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