drivers/iio/trigger/stm32-timer-trigger.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) STMicroelectronics 2016
   4  *
   5  * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
   6  *
   7  */
   8
   9 #include <linux/iio/iio.h>
  10 #include <linux/iio/sysfs.h>
  11 #include <linux/iio/timer/stm32-timer-trigger.h>
  12 #include <linux/iio/trigger.h>
  13 #include <linux/mfd/stm32-timers.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/of_device.h>
  17
  18 #define MAX_TRIGGERS 7
  19 #define MAX_VALIDS 5
  20
  21 /* List the triggers created by each timer */
  22 static const void *triggers_table[][MAX_TRIGGERS] = {
  23         { TIM1_TRGO, TIM1_TRGO2, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4,},
  24         { TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4,},
  25         { TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4,},
  26         { TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4,},
  27         { TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4,},
  28         { TIM6_TRGO,},
  29         { TIM7_TRGO,},
  30         { TIM8_TRGO, TIM8_TRGO2, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},
  31         { TIM9_TRGO, TIM9_CH1, TIM9_CH2,},
  32         { TIM10_OC1,},
  33         { TIM11_OC1,},
  34         { TIM12_TRGO, TIM12_CH1, TIM12_CH2,},
  35         { TIM13_OC1,},
  36         { TIM14_OC1,},
  37         { TIM15_TRGO,},
  38         { TIM16_OC1,},
  39         { TIM17_OC1,},
  40 };
  41
  42 /* List the triggers accepted by each timer */
  43 static const void *valids_table[][MAX_VALIDS] = {
  44         { TIM5_TRGO, TIM2_TRGO, TIM3_TRGO, TIM4_TRGO,},
  45         { TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
  46         { TIM1_TRGO, TIM2_TRGO, TIM5_TRGO, TIM4_TRGO,},
  47         { TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,},
  48         { TIM2_TRGO, TIM3_TRGO, TIM4_TRGO, TIM8_TRGO,},
  49         { }, /* timer 6 */
  50         { }, /* timer 7 */
  51         { TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,},
  52         { TIM2_TRGO, TIM3_TRGO, TIM10_OC1, TIM11_OC1,},
  53         { }, /* timer 10 */
  54         { }, /* timer 11 */
  55         { TIM4_TRGO, TIM5_TRGO, TIM13_OC1, TIM14_OC1,},
  56 };
  57
  58 static const void *stm32h7_valids_table[][MAX_VALIDS] = {
  59         { TIM15_TRGO, TIM2_TRGO, TIM3_TRGO, TIM4_TRGO,},
  60         { TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
  61         { TIM1_TRGO, TIM2_TRGO, TIM15_TRGO, TIM4_TRGO,},
  62         { TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,},
  63         { TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},
  64         { }, /* timer 6 */
  65         { }, /* timer 7 */
  66         { TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,},
  67         { }, /* timer 9 */
  68         { }, /* timer 10 */
  69         { }, /* timer 11 */
  70         { TIM4_TRGO, TIM5_TRGO, TIM13_OC1, TIM14_OC1,},
  71         { }, /* timer 13 */
  72         { }, /* timer 14 */
  73         { TIM1_TRGO, TIM3_TRGO, TIM16_OC1, TIM17_OC1,},
  74         { }, /* timer 16 */
  75         { }, /* timer 17 */
  76 };
  77
  78 struct stm32_timer_trigger {
  79         struct device *dev;
  80         struct regmap *regmap;
  81         struct clk *clk;
  82         u32 max_arr;
  83         const void *triggers;
  84         const void *valids;
  85         bool has_trgo2;
  86 };
  87
  88 struct stm32_timer_trigger_cfg {
  89         const void *(*valids_table)[MAX_VALIDS];
  90         const unsigned int num_valids_table;
  91 };
  92
  93 static bool stm32_timer_is_trgo2_name(const char *name)
  94 {
  95         return !!strstr(name, "trgo2");
  96 }
  97
  98 static bool stm32_timer_is_trgo_name(const char *name)
  99 {
 100         return (!!strstr(name, "trgo") && !strstr(name, "trgo2"));
 101 }
 102
 103 static int stm32_timer_start(struct stm32_timer_trigger *priv,
 104                              struct iio_trigger *trig,
 105                              unsigned int frequency)
 106 {
 107         unsigned long long prd, div;
 108         int prescaler = 0;
 109         u32 ccer, cr1;
 110
 111         /* Period and prescaler values depends of clock rate */
 112         div = (unsigned long long)clk_get_rate(priv->clk);
 113
 114         do_div(div, frequency);
 115
 116         prd = div;
 117
 118         /*
 119          * Increase prescaler value until we get a result that fit
 120          * with auto reload register maximum value.
