LXR linux/drivers/input/touchscreen/wm831x-ts.c

   1/*
   2 * Touchscreen driver for WM831x PMICs
   3 *
   4 * Copyright 2011 Wolfson Microelectronics plc.
   5 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   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#include <linux/module.h>
  14#include <linux/moduleparam.h>
  15#include <linux/kernel.h>
  16#include <linux/string.h>
  17#include <linux/pm.h>
  18#include <linux/input.h>
  19#include <linux/interrupt.h>
  20#include <linux/io.h>
  21#include <linux/mfd/wm831x/core.h>
  22#include <linux/mfd/wm831x/irq.h>
  23#include <linux/mfd/wm831x/pdata.h>
  24#include <linux/platform_device.h>
  25#include <linux/slab.h>
  26#include <linux/types.h>
  27
  28/*
  29 * R16424 (0x4028) - Touch Control 1
  30 */
  31#define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
  32#define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
  33#define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
  34#define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
  35#define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
  36#define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
  37#define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
  38#define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
  39#define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
  40#define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
  41#define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
  42#define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */
  43
  44/*
  45 * R16425 (0x4029) - Touch Control 2
  46 */
  47#define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
  48#define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
  49#define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
  50#define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
  51#define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
  52#define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
  53#define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */
  54
  55/*
  56 * R16426-8 (0x402A-C) - Touch Data X/Y/X
  57 */
  58#define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
  59#define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
  60#define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
  61#define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */
  62
  63struct wm831x_ts {
  64        struct input_dev *input_dev;
  65        struct wm831x *wm831x;
  66        unsigned int data_irq;
  67        unsigned int pd_irq;
  68        bool pressure;
  69        bool pen_down;
  70        struct work_struct pd_data_work;
  71};
  72
  73static void wm831x_pd_data_work(struct work_struct *work)
  74{
  75        struct wm831x_ts *wm831x_ts =
  76                container_of(work, struct wm831x_ts, pd_data_work);
  77
  78        if (wm831x_ts->pen_down) {
  79                enable_irq(wm831x_ts->data_irq);
  80                dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
  81        } else {
  82                enable_irq(wm831x_ts->pd_irq);
  83                dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
  84        }
  85}
  86
  87static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
  88{
  89        struct wm831x_ts *wm831x_ts = irq_data;
  90        struct wm831x *wm831x = wm831x_ts->wm831x;
  91        static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
  92        u16 data[3];
  93        int count;
  94        int i, ret;
  95
  96        if (wm831x_ts->pressure)
  97                count = 3;
  98        else
  99                count = 2;
 100
 101        wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 102                        WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 103
 104        ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
 105                               data);
 106        if (ret != 0) {
 107                dev_err(wm831x->dev, "Failed to read touch data: %d\n",
 108                        ret);
 109                return IRQ_NONE;
 110        }
 111
 112        /*
 113         * We get a pen down reading on every reading, report pen up if any
 114         * individual reading does so.
