LXR linux/drivers/input/touchscreen/stmpe-ts.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * STMicroelectronics STMPE811 Touchscreen Driver
   4 *
   5 * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
   6 * All rights reserved.
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11#include <linux/sched.h>
  12#include <linux/interrupt.h>
  13#include <linux/device.h>
  14#include <linux/of.h>
  15#include <linux/platform_device.h>
  16#include <linux/input.h>
  17#include <linux/input/touchscreen.h>
  18#include <linux/slab.h>
  19#include <linux/delay.h>
  20#include <linux/i2c.h>
  21#include <linux/workqueue.h>
  22
  23#include <linux/mfd/stmpe.h>
  24
  25/* Register layouts and functionalities are identical on all stmpexxx variants
  26 * with touchscreen controller
  27 */
  28#define STMPE_REG_INT_STA               0x0B
  29#define STMPE_REG_TSC_CTRL              0x40
  30#define STMPE_REG_TSC_CFG               0x41
  31#define STMPE_REG_FIFO_TH               0x4A
  32#define STMPE_REG_FIFO_STA              0x4B
  33#define STMPE_REG_FIFO_SIZE             0x4C
  34#define STMPE_REG_TSC_DATA_XYZ          0x52
  35#define STMPE_REG_TSC_FRACTION_Z        0x56
  36#define STMPE_REG_TSC_I_DRIVE           0x58
  37
  38#define OP_MOD_XYZ                      0
  39
  40#define STMPE_TSC_CTRL_TSC_EN           (1<<0)
  41
  42#define STMPE_FIFO_STA_RESET            (1<<0)
  43
  44#define STMPE_IRQ_TOUCH_DET             0
  45
  46#define STMPE_TS_NAME                   "stmpe-ts"
  47#define XY_MASK                         0xfff
  48
  49/**
  50 * struct stmpe_touch - stmpe811 touch screen controller state
  51 * @stmpe: pointer back to STMPE MFD container
  52 * @idev: registered input device
  53 * @work: a work item used to scan the device
  54 * @dev: a pointer back to the MFD cell struct device*
  55 * @prop: Touchscreen properties
  56 * @ave_ctrl: Sample average control
  57 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples)
  58 * @touch_det_delay: Touch detect interrupt delay
  59 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us,
  60 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms)
  61 * recommended is 3
  62 * @settling: Panel driver settling time
  63 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms,
  64 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms)
  65 * recommended is 2
  66 * @fraction_z: Length of the fractional part in z
  67 * (fraction_z ([0..7]) = Count of the fractional part)
  68 * recommended is 7
  69 * @i_drive: current limit value of the touchscreen drivers
  70 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max)
  71 */
  72struct stmpe_touch {
  73        struct stmpe *stmpe;
  74        struct input_dev *idev;
  75        struct delayed_work work;
  76        struct device *dev;
  77        struct touchscreen_properties prop;
  78        u8 ave_ctrl;
  79        u8 touch_det_delay;
  80        u8 settling;
  81        u8 fraction_z;
  82        u8 i_drive;
  83};
  84
  85static int __stmpe_reset_fifo(struct stmpe *stmpe)
  86{
  87        int ret;
  88
  89        ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  90                        STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
  91        if (ret)
  92                return ret;
  93
  94        return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
  95                        STMPE_FIFO_STA_RESET, 0);
  96}
  97
  98static void stmpe_work(struct work_struct *work)
  99{
 100        int int_sta;
 101        u32 timeout = 40;
 102
 103        struct stmpe_touch *ts =
 104            container_of(work, struct stmpe_touch, work.work);
 105
 106        int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 107
 108        /*
 109         * touch_det sometimes get desasserted or just get stuck. This appears
 110         * to be a silicon bug, We still have to clearify this with the
 111         * manufacture. As a workaround We release the key anyway if the
 112         * touch_det keeps coming in after 4ms, while the FIFO contains no value
 113         * during the whole time.
