drivers/input/touchscreen/stmpe-ts.c

   1 /*
   2  * STMicroelectronics STMPE811 Touchscreen Driver
   3  *
   4  * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
   5  * All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute  it and/or modify it
   8  *  under  the terms of  the GNU General  Public License as published by the
   9  *  Free Software Foundation;  either version 2 of the  License, or (at your
  10  *  option) any later version.
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/init.h>
  19 #include <linux/device.h>
  20 #include <linux/of.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/input.h>
  23 #include <linux/slab.h>
  24 #include <linux/delay.h>
  25 #include <linux/i2c.h>
  26 #include <linux/workqueue.h>
  27
  28 #include <linux/mfd/stmpe.h>
  29
  30 /* Register layouts and functionalities are identical on all stmpexxx variants
  31  * with touchscreen controller
  32  */
  33 #define STMPE_REG_INT_STA               0x0B
  34 #define STMPE_REG_ADC_CTRL1             0x20
  35 #define STMPE_REG_ADC_CTRL2             0x21
  36 #define STMPE_REG_TSC_CTRL              0x40
  37 #define STMPE_REG_TSC_CFG               0x41
  38 #define STMPE_REG_FIFO_TH               0x4A
  39 #define STMPE_REG_FIFO_STA              0x4B
  40 #define STMPE_REG_FIFO_SIZE             0x4C
  41 #define STMPE_REG_TSC_DATA_XYZ          0x52
  42 #define STMPE_REG_TSC_FRACTION_Z        0x56
  43 #define STMPE_REG_TSC_I_DRIVE           0x58
  44
  45 #define OP_MOD_XYZ                      0
  46
  47 #define STMPE_TSC_CTRL_TSC_EN           (1<<0)
  48
  49 #define STMPE_FIFO_STA_RESET            (1<<0)
  50
  51 #define STMPE_IRQ_TOUCH_DET             0
  52
  53 #define SAMPLE_TIME(x)                  ((x & 0xf) << 4)
  54 #define MOD_12B(x)                      ((x & 0x1) << 3)
  55 #define REF_SEL(x)                      ((x & 0x1) << 1)
  56 #define ADC_FREQ(x)                     (x & 0x3)
  57 #define AVE_CTRL(x)                     ((x & 0x3) << 6)
  58 #define DET_DELAY(x)                    ((x & 0x7) << 3)
  59 #define SETTLING(x)                     (x & 0x7)
  60 #define FRACTION_Z(x)                   (x & 0x7)
  61 #define I_DRIVE(x)                      (x & 0x1)
  62 #define OP_MODE(x)                      ((x & 0x7) << 1)
  63
  64 #define STMPE_TS_NAME                   "stmpe-ts"
  65 #define XY_MASK                         0xfff
  66
  67 struct stmpe_touch {
  68         struct stmpe *stmpe;
  69         struct input_dev *idev;
  70         struct delayed_work work;
  71         struct device *dev;
  72         u8 sample_time;
  73         u8 mod_12b;
  74         u8 ref_sel;
  75         u8 adc_freq;
  76         u8 ave_ctrl;
  77         u8 touch_det_delay;
  78         u8 settling;
  79         u8 fraction_z;
  80         u8 i_drive;
  81 };
  82
  83 static int __stmpe_reset_fifo(struct stmpe *stmpe)
  84 {
  85         int ret;
  86
  87         ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  88                         STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
  89         if (ret)
  90                 return ret;
  91
  92         return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  93                         STMPE_FIFO_STA_RESET, 0);
  94 }
  95
  96 static void stmpe_work(struct work_struct *work)
  97 {
  98         int int_sta;
  99         u32 timeout = 40;
 100
 101         struct stmpe_touch *ts =
 102             container_of(work, struct stmpe_touch, work.work);
 103
 104         int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 105
 106         /*
 107          * touch_det sometimes get desasserted or just get stuck. This appears
 108          * to be a silicon bug, We still have to clearify this with the
 109          * manufacture. As a workaround We release the key anyway if the
 110          * touch_det keeps coming in after 4ms, while the FIFO contains no value
 111          * during the whole time.
