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