drivers/input/touchscreen/bcm_iproc_tsc.c

   1 /*
   2 * Copyright (C) 2015 Broadcom Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License as
   6 * published by the Free Software Foundation version 2.
   7 *
   8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
   9 * kind, whether express or implied; without even the implied warranty
  10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11 * GNU General Public License for more details.
  12 */
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/input.h>
  16 #include <linux/delay.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/keyboard.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/slab.h>
  21 #include <linux/of.h>
  22 #include <asm/irq.h>
  23 #include <linux/io.h>
  24 #include <linux/clk.h>
  25 #include <linux/serio.h>
  26 #include <linux/mfd/syscon.h>
  27 #include <linux/regmap.h>
  28
  29 #define IPROC_TS_NAME "iproc-ts"
  30
  31 #define PEN_DOWN_STATUS     1
  32 #define PEN_UP_STATUS       0
  33
  34 #define X_MIN               0
  35 #define Y_MIN               0
  36 #define X_MAX               0xFFF
  37 #define Y_MAX               0xFFF
  38
  39 /* Value given by controller for invalid coordinate. */
  40 #define INVALID_COORD       0xFFFFFFFF
  41
  42 /* Register offsets */
  43 #define REGCTL1             0x00
  44 #define REGCTL2             0x04
  45 #define INTERRUPT_THRES     0x08
  46 #define INTERRUPT_MASK      0x0c
  47
  48 #define INTERRUPT_STATUS    0x10
  49 #define CONTROLLER_STATUS   0x14
  50 #define FIFO_DATA           0x18
  51 #define FIFO_DATA_X_Y_MASK  0xFFFF
  52 #define ANALOG_CONTROL      0x1c
  53
  54 #define AUX_DATA            0x20
  55 #define DEBOUNCE_CNTR_STAT  0x24
  56 #define SCAN_CNTR_STAT      0x28
  57 #define REM_CNTR_STAT       0x2c
  58
  59 #define SETTLING_TIMER_STAT 0x30
  60 #define SPARE_REG           0x34
  61 #define SOFT_BYPASS_CONTROL 0x38
  62 #define SOFT_BYPASS_DATA    0x3c
  63
  64
  65 /* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
  66 #define TS_PEN_INTR_MASK        BIT(0)
  67 #define TS_FIFO_INTR_MASK       BIT(2)
  68
  69 /* Bit values for CONTROLLER_STATUS reg1 */
  70 #define TS_PEN_DOWN             BIT(0)
  71
  72 /* Shift values for control reg1 */
  73 #define SCANNING_PERIOD_SHIFT   24
  74 #define DEBOUNCE_TIMEOUT_SHIFT  16
  75 #define SETTLING_TIMEOUT_SHIFT  8
  76 #define TOUCH_TIMEOUT_SHIFT     0
  77
  78 /* Shift values for coordinates from fifo */
  79 #define X_COORD_SHIFT  0
  80 #define Y_COORD_SHIFT  16
  81
  82 /* Bit values for REGCTL2 */
  83 #define TS_CONTROLLER_EN_BIT    BIT(16)
  84 #define TS_CONTROLLER_AVGDATA_SHIFT 8
  85 #define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
  86 #define TS_CONTROLLER_PWR_LDO   BIT(5)
  87 #define TS_CONTROLLER_PWR_ADC   BIT(4)
  88 #define TS_CONTROLLER_PWR_BGP   BIT(3)
  89 #define TS_CONTROLLER_PWR_TS    BIT(2)
  90 #define TS_WIRE_MODE_BIT        BIT(1)
  91
  92 #define dbg_reg(dev, priv, reg) \
  93 do { \
  94         u32 val; \
  95         regmap_read(priv->regmap, reg, &val); \
  96         dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
  97 } while (0)
  98
  99 struct tsc_param {
 100         /* Each step is 1024 us.  Valid 1-256 */
 101         u32 scanning_period;
 102
 103         /*  Each step is 512 us.  Valid 0-255 */
 104         u32 debounce_timeout;
 105
 106         /*
 107          * The settling duration (in ms) is the amount of time the tsc
 108          * waits to allow the voltage to settle after turning on the
 109          * drivers in detection mode. Valid values: 0-11
 110          *   0 =  0.008 ms
 111          *   1 =  0.01 ms
 112          *   2 =  0.02 ms
 113          *   3 =  0.04 ms
 114          *   4 =  0.08 ms
 115          *   5 =  0.16 ms
 116          *   6 =  0.32 ms
 117          *   7 =  0.64 ms
 118          *   8 =  1.28 ms
 119          *   9 =  2.56 ms
 120          *   10 = 5.12 ms
 121          *   11 = 10.24 ms
 122          */
 123         u32 settling_timeout;
 124
 125         /* touch timeout in sample counts */
 126         u32 touch_timeout;
 127
 128         /*
 129          * Number of data samples which are averaged before a final data point
 130          * is placed into the FIFO
 131          */
 132         u32 average_data;
 133
 134         /* FIFO threshold */
 135         u32 fifo_threshold;
 136
 137         /* Optional standard touchscreen properties. */
 138         u32 max_x;
 139         u32 max_y;
 140         u32 fuzz_x;
 141         u32 fuzz_y;
 142         bool invert_x;
 143         bool invert_y;
 144 };
 145
 146 struct iproc_ts_priv {
 147         struct platform_device *pdev;
 148         struct input_dev *idev;
 149
 150         struct regmap *regmap;
 151         struct clk *tsc_clk;
 152
 153         int  pen_status;
 154         struct tsc_param cfg_params;
 155 };
 156
 157 /*
 158  * Set default values the same as hardware reset values
 159  * except for fifo_threshold with is set to 1.
