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 };
  72
  73 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
  74 {
  75         struct wm831x_ts *wm831x_ts = irq_data;
  76         struct wm831x *wm831x = wm831x_ts->wm831x;
  77         static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
  78         u16 data[3];
  79         int count;
  80         int i, ret;
  81
  82         if (wm831x_ts->pressure)
  83                 count = 3;
  84         else
  85                 count = 2;
  86
  87         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
  88                         WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
  89
  90         ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
  91                                data);
  92         if (ret != 0) {
  93                 dev_err(wm831x->dev, "Failed to read touch data: %d\n",
  94                         ret);
  95                 return IRQ_NONE;
  96         }
  97
  98         /*
  99          * We get a pen down reading on every reading, report pen up if any
 100          * individual reading does so.
 101          */
 102         wm831x_ts->pen_down = true;
 103         for (i = 0; i < count; i++) {
 104                 if (!(data[i] & WM831X_TCH_PD)) {
 105                         wm831x_ts->pen_down = false;
 106                         continue;
 107                 }
 108                 input_report_abs(wm831x_ts->input_dev, data_types[i],
 109                                  data[i] & WM831X_TCH_DATA_MASK);
 110         }
 111
 112         if (!wm831x_ts->pen_down) {
 113                 disable_irq_nosync(wm831x_ts->data_irq);
 114
 115                 /* Don't need data any more */
 116                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 117                                 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 118                                 WM831X_TCH_Z_ENA, 0);
 119
 120                 /* Flush any final samples that arrived while reading */
 121                 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 122                                 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 123
 124                 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
 125
 126                 if (wm831x_ts->pressure)
 127                         input_report_abs(wm831x_ts->input_dev,
 128                                          ABS_PRESSURE, 0);
 129
 130                 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
 131         }
 132
 133         input_sync(wm831x_ts->input_dev);
 134
 135         return IRQ_HANDLED;
 136 }
 137
 138 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
 139 {
 140         struct wm831x_ts *wm831x_ts = irq_data;
 141         struct wm831x *wm831x = wm831x_ts->wm831x;
 142         int ena = 0;
 143
 144         /* Start collecting data */
 145         if (wm831x_ts->pressure)
 146                 ena |= WM831X_TCH_Z_ENA;
 147
 148         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 149                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
 150                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
 151
 152         input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
 153         input_sync(wm831x_ts->input_dev);
 154
 155         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 156                         WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
 157
 158         wm831x_ts->pen_down = true;
 159         enable_irq(wm831x_ts->data_irq);
 160
 161         return IRQ_HANDLED;
 162 }
 163
 164 static int wm831x_ts_input_open(struct input_dev *idev)
 165 {
 166         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 167         struct wm831x *wm831x = wm831x_ts->wm831x;
 168
 169         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 170                         WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
 171                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 172                         WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
 173
 174         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 175                         WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
 176
 177         return 0;
 178 }
 179
 180 static void wm831x_ts_input_close(struct input_dev *idev)
 181 {
 182         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 183         struct wm831x *wm831x = wm831x_ts->wm831x;
 184
 185         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 186                         WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
 187                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 188                         WM831X_TCH_Z_ENA, 0);
 189
 190         if (wm831x_ts->pen_down)
 191                 disable_irq(wm831x_ts->data_irq);
 192 }
 193
 194 static __devinit int wm831x_ts_probe(struct platform_device *pdev)
 195 {
 196         struct wm831x_ts *wm831x_ts;
 197         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 198         struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
 199         struct wm831x_touch_pdata *pdata = NULL;
 200         struct input_dev *input_dev;
 201         int error;
 202
 203         if (core_pdata)
 204                 pdata = core_pdata->touch;
 205
 206         wm831x_ts = kzalloc(sizeof(struct wm831x_ts), GFP_KERNEL);
 207         input_dev = input_allocate_device();
 208         if (!wm831x_ts || !input_dev) {
 209                 error = -ENOMEM;
 210                 goto err_alloc;
 211         }
 212
 213         wm831x_ts->wm831x = wm831x;
 214         wm831x_ts->input_dev = input_dev;
 215
 216         /*
 217          * If we have a direct IRQ use it, otherwise use the interrupt
 218          * from the WM831x IRQ controller.