 114         */
 115        while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
 116                timeout--;
 117                int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
 118                udelay(100);
 119        }
 120
 121        /* reset the FIFO before we report release event */
 122        __stmpe_reset_fifo(ts->stmpe);
 123
 124        input_report_abs(ts->idev, ABS_PRESSURE, 0);
 125        input_report_key(ts->idev, BTN_TOUCH, 0);
 126        input_sync(ts->idev);
 127}
 128
 129static irqreturn_t stmpe_ts_handler(int irq, void *data)
 130{
 131        u8 data_set[4];
 132        int x, y, z;
 133        struct stmpe_touch *ts = data;
 134
 135        /*
 136         * Cancel scheduled polling for release if we have new value
 137         * available. Wait if the polling is already running.
 138         */
 139        cancel_delayed_work_sync(&ts->work);
 140
 141        /*
 142         * The FIFO sometimes just crashes and stops generating interrupts. This
 143         * appears to be a silicon bug. We still have to clearify this with
 144         * the manufacture. As a workaround we disable the TSC while we are
 145         * collecting data and flush the FIFO after reading
 146         */
 147        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 148                                STMPE_TSC_CTRL_TSC_EN, 0);
 149
 150        stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
 151
 152        x = (data_set[0] << 4) | (data_set[1] >> 4);
 153        y = ((data_set[1] & 0xf) << 8) | data_set[2];
 154        z = data_set[3];
 155
 156        touchscreen_report_pos(ts->idev, &ts->prop, x, y, false);
 157        input_report_abs(ts->idev, ABS_PRESSURE, z);
 158        input_report_key(ts->idev, BTN_TOUCH, 1);
 159        input_sync(ts->idev);
 160
 161       /* flush the FIFO after we have read out our values. */
 162        __stmpe_reset_fifo(ts->stmpe);
 163
 164        /* reenable the tsc */
 165        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 166                        STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 167
 168        /* start polling for touch_det to detect release */
 169        schedule_delayed_work(&ts->work, msecs_to_jiffies(50));
 170
 171        return IRQ_HANDLED;
 172}
 173
 174static int stmpe_init_hw(struct stmpe_touch *ts)
 175{
 176        int ret;
 177        u8 tsc_cfg, tsc_cfg_mask;
 178        struct stmpe *stmpe = ts->stmpe;
 179        struct device *dev = ts->dev;
 180
 181        ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
 182        if (ret) {
 183                dev_err(dev, "Could not enable clock for ADC and TS\n");
 184                return ret;
 185        }
 186
 187        ret = stmpe811_adc_common_init(stmpe);
 188        if (ret) {
 189                stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
 190                return ret;
 191        }
 192
 193        tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) |
 194                  STMPE_DET_DELAY(ts->touch_det_delay) |
 195                  STMPE_SETTLING(ts->settling);
 196        tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) |
 197                       STMPE_SETTLING(0xff);
 198
 199        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
 200        if (ret) {
 201                dev_err(dev, "Could not config touch\n");
 202                return ret;
 203        }
 204
 205        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
 206                        STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z));
 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_I_DRIVE,
 213                        STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive));
 214        if (ret) {
 215                dev_err(dev, "Could not config touch\n");
 216                return ret;
 217        }
 218
 219        /* set FIFO to 1 for single point reading */
 220        ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
 221        if (ret) {
 222                dev_err(dev, "Could not set FIFO\n");
 223                return ret;
 224        }
 225
 226        ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
 227                        STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ));
 228        if (ret) {
 229                dev_err(dev, "Could not set mode\n");
 230                return ret;
 231        }
 232
 233        return 0;
 234}
 235
 236static int stmpe_ts_open(struct input_dev *dev)
 237{
 238        struct stmpe_touch *ts = input_get_drvdata(dev);
 239        int ret = 0;
 240
 241        ret = __stmpe_reset_fifo(ts->stmpe);
 242        if (ret)
 243                return ret;
 244
 245        return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 246                        STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
