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