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