
 446                 case 10:
 447                 case 19:
 448                 case 30:
 449                 case 31:
 450                         data->channel_scale[i] = 3;
 451                         break;
 452                 case 7:
 453                 case 9:
 454                         data->channel_scale[i] = 2;
 455                         break;
 456                 case 13:
 457                         data->channel_scale[i] = 1;
 458                         break;
 459                 default:
 460                         data->channel_scale[i] = 0;
 461                         break;
 462                 }
 463         }
 464 }
 465
 466 static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
 467 {
 468         int i;
 469         /*
 470          * In the current software design, SC2731 support 2 scales,
 471          * channels 5 uses big scale, others use smale.
 472          */
 473         for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
 474                 switch (i) {
 475                 case 5:
 476                         data->channel_scale[i] = 1;
 477                         break;
 478                 default:
 479                         data->channel_scale[i] = 0;
 480                         break;
 481                 }
 482         }
 483 }
 484
 485 static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
 486                            int scale, int *val)
 487 {
 488         int ret, ret_volref;
 489         u32 tmp, value, status;
 490
 491         ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
 492         if (ret) {
 493                 dev_err(data->dev, "timeout to get the hwspinlock\n");
 494                 return ret;
 495         }
 496
 497         /*
 498          * According to the sc2721 chip data sheet, the reference voltage of
 499          * specific channel 30 and channel 31 in ADC module needs to be set from
 500          * the default 2.8v to 3.5v.
 501          */
 502         if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
 503                 ret = regulator_set_voltage(data->volref,
 504                                         SC27XX_ADC_REFVOL_VDD35,
 505                                         SC27XX_ADC_REFVOL_VDD35);
 506                 if (ret) {
 507                         dev_err(data->dev, "failed to set the volref 3.5v\n");
 508                         goto unlock_adc;
 509                 }
 510         }
 511
 512         ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
 513                                  SC27XX_ADC_EN, SC27XX_ADC_EN);
 514         if (ret)
 515                 goto regulator_restore;
 516
 517         ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
 518                                  SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
 519         if (ret)
 520                 goto disable_adc;
 521
 522         /* Configure the channel id and scale */
 523         tmp = (scale << data->var_data->scale_shift) & data->var_data->scale_mask;
 524         tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
 525         ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
 526                                  SC27XX_ADC_CHN_ID_MASK |
 527                                  data->var_data->scale_mask,
 528                                  tmp);
 529         if (ret)
 530                 goto disable_adc;
 531
 532         /* Select 12bit conversion mode, and only sample 1 time */
 533         tmp = SC27XX_ADC_12BIT_MODE;
 534         tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK;
 535         ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
 536                                  SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE,
 537                                  tmp);
 538         if (ret)
 539                 goto disable_adc;
 540
 541         ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
 542                                  SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN);
 543         if (ret)
 544                 goto disable_adc;
 545
 546         ret = regmap_read_poll_timeout(data->regmap,
 547                                        data->base + SC27XX_ADC_INT_RAW,
 548                                        status, (status & SC27XX_ADC_IRQ_RAW),
 549                                        SC27XX_ADC_POLL_RAW_STATUS,
 550                                        SC27XX_ADC_RDY_TIMEOUT);
 551         if (ret) {
 552                 dev_err(data->dev, "read adc timeout, status = 0x%x\n", status);
 553                 goto disable_adc;
 554         }
 555
 556         ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value);
 557         if (ret)
 558                 goto disable_adc;
 559
 560         value &= SC27XX_ADC_DATA_MASK;
 561
 562 disable_adc:
 563         regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
 564                            SC27XX_ADC_EN, 0);
 565 regulator_restore:
 566         if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
 567                 ret_volref = regulator_set_voltage(data->volref,
 568                                             SC27XX_ADC_REFVOL_VDD28,
 569                                             SC27XX_ADC_REFVOL_VDD28);
 570                 if (ret_volref) {
 571                         dev_err(data->dev, "failed to set the volref 2.8v,ret_volref = 0x%x\n",
 572                                          ret_volref);
 573                         ret = ret || ret_volref;
 574                 }
 575         }
 576 unlock_adc:
 577         hwspin_unlock_raw(data->hwlock);
 578
 579         if (!ret)
 580                 *val = value;
 581
 582         return ret;
 583 }
 584
 585 static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, int channel, int scale,
 586                                   struct u32_fract *fract)
 587 {
 588         u32 ratio;
 589
 590         ratio = data->var_data->get_ratio(channel, scale);
 591         fract->numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
 592         fract->denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
 593 }
 594
 595 static int adc_to_volt(struct sc27xx_adc_linear_graph *graph,
 596                               int raw_adc)
 597 {
 598         int tmp;
 599
 600         tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1);
 601         tmp /= (graph->adc0 - graph->adc1);
 602         tmp += graph->volt1;
 603
 604         return tmp;
 605 }
 606
 607 static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph,
 608                               int raw_adc)
 609 {
 610         int tmp;
 611
 612         tmp = adc_to_volt(graph, raw_adc);
 613
 614         return tmp < 0 ? 0 : tmp;
 615 }
 616
 617 static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel,
 618                                    int scale, int raw_adc)
 619 {
 620         struct u32_fract fract;
 621         u32 volt;
 622
 623         /*
 624          * Convert ADC values to voltage values according to the linear graph,
 625          * and channel 5 and channel 1 has been calibrated, so we can just
 626          * return the voltage values calculated by the linear graph. But other
 627          * channels need be calculated to the real voltage values with the
 628          * voltage ratio.