 121          */
 122         while (div > priv->max_arr) {
 123                 prescaler++;
 124                 div = prd;
 125                 do_div(div, (prescaler + 1));
 126         }
 127         prd = div;
 128
 129         if (prescaler > MAX_TIM_PSC) {
 130                 dev_err(priv->dev, "prescaler exceeds the maximum value\n");
 131                 return -EINVAL;
 132         }
 133
 134         /* Check if nobody else use the timer */
 135         regmap_read(priv->regmap, TIM_CCER, &ccer);
 136         if (ccer & TIM_CCER_CCXE)
 137                 return -EBUSY;
 138
 139         regmap_read(priv->regmap, TIM_CR1, &cr1);
 140         if (!(cr1 & TIM_CR1_CEN))
 141                 clk_enable(priv->clk);
 142
 143         regmap_write(priv->regmap, TIM_PSC, prescaler);
 144         regmap_write(priv->regmap, TIM_ARR, prd - 1);
 145         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
 146
 147         /* Force master mode to update mode */
 148         if (stm32_timer_is_trgo2_name(trig->name))
 149                 regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2,
 150                                    0x2 << TIM_CR2_MMS2_SHIFT);
 151         else
 152                 regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS,
 153                                    0x2 << TIM_CR2_MMS_SHIFT);
 154
 155         /* Make sure that registers are updated */
 156         regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
 157
 158         /* Enable controller */
 159         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN);
 160
 161         return 0;
 162 }
 163
 164 static void stm32_timer_stop(struct stm32_timer_trigger *priv)
 165 {
 166         u32 ccer, cr1;
 167
 168         regmap_read(priv->regmap, TIM_CCER, &ccer);
 169         if (ccer & TIM_CCER_CCXE)
 170                 return;
 171
 172         regmap_read(priv->regmap, TIM_CR1, &cr1);
 173         if (cr1 & TIM_CR1_CEN)
 174                 clk_disable(priv->clk);
 175
 176         /* Stop timer */
 177         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 178         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 179         regmap_write(priv->regmap, TIM_PSC, 0);
 180         regmap_write(priv->regmap, TIM_ARR, 0);
 181
 182         /* Make sure that registers are updated */
 183         regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
 184 }
 185
 186 static ssize_t stm32_tt_store_frequency(struct device *dev,
 187                                         struct device_attribute *attr,
 188                                         const char *buf, size_t len)
 189 {
 190         struct iio_trigger *trig = to_iio_trigger(dev);
 191         struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
 192         unsigned int freq;
 193         int ret;
 194
 195         ret = kstrtouint(buf, 10, &freq);
 196         if (ret)
 197                 return ret;
 198
 199         if (freq == 0) {
 200                 stm32_timer_stop(priv);
 201         } else {
 202                 ret = stm32_timer_start(priv, trig, freq);
 203                 if (ret)
 204                         return ret;
 205         }
 206
 207         return len;
 208 }
 209
 210 static ssize_t stm32_tt_read_frequency(struct device *dev,
 211                                        struct device_attribute *attr, char *buf)
 212 {
 213         struct iio_trigger *trig = to_iio_trigger(dev);
 214         struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig);
 215         u32 psc, arr, cr1;
 216         unsigned long long freq = 0;
 217
 218         regmap_read(priv->regmap, TIM_CR1, &cr1);
 219         regmap_read(priv->regmap, TIM_PSC, &psc);
 220         regmap_read(priv->regmap, TIM_ARR, &arr);
 221
 222         if (cr1 & TIM_CR1_CEN) {
 223                 freq = (unsigned long long)clk_get_rate(priv->clk);
 224                 do_div(freq, psc + 1);
 225                 do_div(freq, arr + 1);
 226         }
 227
 228         return sprintf(buf, "%d\n", (unsigned int)freq);
 229 }
 230
 231 static IIO_DEV_ATTR_SAMP_FREQ(0660,
