drivers/input/touchscreen/stmpe-ts.c

   1 /* STMicroelectronics STMPE811 Touchscreen Driver
   2  *
   3  * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
   4  * All rights reserved.
   5  *
   6  *  This program is free software; you can redistribute  it and/or modify it
   7  *  under  the terms of  the GNU General  Public License as published by the
   8  *  Free Software Foundation;  either version 2 of the  License, or (at your
   9  *  option) any later version.
  10  *
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/init.h>
  18 #include <linux/device.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/input.h>
  21 #include <linux/slab.h>
  22 #include <linux/delay.h>
  23 #include <linux/i2c.h>
  24 #include <linux/workqueue.h>
  25
  26 #include <linux/mfd/stmpe.h>
  27
  28 /* Register layouts and functionalities are identical on all stmpexxx variants
  29  * with touchscreen controller
  30  */
  31 #define STMPE_REG_INT_STA               0x0B
  32 #define STMPE_REG_ADC_CTRL1             0x20
  33 #define STMPE_REG_ADC_CTRL2             0x21
  34 #define STMPE_REG_TSC_CTRL              0x40
  35 #define STMPE_REG_TSC_CFG               0x41
  36 #define STMPE_REG_FIFO_TH               0x4A
  37 #define STMPE_REG_FIFO_STA              0x4B
  38 #define STMPE_REG_FIFO_SIZE             0x4C
  39 #define STMPE_REG_TSC_DATA_XYZ          0x52
  40 #define STMPE_REG_TSC_FRACTION_Z        0x56
  41 #define STMPE_REG_TSC_I_DRIVE           0x58
  42
  43 #define OP_MOD_XYZ                      0
  44
  45 #define STMPE_TSC_CTRL_TSC_EN           (1<<0)
  46
  47 #define STMPE_FIFO_STA_RESET            (1<<0)
  48
  49 #define STMPE_IRQ_TOUCH_DET             0
  50
  51 #define SAMPLE_TIME(x)                  ((x & 0xf) << 4)
  52 #define MOD_12B(x)                      ((x & 0x1) << 3)
  53 #define REF_SEL(x)                      ((x & 0x1) << 1)
  54 #define ADC_FREQ(x)                     (x & 0x3)
  55 #define AVE_CTRL(x)                     ((x & 0x3) << 6)
  56 #define DET_DELAY(x)                    ((x & 0x7) << 3)
  57 #define SETTLING(x)                     (x & 0x7)
  58 #define FRACTION_Z(x)                   (x & 0x7)
  59 #define I_DRIVE(x)                      (x & 0x1)
  60 #define OP_MODE(x)                      ((x & 0x7) << 1)
  61
  62 #define STMPE_TS_NAME                   "stmpe-ts"
  63 #define XY_MASK                         0xfff
  64
  65 struct stmpe_touch {
  66         struct stmpe *stmpe;
  67         struct input_dev *idev;
  68         struct delayed_work work;
  69         struct device *dev;
  70         u8 sample_time;
  71         u8 mod_12b;
  72         u8 ref_sel;
  73         u8 adc_freq;
  74         u8 ave_ctrl;
  75         u8 touch_det_delay;
  76         u8 settling;
  77         u8 fraction_z;
  78         u8 i_drive;
  79 };
  80
  81 static int __stmpe_reset_fifo(struct stmpe *stmpe)
  82 {
  83         int ret;
  84
  85         ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  86                         STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
  87         if (ret)
  88                 return ret;
  89
  90         return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  91                         STMPE_FIFO_STA_RESET, 0);
  92 }
  93
  94 static void stmpe_work(struct work_struct *work)
  95 {
  96         int int_sta;
  97         u32 timeout = 40;
  98
  99         struct stmpe_touch *ts =
 100             container_of(work, struct stmpe_touch, work.work);
 101
 102         int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 103
 104         /*
 105          * touch_det sometimes get desasserted or just get stuck. This appears
 106          * to be a silicon bug, We still have to clearify this with the
 107          * manufacture. As a workaround We release the key anyway if the
 108          * touch_det keeps coming in after 4ms, while the FIFO contains no value
 109          * during the whole time.
