drivers/input/touchscreen/fsl-imx25-tcq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
   4 // Based on driver from 2011:
   5 //   Juergen Beisert, Pengutronix <kernel@pengutronix.de>
   6 //
   7 // This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
   8 // connected to the imx25 ADC.
   9
  10 #include <linux/clk.h>
  11 #include <linux/device.h>
  12 #include <linux/input.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/mfd/imx25-tsadc.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/regmap.h>
  19
  20 static const char mx25_tcq_name[] = "mx25-tcq";
  21
  22 enum mx25_tcq_mode {
  23         MX25_TS_4WIRE,
  24 };
  25
  26 struct mx25_tcq_priv {
  27         struct regmap *regs;
  28         struct regmap *core_regs;
  29         struct input_dev *idev;
  30         enum mx25_tcq_mode mode;
  31         unsigned int pen_threshold;
  32         unsigned int sample_count;
  33         unsigned int expected_samples;
  34         unsigned int pen_debounce;
  35         unsigned int settling_time;
  36         struct clk *clk;
  37         int irq;
  38         struct device *dev;
  39 };
  40
  41 static struct regmap_config mx25_tcq_regconfig = {
  42         .fast_io = true,
  43         .max_register = 0x5c,
  44         .reg_bits = 32,
  45         .val_bits = 32,
  46         .reg_stride = 4,
  47 };
  48
  49 static const struct of_device_id mx25_tcq_ids[] = {
  50         { .compatible = "fsl,imx25-tcq", },
  51         { /* Sentinel */ }
  52 };
  53 MODULE_DEVICE_TABLE(of, mx25_tcq_ids);
  54
  55 #define TSC_4WIRE_PRE_INDEX 0
  56 #define TSC_4WIRE_X_INDEX 1
  57 #define TSC_4WIRE_Y_INDEX 2
  58 #define TSC_4WIRE_POST_INDEX 3
  59 #define TSC_4WIRE_LEAVE 4
  60
  61 #define MX25_TSC_DEF_THRESHOLD 80
  62 #define TSC_MAX_SAMPLES 16
  63
  64 #define MX25_TSC_REPEAT_WAIT 14
  65
  66 enum mx25_adc_configurations {
  67         MX25_CFG_PRECHARGE = 0,
  68         MX25_CFG_TOUCH_DETECT,
  69         MX25_CFG_X_MEASUREMENT,
  70         MX25_CFG_Y_MEASUREMENT,
  71 };
  72
  73 #define MX25_PRECHARGE_VALUE (\
  74                         MX25_ADCQ_CFG_YPLL_OFF | \
  75                         MX25_ADCQ_CFG_XNUR_OFF | \
  76                         MX25_ADCQ_CFG_XPUL_HIGH | \
  77                         MX25_ADCQ_CFG_REFP_INT | \
  78                         MX25_ADCQ_CFG_IN_XP | \
  79                         MX25_ADCQ_CFG_REFN_NGND2 | \
  80                         MX25_ADCQ_CFG_IGS)
  81
  82 #define MX25_TOUCH_DETECT_VALUE (\
  83                         MX25_ADCQ_CFG_YNLR | \
  84                         MX25_ADCQ_CFG_YPLL_OFF | \
  85                         MX25_ADCQ_CFG_XNUR_OFF | \
  86                         MX25_ADCQ_CFG_XPUL_OFF | \
  87                         MX25_ADCQ_CFG_REFP_INT | \
  88                         MX25_ADCQ_CFG_IN_XP | \
  89                         MX25_ADCQ_CFG_REFN_NGND2 | \
  90                         MX25_ADCQ_CFG_PENIACK)
  91
  92 static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv,
  93                                    unsigned int settling_cnt)
  94 {
  95         u32 precharge_cfg =
  96                         MX25_PRECHARGE_VALUE |
  97                         MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt);
  98         u32 touch_detect_cfg =
  99                         MX25_TOUCH_DETECT_VALUE |
 100                         MX25_ADCQ_CFG_NOS(1) |
 101                         MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt);
 102
 103         regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg);
 104
 105         /* PRECHARGE */
 106         regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE),
 107                      precharge_cfg);
 108
 109         /* TOUCH_DETECT */
 110         regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT),
 111                      touch_detect_cfg);
 112
 113         /* X Measurement */
 114         regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT),
 115                      MX25_ADCQ_CFG_YPLL_OFF |
 116                      MX25_ADCQ_CFG_XNUR_LOW |
 117                      MX25_ADCQ_CFG_XPUL_HIGH |
 118                      MX25_ADCQ_CFG_REFP_XP |
 119                      MX25_ADCQ_CFG_IN_YP |
 120                      MX25_ADCQ_CFG_REFN_XN |
