drivers/input/touchscreen/mainstone-wm97xx.c

   1 /*
   2  * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
   3  *                         Wolfson WM97xx AC97 Codecs.
   4  *
   5  * Copyright 2004, 2007 Wolfson Microelectronics PLC.
   6  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
   7  * Parts Copyright : Ian Molton <spyro@f2s.com>
   8  *                   Andrew Zabolotny <zap@homelink.ru>
   9  *
  10  *  This program is free software; you can redistribute  it and/or modify it
  11  *  under  the terms of  the GNU General  Public License as published by the
  12  *  Free Software Foundation;  either version 2 of the  License, or (at your
  13  *  option) any later version.
  14  *
  15  * Notes:
  16  *     This is a wm97xx extended touch driver to capture touch
  17  *     data in a continuous manner on the Intel XScale archictecture
  18  *
  19  *  Features:
  20  *       - codecs supported:- WM9705, WM9712, WM9713
  21  *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
  22  *
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/delay.h>
  30 #include <linux/irq.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/wm97xx.h>
  33 #include <linux/io.h>
  34 #include <mach/regs-ac97.h>
  35
  36 #define VERSION         "0.13"
  37
  38 struct continuous {
  39         u16 id;    /* codec id */
  40         u8 code;   /* continuous code */
  41         u8 reads;  /* number of coord reads per read cycle */
  42         u32 speed; /* number of coords per second */
  43 };
  44
  45 #define WM_READS(sp) ((sp / HZ) + 1)
  46
  47 static const struct continuous cinfo[] = {
  48         {WM9705_ID2, 0, WM_READS(94), 94},
  49         {WM9705_ID2, 1, WM_READS(188), 188},
  50         {WM9705_ID2, 2, WM_READS(375), 375},
  51         {WM9705_ID2, 3, WM_READS(750), 750},
  52         {WM9712_ID2, 0, WM_READS(94), 94},
  53         {WM9712_ID2, 1, WM_READS(188), 188},
  54         {WM9712_ID2, 2, WM_READS(375), 375},
  55         {WM9712_ID2, 3, WM_READS(750), 750},
  56         {WM9713_ID2, 0, WM_READS(94), 94},
  57         {WM9713_ID2, 1, WM_READS(120), 120},
  58         {WM9713_ID2, 2, WM_READS(154), 154},
  59         {WM9713_ID2, 3, WM_READS(188), 188},
  60 };
  61
  62 /* continuous speed index */
  63 static int sp_idx;
  64 static u16 last, tries;
  65
  66 /*
  67  * Pen sampling frequency (Hz) in continuous mode.
  68  */
  69 static int cont_rate = 200;
  70 module_param(cont_rate, int, 0);
  71 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  72
  73 /*
  74  * Pen down detection.
  75  *
  76  * This driver can either poll or use an interrupt to indicate a pen down
  77  * event. If the irq request fails then it will fall back to polling mode.
  78  */
  79 static int pen_int;
  80 module_param(pen_int, int, 0);
  81 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
  82
  83 /*
  84  * Pressure readback.
  85  *
  86  * Set to 1 to read back pen down pressure
  87  */
  88 static int pressure;
  89 module_param(pressure, int, 0);
  90 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  91
  92 /*
  93  * AC97 touch data slot.
  94  *
  95  * Touch screen readback data ac97 slot
  96  */
  97 static int ac97_touch_slot = 5;
  98 module_param(ac97_touch_slot, int, 0);
  99 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
 100
 101
 102 /* flush AC97 slot 5 FIFO on pxa machines */
 103 #ifdef CONFIG_PXA27x
 104 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 105 {
 106         schedule_timeout_uninterruptible(1);
 107
 108         while (MISR & (1 << 2))
 109                 MODR;
 110 }
 111 #else
 112 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 113 {
 114         unsigned int count;
 115
 116         schedule_timeout_uninterruptible(1);
 117
 118         for (count = 0; count < 16; count++)
 119                 MODR;
 120 }
 121 #endif
 122
 123 static int wm97xx_acc_pen_down(struct wm97xx *wm)
 124 {
 125         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
 126         int reads = 0;
 127
 128         /* When the AC97 queue has been drained we need to allow time
 129          * to buffer up samples otherwise we end up spinning polling
 130          * for samples.  The controller can't have a suitably low
 131          * threashold set to use the notifications it gives.