 232                               stm32_tt_read_frequency,
 233                               stm32_tt_store_frequency);
 234
 235 #define MASTER_MODE_MAX         7
 236 #define MASTER_MODE2_MAX        15
 237
 238 static char *master_mode_table[] = {
 239         "reset",
 240         "enable",
 241         "update",
 242         "compare_pulse",
 243         "OC1REF",
 244         "OC2REF",
 245         "OC3REF",
 246         "OC4REF",
 247         /* Master mode selection 2 only */
 248         "OC5REF",
 249         "OC6REF",
 250         "compare_pulse_OC4REF",
 251         "compare_pulse_OC6REF",
 252         "compare_pulse_OC4REF_r_or_OC6REF_r",
 253         "compare_pulse_OC4REF_r_or_OC6REF_f",
 254         "compare_pulse_OC5REF_r_or_OC6REF_r",
 255         "compare_pulse_OC5REF_r_or_OC6REF_f",
 256 };
 257
 258 static ssize_t stm32_tt_show_master_mode(struct device *dev,
 259                                          struct device_attribute *attr,
 260                                          char *buf)
 261 {
 262         struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
 263         struct iio_trigger *trig = to_iio_trigger(dev);
 264         u32 cr2;
 265
 266         regmap_read(priv->regmap, TIM_CR2, &cr2);
 267
 268         if (stm32_timer_is_trgo2_name(trig->name))
 269                 cr2 = (cr2 & TIM_CR2_MMS2) >> TIM_CR2_MMS2_SHIFT;
 270         else
 271                 cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT;
 272
 273         return snprintf(buf, PAGE_SIZE, "%s\n", master_mode_table[cr2]);
 274 }
 275
 276 static ssize_t stm32_tt_store_master_mode(struct device *dev,
 277                                           struct device_attribute *attr,
 278                                           const char *buf, size_t len)
 279 {
 280         struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
 281         struct iio_trigger *trig = to_iio_trigger(dev);
 282         u32 mask, shift, master_mode_max;
 283         int i;
 284
 285         if (stm32_timer_is_trgo2_name(trig->name)) {
 286                 mask = TIM_CR2_MMS2;
 287                 shift = TIM_CR2_MMS2_SHIFT;
 288                 master_mode_max = MASTER_MODE2_MAX;
 289         } else {
 290                 mask = TIM_CR2_MMS;
 291                 shift = TIM_CR2_MMS_SHIFT;
 292                 master_mode_max = MASTER_MODE_MAX;
 293         }
 294
 295         for (i = 0; i <= master_mode_max; i++) {
 296                 if (!strncmp(master_mode_table[i], buf,
 297                              strlen(master_mode_table[i]))) {
 298                         regmap_update_bits(priv->regmap, TIM_CR2, mask,
 299                                            i << shift);
 300                         /* Make sure that registers are updated */
 301                         regmap_update_bits(priv->regmap, TIM_EGR,
 302                                            TIM_EGR_UG, TIM_EGR_UG);
 303                         return len;
 304                 }
 305         }
 306
 307         return -EINVAL;
 308 }
 309
 310 static ssize_t stm32_tt_show_master_mode_avail(struct device *dev,
 311                                                struct device_attribute *attr,
 312                                                char *buf)
 313 {
 314         struct iio_trigger *trig = to_iio_trigger(dev);
 315         unsigned int i, master_mode_max;
 316         size_t len = 0;
 317
 318         if (stm32_timer_is_trgo2_name(trig->name))
 319                 master_mode_max = MASTER_MODE2_MAX;
 320         else
 321                 master_mode_max = MASTER_MODE_MAX;
 322
 323         for (i = 0; i <= master_mode_max; i++)
 324                 len += scnprintf(buf + len, PAGE_SIZE - len,
 325                         "%s ", master_mode_table[i]);
 326
 327         /* replace trailing space by newline */
 328         buf[len - 1] = '\n';
 329
 330         return len;
 331 }
 332
 333 static IIO_DEVICE_ATTR(master_mode_available, 0444,
 334                        stm32_tt_show_master_mode_avail, NULL, 0);
 335