 121                      MX25_ADCQ_CFG_NOS(priv->sample_count) |
 122                      MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt));
 123
 124         /* Y Measurement */
 125         regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT),
 126                      MX25_ADCQ_CFG_YNLR |
 127                      MX25_ADCQ_CFG_YPLL_HIGH |
 128                      MX25_ADCQ_CFG_XNUR_OFF |
 129                      MX25_ADCQ_CFG_XPUL_OFF |
 130                      MX25_ADCQ_CFG_REFP_YP |
 131                      MX25_ADCQ_CFG_IN_XP |
 132                      MX25_ADCQ_CFG_REFN_YN |
 133                      MX25_ADCQ_CFG_NOS(priv->sample_count) |
 134                      MX25_ADCQ_CFG_SETTLING_TIME(settling_cnt));
 135
 136         /* Enable the touch detection right now */
 137         regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg |
 138                      MX25_ADCQ_CFG_IGS);
 139 }
 140
 141 static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv,
 142                                    unsigned settling_cnt, int *items)
 143 {
 144         imx25_setup_queue_cfgs(priv, settling_cnt);
 145
 146         /* Setup the conversion queue */
 147         regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
 148                      MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) |
 149                      MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) |
 150                      MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) |
 151                      MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) |
 152                      MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) |
 153                      MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT));
 154
 155         /*
 156          * We measure X/Y with 'sample_count' number of samples and execute a
 157          * touch detection twice, with 1 sample each
 158          */
 159         priv->expected_samples = priv->sample_count * 2 + 2;
 160         *items = 6;
 161
 162         return 0;
 163 }
 164
 165 static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv)
 166 {
 167         regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK,
 168                            MX25_ADCQ_CR_PDMSK);
 169 }
 170
 171 static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv)
 172 {
 173         regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0);
 174 }
 175
 176 static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv)
 177 {
 178         regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ,
 179                            MX25_ADCQ_MR_FDRY_IRQ);
 180 }
 181
 182 static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv)
 183 {
 184         regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0);
 185 }
 186
 187 static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv)
 188 {
 189         regmap_update_bits(priv->regs, MX25_ADCQ_CR,
 190                            MX25_ADCQ_CR_FQS,
 191                            MX25_ADCQ_CR_FQS);
 192 }
 193
 194 static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv)
 195 {
 196         regmap_update_bits(priv->regs, MX25_ADCQ_CR,
 197                            MX25_ADCQ_CR_FQS, 0);
 198 }
 199
 200 static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv)
 201 {
 202         u32 tcqcr;
 203
 204         regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr);
 205         regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
 206                            MX25_ADCQ_CR_FRST);
 207         regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, 0);
 208         regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr);
 209 }
 210
 211 static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv)
 212 {
 213         /* stop the queue from looping */
 214         mx25_tcq_force_queue_stop(priv);
 215
 216         /* for a clean touch detection, preload the X plane */
 217         regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE);
 218
 219         /* waste some time now to pre-load the X plate to high voltage */
 220         mx25_tcq_fifo_reset(priv);
 221
 222         /* re-enable the detection right now */
 223         regmap_write(priv->core_regs, MX25_TSC_TICR,
