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 architecture
  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/delay.h>
  29 #include <linux/irq.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/wm97xx.h>
  32 #include <linux/io.h>
  33 #include <linux/gpio.h>
  34
  35 #include <mach/regs-ac97.h>
  36
  37 #include <asm/mach-types.h>
  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 static int irq;
  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         unsigned int count;
 117
 118         schedule_timeout_uninterruptible(1);
 119
 120         for (count = 0; count < 16; count++)
 121                 MODR;
 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          * threshold 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                 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 156                         x, y, p);
 157
 158                 /* are samples valid */
 159                 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 160                     (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 161                     (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 162                         goto up;
 163
 164                 /* coordinate is good */
 165                 tries = 0;
 166                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 167                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 168                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 169                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 170                 input_sync(wm->input_dev);
 171                 reads++;
 172         } while (reads < cinfo[sp_idx].reads);
 173 up:
 174         return RC_PENDOWN | RC_AGAIN;
 175 }
 176
 177 static int wm97xx_acc_startup(struct wm97xx *wm)
 178 {
 179         int idx = 0, ret = 0;
 180
 181         /* check we have a codec */
 182         if (wm->ac97 == NULL)
 183                 return -ENODEV;
 184
 185         /* Go you big red fire engine */
 186         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 187                 if (wm->id != cinfo[idx].id)
 188                         continue;
 189                 sp_idx = idx;
 190                 if (cont_rate <= cinfo[idx].speed)
 191                         break;
 192         }
 193         wm->acc_rate = cinfo[sp_idx].code;
 194         wm->acc_slot = ac97_touch_slot;
 195         dev_info(wm->dev,
 196                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
 197                  cinfo[sp_idx].speed);
 198
 199         /* IRQ driven touchscreen is used on Palm hardware */
 200         if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
 201                 pen_int = 1;
 202                 irq = 27;
 203                 /* There is some obscure mutant of WM9712 interbred with WM9713
 204                  * used on Palm HW */
 205                 wm->variant = WM97xx_WM1613;
 206         } else if (machine_is_mainstone() && pen_int)
 207                 irq = 4;
 208
 209         if (irq) {
 210                 ret = gpio_request(irq, "Touchscreen IRQ");
 211                 if (ret)
 212                         goto out;
 213
 214                 ret = gpio_direction_input(irq);
 215                 if (ret) {
 216                         gpio_free(irq);
 217                         goto out;
 218                 }
 219
 220                 wm->pen_irq = gpio_to_irq(irq);
 221                 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 222         } else /* pen irq not supported */
 223                 pen_int = 0;
 224
 225         /* codec specific irq config */
 226         if (pen_int) {
 227                 switch (wm->id) {
 228                 case WM9705_ID2:
 229                         break;
 230                 case WM9712_ID2:
 231                 case WM9713_ID2:
 232                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
 233                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 234                                            WM97XX_GPIO_POL_HIGH,
 235                                            WM97XX_GPIO_STICKY,
 236                                            WM97XX_GPIO_WAKE);
 237                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 238                                            WM97XX_GPIO_POL_HIGH,
 239                                            WM97XX_GPIO_NOTSTICKY,
 240                                            WM97XX_GPIO_NOWAKE);
 241                         break;
 242                 default:
 243                         dev_err(wm->dev,
 244                                 "pen down irq not supported on this device\n");
 245                         pen_int = 0;
 246                         break;
 247                 }
 248         }
 249
 250 out:
 251         return ret;
 252 }
 253
 254 static void wm97xx_acc_shutdown(struct wm97xx *wm)
 255 {
 256         /* codec specific deconfig */
 257         if (pen_int) {
 258                 if (irq)
 259                         gpio_free(irq);
 260                 wm->pen_irq = 0;
 261         }
 262 }
 263
 264 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 265 {
 266         if (enable)
 267                 enable_irq(wm->pen_irq);
 268         else
 269                 disable_irq_nosync(wm->pen_irq);
 270 }
 271
 272 static struct wm97xx_mach_ops mainstone_mach_ops = {
 273         .acc_enabled = 1,
 274         .acc_pen_up = wm97xx_acc_pen_up,
 275         .acc_pen_down = wm97xx_acc_pen_down,
 276         .acc_startup = wm97xx_acc_startup,
 277         .acc_shutdown = wm97xx_acc_shutdown,
 278         .irq_enable = wm97xx_irq_enable,
 279         .irq_gpio = WM97XX_GPIO_2,
 280 };
 281
 282 static int mainstone_wm97xx_probe(struct platform_device *pdev)
 283 {
 284         struct wm97xx *wm = platform_get_drvdata(pdev);
 285
 286         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
 287 }
 288
 289 static int mainstone_wm97xx_remove(struct platform_device *pdev)
 290 {
 291         struct wm97xx *wm = platform_get_drvdata(pdev);
 292
 293         wm97xx_unregister_mach_ops(wm);
 294         return 0;
 295 }
 296
 297 static struct platform_driver mainstone_wm97xx_driver = {
 298         .probe = mainstone_wm97xx_probe,
 299         .remove = mainstone_wm97xx_remove,
 300         .driver = {
 301                 .name = "wm97xx-touch",
 302         },
 303 };
 304 module_platform_driver(mainstone_wm97xx_driver);
 305
 306 /* Module information */
 307 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 308 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 309 MODULE_LICENSE("GPL");