LXR linux/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/**
  67 * struct stmpe_touch - stmpe811 touch screen controller state
  68 * @stmpe: pointer back to STMPE MFD container
  69 * @idev: registered input device
  70 * @work: a work item used to scan the device
  71 * @dev: a pointer back to the MFD cell struct device*
  72 * @sample_time: ADC converstion time in number of clock.
  73 * (0 -> 36 clocks, 1 -> 44 clocks, 2 -> 56 clocks, 3 -> 64 clocks,
  74 * 4 -> 80 clocks, 5 -> 96 clocks, 6 -> 144 clocks),
  75 * recommended is 4.
  76 * @mod_12b: ADC Bit mode (0 -> 10bit ADC, 1 -> 12bit ADC)
  77 * @ref_sel: ADC reference source
  78 * (0 -> internal reference, 1 -> external reference)
  79 * @adc_freq: ADC Clock speed
  80 * (0 -> 1.625 MHz, 1 -> 3.25 MHz, 2 || 3 -> 6.5 MHz)
  81 * @ave_ctrl: Sample average control
  82 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples)
  83 * @touch_det_delay: Touch detect interrupt delay
  84 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us,
  85 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms)
  86 * recommended is 3
  87 * @settling: Panel driver settling time
  88 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms,
  89 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms)
  90 * recommended is 2
  91 * @fraction_z: Length of the fractional part in z
  92 * (fraction_z ([0..7]) = Count of the fractional part)
  93 * recommended is 7
  94 * @i_drive: current limit value of the touchscreen drivers
  95 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max)
  96 */
  97struct stmpe_touch {
  98        struct stmpe *stmpe;
  99        struct input_dev *idev;
 100        struct delayed_work work;
 101        struct device *dev;
 102        u8 sample_time;
 103        u8 mod_12b;
 104        u8 ref_sel;
 105        u8 adc_freq;
 106        u8 ave_ctrl;
 107        u8 touch_det_delay;
 108        u8 settling;
 109        u8 fraction_z;
 110        u8 i_drive;
 111};
 112
 113static int __stmpe_reset_fifo(struct stmpe *stmpe)
 114{
 115        int ret;
 116
 117        ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
 118                        STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
 119        if (ret)
 120                return ret;
 121
 122        return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
 123                        STMPE_FIFO_STA_RESET, 0);
 124}
 125
 126static void stmpe_work(struct work_struct *work)
 127{
 128        int int_sta;
 129        u32 timeout = 40;
 130
 131        struct stmpe_touch *ts =
 132            container_of(work, struct stmpe_touch, work.work);
 133
 134        int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 135
 136        /*
 137         * touch_det sometimes get desasserted or just get stuck. This appears
 138         * to be a silicon bug, We still have to clearify this with the
 139         * manufacture. As a workaround We release the key anyway if the
 140         * touch_det keeps coming in after 4ms, while the FIFO contains no value
 141         * during the whole time.
 142         */
 143        while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
 144                timeout--;
 145                int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 146                udelay(100);
 147        }
 148
 149        /* reset the FIFO before we report release event */
 150        __stmpe_reset_fifo(ts->stmpe);
 151
 152        input_report_abs(ts->idev, ABS_PRESSURE, 0);
 153        input_report_key(ts->idev, BTN_TOUCH, 0);
 154        input_sync(ts->idev);
 155}
 156
 157static irqreturn_t stmpe_ts_handler(int irq, void *data)
 158{
 159        u8 data_set[4];
 160        int x, y, z;
 161        struct stmpe_touch *ts = data;
 162
 163        /*
 164         * Cancel scheduled polling for release if we have new value
 165         * available. Wait if the polling is already running.
 166         */
 167        cancel_delayed_work_sync(&ts->work);
 168
 169        /*
 170         * The FIFO sometimes just crashes and stops generating interrupts. This
 171         * appears to be a silicon bug. We still have to clearify this with
 172         * the manufacture. As a workaround we disable the TSC while we are
 173         * collecting data and flush the FIFO after reading
 174         */
 175        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 176                                STMPE_TSC_CTRL_TSC_EN, 0);
 177
 178        stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
 179
 180        x = (data_set[0] << 4) | (data_set[1] >> 4);
 181        y = ((data_set[1] & 0xf) << 8) | data_set[2];
 182        z = data_set[3];
 183
 184        input_report_abs(ts->idev, ABS_X, x);
 185        input_report_abs(ts->idev, ABS_Y, y);
 186        input_report_abs(ts->idev, ABS_PRESSURE, z);
 187        input_report_key(ts->idev, BTN_TOUCH, 1);
 188        input_sync(ts->idev);
 189
 190       /* flush the FIFO after we have read out our values. */
 191        __stmpe_reset_fifo(ts->stmpe);
 192
 193        /* reenable the tsc */
 194        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 195                        STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 196
 197        /* start polling for touch_det to detect release */
 198        schedule_delayed_work(&ts->work, msecs_to_jiffies(50));
 199
 200        return IRQ_HANDLED;
 201}
 202
 203static int stmpe_init_hw(struct stmpe_touch *ts)
 204{
 205        int ret;
 206        u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
 207        struct stmpe *stmpe = ts->stmpe;
 208        struct device *dev = ts->dev;
 209
 210        ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
 211        if (ret) {
 212                dev_err(dev, "Could not enable clock for ADC and TS\n");
 213                return ret;
 214        }
 215
 216        adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
 217                REF_SEL(ts->ref_sel);
 218        adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
 219
 220        ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
 221                        adc_ctrl1_mask, adc_ctrl1);
 222        if (ret) {
 223                dev_err(dev, "Could not setup ADC\n");
 224                return ret;
 225        }
 226
 227        ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
 228                        ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
 229        if (ret) {
 230                dev_err(dev, "Could not setup ADC\n");
 231                return ret;
 232        }
 233
