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