 115         */
 116        wm831x_ts->pen_down = true;
 117        for (i = 0; i < count; i++) {
 118                if (!(data[i] & WM831X_TCH_PD)) {
 119                        wm831x_ts->pen_down = false;
 120                        continue;
 121                }
 122                input_report_abs(wm831x_ts->input_dev, data_types[i],
 123                                 data[i] & WM831X_TCH_DATA_MASK);
 124        }
 125
 126        if (!wm831x_ts->pen_down) {
 127                /* Switch from data to pen down */
 128                dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
 129
 130                disable_irq_nosync(wm831x_ts->data_irq);
 131
 132                /* Don't need data any more */
 133                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 134                                WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 135                                WM831X_TCH_Z_ENA, 0);
 136
 137                /* Flush any final samples that arrived while reading */
 138                wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 139                                WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 140
 141                wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
 142
 143                if (wm831x_ts->pressure)
 144                        input_report_abs(wm831x_ts->input_dev,
 145                                         ABS_PRESSURE, 0);
 146
 147                input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
 148
 149                schedule_work(&wm831x_ts->pd_data_work);
 150        } else {
 151                input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
 152        }
 153
 154        input_sync(wm831x_ts->input_dev);
 155
 156        return IRQ_HANDLED;
 157}
 158
 159static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
 160{
 161        struct wm831x_ts *wm831x_ts = irq_data;
 162        struct wm831x *wm831x = wm831x_ts->wm831x;
 163        int ena = 0;
 164
 165        if (wm831x_ts->pen_down)
 166                return IRQ_HANDLED;
 167
 168        disable_irq_nosync(wm831x_ts->pd_irq);
 169
 170        /* Start collecting data */
 171        if (wm831x_ts->pressure)
 172                ena |= WM831X_TCH_Z_ENA;
 173
 174        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 175                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
 176                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
 177
 178        wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 179                        WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
 180
 181        wm831x_ts->pen_down = true;
 182
 183        /* Switch from pen down to data */
 184        dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
 185        schedule_work(&wm831x_ts->pd_data_work);
 186
 187        return IRQ_HANDLED;
 188}
 189
 190static int wm831x_ts_input_open(struct input_dev *idev)
 191{
 192        struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 193        struct wm831x *wm831x = wm831x_ts->wm831x;
 194
 195        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 196                        WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
 197                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 198                        WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
 199
 200        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 201                        WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
 202
 203        return 0;
 204}
 205
 206static void wm831x_ts_input_close(struct input_dev *idev)
 207{
 208        struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 209        struct wm831x *wm831x = wm831x_ts->wm831x;
 210
 211        /* Shut the controller down, disabling all other functionality too */
 212        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 213                        WM831X_TCH_ENA | WM831X_TCH_X_ENA |
 214                        WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
 215
 216        /* Make sure any pending IRQs are done, the above will prevent
 217         * new ones firing.
 218         */
 219        synchronize_irq(wm831x_ts->data_irq);
 220        synchronize_irq(wm831x_ts->pd_irq);
 221
 222        /* Make sure the IRQ completion work is quiesced */
 223        flush_work(&wm831x_ts->pd_data_work);
 224
 225        /* If we ended up with the pen down then make sure we revert back
 226         * to pen detection state for the next time we start up.
 227         */
 228        if (wm831x_ts->pen_down) {
 229                disable_irq(wm831x_ts->data_irq);
 230                enable_irq(wm831x_ts->pd_irq);
 231                wm831x_ts->pen_down = false;
 232        }
 233}
 234
 235static int wm831x_ts_probe(struct platform_device *pdev)
 236{
 237        struct wm831x_ts *wm831x_ts;
 238        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 239        struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
 240        struct wm831x_touch_pdata *pdata = NULL;
 241        struct input_dev *input_dev;
 242        int error, irqf;
 243
 244        if (core_pdata)
 245                pdata = core_pdata->touch;
 246
 247        wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
 248                                 GFP_KERNEL);
 249        input_dev = devm_input_allocate_device(&pdev->dev);
 250        if (!wm831x_ts || !input_dev) {
 251                error = -ENOMEM;
 252                goto err_alloc;
 253        }
 254
 255        wm831x_ts->wm831x = wm831x;
 256        wm831x_ts->input_dev = input_dev;
 257        INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
 258
 259        /*
 260         * If we have a direct IRQ use it, otherwise use the interrupt
 261         * from the WM831x IRQ controller.