 336 static IIO_DEVICE_ATTR(master_mode, 0660,
 337                        stm32_tt_show_master_mode,
 338                        stm32_tt_store_master_mode,
 339                        0);
 340
 341 static struct attribute *stm32_trigger_attrs[] = {
 342         &iio_dev_attr_sampling_frequency.dev_attr.attr,
 343         &iio_dev_attr_master_mode.dev_attr.attr,
 344         &iio_dev_attr_master_mode_available.dev_attr.attr,
 345         NULL,
 346 };
 347
 348 static const struct attribute_group stm32_trigger_attr_group = {
 349         .attrs = stm32_trigger_attrs,
 350 };
 351
 352 static const struct attribute_group *stm32_trigger_attr_groups[] = {
 353         &stm32_trigger_attr_group,
 354         NULL,
 355 };
 356
 357 static const struct iio_trigger_ops timer_trigger_ops = {
 358 };
 359
 360 static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv)
 361 {
 362         int ret;
 363         const char * const *cur = priv->triggers;
 364
 365         while (cur && *cur) {
 366                 struct iio_trigger *trig;
 367                 bool cur_is_trgo = stm32_timer_is_trgo_name(*cur);
 368                 bool cur_is_trgo2 = stm32_timer_is_trgo2_name(*cur);
 369
 370                 if (cur_is_trgo2 && !priv->has_trgo2) {
 371                         cur++;
 372                         continue;
 373                 }
 374
 375                 trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur);
 376                 if  (!trig)
 377                         return -ENOMEM;
 378
 379                 trig->dev.parent = priv->dev->parent;
 380                 trig->ops = &timer_trigger_ops;
 381
 382                 /*
 383                  * sampling frequency and master mode attributes
 384                  * should only be available on trgo/trgo2 triggers
 385                  */
 386                 if (cur_is_trgo || cur_is_trgo2)
 387                         trig->dev.groups = stm32_trigger_attr_groups;
 388
 389                 iio_trigger_set_drvdata(trig, priv);
 390
 391                 ret = devm_iio_trigger_register(priv->dev, trig);
 392                 if (ret)
 393                         return ret;
 394                 cur++;
 395         }
 396
 397         return 0;
 398 }
 399
 400 static int stm32_counter_read_raw(struct iio_dev *indio_dev,
 401                                   struct iio_chan_spec const *chan,
 402                                   int *val, int *val2, long mask)
 403 {
 404         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 405         u32 dat;
 406
 407         switch (mask) {
 408         case IIO_CHAN_INFO_RAW:
 409                 regmap_read(priv->regmap, TIM_CNT, &dat);
 410                 *val = dat;
 411                 return IIO_VAL_INT;
 412
 413         case IIO_CHAN_INFO_ENABLE:
 414                 regmap_read(priv->regmap, TIM_CR1, &dat);
 415                 *val = (dat & TIM_CR1_CEN) ? 1 : 0;
 416                 return IIO_VAL_INT;
 417
 418         case IIO_CHAN_INFO_SCALE:
 419                 regmap_read(priv->regmap, TIM_SMCR, &dat);
 420                 dat &= TIM_SMCR_SMS;
 421
 422                 *val = 1;
 423                 *val2 = 0;
 424
 425                 /* in quadrature case scale = 0.25 */
 426                 if (dat == 3)
 427                         *val2 = 2;
 428
 429                 return IIO_VAL_FRACTIONAL_LOG2;
 430         }
 431
 432         return -EINVAL;
 433 }
 434
 435 static int stm32_counter_write_raw(struct iio_dev *indio_dev,
 436                                    struct iio_chan_spec const *chan,
 437                                    int val, int val2, long mask)
 438 {
 439         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 440         u32 dat;
 441
 442         switch (mask) {
 443         case IIO_CHAN_INFO_RAW:
 444                 return regmap_write(priv->regmap, TIM_CNT, val);
 445
 446         case IIO_CHAN_INFO_SCALE:
 447                 /* fixed scale */
 448                 return -EINVAL;
 449
 450         case IIO_CHAN_INFO_ENABLE:
 451                 if (val) {