 234        tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
 235                        SETTLING(ts->settling);
 236        tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
 237
 238        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
 239        if (ret) {
 240                dev_err(dev, "Could not config touch\n");
 241                return ret;
 242        }
 243
 244        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
 245                        FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
 246        if (ret) {
 247                dev_err(dev, "Could not config touch\n");
 248                return ret;
 249        }
 250
 251        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
 252                        I_DRIVE(0xff), I_DRIVE(ts->i_drive));
 253        if (ret) {
 254                dev_err(dev, "Could not config touch\n");
 255                return ret;
 256        }
 257
 258        /* set FIFO to 1 for single point reading */
 259        ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
 260        if (ret) {
 261                dev_err(dev, "Could not set FIFO\n");
 262                return ret;
 263        }
 264
 265        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
 266                        OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
 267        if (ret) {
 268                dev_err(dev, "Could not set mode\n");
 269                return ret;
 270        }
 271
 272        return 0;
 273}
 274
 275static int stmpe_ts_open(struct input_dev *dev)
 276{
 277        struct stmpe_touch *ts = input_get_drvdata(dev);
 278        int ret = 0;
 279
 280        ret = __stmpe_reset_fifo(ts->stmpe);
 281        if (ret)
 282                return ret;
 283
 284        return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 285                        STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 286}
 287
 288static void stmpe_ts_close(struct input_dev *dev)
 289{
 290        struct stmpe_touch *ts = input_get_drvdata(dev);
 291
 292        cancel_delayed_work_sync(&ts->work);
 293
 294        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 295                        STMPE_TSC_CTRL_TSC_EN, 0);
 296}
 297
 298static void stmpe_ts_get_platform_info(struct platform_device *pdev,
 299                                        struct stmpe_touch *ts)
 300{
 301        struct device_node *np = pdev->dev.of_node;
 302        u32 val;
 303
 304        if (np) {
 305                if (!of_property_read_u32(np, "st,sample-time", &val))
 306                        ts->sample_time = val;
 307                if (!of_property_read_u32(np, "st,mod-12b", &val))
 308                        ts->mod_12b = val;
 309                if (!of_property_read_u32(np, "st,ref-sel", &val))
 310                        ts->ref_sel = val;
 311                if (!of_property_read_u32(np, "st,adc-freq", &val))
 312                        ts->adc_freq = val;
 313                if (!of_property_read_u32(np, "st,ave-ctrl", &val))
 314                        ts->ave_ctrl = val;
 315                if (!of_property_read_u32(np, "st,touch-det-delay", &val))
 316                        ts->touch_det_delay = val;
 317                if (!of_property_read_u32(np, "st,settling", &val))
 318                        ts->settling = val;
 319                if (!of_property_read_u32(np, "st,fraction-z", &val))
 320                        ts->fraction_z = val;
 321                if (!of_property_read_u32(np, "st,i-drive", &val))
 322                        ts->i_drive = val;
 323        }
 324}
 325
 326static int stmpe_input_probe(struct platform_device *pdev)
 327{
 328        struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 329        struct stmpe_touch *ts;
 330        struct input_dev *idev;
 331        int error;
 332        int ts_irq;
 333
 334        ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
 335        if (ts_irq < 0)
 336                return ts_irq;
 337
 338        ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
 339        if (!ts)
 340                return -ENOMEM;
 341
 342        idev = devm_input_allocate_device(&pdev->dev);
 343        if (!idev)
 344                return -ENOMEM;
 345
 346        platform_set_drvdata(pdev, ts);
 347        ts->stmpe = stmpe;
 348        ts->idev = idev;
 349        ts->dev = &pdev->dev;
 350
 351        stmpe_ts_get_platform_info(pdev, ts);
 352
 353        INIT_DELAYED_WORK(&ts->work, stmpe_work);
 354
 355        error = devm_request_threaded_irq(&pdev->dev, ts_irq,
 356                                          NULL, stmpe_ts_handler,
 357                                          IRQF_ONESHOT, STMPE_TS_NAME, ts);
 358        if (error) {
 359                dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
 360                return error;
 361        }
 362
 363        error = stmpe_init_hw(ts);
 364        if (error)
 365                return error;
 366
 367        idev->name = STMPE_TS_NAME;
 368        idev->phys = STMPE_TS_NAME"/input0";
 369        idev->id.bustype = BUS_I2C;
 370
 371        idev->open = stmpe_ts_open;
 372        idev->close = stmpe_ts_close;
 373
 374        input_set_drvdata(idev, ts);
 375
 376        input_set_capability(idev, EV_KEY, BTN_TOUCH);
 377        input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
 378        input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
 379        input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
 380
 381        error = input_register_device(idev);
 382        if (error) {
 383                dev_err(&pdev->dev, "Could not register input device\n");
 384                return error;
 385        }
 386
 387        return 0;
 388}
 389
 390static int stmpe_ts_remove(struct platform_device *pdev)
 391{
 392        struct stmpe_touch *ts = platform_get_drvdata(pdev);
 393
 394        stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
 395
 396        return 0;
 397}
 398
 399static struct platform_driver stmpe_ts_driver = {
 400        .driver = {
 401                .name = STMPE_TS_NAME,
 402        },
 403        .probe = stmpe_input_probe,
 404        .remove = stmpe_ts_remove,
 405};
 406module_platform_driver(stmpe_ts_driver);
 407
 408static const struct of_device_id stmpe_ts_ids[] = {
 409        { .compatible = "st,stmpe-ts", },
 410        { },
 411};
 412MODULE_DEVICE_TABLE(of, stmpe_ts_ids);
 413
 414MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 415MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
 416MODULE_LICENSE("GPL");
 417