 110          */
 111         while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
 112                 timeout--;
 113                 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 114                 udelay(100);
 115         }
 116
 117         /* reset the FIFO before we report release event */
 118         __stmpe_reset_fifo(ts->stmpe);
 119
 120         input_report_abs(ts->idev, ABS_PRESSURE, 0);
 121         input_sync(ts->idev);
 122 }
 123
 124 static irqreturn_t stmpe_ts_handler(int irq, void *data)
 125 {
 126         u8 data_set[4];
 127         int x, y, z;
 128         struct stmpe_touch *ts = data;
 129
 130         /*
 131          * Cancel scheduled polling for release if we have new value
 132          * available. Wait if the polling is already running.
 133          */
 134         cancel_delayed_work_sync(&ts->work);
 135
 136         /*
 137          * The FIFO sometimes just crashes and stops generating interrupts. This
 138          * appears to be a silicon bug. We still have to clearify this with
 139          * the manufacture. As a workaround we disable the TSC while we are
 140          * collecting data and flush the FIFO after reading
 141          */
 142         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 143                                 STMPE_TSC_CTRL_TSC_EN, 0);
 144
 145         stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
 146
 147         x = (data_set[0] << 4) | (data_set[1] >> 4);
 148         y = ((data_set[1] & 0xf) << 8) | data_set[2];
 149         z = data_set[3];
 150
 151         input_report_abs(ts->idev, ABS_X, x);
 152         input_report_abs(ts->idev, ABS_Y, y);
 153         input_report_abs(ts->idev, ABS_PRESSURE, z);
 154         input_sync(ts->idev);
 155
 156        /* flush the FIFO after we have read out our values. */
 157         __stmpe_reset_fifo(ts->stmpe);
 158
 159         /* reenable the tsc */
 160         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 161                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 162
 163         /* start polling for touch_det to detect release */
 164         schedule_delayed_work(&ts->work, HZ / 50);
 165
 166         return IRQ_HANDLED;
 167 }
 168
 169 static int __devinit stmpe_init_hw(struct stmpe_touch *ts)
 170 {
 171         int ret;
 172         u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
 173         struct stmpe *stmpe = ts->stmpe;
 174         struct device *dev = ts->dev;
 175
 176         ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
 177         if (ret) {
 178                 dev_err(dev, "Could not enable clock for ADC and TS\n");
 179                 return ret;
 180         }
 181
 182         adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
 183                 REF_SEL(ts->ref_sel);
 184         adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
 185
 186         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
 187                         adc_ctrl1_mask, adc_ctrl1);
 188         if (ret) {
 189                 dev_err(dev, "Could not setup ADC\n");
 190                 return ret;
 191         }
 192
 193         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
 194                         ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
 195         if (ret) {
 196                 dev_err(dev, "Could not setup ADC\n");
 197                 return ret;
 198         }
 199
 200         tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
 201                         SETTLING(ts->settling);
 202         tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
 203
 204         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
 205         if (ret) {
 206                 dev_err(dev, "Could not config touch\n");
 207                 return ret;
 208         }
 209
 210         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
 211                         FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
 212         if (ret) {
 213                 dev_err(dev, "Could not config touch\n");
 214                 return ret;
 215         }
 216
 217         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
 218                         I_DRIVE(0xff), I_DRIVE(ts->i_drive));
 219         if (ret) {
 220                 dev_err(dev, "Could not config touch\n");
 221                 return ret;
 222         }
 223
 224         /* set FIFO to 1 for single point reading */
 225         ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
 226         if (ret) {
 227                 dev_err(dev, "Could not set FIFO\n");
 228                 return ret;
 229         }
 230
 231         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
 232                         OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
 233         if (ret) {
 234                 dev_err(dev, "Could not set mode\n");
 235                 return ret;
 236         }
 237
 238         return 0;
 239 }