 160  */
 161 static const struct tsc_param iproc_default_config = {
 162         .scanning_period  = 0x5,  /* 1 to 256 */
 163         .debounce_timeout = 0x28, /* 0 to 255 */
 164         .settling_timeout = 0x7,  /* 0 to 11 */
 165         .touch_timeout    = 0xa,  /* 0 to 255 */
 166         .average_data     = 5,    /* entry 5 = 32 pts */
 167         .fifo_threshold   = 1,    /* 0 to 31 */
 168         .max_x            = X_MAX,
 169         .max_y            = Y_MAX,
 170 };
 171
 172 static void ts_reg_dump(struct iproc_ts_priv *priv)
 173 {
 174         struct device *dev = &priv->pdev->dev;
 175
 176         dbg_reg(dev, priv, REGCTL1);
 177         dbg_reg(dev, priv, REGCTL2);
 178         dbg_reg(dev, priv, INTERRUPT_THRES);
 179         dbg_reg(dev, priv, INTERRUPT_MASK);
 180         dbg_reg(dev, priv, INTERRUPT_STATUS);
 181         dbg_reg(dev, priv, CONTROLLER_STATUS);
 182         dbg_reg(dev, priv, FIFO_DATA);
 183         dbg_reg(dev, priv, ANALOG_CONTROL);
 184         dbg_reg(dev, priv, AUX_DATA);
 185         dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
 186         dbg_reg(dev, priv, SCAN_CNTR_STAT);
 187         dbg_reg(dev, priv, REM_CNTR_STAT);
 188         dbg_reg(dev, priv, SETTLING_TIMER_STAT);
 189         dbg_reg(dev, priv, SPARE_REG);
 190         dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
 191         dbg_reg(dev, priv, SOFT_BYPASS_DATA);
 192 }
 193
 194 static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
 195 {
 196         struct platform_device *pdev = data;
 197         struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
 198         u32 intr_status;
 199         u32 raw_coordinate;
 200         u16 x;
 201         u16 y;
 202         int i;
 203         bool needs_sync = false;
 204
 205         regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);
 206         intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
 207         if (intr_status == 0)
 208                 return IRQ_NONE;
 209
 210         /* Clear all interrupt status bits, write-1-clear */
 211         regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
 212         /* Pen up/down */
 213         if (intr_status & TS_PEN_INTR_MASK) {
 214                 regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);
 215                 if (priv->pen_status & TS_PEN_DOWN)
 216                         priv->pen_status = PEN_DOWN_STATUS;
 217                 else
 218                         priv->pen_status = PEN_UP_STATUS;
 219
 220                 input_report_key(priv->idev, BTN_TOUCH, priv->pen_status);
 221                 needs_sync = true;
 222
 223                 dev_dbg(&priv->pdev->dev,
 224                         "pen up-down (%d)\n", priv->pen_status);
 225         }
 226
 227         /* coordinates in FIFO exceed the theshold */
 228         if (intr_status & TS_FIFO_INTR_MASK) {
 229                 for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
 230                         regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
 231                         if (raw_coordinate == INVALID_COORD)
 232                                 continue;
 233
 234                         /*
 235                          * The x and y coordinate are 16 bits each
 236                          * with the x in the lower 16 bits and y in the
 237                          * upper 16 bits.