 132          */
 133         schedule_timeout_uninterruptible(1);
 134
 135         if (tries > 5) {
 136                 tries = 0;
 137                 return RC_PENUP;
 138         }
 139
 140         x = MODR;
 141         if (x == last) {
 142                 tries++;
 143                 return RC_AGAIN;
 144         }
 145         last = x;
 146         do {
 147                 if (reads)
 148                         x = MODR;
 149                 y = MODR;
 150                 if (pressure)
 151                         p = MODR;
 152
 153                 /* are samples valid */
 154                 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X ||
 155                     (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y ||
 156                     (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES)
 157                         goto up;
 158
 159                 /* coordinate is good */
 160                 tries = 0;
 161                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 162                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 163                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 164                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 165                 input_sync(wm->input_dev);
 166                 reads++;
 167         } while (reads < cinfo[sp_idx].reads);
 168 up:
 169         return RC_PENDOWN | RC_AGAIN;
 170 }
 171
 172 static int wm97xx_acc_startup(struct wm97xx *wm)
 173 {
 174         int idx = 0;
 175
 176         /* check we have a codec */
 177         if (wm->ac97 == NULL)
 178                 return -ENODEV;
 179
 180         /* Go you big red fire engine */
 181         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 182                 if (wm->id != cinfo[idx].id)
 183                         continue;
 184                 sp_idx = idx;
 185                 if (cont_rate <= cinfo[idx].speed)
 186                         break;
 187         }
 188         wm->acc_rate = cinfo[sp_idx].code;
 189         wm->acc_slot = ac97_touch_slot;
 190         dev_info(wm->dev,
 191                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
 192                  cinfo[sp_idx].speed);
 193
 194         /* codec specific irq config */
 195         if (pen_int) {
 196                 switch (wm->id) {
 197                 case WM9705_ID2:
 198                         wm->pen_irq = IRQ_GPIO(4);
 199                         set_irq_type(IRQ_GPIO(4), IRQ_TYPE_EDGE_BOTH);
 200                         break;
 201                 case WM9712_ID2:
 202                 case WM9713_ID2:
 203                         /* enable pen down interrupt */
 204                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
 205                         wm->pen_irq = MAINSTONE_AC97_IRQ;
 206                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 207                                            WM97XX_GPIO_POL_HIGH,
 208                                            WM97XX_GPIO_STICKY,
 209                                            WM97XX_GPIO_WAKE);
 210                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 211                                            WM97XX_GPIO_POL_HIGH,
 212                                            WM97XX_GPIO_NOTSTICKY,
 213                                            WM97XX_GPIO_NOWAKE);
 214                         break;
 215                 default:
 216                         dev_err(wm->dev,
 217                                 "pen down irq not supported on this device\n");
 218                         pen_int = 0;
 219                         break;
 220                 }
 221         }
 222
 223         return 0;
 224 }
 225
 226 static void wm97xx_acc_shutdown(struct wm97xx *wm)
 227 {
 228         /* codec specific deconfig */
 229         if (pen_int) {
 230                 switch (wm->id & 0xffff) {
 231                 case WM9705_ID2:
 232                         wm->pen_irq = 0;
 233                         break;
 234                 case WM9712_ID2:
 235                 case WM9713_ID2:
 236                         /* disable interrupt */
 237                         wm->pen_irq = 0;
 238                         break;
 239                 }
 240         }
 241 }
 242
 243 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 244 {
 245         if (enable)
 246                 enable_irq(wm->pen_irq);
 247         else
 248                 disable_irq_nosync(wm->pen_irq);
 249 }
 250
 251 static struct wm97xx_mach_ops mainstone_mach_ops = {
 252         .acc_enabled = 1,
 253         .acc_pen_up = wm97xx_acc_pen_up,
 254         .acc_pen_down = wm97xx_acc_pen_down,
 255         .acc_startup = wm97xx_acc_startup,
 256         .acc_shutdown = wm97xx_acc_shutdown,
 257         .irq_enable = wm97xx_irq_enable,
 258         .irq_gpio = WM97XX_GPIO_2,
 259 };
 260
 261 static int mainstone_wm97xx_probe(struct platform_device *pdev)
 262 {
 263         struct wm97xx *wm = platform_get_drvdata(pdev);
 264
 265         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
 266 }
 267
 268 static int mainstone_wm97xx_remove(struct platform_device *pdev)
 269 {
 270         struct wm97xx *wm = platform_get_drvdata(pdev);
 271
 272         wm97xx_unregister_mach_ops(wm);
 273         return 0;
 274 }
 275
 276 static struct platform_driver mainstone_wm97xx_driver = {
 277         .probe = mainstone_wm97xx_probe,
 278         .remove = mainstone_wm97xx_remove,
 279         .driver = {
 280                 .name = "wm97xx-touch",
 281         },
 282 };
 283
 284 static int __init mainstone_wm97xx_init(void)
 285 {
 286         return platform_driver_register(&mainstone_wm97xx_driver);
 287 }
 288
 289 static void __exit mainstone_wm97xx_exit(void)
 290 {
 291         platform_driver_unregister(&mainstone_wm97xx_driver);
 292 }
 293
 294 module_init(mainstone_wm97xx_init);
 295 module_exit(mainstone_wm97xx_exit);
 296
 297 /* Module information */
 298 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 299 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 300 MODULE_LICENSE("GPL");