 240
 241 static int stmpe_ts_open(struct input_dev *dev)
 242 {
 243         struct stmpe_touch *ts = input_get_drvdata(dev);
 244         int ret = 0;
 245
 246         ret = __stmpe_reset_fifo(ts->stmpe);
 247         if (ret)
 248                 return ret;
 249
 250         return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 251                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 252 }
 253
 254 static void stmpe_ts_close(struct input_dev *dev)
 255 {
 256         struct stmpe_touch *ts = input_get_drvdata(dev);
 257
 258         cancel_delayed_work_sync(&ts->work);
 259
 260         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 261                         STMPE_TSC_CTRL_TSC_EN, 0);
 262 }
 263
 264 static int __devinit stmpe_input_probe(struct platform_device *pdev)
 265 {
 266         struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 267         struct stmpe_platform_data *pdata = stmpe->pdata;
 268         struct stmpe_touch *ts;
 269         struct input_dev *idev;
 270         struct stmpe_ts_platform_data *ts_pdata = NULL;
 271         int ret;
 272         int ts_irq;
 273
 274         ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
 275         if (ts_irq < 0)
 276                 return ts_irq;
 277
 278         ts = kzalloc(sizeof(*ts), GFP_KERNEL);
 279         if (!ts) {
 280                 ret = -ENOMEM;
 281                 goto err_out;
 282         }
 283
 284         idev = input_allocate_device();
 285         if (!idev) {
 286                 ret = -ENOMEM;
 287                 goto err_free_ts;
 288         }
 289
 290         platform_set_drvdata(pdev, ts);
 291         ts->stmpe = stmpe;
 292         ts->idev = idev;
 293         ts->dev = &pdev->dev;
 294
 295         if (pdata)
 296                 ts_pdata = pdata->ts;
 297
 298         if (ts_pdata) {
 299                 ts->sample_time = ts_pdata->sample_time;
 300                 ts->mod_12b = ts_pdata->mod_12b;
 301                 ts->ref_sel = ts_pdata->ref_sel;
 302                 ts->adc_freq = ts_pdata->adc_freq;
 303                 ts->ave_ctrl = ts_pdata->ave_ctrl;
 304                 ts->touch_det_delay = ts_pdata->touch_det_delay;
 305                 ts->settling = ts_pdata->settling;
 306                 ts->fraction_z = ts_pdata->fraction_z;
 307                 ts->i_drive = ts_pdata->i_drive;
 308         }
 309
 310         INIT_DELAYED_WORK(&ts->work, stmpe_work);
 311
 312         ret = request_threaded_irq(ts_irq, NULL, stmpe_ts_handler,
 313                         IRQF_ONESHOT, STMPE_TS_NAME, ts);
 314         if (ret) {
 315                 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
 316                 goto err_free_input;
 317         }
 318
 319         ret = stmpe_init_hw(ts);
 320         if (ret)
 321                 goto err_free_irq;
 322
 323         idev->name = STMPE_TS_NAME;
 324         idev->id.bustype = BUS_I2C;
 325         idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 326         idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 327
 328         idev->open = stmpe_ts_open;
 329         idev->close = stmpe_ts_close;
 330
 331         input_set_drvdata(idev, ts);
 332
 333         input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
 334         input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
 335         input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
 336
 337         ret = input_register_device(idev);
 338         if (ret) {
 339                 dev_err(&pdev->dev, "Could not register input device\n");
 340                 goto err_free_irq;
 341         }
 342
 343         return ret;
 344
 345 err_free_irq:
 346         free_irq(ts_irq, ts);
 347 err_free_input:
 348         input_free_device(idev);
 349         platform_set_drvdata(pdev, NULL);
 350 err_free_ts:
 351         kfree(ts);
 352 err_out:
 353         return ret;
 354 }
 355
 356 static int __devexit stmpe_ts_remove(struct platform_device *pdev)
 357 {
 358         struct stmpe_touch *ts = platform_get_drvdata(pdev);
 359         unsigned int ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
 360
 361         stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
 362
 363         free_irq(ts_irq, ts);
 364
 365         platform_set_drvdata(pdev, NULL);
 366
 367         input_unregister_device(ts->idev);
 368
 369         kfree(ts);
 370
 371         return 0;
 372 }
 373
 374 static struct platform_driver stmpe_ts_driver = {
 375         .driver = {
 376                    .name = STMPE_TS_NAME,
 377                    .owner = THIS_MODULE,
 378                    },
 379         .probe = stmpe_input_probe,
 380         .remove = __devexit_p(stmpe_ts_remove),
 381 };
 382 module_platform_driver(stmpe_ts_driver);
 383
 384 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 385 MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
 386 MODULE_LICENSE("GPL");
 387 MODULE_ALIAS("platform:" STMPE_TS_NAME);