 247}
 248
 249static void stmpe_ts_close(struct input_dev *dev)
 250{
 251        struct stmpe_touch *ts = input_get_drvdata(dev);
 252
 253        cancel_delayed_work_sync(&ts->work);
 254
 255        stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
 256                        STMPE_TSC_CTRL_TSC_EN, 0);
 257}
 258
 259static void stmpe_ts_get_platform_info(struct platform_device *pdev,
 260                                        struct stmpe_touch *ts)
 261{
 262        struct device_node *np = pdev->dev.of_node;
 263        u32 val;
 264
 265        if (np) {
 266                if (!of_property_read_u32(np, "st,sample-time", &val))
 267                        ts->stmpe->sample_time = val;
 268                if (!of_property_read_u32(np, "st,mod-12b", &val))
 269                        ts->stmpe->mod_12b = val;
 270                if (!of_property_read_u32(np, "st,ref-sel", &val))
 271                        ts->stmpe->ref_sel = val;
 272                if (!of_property_read_u32(np, "st,adc-freq", &val))
 273                        ts->stmpe->adc_freq = val;
 274                if (!of_property_read_u32(np, "st,ave-ctrl", &val))
 275                        ts->ave_ctrl = val;
 276                if (!of_property_read_u32(np, "st,touch-det-delay", &val))
 277                        ts->touch_det_delay = val;
 278                if (!of_property_read_u32(np, "st,settling", &val))
 279                        ts->settling = val;
 280                if (!of_property_read_u32(np, "st,fraction-z", &val))
 281                        ts->fraction_z = val;
 282                if (!of_property_read_u32(np, "st,i-drive", &val))
 283                        ts->i_drive = val;
 284        }
 285}
 286
 287static int stmpe_input_probe(struct platform_device *pdev)
 288{
 289        struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 290        struct stmpe_touch *ts;
 291        struct input_dev *idev;
 292        int error;
 293        int ts_irq;
 294
 295        ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
 296        if (ts_irq < 0)
 297                return ts_irq;
 298
 299        ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
 300        if (!ts)
 301                return -ENOMEM;
 302
 303        idev = devm_input_allocate_device(&pdev->dev);
 304        if (!idev)
 305                return -ENOMEM;
 306
 307        platform_set_drvdata(pdev, ts);
 308        ts->stmpe = stmpe;
 309        ts->idev = idev;
 310        ts->dev = &pdev->dev;
 311
 312        stmpe_ts_get_platform_info(pdev, ts);
 313
 314        INIT_DELAYED_WORK(&ts->work, stmpe_work);
 315
 316        error = devm_request_threaded_irq(&pdev->dev, ts_irq,
 317                                          NULL, stmpe_ts_handler,
 318                                          IRQF_ONESHOT, STMPE_TS_NAME, ts);
 319        if (error) {
 320                dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
 321                return error;
 322        }
 323
 324        error = stmpe_init_hw(ts);
 325        if (error)
 326                return error;
 327
 328        idev->name = STMPE_TS_NAME;
 329        idev->phys = STMPE_TS_NAME"/input0";
 330        idev->id.bustype = BUS_I2C;
 331
 332        idev->open = stmpe_ts_open;
 333        idev->close = stmpe_ts_close;
 334
 335        input_set_drvdata(idev, ts);
 336
 337        input_set_capability(idev, EV_KEY, BTN_TOUCH);
 338        input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
 339        input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
 340        input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
 341
 342        touchscreen_parse_properties(idev, false, &ts->prop);
 343
 344        error = input_register_device(idev);
 345        if (error) {
 346                dev_err(&pdev->dev, "Could not register input device\n");
 347                return error;
 348        }
 349
 350        return 0;
 351}
 352
 353static int stmpe_ts_remove(struct platform_device *pdev)
 354{
 355        struct stmpe_touch *ts = platform_get_drvdata(pdev);
 356
 357        stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
 358
 359        return 0;
 360}
 361
 362static struct platform_driver stmpe_ts_driver = {
 363        .driver = {
 364                .name = STMPE_TS_NAME,
 365        },
 366        .probe = stmpe_input_probe,
 367        .remove = stmpe_ts_remove,
 368};
 369module_platform_driver(stmpe_ts_driver);
 370
 371static const struct of_device_id stmpe_ts_ids[] = {
 372        { .compatible = "st,stmpe-ts", },
 373        { },
 374};
 375MODULE_DEVICE_TABLE(of, stmpe_ts_ids);
 376
 377MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 378MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
 379MODULE_LICENSE("GPL");
 380