 629          */
 630         switch (channel) {
 631         case 5:
 632                 return sc27xx_adc_to_volt(&big_scale_graph, raw_adc);
 633
 634         case 1:
 635                 return sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
 636
 637         default:
 638                 volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
 639                 break;
 640         }
 641
 642         sc27xx_adc_volt_ratio(data, channel, scale, &fract);
 643
 644         return DIV_ROUND_CLOSEST(volt * fract.denominator, fract.numerator);
 645 }
 646
 647 static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data,
 648                                      int channel, int scale, int *val)
 649 {
 650         int ret, raw_adc;
 651
 652         ret = sc27xx_adc_read(data, channel, scale, &raw_adc);
 653         if (ret)
 654                 return ret;
 655
 656         *val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc);
 657         return 0;
 658 }
 659
 660 static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
 661                                struct iio_chan_spec const *chan,
 662                                int *val, int *val2, long mask)
 663 {
 664         struct sc27xx_adc_data *data = iio_priv(indio_dev);
 665         int scale = data->channel_scale[chan->channel];
 666         int ret, tmp;
 667
 668         switch (mask) {
 669         case IIO_CHAN_INFO_RAW:
 670                 mutex_lock(&data->lock);
 671                 ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
 672                 mutex_unlock(&data->lock);
 673
 674                 if (ret)
 675                         return ret;
 676
 677                 *val = tmp;
 678                 return IIO_VAL_INT;
 679
 680         case IIO_CHAN_INFO_PROCESSED:
 681                 mutex_lock(&data->lock);
 682                 ret = sc27xx_adc_read_processed(data, chan->channel, scale,
 683                                                 &tmp);
 684                 mutex_unlock(&data->lock);
 685
 686                 if (ret)
 687                         return ret;
 688
 689                 *val = tmp;
 690                 return IIO_VAL_INT;
 691
 692         case IIO_CHAN_INFO_SCALE:
 693                 *val = scale;
 694                 return IIO_VAL_INT;
 695
 696         default:
 697                 return -EINVAL;
 698         }
 699 }
 700
 701 static int sc27xx_adc_write_raw(struct iio_dev *indio_dev,
 702                                 struct iio_chan_spec const *chan,
 703                                 int val, int val2, long mask)
 704 {
 705         struct sc27xx_adc_data *data = iio_priv(indio_dev);
 706
 707         switch (mask) {
 708         case IIO_CHAN_INFO_SCALE:
 709                 data->channel_scale[chan->channel] = val;
 710                 return IIO_VAL_INT;
 711
 712         default:
 713                 return -EINVAL;
 714         }
 715 }
 716
 717 static const struct iio_info sc27xx_info = {
 718         .read_raw = &sc27xx_adc_read_raw,
 719         .write_raw = &sc27xx_adc_write_raw,
 720 };
 721
 722 #define SC27XX_ADC_CHANNEL(index, mask) {                       \
 723         .type = IIO_VOLTAGE,                                    \
 724         .channel = index,                                       \
 725         .info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE),  \
 726         .datasheet_name = "CH##index",                          \
 727         .indexed = 1,                                           \
 728 }
 729
 730 static const struct iio_chan_spec sc27xx_channels[] = {
 731         SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
 732         SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
 733         SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
 734         SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
 735         SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
 736         SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
 737         SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
 738         SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
 739         SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
 740         SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
 741         SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
 742         SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
 743         SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
 744         SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
 745         SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
