Pileus Git - ~andy/linux/blob - drivers/input/touchscreen/tps6507x-ts.c

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