 452                         regmap_read(priv->regmap, TIM_CR1, &dat);
 453                         if (!(dat & TIM_CR1_CEN))
 454                                 clk_enable(priv->clk);
 455                         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
 456                                            TIM_CR1_CEN);
 457                 } else {
 458                         regmap_read(priv->regmap, TIM_CR1, &dat);
 459                         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
 460                                            0);
 461                         if (dat & TIM_CR1_CEN)
 462                                 clk_disable(priv->clk);
 463                 }
 464                 return 0;
 465         }
 466
 467         return -EINVAL;
 468 }
 469
 470 static int stm32_counter_validate_trigger(struct iio_dev *indio_dev,
 471                                           struct iio_trigger *trig)
 472 {
 473         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 474         const char * const *cur = priv->valids;
 475         unsigned int i = 0;
 476
 477         if (!is_stm32_timer_trigger(trig))
 478                 return -EINVAL;
 479
 480         while (cur && *cur) {
 481                 if (!strncmp(trig->name, *cur, strlen(trig->name))) {
 482                         regmap_update_bits(priv->regmap,
 483                                            TIM_SMCR, TIM_SMCR_TS,
 484                                            i << TIM_SMCR_TS_SHIFT);
 485                         return 0;
 486                 }
 487                 cur++;
 488                 i++;
 489         }
 490
 491         return -EINVAL;
 492 }
 493
 494 static const struct iio_info stm32_trigger_info = {
 495         .validate_trigger = stm32_counter_validate_trigger,
 496         .read_raw = stm32_counter_read_raw,
 497         .write_raw = stm32_counter_write_raw
 498 };
 499
 500 static const char *const stm32_trigger_modes[] = {
 501         "trigger",
 502 };
 503
 504 static int stm32_set_trigger_mode(struct iio_dev *indio_dev,
 505                                   const struct iio_chan_spec *chan,
 506                                   unsigned int mode)
 507 {
 508         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 509
 510         regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, TIM_SMCR_SMS);
 511
 512         return 0;
 513 }
 514
 515 static int stm32_get_trigger_mode(struct iio_dev *indio_dev,
 516                                   const struct iio_chan_spec *chan)
 517 {
 518         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 519         u32 smcr;
 520
 521         regmap_read(priv->regmap, TIM_SMCR, &smcr);
 522
 523         return (smcr & TIM_SMCR_SMS) == TIM_SMCR_SMS ? 0 : -EINVAL;
 524 }
 525
 526 static const struct iio_enum stm32_trigger_mode_enum = {
 527         .items = stm32_trigger_modes,
 528         .num_items = ARRAY_SIZE(stm32_trigger_modes),
 529         .set = stm32_set_trigger_mode,
 530         .get = stm32_get_trigger_mode
 531 };
 532
 533 static const char *const stm32_enable_modes[] = {
 534         "always",
 535         "gated",
 536         "triggered",
 537 };
 538
 539 static int stm32_enable_mode2sms(int mode)
 540 {
 541         switch (mode) {
 542         case 0:
 543                 return 0;
 544         case 1:
 545                 return 5;
 546         case 2:
 547                 return 6;
 548         }
 549
 550         return -EINVAL;
 551 }
 552
 553 static int stm32_set_enable_mode(struct iio_dev *indio_dev,
 554                                  const struct iio_chan_spec *chan,
 555                                  unsigned int mode)
 556 {
 557         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 558         int sms = stm32_enable_mode2sms(mode);
 559         u32 val;
 560
 561         if (sms < 0)
 562                 return sms;
 563         /*
 564          * Triggered mode sets CEN bit automatically by hardware. So, first
 565          * enable counter clock, so it can use it. Keeps it in sync with CEN.