 746         SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
 747         SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
 748         SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
 749         SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
 750         SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
 751         SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
 752         SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
 753         SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
 754         SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
 755         SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
 756         SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
 757         SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
 758         SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
 759         SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
 760         SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
 761         SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
 762         SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
 763 };
 764
 765 static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
 766 {
 767         int ret;
 768
 769         ret = regmap_update_bits(data->regmap, data->var_data->module_en,
 770                                  SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN);
 771         if (ret)
 772                 return ret;
 773
 774         /* Enable ADC work clock and controller clock */
 775         ret = regmap_update_bits(data->regmap, data->var_data->clk_en,
 776                                  SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN,
 777                                  SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
 778         if (ret)
 779                 goto disable_adc;
 780
 781         /* ADC channel scales' calibration from nvmem device */
 782         ret = sc27xx_adc_scale_calibration(data, true);
 783         if (ret)
 784                 goto disable_clk;
 785
 786         ret = sc27xx_adc_scale_calibration(data, false);
 787         if (ret)
 788                 goto disable_clk;
 789
 790         return 0;
 791
 792 disable_clk:
 793         regmap_update_bits(data->regmap, data->var_data->clk_en,
 794                            SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
 795 disable_adc:
 796         regmap_update_bits(data->regmap, data->var_data->module_en,
 797                            SC27XX_MODULE_ADC_EN, 0);
 798
 799         return ret;
 800 }
 801
 802 static void sc27xx_adc_disable(void *_data)
 803 {
 804         struct sc27xx_adc_data *data = _data;
 805
 806         /* Disable ADC work clock and controller clock */
 807         regmap_update_bits(data->regmap, data->var_data->clk_en,
 808                            SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
 809
 810         regmap_update_bits(data->regmap, data->var_data->module_en,
 811                            SC27XX_MODULE_ADC_EN, 0);
 812 }
 813
 814 static const struct sc27xx_adc_variant_data sc2731_data = {
 815         .module_en = SC2731_MODULE_EN,
 816         .clk_en = SC2731_ARM_CLK_EN,
 817         .scale_shift = SC27XX_ADC_SCALE_SHIFT,
 818         .scale_mask = SC27XX_ADC_SCALE_MASK,
 819         .bscale_cal = &sc2731_big_scale_graph_calib,
 820         .sscale_cal = &sc2731_small_scale_graph_calib,
 821         .init_scale = sc2731_adc_scale_init,
 822         .get_ratio = sc2731_adc_get_ratio,
 823         .set_volref = false,
 824 };
 825
 826 static const struct sc27xx_adc_variant_data sc2730_data = {
 827         .module_en = SC2730_MODULE_EN,
 828         .clk_en = SC2730_ARM_CLK_EN,
 829         .scale_shift = SC27XX_ADC_SCALE_SHIFT,
 830         .scale_mask = SC27XX_ADC_SCALE_MASK,
 831         .bscale_cal = &big_scale_graph_calib,
 832         .sscale_cal = &small_scale_graph_calib,
 833         .init_scale = sc2730_adc_scale_init,
 834         .get_ratio = sc2730_adc_get_ratio,
 835         .set_volref = false,
 836 };
 837
 838 static const struct sc27xx_adc_variant_data sc2721_data = {
 839         .module_en = SC2731_MODULE_EN,
 840         .clk_en = SC2721_ARM_CLK_EN,
 841         .scale_shift = SC2721_ADC_SCALE_SHIFT,
 842         .scale_mask = SC2721_ADC_SCALE_MASK,
 843         .bscale_cal = &sc2731_big_scale_graph_calib,
 844         .sscale_cal = &sc2731_small_scale_graph_calib,
 845         .init_scale = sc2731_adc_scale_init,
 846         .get_ratio = sc2721_adc_get_ratio,
 847         .set_volref = true,
 848 };
 849