 224                      MX25_TOUCH_DETECT_VALUE | MX25_ADCQ_CFG_IGS);
 225
 226         regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD,
 227                            MX25_ADCQ_SR_PD);
 228
 229         /* enable the pen down event to be a source for the interrupt */
 230         regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0);
 231
 232         /* lets fire the next IRQ if someone touches the touchscreen */
 233         mx25_tcq_enable_touch_irq(priv);
 234 }
 235
 236 static void mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
 237                                             u32 *sample_buf,
 238                                             unsigned int samples)
 239 {
 240         unsigned int x_pos = 0;
 241         unsigned int y_pos = 0;
 242         unsigned int touch_pre = 0;
 243         unsigned int touch_post = 0;
 244         unsigned int i;
 245
 246         for (i = 0; i < samples; i++) {
 247                 unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]);
 248                 unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]);
 249
 250                 switch (index) {
 251                 case 1:
 252                         touch_pre = val;
 253                         break;
 254                 case 2:
 255                         x_pos = val;
 256                         break;
 257                 case 3:
 258                         y_pos = val;
 259                         break;
 260                 case 5:
 261                         touch_post = val;
 262                         break;
 263                 default:
 264                         dev_dbg(priv->dev, "Dropped samples because of invalid index %d\n",
 265                                 index);
 266                         return;
 267                 }
 268         }
 269
 270         if (samples != 0) {
 271                 /*
 272                  * only if both touch measures are below a threshold,
 273                  * the position is valid
 274                  */
 275                 if (touch_pre < priv->pen_threshold &&
 276                     touch_post < priv->pen_threshold) {
 277                         /* valid samples, generate a report */
 278                         x_pos /= priv->sample_count;
 279                         y_pos /= priv->sample_count;
 280                         input_report_abs(priv->idev, ABS_X, x_pos);
 281                         input_report_abs(priv->idev, ABS_Y, y_pos);
 282                         input_report_key(priv->idev, BTN_TOUCH, 1);
 283                         input_sync(priv->idev);
 284
 285                         /* get next sample */
 286                         mx25_tcq_enable_fifo_irq(priv);
 287                 } else if (touch_pre >= priv->pen_threshold &&
 288                            touch_post >= priv->pen_threshold) {
 289                         /*
 290                          * if both samples are invalid,
 291                          * generate a release report
 292                          */
 293                         input_report_key(priv->idev, BTN_TOUCH, 0);
 294                         input_sync(priv->idev);
 295                         mx25_tcq_re_enable_touch_detection(priv);
 296                 } else {
 297                         /*
 298                          * if only one of both touch measurements are
 299                          * below the threshold, still some bouncing
 300                          * happens. Take additional samples in this
 301                          * case to be sure
 302                          */
 303                         mx25_tcq_enable_fifo_irq(priv);
 304                 }
 305         }
 306 }
 307
 308 static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)
 309 {
 310         struct mx25_tcq_priv *priv = dev_id;
 311         u32 sample_buf[TSC_MAX_SAMPLES];
 312         unsigned int samples;
 313         u32 stats;
 314         unsigned int i;
 315
 316         /*
 317          * Check how many samples are available. We always have to read exactly
 318          * sample_count samples from the fifo, or a multiple of sample_count.
 319          * Otherwise we mixup samples into different touch events.