 566          */
 567         if (sms == 6) {
 568                 regmap_read(priv->regmap, TIM_CR1, &val);
 569                 if (!(val & TIM_CR1_CEN))
 570                         clk_enable(priv->clk);
 571         }
 572
 573         regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);
 574
 575         return 0;
 576 }
 577
 578 static int stm32_sms2enable_mode(int mode)
 579 {
 580         switch (mode) {
 581         case 0:
 582                 return 0;
 583         case 5:
 584                 return 1;
 585         case 6:
 586                 return 2;
 587         }
 588
 589         return -EINVAL;
 590 }
 591
 592 static int stm32_get_enable_mode(struct iio_dev *indio_dev,
 593                                  const struct iio_chan_spec *chan)
 594 {
 595         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 596         u32 smcr;
 597
 598         regmap_read(priv->regmap, TIM_SMCR, &smcr);
 599         smcr &= TIM_SMCR_SMS;
 600
 601         return stm32_sms2enable_mode(smcr);
 602 }
 603
 604 static const struct iio_enum stm32_enable_mode_enum = {
 605         .items = stm32_enable_modes,
 606         .num_items = ARRAY_SIZE(stm32_enable_modes),
 607         .set = stm32_set_enable_mode,
 608         .get = stm32_get_enable_mode
 609 };
 610
 611 static ssize_t stm32_count_get_preset(struct iio_dev *indio_dev,
 612                                       uintptr_t private,
 613                                       const struct iio_chan_spec *chan,
 614                                       char *buf)
 615 {
 616         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 617         u32 arr;
 618
 619         regmap_read(priv->regmap, TIM_ARR, &arr);
 620
 621         return snprintf(buf, PAGE_SIZE, "%u\n", arr);
 622 }
 623
 624 static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev,
 625                                       uintptr_t private,
 626                                       const struct iio_chan_spec *chan,
 627                                       const char *buf, size_t len)
 628 {
 629         struct stm32_timer_trigger *priv = iio_priv(indio_dev);
 630         unsigned int preset;
 631         int ret;
 632
 633         ret = kstrtouint(buf, 0, &preset);
 634         if (ret)
 635                 return ret;
 636
 637         /* TIMx_ARR register shouldn't be buffered (ARPE=0) */
 638         regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 639         regmap_write(priv->regmap, TIM_ARR, preset);
 640
 641         return len;
 642 }
 643
 644 static const struct iio_chan_spec_ext_info stm32_trigger_count_info[] = {
 645         {
 646                 .name = "preset",
 647                 .shared = IIO_SEPARATE,
 648                 .read = stm32_count_get_preset,
 649                 .write = stm32_count_set_preset
 650         },
 651         IIO_ENUM("enable_mode", IIO_SEPARATE, &stm32_enable_mode_enum),
 652         IIO_ENUM_AVAILABLE("enable_mode", &stm32_enable_mode_enum),
 653         IIO_ENUM("trigger_mode", IIO_SEPARATE, &stm32_trigger_mode_enum),
 654         IIO_ENUM_AVAILABLE("trigger_mode", &stm32_trigger_mode_enum),
 655         {}
 656 };
 657
 658 static const struct iio_chan_spec stm32_trigger_channel = {
 659         .type = IIO_COUNT,
 660         .channel = 0,
 661         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 662                               BIT(IIO_CHAN_INFO_ENABLE) |
 663                               BIT(IIO_CHAN_INFO_SCALE),
 664         .ext_info = stm32_trigger_count_info,
 665         .indexed = 1
 666 };
 667
 668 static struct stm32_timer_trigger *stm32_setup_counter_device(struct device *dev)
 669 {
 670         struct iio_dev *indio_dev;
 671         int ret;
 672
 673         indio_dev = devm_iio_device_alloc(dev,
 674                                           sizeof(struct stm32_timer_trigger));
 675         if (!indio_dev)
 676                 return NULL;
 677
 678         indio_dev->name = dev_name(dev);
 679         indio_dev->dev.parent = dev;
 680         indio_dev->info = &stm32_trigger_info;
 681         indio_dev->modes = INDIO_HARDWARE_TRIGGERED;
 682         indio_dev->num_channels = 1;
 683         indio_dev->channels = &stm32_trigger_channel;
 684         indio_dev->dev.of_node = dev->of_node;
 685
 686         ret = devm_iio_device_register(dev, indio_dev);
 687         if (ret)
 688                 return NULL;
 689
 690         return iio_priv(indio_dev);
 691 }
 692
 693 /**
 694  * is_stm32_timer_trigger
 695  * @trig: trigger to be checked
 696  *
 697  * return true if the trigger is a valid stm32 iio timer trigger
 698  * either return false
 699  */
 700 bool is_stm32_timer_trigger(struct iio_trigger *trig)
 701 {
 702         return (trig->ops == &timer_trigger_ops);
 703 }
 704 EXPORT_SYMBOL(is_stm32_timer_trigger);
 705
 706 static void stm32_timer_detect_trgo2(struct stm32_timer_trigger *priv)
 707 {
 708         u32 val;
 709
 710         /*
 711          * Master mode selection 2 bits can only be written and read back when
 712          * timer supports it.