 262         */
 263        wm831x_ts->data_irq = wm831x_irq(wm831x,
 264                                         platform_get_irq_byname(pdev,
 265                                                                 "TCHDATA"));
 266        if (pdata && pdata->data_irq)
 267                wm831x_ts->data_irq = pdata->data_irq;
 268
 269        wm831x_ts->pd_irq = wm831x_irq(wm831x,
 270                                       platform_get_irq_byname(pdev, "TCHPD"));
 271        if (pdata && pdata->pd_irq)
 272                wm831x_ts->pd_irq = pdata->pd_irq;
 273
 274        if (pdata)
 275                wm831x_ts->pressure = pdata->pressure;
 276        else
 277                wm831x_ts->pressure = true;
 278
 279        /* Five wire touchscreens can't report pressure */
 280        if (pdata && pdata->fivewire) {
 281                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 282                                WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
 283
 284                /* Pressure measurements are not possible for five wire mode */
 285                WARN_ON(pdata->pressure && pdata->fivewire);
 286                wm831x_ts->pressure = false;
 287        } else {
 288                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 289                                WM831X_TCH_5WIRE, 0);
 290        }
 291
 292        if (pdata) {
 293                switch (pdata->isel) {
 294                default:
 295                        dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
 296                                pdata->isel);
 297                        /* Fall through */
 298                case 200:
 299                case 0:
 300                        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 301                                        WM831X_TCH_ISEL, 0);
 302                        break;
 303                case 400:
 304                        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 305                                        WM831X_TCH_ISEL, WM831X_TCH_ISEL);
 306                        break;
 307                }
 308        }
 309
 310        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 311                        WM831X_TCH_PDONLY, 0);
 312
 313        /* Default to 96 samples/sec */
 314        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 315                        WM831X_TCH_RATE_MASK, 6);
 316
 317        if (pdata && pdata->data_irqf)
 318                irqf = pdata->data_irqf;
 319        else
 320                irqf = IRQF_TRIGGER_HIGH;
 321
 322        error = request_threaded_irq(wm831x_ts->data_irq,
 323                                     NULL, wm831x_ts_data_irq,
 324                                     irqf | IRQF_ONESHOT,
 325                                     "Touchscreen data", wm831x_ts);
 326        if (error) {
 327                dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
 328                        wm831x_ts->data_irq, error);
 329                goto err_alloc;
 330        }
 331        disable_irq(wm831x_ts->data_irq);
 332
 333        if (pdata && pdata->pd_irqf)
 334                irqf = pdata->pd_irqf;
 335        else
 336                irqf = IRQF_TRIGGER_HIGH;
 337
 338        error = request_threaded_irq(wm831x_ts->pd_irq,
 339                                     NULL, wm831x_ts_pen_down_irq,
 340                                     irqf | IRQF_ONESHOT,
 341                                     "Touchscreen pen down", wm831x_ts);
 342        if (error) {
 343                dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
 344                        wm831x_ts->pd_irq, error);
 345                goto err_data_irq;
 346        }
 347
 348        /* set up touch configuration */
 349        input_dev->name = "WM831x touchscreen";
 350        input_dev->phys = "wm831x";
 351        input_dev->open = wm831x_ts_input_open;
 352        input_dev->close = wm831x_ts_input_close;
 353
 354        __set_bit(EV_ABS, input_dev->evbit);
 355        __set_bit(EV_KEY, input_dev->evbit);
 356        __set_bit(BTN_TOUCH, input_dev->keybit);
 357
 358        input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
 359        input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
 360        if (wm831x_ts->pressure)
 361                input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
 362
 363        input_set_drvdata(input_dev, wm831x_ts);
 364        input_dev->dev.parent = &pdev->dev;
 365
 366        error = input_register_device(input_dev);
 367        if (error)
 368                goto err_pd_irq;
 369
 370        platform_set_drvdata(pdev, wm831x_ts);
 371        return 0;
 372
 373err_pd_irq:
 374        free_irq(wm831x_ts->pd_irq, wm831x_ts);
 375err_data_irq:
 376        free_irq(wm831x_ts->data_irq, wm831x_ts);
 377err_alloc:
 378
 379        return error;
 380}
 381
 382static int wm831x_ts_remove(struct platform_device *pdev)
 383{
 384        struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
 385
 386        free_irq(wm831x_ts->pd_irq, wm831x_ts);
 387        free_irq(wm831x_ts->data_irq, wm831x_ts);
 388
 389        return 0;
 390}
 391
 392static struct platform_driver wm831x_ts_driver = {
 393        .driver = {
 394                .name = "wm831x-touch",
 395        },
 396        .probe = wm831x_ts_probe,
 397        .remove = wm831x_ts_remove,
 398};
 399module_platform_driver(wm831x_ts_driver);
 400
 401/* Module information */
 402MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 403MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
 404MODULE_LICENSE("GPL");
 405MODULE_ALIAS("platform:wm831x-touch");
 406