drivers/input/touchscreen/tps6507x-ts.c

   1 /*
   2  * drivers/input/touchscreen/tps6507x_ts.c
   3  *
   4  * Touchscreen driver for the tps6507x chip.
   5  *
   6  * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
   7  *
   8  * Credits:
   9  *
  10  *    Using code from tsc2007, MtekVision Co., Ltd.
  11  *
  12  * For licencing details see kernel-base/COPYING
  13  *
  14  * TPS65070, TPS65073, TPS650731, and TPS650732 support
  15  * 10 bit touch screen interface.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/slab.h>
  21 #include <linux/input.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/mfd/tps6507x.h>
  24 #include <linux/input/tps6507x-ts.h>
  25 #include <linux/delay.h>
  26
  27 #define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
  28 #define TPS_DEFAULT_MIN_PRESSURE 0x30
  29 #define MAX_10BIT ((1 << 10) - 1)
  30
  31 #define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
  32                                          TPS6507X_ADCONFIG_START_CONVERSION | \
  33                                          TPS6507X_ADCONFIG_INPUT_REAL_TSC)
  34 #define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)
  35
  36 struct ts_event {
  37         u16     x;
  38         u16     y;
  39         u16     pressure;
  40 };
  41
  42 struct tps6507x_ts {
  43         struct input_dev        *input_dev;
  44         struct device           *dev;
  45         char                    phys[32];
  46         struct workqueue_struct *wq;
  47         struct delayed_work     work;
  48         unsigned                polling;        /* polling is active */
  49         struct ts_event         tc;
  50         struct tps6507x_dev     *mfd;
  51         u16                     model;
  52         unsigned                pendown;
  53         int                     irq;
  54         void                    (*clear_penirq)(void);
  55         unsigned long           poll_period;    /* ms */
  56         u16                     min_pressure;
  57         int                     vref;           /* non-zero to leave vref on */
  58 };
  59
  60 static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
  61 {
  62         int err;
  63
  64         err = tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
  65
  66         if (err)
  67                 return err;
  68
  69         return 0;
  70 }
  71
  72 static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
  73 {
  74         return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
  75 }
  76
  77 static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
  78                                    u8 tsc_mode, u16 *value)
  79 {
  80         s32 ret;
  81         u8 adc_status;
  82         u8 result;
  83
  84         /* Route input signal to A/D converter */
  85
  86         ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
  87         if (ret) {
  88                 dev_err(tsc->dev, "TSC mode read failed\n");
  89                 goto err;
  90         }
  91
  92         /* Start A/D conversion */
  93
  94         ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
  95                                 TPS6507X_ADCONFIG_CONVERT_TS);
  96         if (ret) {
  97                 dev_err(tsc->dev, "ADC config write failed\n");
  98                 return ret;
  99         }
 100
 101         do {
 102                 ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
 103                                        &adc_status);
 104                 if (ret) {
 105                         dev_err(tsc->dev, "ADC config read failed\n");
 106                         goto err;
 107                 }
 108         } while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);
 109
 110         ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
 111         if (ret) {
 112                 dev_err(tsc->dev, "ADC result 2 read failed\n");
 113                 goto err;
 114         }
 115
 116         *value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;
 117
 118         ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
 119         if (ret) {
 120                 dev_err(tsc->dev, "ADC result 1 read failed\n");
 121                 goto err;
 122         }
 123
 124         *value |= result;
 125
 126         dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);
 127
 128 err:
 129         return ret;
 130 }
 131
 132 /* Need to call tps6507x_adc_standby() after using A/D converter for the
 133  * touch screen interrupt to work properly.