 850 static const struct sc27xx_adc_variant_data sc2720_data = {
 851         .module_en = SC2731_MODULE_EN,
 852         .clk_en = SC2721_ARM_CLK_EN,
 853         .scale_shift = SC27XX_ADC_SCALE_SHIFT,
 854         .scale_mask = SC27XX_ADC_SCALE_MASK,
 855         .bscale_cal = &big_scale_graph_calib,
 856         .sscale_cal = &small_scale_graph_calib,
 857         .init_scale = sc2720_adc_scale_init,
 858         .get_ratio = sc2720_adc_get_ratio,
 859         .set_volref = false,
 860 };
 861
 862 static int sc27xx_adc_probe(struct platform_device *pdev)
 863 {
 864         struct device *dev = &pdev->dev;
 865         struct device_node *np = dev->of_node;
 866         struct sc27xx_adc_data *sc27xx_data;
 867         const struct sc27xx_adc_variant_data *pdata;
 868         struct iio_dev *indio_dev;
 869         int ret;
 870
 871         pdata = of_device_get_match_data(dev);
 872         if (!pdata) {
 873                 dev_err(dev, "No matching driver data found\n");
 874                 return -EINVAL;
 875         }
 876
 877         indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data));
 878         if (!indio_dev)
 879                 return -ENOMEM;
 880
 881         sc27xx_data = iio_priv(indio_dev);
 882
 883         sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL);
 884         if (!sc27xx_data->regmap) {
 885                 dev_err(dev, "failed to get ADC regmap\n");
 886                 return -ENODEV;
 887         }
 888
 889         ret = of_property_read_u32(np, "reg", &sc27xx_data->base);
 890         if (ret) {
 891                 dev_err(dev, "failed to get ADC base address\n");
 892                 return ret;
 893         }
 894
 895         sc27xx_data->irq = platform_get_irq(pdev, 0);
 896         if (sc27xx_data->irq < 0)
 897                 return sc27xx_data->irq;
 898
 899         ret = of_hwspin_lock_get_id(np, 0);
 900         if (ret < 0) {
 901                 dev_err(dev, "failed to get hwspinlock id\n");
 902                 return ret;
 903         }
 904
 905         sc27xx_data->hwlock = devm_hwspin_lock_request_specific(dev, ret);
 906         if (!sc27xx_data->hwlock) {
 907                 dev_err(dev, "failed to request hwspinlock\n");
 908                 return -ENXIO;
 909         }
 910
 911         sc27xx_data->dev = dev;
 912         if (pdata->set_volref) {
 913                 sc27xx_data->volref = devm_regulator_get(dev, "vref");
 914                 if (IS_ERR(sc27xx_data->volref)) {
 915                         ret = PTR_ERR(sc27xx_data->volref);
 916                         return dev_err_probe(dev, ret, "failed to get ADC volref\n");
 917                 }
 918         }
 919
 920         sc27xx_data->var_data = pdata;
 921         sc27xx_data->var_data->init_scale(sc27xx_data);
 922
 923         ret = sc27xx_adc_enable(sc27xx_data);
 924         if (ret) {
 925                 dev_err(dev, "failed to enable ADC module\n");
 926                 return ret;
 927         }
 928
 929         ret = devm_add_action_or_reset(dev, sc27xx_adc_disable, sc27xx_data);
 930         if (ret) {
 931                 dev_err(dev, "failed to add ADC disable action\n");
 932                 return ret;
 933         }
 934
 935         indio_dev->name = dev_name(dev);
 936         indio_dev->modes = INDIO_DIRECT_MODE;
 937         indio_dev->info = &sc27xx_info;
 938         indio_dev->channels = sc27xx_channels;
 939         indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);
 940
 941         mutex_init(&sc27xx_data->lock);
 942
 943         ret = devm_iio_device_register(dev, indio_dev);
 944         if (ret)
 945                 dev_err(dev, "could not register iio (ADC)");
 946
 947         return ret;
 948 }
 949
 950 static const struct of_device_id sc27xx_adc_of_match[] = {
 951         { .compatible = "sprd,sc2731-adc", .data = &sc2731_data},
 952         { .compatible = "sprd,sc2730-adc", .data = &sc2730_data},
 953         { .compatible = "sprd,sc2721-adc", .data = &sc2721_data},
 954         { .compatible = "sprd,sc2720-adc", .data = &sc2720_data},
 955         { }
 956 };
 957 MODULE_DEVICE_TABLE(of, sc27xx_adc_of_match);
 958
 959 static struct platform_driver sc27xx_adc_driver = {
 960         .probe = sc27xx_adc_probe,
 961         .driver = {
 962                 .name = "sc27xx-adc",
 963                 .of_match_table = sc27xx_adc_of_match,
 964         },
 965 };
 966
 967 module_platform_driver(sc27xx_adc_driver);
 968
 969 MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
 970 MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver");
 971 MODULE_LICENSE("GPL v2");