 320          */
 321         regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
 322         samples = MX25_ADCQ_SR_FDN(stats);
 323         samples -= samples % priv->sample_count;
 324
 325         if (!samples)
 326                 return IRQ_HANDLED;
 327
 328         for (i = 0; i != samples; ++i)
 329                 regmap_read(priv->regs, MX25_ADCQ_FIFO, &sample_buf[i]);
 330
 331         mx25_tcq_create_event_for_4wire(priv, sample_buf, samples);
 332
 333         return IRQ_HANDLED;
 334 }
 335
 336 static irqreturn_t mx25_tcq_irq(int irq, void *dev_id)
 337 {
 338         struct mx25_tcq_priv *priv = dev_id;
 339         u32 stat;
 340         int ret = IRQ_HANDLED;
 341
 342         regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
 343
 344         if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
 345                 mx25_tcq_re_enable_touch_detection(priv);
 346
 347         if (stat & MX25_ADCQ_SR_PD) {
 348                 mx25_tcq_disable_touch_irq(priv);
 349                 mx25_tcq_force_queue_start(priv);
 350                 mx25_tcq_enable_fifo_irq(priv);
 351         }
 352
 353         if (stat & MX25_ADCQ_SR_FDRY) {
 354                 mx25_tcq_disable_fifo_irq(priv);
 355                 ret = IRQ_WAKE_THREAD;
 356         }
 357
 358         regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
 359                            MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
 360                            MX25_ADCQ_SR_PD,
 361                            MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR |
 362                            MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD);
 363
 364         return ret;
 365 }
 366
 367 /* configure the state machine for a 4-wire touchscreen */
 368 static int mx25_tcq_init(struct mx25_tcq_priv *priv)
 369 {
 370         u32 tgcr;
 371         unsigned int ipg_div;
 372         unsigned int adc_period;
 373         unsigned int debounce_cnt;
 374         unsigned int settling_cnt;
 375         int itemct;
 376         int error;
 377
 378         regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
 379         ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
 380         adc_period = USEC_PER_SEC * ipg_div * 2 + 2;
 381         adc_period /= clk_get_rate(priv->clk) / 1000 + 1;
 382         debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
 383         settling_cnt = DIV_ROUND_UP(priv->settling_time, adc_period * 8) - 1;
 384
 385         /* Reset */
 386         regmap_write(priv->regs, MX25_ADCQ_CR,
 387                      MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST);
 388         regmap_update_bits(priv->regs, MX25_ADCQ_CR,
 389                            MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST, 0);
 390
 391         /* up to 128 * 8 ADC clocks are possible */
 392         if (debounce_cnt > 127)
 393                 debounce_cnt = 127;
 394
 395         /* up to 255 * 8 ADC clocks are possible */
 396         if (settling_cnt > 255)
 397                 settling_cnt = 255;
 398
 399         error = imx25_setup_queue_4wire(priv, settling_cnt, &itemct);
 400         if (error)
 401                 return error;
 402
 403         regmap_update_bits(priv->regs, MX25_ADCQ_CR,
 404                            MX25_ADCQ_CR_LITEMID_MASK | MX25_ADCQ_CR_WMRK_MASK,
 405                            MX25_ADCQ_CR_LITEMID(itemct - 1) |
 406                            MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
 407
 408         /* setup debounce count */
 409         regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
 410                            MX25_TGCR_PDBTIME_MASK,
 411                            MX25_TGCR_PDBTIME(debounce_cnt));
 412
 413         /* enable debounce */
 414         regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
 415                            MX25_TGCR_PDBEN);
 416         regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
 417                            MX25_TGCR_PDEN);
 418
 419         /* enable the engine on demand */
 420         regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_MASK,
 421                            MX25_ADCQ_CR_QSM_FQS);
 422
 423         /* Enable repeat and repeat wait */
 424         regmap_update_bits(priv->regs, MX25_ADCQ_CR,
 425                            MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK,
 426                            MX25_ADCQ_CR_RPT |
 427                            MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT));
 428
 429         return 0;
 430 }
 431
 432 static int mx25_tcq_parse_dt(struct platform_device *pdev,
 433                              struct mx25_tcq_priv *priv)
 434 {
 435         struct device_node *np = pdev->dev.of_node;
 436         u32 wires;
 437         int error;
 438
 439         /* Setup defaults */
 440         priv->pen_threshold = 500;
 441         priv->sample_count = 3;
 442         priv->pen_debounce = 1000000;
 443         priv->settling_time = 250000;
 444
 445         error = of_property_read_u32(np, "fsl,wires", &wires);