 134  */
 135
 136 static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
 137 {
 138         s32 ret;
 139         s32 loops = 0;
 140         u8 val;
 141
 142         ret = tps6507x_write_u8(tsc,  TPS6507X_REG_ADCONFIG,
 143                                 TPS6507X_ADCONFIG_INPUT_TSC);
 144         if (ret)
 145                 return ret;
 146
 147         ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
 148                                 TPS6507X_TSCMODE_STANDBY);
 149         if (ret)
 150                 return ret;
 151
 152         ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
 153         if (ret)
 154                 return ret;
 155
 156         while (val & TPS6507X_REG_TSC_INT) {
 157                 mdelay(10);
 158                 ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
 159                 if (ret)
 160                         return ret;
 161                 loops++;
 162         }
 163
 164         return ret;
 165 }
 166
 167 static void tps6507x_ts_handler(struct work_struct *work)
 168 {
 169         struct tps6507x_ts *tsc =  container_of(work,
 170                                 struct tps6507x_ts, work.work);
 171         struct input_dev *input_dev = tsc->input_dev;
 172         int pendown;
 173         int schd;
 174         int poll = 0;
 175         s32 ret;
 176
 177         ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
 178                                        &tsc->tc.pressure);
 179         if (ret)
 180                 goto done;
 181
 182         pendown = tsc->tc.pressure > tsc->min_pressure;
 183
 184         if (unlikely(!pendown && tsc->pendown)) {
 185                 dev_dbg(tsc->dev, "UP\n");
 186                 input_report_key(input_dev, BTN_TOUCH, 0);
 187                 input_report_abs(input_dev, ABS_PRESSURE, 0);
 188                 input_sync(input_dev);
 189                 tsc->pendown = 0;
 190         }
 191
 192         if (pendown) {
 193
 194                 if (!tsc->pendown) {
 195                         dev_dbg(tsc->dev, "DOWN\n");
 196                         input_report_key(input_dev, BTN_TOUCH, 1);
 197                 } else
 198                         dev_dbg(tsc->dev, "still down\n");
 199
 200                 ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
 201                                                &tsc->tc.x);
 202                 if (ret)
 203                         goto done;
 204
 205                 ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
 206                                                &tsc->tc.y);
 207                 if (ret)
 208                         goto done;
 209
 210                 input_report_abs(input_dev, ABS_X, tsc->tc.x);
 211                 input_report_abs(input_dev, ABS_Y, tsc->tc.y);
 212                 input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
 213                 input_sync(input_dev);
 214                 tsc->pendown = 1;
 215                 poll = 1;
 216         }
 217
 218 done:
 219         /* always poll if not using interrupts */
 220         poll = 1;
 221
 222         if (poll) {
 223                 schd = queue_delayed_work(tsc->wq, &tsc->work,
 224                                           msecs_to_jiffies(tsc->poll_period));
 225                 if (schd)
 226                         tsc->polling = 1;
 227                 else {
 228                         tsc->polling = 0;
 229                         dev_err(tsc->dev, "re-schedule failed");
 230                 }
 231         } else
 232                 tsc->polling = 0;
 233
 234         ret = tps6507x_adc_standby(tsc);
 235 }
 236
 237 static int tps6507x_ts_probe(struct platform_device *pdev)
 238 {
 239         int error;
 240         struct tps6507x_ts *tsc;
 241         struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
 242         struct touchscreen_init_data *init_data;
 243         struct input_dev *input_dev;
 244         struct tps6507x_board *tps_board;
 245         int schd;
 246
 247         /**
 248          * tps_board points to pmic related constants
 249          * coming from the board-evm file.
 250          */
 251
 252         tps_board = (struct tps6507x_board *)tps6507x_dev->dev->platform_data;
 253
 254         if (!tps_board) {
 255                 dev_err(tps6507x_dev->dev,
 256                         "Could not find tps6507x platform data\n");
 257                 return -EIO;
 258         }
 259
 260         /**
 261          * init_data points to array of regulator_init structures
 262          * coming from the board-evm file.
