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