 112          */
 113         while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
 114                 timeout--;
 115                 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 116                 udelay(100);
 117         }
 118
 119         /* reset the FIFO before we report release event */
 120         __stmpe_reset_fifo(ts->stmpe);
 121
 122         input_report_abs(ts->idev, ABS_PRESSURE, 0);
 123         input_sync(ts->idev);
 124 }
 125
 126 static irqreturn_t stmpe_ts_handler(int irq, void *data)
 127 {
 128         u8 data_set[4];
 129         int x, y, z;
 130         struct stmpe_touch *ts = data;
 131
 132         /*
 133          * Cancel scheduled polling for release if we have new value
 134          * available. Wait if the polling is already running.
 135          */
 136         cancel_delayed_work_sync(&ts->work);
 137
 138         /*
 139          * The FIFO sometimes just crashes and stops generating interrupts. This
 140          * appears to be a silicon bug. We still have to clearify this with
 141          * the manufacture. As a workaround we disable the TSC while we are
 142          * collecting data and flush the FIFO after reading
 143          */
 144         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 145                                 STMPE_TSC_CTRL_TSC_EN, 0);
 146
 147         stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
 148
 149         x = (data_set[0] << 4) | (data_set[1] >> 4);
 150         y = ((data_set[1] & 0xf) << 8) | data_set[2];
 151         z = data_set[3];
 152
 153         input_report_abs(ts->idev, ABS_X, x);
 154         input_report_abs(ts->idev, ABS_Y, y);
 155         input_report_abs(ts->idev, ABS_PRESSURE, z);
 156         input_sync(ts->idev);
 157
 158        /* flush the FIFO after we have read out our values. */
 159         __stmpe_reset_fifo(ts->stmpe);
 160
 161         /* reenable the tsc */
 162         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 163                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 164
 165         /* start polling for touch_det to detect release */
 166         schedule_delayed_work(&ts->work, HZ / 50);
 167
 168         return IRQ_HANDLED;
 169 }
 170
 171 static int stmpe_init_hw(struct stmpe_touch *ts)
 172 {
 173         int ret;
 174         u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
 175         struct stmpe *stmpe = ts->stmpe;
 176         struct device *dev = ts->dev;
 177
 178         ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
 179         if (ret) {
 180                 dev_err(dev, "Could not enable clock for ADC and TS\n");
 181                 return ret;
 182         }
 183
 184         adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
 185                 REF_SEL(ts->ref_sel);
 186         adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
 187
 188         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
 189                         adc_ctrl1_mask, adc_ctrl1);
 190         if (ret) {
 191                 dev_err(dev, "Could not setup ADC\n");
 192                 return ret;
 193         }
 194
 195         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
 196                         ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
 197         if (ret) {
 198                 dev_err(dev, "Could not setup ADC\n");
 199                 return ret;
 200         }
 201
 202         tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
 203                         SETTLING(ts->settling);
 204         tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
 205
 206         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
 207         if (ret) {
 208                 dev_err(dev, "Could not config touch\n");
 209                 return ret;
 210         }
 211
 212         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
 213                         FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
 214         if (ret) {
 215                 dev_err(dev, "Could not config touch\n");
 216                 return ret;
 217         }
 218
 219         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
 220                         I_DRIVE(0xff), I_DRIVE(ts->i_drive));
 221         if (ret) {
 222                 dev_err(dev, "Could not config touch\n");
 223                 return ret;
 224         }
 225
 226         /* set FIFO to 1 for single point reading */
 227         ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
 228         if (ret) {
 229                 dev_err(dev, "Could not set FIFO\n");
 230                 return ret;
 231         }
 232
 233         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
 234                         OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
 235         if (ret) {
 236                 dev_err(dev, "Could not set mode\n");
 237                 return ret;
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int stmpe_ts_open(struct input_dev *dev)
 244 {
 245         struct stmpe_touch *ts = input_get_drvdata(dev);
 246         int ret = 0;
 247
 248         ret = __stmpe_reset_fifo(ts->stmpe);
 249         if (ret)
 250                 return ret;
 251
 252         return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 253                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 254 }
 255
 256 static void stmpe_ts_close(struct input_dev *dev)