 263          */
 264
 265         init_data = tps_board->tps6507x_ts_init_data;
 266
 267         tsc = kzalloc(sizeof(struct tps6507x_ts), GFP_KERNEL);
 268         if (!tsc) {
 269                 dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
 270                 error = -ENOMEM;
 271                 goto err0;
 272         }
 273
 274         tps6507x_dev->ts = tsc;
 275         tsc->mfd = tps6507x_dev;
 276         tsc->dev = tps6507x_dev->dev;
 277         input_dev = input_allocate_device();
 278         if (!input_dev) {
 279                 dev_err(tsc->dev, "Failed to allocate input device.\n");
 280                 error = -ENOMEM;
 281                 goto err1;
 282         }
 283
 284         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 285         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 286
 287         input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
 288         input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
 289         input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);
 290
 291         input_dev->name = "TPS6507x Touchscreen";
 292         input_dev->id.bustype = BUS_I2C;
 293         input_dev->dev.parent = tsc->dev;
 294
 295         snprintf(tsc->phys, sizeof(tsc->phys),
 296                  "%s/input0", dev_name(tsc->dev));
 297         input_dev->phys = tsc->phys;
 298
 299         dev_dbg(tsc->dev, "device: %s\n", input_dev->phys);
 300
 301         input_set_drvdata(input_dev, tsc);
 302
 303         tsc->input_dev = input_dev;
 304
 305         INIT_DELAYED_WORK(&tsc->work, tps6507x_ts_handler);
 306         tsc->wq = create_workqueue("TPS6507x Touchscreen");
 307
 308         if (init_data) {
 309                 tsc->poll_period = init_data->poll_period;
 310                 tsc->vref = init_data->vref;
 311                 tsc->min_pressure = init_data->min_pressure;
 312                 input_dev->id.vendor = init_data->vendor;
 313                 input_dev->id.product = init_data->product;
 314                 input_dev->id.version = init_data->version;
 315         } else {
 316                 tsc->poll_period = TSC_DEFAULT_POLL_PERIOD;
 317                 tsc->min_pressure = TPS_DEFAULT_MIN_PRESSURE;
 318         }
 319
 320         error = tps6507x_adc_standby(tsc);
 321         if (error)
 322                 goto err2;
 323
 324         error = input_register_device(input_dev);
 325         if (error)
 326                 goto err2;
 327
 328         schd = queue_delayed_work(tsc->wq, &tsc->work,
 329                                   msecs_to_jiffies(tsc->poll_period));
 330
 331         if (schd)
 332                 tsc->polling = 1;
 333         else {
 334                 tsc->polling = 0;
 335                 dev_err(tsc->dev, "schedule failed");
 336                 goto err2;
 337          }
 338
 339         return 0;
 340
 341 err2:
 342         cancel_delayed_work_sync(&tsc->work);
 343         destroy_workqueue(tsc->wq);
 344         input_free_device(input_dev);
 345 err1:
 346         kfree(tsc);
 347         tps6507x_dev->ts = NULL;
 348 err0:
 349         return error;
 350 }
 351
 352 static int __devexit tps6507x_ts_remove(struct platform_device *pdev)
 353 {
 354         struct tps6507x_dev *tps6507x_dev = platform_get_drvdata(pdev);
 355         struct tps6507x_ts *tsc = tps6507x_dev->ts;
 356         struct input_dev *input_dev = tsc->input_dev;
 357
 358         if (!tsc)
 359                 return 0;
 360
 361         cancel_delayed_work_sync(&tsc->work);
 362         destroy_workqueue(tsc->wq);
 363
 364         input_free_device(input_dev);
 365
 366         tps6507x_dev->ts = NULL;
 367         kfree(tsc);
 368
 369         return 0;
 370 }
 371
 372 static struct platform_driver tps6507x_ts_driver = {
 373         .driver = {
 374                 .name = "tps6507x-ts",
 375                 .owner = THIS_MODULE,
 376         },
 377         .probe = tps6507x_ts_probe,
 378         .remove = __devexit_p(tps6507x_ts_remove),
 379 };
 380
 381 static int __init tps6507x_ts_init(void)
 382 {
 383         return platform_driver_register(&tps6507x_ts_driver);
 384 }
 385 module_init(tps6507x_ts_init);
 386
 387 static void __exit tps6507x_ts_exit(void)
 388 {
 389         platform_driver_unregister(&tps6507x_ts_driver);
 390 }
 391 module_exit(tps6507x_ts_exit);
 392
 393 MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
 394 MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
 395 MODULE_LICENSE("GPL v2");
 396 MODULE_ALIAS("platform:tps6507x-tsc");