 238                          */
 239                         x = (raw_coordinate >> X_COORD_SHIFT) &
 240                                 FIFO_DATA_X_Y_MASK;
 241                         y = (raw_coordinate >> Y_COORD_SHIFT) &
 242                                 FIFO_DATA_X_Y_MASK;
 243
 244                         /* We only want to retain the 12 msb of the 16 */
 245                         x = (x >> 4) & 0x0FFF;
 246                         y = (y >> 4) & 0x0FFF;
 247
 248                         /* Adjust x y according to LCD tsc mount angle. */
 249                         if (priv->cfg_params.invert_x)
 250                                 x = priv->cfg_params.max_x - x;
 251
 252                         if (priv->cfg_params.invert_y)
 253                                 y = priv->cfg_params.max_y - y;
 254
 255                         input_report_abs(priv->idev, ABS_X, x);
 256                         input_report_abs(priv->idev, ABS_Y, y);
 257                         needs_sync = true;
 258
 259                         dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
 260                 }
 261         }
 262
 263         if (needs_sync)
 264                 input_sync(priv->idev);
 265
 266         return IRQ_HANDLED;
 267 }
 268
 269 static int iproc_ts_start(struct input_dev *idev)
 270 {
 271         u32 val;
 272         u32 mask;
 273         int error;
 274         struct iproc_ts_priv *priv = input_get_drvdata(idev);
 275
 276         /* Enable clock */
 277         error = clk_prepare_enable(priv->tsc_clk);
 278         if (error) {
 279                 dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
 280                         __func__, error);
 281                 return error;
 282         }
 283
 284         /*
 285          * Interrupt is generated when:
 286          *  FIFO reaches the int_th value, and pen event(up/down)
 287          */
 288         val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
 289         regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);
 290
 291         val = priv->cfg_params.fifo_threshold;
 292         regmap_write(priv->regmap, INTERRUPT_THRES, val);
 293
 294         /* Initialize control reg1 */
 295         val = 0;
 296         val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
 297         val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;
 298         val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;
 299         val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;
 300         regmap_write(priv->regmap, REGCTL1, val);
 301
 302         /* Try to clear all interrupt status */
 303         val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
 304         regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);
 305
 306         /* Initialize control reg2 */
 307         val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
 308         val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;
 309
 310         mask = (TS_CONTROLLER_AVGDATA_MASK);
 311         mask |= (TS_CONTROLLER_PWR_LDO |        /* PWR up LDO */
 312                    TS_CONTROLLER_PWR_ADC |      /* PWR up ADC */
 313                    TS_CONTROLLER_PWR_BGP |      /* PWR up BGP */
 314                    TS_CONTROLLER_PWR_TS);       /* PWR up TS */
 315         mask |= val;
 316         regmap_update_bits(priv->regmap, REGCTL2, mask, val);
 317
 318         ts_reg_dump(priv);
 319
 320         return 0;
 321 }
 322
 323 static void iproc_ts_stop(struct input_dev *dev)
 324 {
 325         u32 val;
 326         struct iproc_ts_priv *priv = input_get_drvdata(dev);
 327
 328         /*
 329          * Disable FIFO int_th and pen event(up/down)Interrupts only
 330          * as the interrupt mask register is shared between ADC, TS and
 331          * flextimer.
 332          */
 333         val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
 334         regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);
 335
 336         /* Only power down touch screen controller */
 337         val = TS_CONTROLLER_PWR_TS;
 338         regmap_update_bits(priv->regmap, REGCTL2, val, val);
 339
 340         clk_disable(priv->tsc_clk);
 341 }
 342
 343 static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
 344 {
 345         struct device_node *np = dev->of_node;
 346         u32 val;
 347
 348         priv->cfg_params = iproc_default_config;
 349
 350         if (!np)
 351                 return 0;
 352
 353         if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
 354                 if (val < 1 || val > 256) {
 355                         dev_err(dev, "scanning_period (%u) must be [1-256]\n",
 356                                 val);
 357                         return -EINVAL;
 358                 }
 359                 priv->cfg_params.scanning_period = val;
 360         }
 361
 362         if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
 363                 if (val > 255) {
 364                         dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
 365                                 val);
 366                         return -EINVAL;
 367                 }
 368                 priv->cfg_params.debounce_timeout = val;
 369         }
 370
 371         if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
 372                 if (val > 11) {
 373                         dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
 374                                 val);
 375                         return -EINVAL;
 376                 }
 377                 priv->cfg_params.settling_timeout = val;
 378         }
 379