 257 {
 258         struct stmpe_touch *ts = input_get_drvdata(dev);
 259
 260         cancel_delayed_work_sync(&ts->work);
 261
 262         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 263                         STMPE_TSC_CTRL_TSC_EN, 0);
 264 }
 265
 266 static void stmpe_ts_get_platform_info(struct platform_device *pdev,
 267                                         struct stmpe_touch *ts)
 268 {
 269         struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 270         struct device_node *np = pdev->dev.of_node;
 271         struct stmpe_ts_platform_data *ts_pdata = NULL;
 272
 273         ts->stmpe = stmpe;
 274
 275         if (stmpe->pdata && stmpe->pdata->ts) {
 276                 ts_pdata = stmpe->pdata->ts;
 277
 278                 ts->sample_time = ts_pdata->sample_time;
 279                 ts->mod_12b = ts_pdata->mod_12b;
 280                 ts->ref_sel = ts_pdata->ref_sel;
 281                 ts->adc_freq = ts_pdata->adc_freq;
 282                 ts->ave_ctrl = ts_pdata->ave_ctrl;
 283                 ts->touch_det_delay = ts_pdata->touch_det_delay;
 284                 ts->settling = ts_pdata->settling;
 285                 ts->fraction_z = ts_pdata->fraction_z;
 286                 ts->i_drive = ts_pdata->i_drive;
 287         } else if (np) {
 288                 u32 val;
 289
 290                 if (!of_property_read_u32(np, "st,sample-time", &val))
 291                         ts->sample_time = val;
 292                 if (!of_property_read_u32(np, "st,mod-12b", &val))
 293                         ts->mod_12b = val;
 294                 if (!of_property_read_u32(np, "st,ref-sel", &val))
 295                         ts->ref_sel = val;
 296                 if (!of_property_read_u32(np, "st,adc-freq", &val))
 297                         ts->adc_freq = val;
 298                 if (!of_property_read_u32(np, "st,ave-ctrl", &val))
 299                         ts->ave_ctrl = val;
 300                 if (!of_property_read_u32(np, "st,touch-det-delay", &val))
 301                         ts->touch_det_delay = val;
 302                 if (!of_property_read_u32(np, "st,settling", &val))
 303                         ts->settling = val;
 304                 if (!of_property_read_u32(np, "st,fraction-z", &val))
 305                         ts->fraction_z = val;
 306                 if (!of_property_read_u32(np, "st,i-drive", &val))
 307                         ts->i_drive = val;
 308         }
 309 }
 310
 311 static int stmpe_input_probe(struct platform_device *pdev)
 312 {
 313         struct stmpe_touch *ts;
 314         struct input_dev *idev;
 315         int error;
 316         int ts_irq;
 317
 318         ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
 319         if (ts_irq < 0)
 320                 return ts_irq;
 321
 322         ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
 323         if (!ts)
 324                 return -ENOMEM;
 325
 326         idev = devm_input_allocate_device(&pdev->dev);
 327         if (!idev)
 328                 return -ENOMEM;
 329
 330         platform_set_drvdata(pdev, ts);
 331         ts->idev = idev;
 332         ts->dev = &pdev->dev;
 333
 334         stmpe_ts_get_platform_info(pdev, ts);
 335
 336         INIT_DELAYED_WORK(&ts->work, stmpe_work);
 337
 338         error = devm_request_threaded_irq(&pdev->dev, ts_irq,
 339                                           NULL, stmpe_ts_handler,
 340                                           IRQF_ONESHOT, STMPE_TS_NAME, ts);
 341         if (error) {
 342                 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
 343                 return error;
 344         }
 345
 346         error = stmpe_init_hw(ts);
 347         if (error)
 348                 return error;
 349
 350         idev->name = STMPE_TS_NAME;
 351         idev->phys = STMPE_TS_NAME"/input0";
 352         idev->id.bustype = BUS_I2C;
 353         idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 354         idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 355
 356         idev->open = stmpe_ts_open;
 357         idev->close = stmpe_ts_close;
 358
 359         input_set_drvdata(idev, ts);
 360
 361         input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
 362         input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
 363         input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
 364
 365         error = input_register_device(idev);
 366         if (error) {
 367                 dev_err(&pdev->dev, "Could not register input device\n");
 368                 return error;
 369         }
 370
 371         return 0;
 372 }
 373
 374 static int stmpe_ts_remove(struct platform_device *pdev)
 375 {
 376         struct stmpe_touch *ts = platform_get_drvdata(pdev);
 377
 378         stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
 379
 380         return 0;
 381 }
 382
 383 static struct platform_driver stmpe_ts_driver = {
 384         .driver = {
 385                    .name = STMPE_TS_NAME,
 386                    .owner = THIS_MODULE,
 387                    },
 388         .probe = stmpe_input_probe,
 389         .remove = stmpe_ts_remove,
 390 };
 391 module_platform_driver(stmpe_ts_driver);
 392
 393 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 394 MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
 395 MODULE_LICENSE("GPL");
 396 MODULE_ALIAS("platform:" STMPE_TS_NAME);