 713          */
 714         regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2, TIM_CR2_MMS2);
 715         regmap_read(priv->regmap, TIM_CR2, &val);
 716         regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS2, 0);
 717         priv->has_trgo2 = !!val;
 718 }
 719
 720 static int stm32_timer_trigger_probe(struct platform_device *pdev)
 721 {
 722         struct device *dev = &pdev->dev;
 723         struct stm32_timer_trigger *priv;
 724         struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
 725         const struct stm32_timer_trigger_cfg *cfg;
 726         unsigned int index;
 727         int ret;
 728
 729         if (of_property_read_u32(dev->of_node, "reg", &index))
 730                 return -EINVAL;
 731
 732         cfg = (const struct stm32_timer_trigger_cfg *)
 733                 of_match_device(dev->driver->of_match_table, dev)->data;
 734
 735         if (index >= ARRAY_SIZE(triggers_table) ||
 736             index >= cfg->num_valids_table)
 737                 return -EINVAL;
 738
 739         /* Create an IIO device only if we have triggers to be validated */
 740         if (*cfg->valids_table[index])
 741                 priv = stm32_setup_counter_device(dev);
 742         else
 743                 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 744
 745         if (!priv)
 746                 return -ENOMEM;
 747
 748         priv->dev = dev;
 749         priv->regmap = ddata->regmap;
 750         priv->clk = ddata->clk;
 751         priv->max_arr = ddata->max_arr;
 752         priv->triggers = triggers_table[index];
 753         priv->valids = cfg->valids_table[index];
 754         stm32_timer_detect_trgo2(priv);
 755
 756         ret = stm32_setup_iio_triggers(priv);
 757         if (ret)
 758                 return ret;
 759
 760         platform_set_drvdata(pdev, priv);
 761
 762         return 0;
 763 }
 764
 765 static const struct stm32_timer_trigger_cfg stm32_timer_trg_cfg = {
 766         .valids_table = valids_table,
 767         .num_valids_table = ARRAY_SIZE(valids_table),
 768 };
 769
 770 static const struct stm32_timer_trigger_cfg stm32h7_timer_trg_cfg = {
 771         .valids_table = stm32h7_valids_table,
 772         .num_valids_table = ARRAY_SIZE(stm32h7_valids_table),
 773 };
 774
 775 static const struct of_device_id stm32_trig_of_match[] = {
 776         {
 777                 .compatible = "st,stm32-timer-trigger",
 778                 .data = (void *)&stm32_timer_trg_cfg,
 779         }, {
 780                 .compatible = "st,stm32h7-timer-trigger",
 781                 .data = (void *)&stm32h7_timer_trg_cfg,
 782         },
 783         { /* end node */ },
 784 };
 785 MODULE_DEVICE_TABLE(of, stm32_trig_of_match);
 786
 787 static struct platform_driver stm32_timer_trigger_driver = {
 788         .probe = stm32_timer_trigger_probe,
 789         .driver = {
 790                 .name = "stm32-timer-trigger",
 791                 .of_match_table = stm32_trig_of_match,
 792         },
 793 };
 794 module_platform_driver(stm32_timer_trigger_driver);
 795
 796 MODULE_ALIAS("platform: stm32-timer-trigger");
 797 MODULE_DESCRIPTION("STMicroelectronics STM32 Timer Trigger driver");
 798 MODULE_LICENSE("GPL v2");