 380         if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
 381                 if (val > 255) {
 382                         dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
 383                                 val);
 384                         return -EINVAL;
 385                 }
 386                 priv->cfg_params.touch_timeout = val;
 387         }
 388
 389         if (of_property_read_u32(np, "average_data", &val) >= 0) {
 390                 if (val > 8) {
 391                         dev_err(dev, "average_data (%u) must be [0-8]\n", val);
 392                         return -EINVAL;
 393                 }
 394                 priv->cfg_params.average_data = val;
 395         }
 396
 397         if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
 398                 if (val > 31) {
 399                         dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
 400                                 val);
 401                         return -EINVAL;
 402                 }
 403                 priv->cfg_params.fifo_threshold = val;
 404         }
 405
 406         /* Parse optional properties. */
 407         of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
 408         of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);
 409
 410         of_property_read_u32(np, "touchscreen-fuzz-x",
 411                              &priv->cfg_params.fuzz_x);
 412         of_property_read_u32(np, "touchscreen-fuzz-y",
 413                              &priv->cfg_params.fuzz_y);
 414
 415         priv->cfg_params.invert_x =
 416                 of_property_read_bool(np, "touchscreen-inverted-x");
 417         priv->cfg_params.invert_y =
 418                 of_property_read_bool(np, "touchscreen-inverted-y");
 419
 420         return 0;
 421 }
 422
 423 static int iproc_ts_probe(struct platform_device *pdev)
 424 {
 425         struct iproc_ts_priv *priv;
 426         struct input_dev *idev;
 427         int irq;
 428         int error;
 429
 430         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 431         if (!priv)
 432                 return -ENOMEM;
 433
 434         /* touchscreen controller memory mapped regs via syscon*/
 435         priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 436                                                         "ts_syscon");
 437         if (IS_ERR(priv->regmap)) {
 438                 error = PTR_ERR(priv->regmap);
 439                 dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);
 440                 return error;
 441         }
 442
 443         priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
 444         if (IS_ERR(priv->tsc_clk)) {
 445                 error = PTR_ERR(priv->tsc_clk);
 446                 dev_err(&pdev->dev,
 447                         "failed getting clock tsc_clk: %d\n", error);
 448                 return error;
 449         }
 450
 451         priv->pdev = pdev;
 452         error = iproc_get_tsc_config(&pdev->dev, priv);
 453         if (error) {
 454                 dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
 455                 return error;
 456         }
 457
 458         idev = devm_input_allocate_device(&pdev->dev);
 459         if (!idev) {
 460                 dev_err(&pdev->dev, "failed to allocate input device\n");
 461                 return -ENOMEM;
 462         }
 463
 464         priv->idev = idev;
 465         priv->pen_status = PEN_UP_STATUS;
 466
 467         /* Set input device info  */
 468         idev->name = IPROC_TS_NAME;
 469         idev->dev.parent = &pdev->dev;
 470
 471         idev->id.bustype = BUS_HOST;
 472         idev->id.vendor = SERIO_UNKNOWN;
 473         idev->id.product = 0;
 474         idev->id.version = 0;
 475
 476         idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 477         __set_bit(BTN_TOUCH, idev->keybit);
 478
 479         input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
 480                              priv->cfg_params.fuzz_x, 0);
 481         input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
 482                              priv->cfg_params.fuzz_y, 0);
 483
 484         idev->open = iproc_ts_start;
 485         idev->close = iproc_ts_stop;
 486
 487         input_set_drvdata(idev, priv);
 488         platform_set_drvdata(pdev, priv);
 489
 490         /* get interrupt */
 491         irq = platform_get_irq(pdev, 0);
 492         if (irq < 0)
 493                 return irq;
 494
 495         error = devm_request_irq(&pdev->dev, irq,
 496                                  iproc_touchscreen_interrupt,
 497                                  IRQF_SHARED, IPROC_TS_NAME, pdev);
 498         if (error)
 499                 return error;
 500
 501         error = input_register_device(priv->idev);
 502         if (error) {
 503                 dev_err(&pdev->dev,
 504                         "failed to register input device: %d\n", error);
 505                 return error;
 506         }
 507
 508         return 0;
 509 }
 510
 511 static const struct of_device_id iproc_ts_of_match[] = {
 512         {.compatible = "brcm,iproc-touchscreen", },
 513         { },
 514 };
 515 MODULE_DEVICE_TABLE(of, iproc_ts_of_match);
 516
 517 static struct platform_driver iproc_ts_driver = {
 518         .probe = iproc_ts_probe,
 519         .driver = {
 520                 .name   = IPROC_TS_NAME,
 521                 .of_match_table = of_match_ptr(iproc_ts_of_match),
 522         },
 523 };
 524
 525 module_platform_driver(iproc_ts_driver);
 526
 527 MODULE_DESCRIPTION("IPROC Touchscreen driver");
 528 MODULE_AUTHOR("Broadcom");
 529 MODULE_LICENSE("GPL v2");