 446         if (error) {
 447                 dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
 448                 return error;
 449         }
 450
 451         if (wires == 4) {
 452                 priv->mode = MX25_TS_4WIRE;
 453         } else {
 454                 dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
 455                 return -EINVAL;
 456         }
 457
 458         /* These are optional, we don't care about the return values */
 459         of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
 460         of_property_read_u32(np, "fsl,settling-time-ns", &priv->settling_time);
 461         of_property_read_u32(np, "fsl,pen-debounce-ns", &priv->pen_debounce);
 462
 463         return 0;
 464 }
 465
 466 static int mx25_tcq_open(struct input_dev *idev)
 467 {
 468         struct device *dev = &idev->dev;
 469         struct mx25_tcq_priv *priv = dev_get_drvdata(dev);
 470         int error;
 471
 472         error = clk_prepare_enable(priv->clk);
 473         if (error) {
 474                 dev_err(dev, "Failed to enable ipg clock\n");
 475                 return error;
 476         }
 477
 478         error = mx25_tcq_init(priv);
 479         if (error) {
 480                 dev_err(dev, "Failed to init tcq\n");
 481                 clk_disable_unprepare(priv->clk);
 482                 return error;
 483         }
 484
 485         mx25_tcq_re_enable_touch_detection(priv);
 486
 487         return 0;
 488 }
 489
 490 static void mx25_tcq_close(struct input_dev *idev)
 491 {
 492         struct mx25_tcq_priv *priv = input_get_drvdata(idev);
 493
 494         mx25_tcq_force_queue_stop(priv);
 495         mx25_tcq_disable_touch_irq(priv);
 496         mx25_tcq_disable_fifo_irq(priv);
 497         clk_disable_unprepare(priv->clk);
 498 }
 499
 500 static int mx25_tcq_probe(struct platform_device *pdev)
 501 {
 502         struct device *dev = &pdev->dev;
 503         struct input_dev *idev;
 504         struct mx25_tcq_priv *priv;
 505         struct mx25_tsadc *tsadc = dev_get_drvdata(dev->parent);
 506         struct resource *res;
 507         void __iomem *mem;
 508         int error;
 509
 510         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 511         if (!priv)
 512                 return -ENOMEM;
 513         priv->dev = dev;
 514
 515         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 516         mem = devm_ioremap_resource(dev, res);
 517         if (IS_ERR(mem))
 518                 return PTR_ERR(mem);
 519
 520         error = mx25_tcq_parse_dt(pdev, priv);
 521         if (error)
 522                 return error;
 523
 524         priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig);
 525         if (IS_ERR(priv->regs)) {
 526                 dev_err(dev, "Failed to initialize regmap\n");
 527                 return PTR_ERR(priv->regs);
 528         }
 529
 530         priv->irq = platform_get_irq(pdev, 0);
 531         if (priv->irq <= 0) {
 532                 dev_err(dev, "Failed to get IRQ\n");
 533                 return priv->irq;
 534         }
 535
 536         idev = devm_input_allocate_device(dev);
 537         if (!idev) {
 538                 dev_err(dev, "Failed to allocate input device\n");
 539                 return -ENOMEM;
 540         }
 541
 542         idev->name = mx25_tcq_name;
 543         input_set_capability(idev, EV_KEY, BTN_TOUCH);
 544         input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
 545         input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
 546
 547         idev->id.bustype = BUS_HOST;
 548         idev->open = mx25_tcq_open;
 549         idev->close = mx25_tcq_close;
 550
 551         priv->idev = idev;
 552         input_set_drvdata(idev, priv);
 553
 554         priv->core_regs = tsadc->regs;
 555         if (!priv->core_regs)
 556                 return -EINVAL;
 557
 558         priv->clk = tsadc->clk;
 559         if (!priv->clk)
 560                 return -EINVAL;
 561
 562         platform_set_drvdata(pdev, priv);
 563
 564         error = devm_request_threaded_irq(dev, priv->irq, mx25_tcq_irq,
 565                                           mx25_tcq_irq_thread, 0, pdev->name,
 566                                           priv);
 567         if (error) {
 568                 dev_err(dev, "Failed requesting IRQ\n");
 569                 return error;
 570         }
 571
 572         error = input_register_device(idev);
 573         if (error) {
 574                 dev_err(dev, "Failed to register input device\n");
 575                 return error;
 576         }
 577
 578         return 0;
 579 }
 580
 581 static struct platform_driver mx25_tcq_driver = {
 582         .driver         = {
 583                 .name   = "mx25-tcq",
 584                 .of_match_table = mx25_tcq_ids,
 585         },
 586         .probe          = mx25_tcq_probe,
 587 };
 588 module_platform_driver(mx25_tcq_driver);
 589
 590 MODULE_DESCRIPTION("TS input driver for Freescale mx25");
 591 MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
 592 MODULE_LICENSE("GPL v2");