 219          */
 220         if (pdata && pdata->data_irq)
 221                 wm831x_ts->data_irq = pdata->data_irq;
 222         else
 223                 wm831x_ts->data_irq = platform_get_irq_byname(pdev, "TCHDATA");
 224
 225         if (pdata && pdata->pd_irq)
 226                 wm831x_ts->pd_irq = pdata->pd_irq;
 227         else
 228                 wm831x_ts->pd_irq = platform_get_irq_byname(pdev, "TCHPD");
 229
 230         if (pdata)
 231                 wm831x_ts->pressure = pdata->pressure;
 232         else
 233                 wm831x_ts->pressure = true;
 234
 235         /* Five wire touchscreens can't report pressure */
 236         if (pdata && pdata->fivewire) {
 237                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 238                                 WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
 239
 240                 /* Pressure measurements are not possible for five wire mode */
 241                 WARN_ON(pdata->pressure && pdata->fivewire);
 242                 wm831x_ts->pressure = false;
 243         } else {
 244                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 245                                 WM831X_TCH_5WIRE, 0);
 246         }
 247
 248         if (pdata) {
 249                 switch (pdata->isel) {
 250                 default:
 251                         dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
 252                                 pdata->isel);
 253                         /* Fall through */
 254                 case 200:
 255                 case 0:
 256                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 257                                         WM831X_TCH_ISEL, 0);
 258                         break;
 259                 case 400:
 260                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 261                                         WM831X_TCH_ISEL, WM831X_TCH_ISEL);
 262                         break;
 263                 }
 264         }
 265
 266         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 267                         WM831X_TCH_PDONLY, 0);
 268
 269         /* Default to 96 samples/sec */
 270         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 271                         WM831X_TCH_RATE_MASK, 6);
 272
 273         error = request_threaded_irq(wm831x_ts->data_irq,
 274                                      NULL, wm831x_ts_data_irq,
 275                                      IRQF_ONESHOT,
 276                                      "Touchscreen data", wm831x_ts);
 277         if (error) {
 278                 dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
 279                         wm831x_ts->data_irq, error);
 280                 goto err_alloc;
 281         }
 282         disable_irq(wm831x_ts->data_irq);
 283
 284         error = request_threaded_irq(wm831x_ts->pd_irq,
 285                                      NULL, wm831x_ts_pen_down_irq,
 286                                      IRQF_ONESHOT,
 287                                      "Touchscreen pen down", wm831x_ts);
 288         if (error) {
 289                 dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
 290                         wm831x_ts->pd_irq, error);
 291                 goto err_data_irq;
 292         }
 293
 294         /* set up touch configuration */
 295         input_dev->name = "WM831x touchscreen";
 296         input_dev->phys = "wm831x";
 297         input_dev->open = wm831x_ts_input_open;
 298         input_dev->close = wm831x_ts_input_close;
 299
 300         __set_bit(EV_ABS, input_dev->evbit);
 301         __set_bit(EV_KEY, input_dev->evbit);
 302         __set_bit(BTN_TOUCH, input_dev->keybit);
 303
 304         input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
 305         input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
 306         if (wm831x_ts->pressure)
 307                 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
 308
 309         input_set_drvdata(input_dev, wm831x_ts);
 310         input_dev->dev.parent = &pdev->dev;
 311
 312         error = input_register_device(input_dev);
 313         if (error)
 314                 goto err_pd_irq;
 315
 316         platform_set_drvdata(pdev, wm831x_ts);
 317         return 0;
 318
 319 err_pd_irq:
 320         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 321 err_data_irq:
 322         free_irq(wm831x_ts->data_irq, wm831x_ts);
 323 err_alloc:
 324         input_free_device(input_dev);
 325         kfree(wm831x_ts);
 326
 327         return error;
 328 }
 329
 330 static __devexit int wm831x_ts_remove(struct platform_device *pdev)
 331 {
 332         struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
 333
 334         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 335         free_irq(wm831x_ts->data_irq, wm831x_ts);
 336         input_unregister_device(wm831x_ts->input_dev);
 337         kfree(wm831x_ts);
 338
 339         platform_set_drvdata(pdev, NULL);
 340         return 0;
 341 }
 342
 343 static struct platform_driver wm831x_ts_driver = {
 344         .driver = {
 345                 .name = "wm831x-touch",
 346                 .owner = THIS_MODULE,
 347         },
 348         .probe = wm831x_ts_probe,
 349         .remove = __devexit_p(wm831x_ts_remove),
 350 };
 351
 352 static int __init wm831x_ts_init(void)
 353 {
 354         return platform_driver_register(&wm831x_ts_driver);
 355 }
 356 module_init(wm831x_ts_init);
 357
 358 static void __exit wm831x_ts_exit(void)
 359 {
 360         platform_driver_unregister(&wm831x_ts_driver);
 361 }
 362 module_exit(wm831x_ts_exit);
 363
 364 /* Module information */
 365 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 366 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
 367 MODULE_LICENSE("GPL");
 368 MODULE_ALIAS("platform:wm831x-touch");