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