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 <linux/gpio.h>
  35
  36 #include <mach/regs-ac97.h>
  37
  38 #include <asm/mach-types.h>
  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 static int irq;
  68
  69 /*
  70  * Pen sampling frequency (Hz) in continuous mode.
  71  */
  72 static int cont_rate = 200;
  73 module_param(cont_rate, int, 0);
  74 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  75
  76 /*
  77  * Pen down detection.
  78  *
  79  * This driver can either poll or use an interrupt to indicate a pen down
  80  * event. If the irq request fails then it will fall back to polling mode.
  81  */
  82 static int pen_int;
  83 module_param(pen_int, int, 0);
  84 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
  85
  86 /*
  87  * Pressure readback.
  88  *
  89  * Set to 1 to read back pen down pressure
  90  */
  91 static int pressure;
  92 module_param(pressure, int, 0);
  93 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  94
  95 /*
  96  * AC97 touch data slot.
  97  *
  98  * Touch screen readback data ac97 slot
  99  */
 100 static int ac97_touch_slot = 5;
 101 module_param(ac97_touch_slot, int, 0);
 102 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
 103
 104
 105 /* flush AC97 slot 5 FIFO on pxa machines */
 106 #ifdef CONFIG_PXA27x
 107 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 108 {
 109         schedule_timeout_uninterruptible(1);
 110
 111         while (MISR & (1 << 2))
 112                 MODR;
 113 }
 114 #else
 115 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 116 {
 117         unsigned int count;
 118
 119         schedule_timeout_uninterruptible(1);
 120
 121         for (count = 0; count < 16; count++)
 122                 MODR;
 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_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 168                 input_sync(wm->input_dev);
 169                 reads++;
 170         } while (reads < cinfo[sp_idx].reads);
 171 up:
 172         return RC_PENDOWN | RC_AGAIN;
 173 }
 174
 175 static int wm97xx_acc_startup(struct wm97xx *wm)
 176 {
 177         int idx = 0, ret = 0;
 178
 179         /* check we have a codec */
 180         if (wm->ac97 == NULL)
 181                 return -ENODEV;
 182
 183         /* Go you big red fire engine */
 184         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 185                 if (wm->id != cinfo[idx].id)
 186                         continue;
 187                 sp_idx = idx;
 188                 if (cont_rate <= cinfo[idx].speed)
 189                         break;
 190         }
 191         wm->acc_rate = cinfo[sp_idx].code;
 192         wm->acc_slot = ac97_touch_slot;
 193         dev_info(wm->dev,
 194                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
 195                  cinfo[sp_idx].speed);
 196
 197         /* IRQ driven touchscreen is used on Palm hardware */
 198         if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
 199                 pen_int = 1;
 200                 irq = 27;
 201                 /* There is some obscure mutant of WM9712 interbred with WM9713
 202                  * used on Palm HW */
 203                 wm->variant = WM97xx_WM1613;
 204         } else if (machine_is_mainstone() && pen_int)
 205                 irq = 4;
 206
 207         if (irq) {
 208                 ret = gpio_request(irq, "Touchscreen IRQ");
 209                 if (ret)
 210                         goto out;
 211
 212                 ret = gpio_direction_input(irq);
 213                 if (ret) {
 214                         gpio_free(irq);
 215                         goto out;
 216                 }
 217
 218                 wm->pen_irq = gpio_to_irq(irq);
 219                 set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 220         } else /* pen irq not supported */
 221                 pen_int = 0;
 222
 223         /* codec specific irq config */
 224         if (pen_int) {
 225                 switch (wm->id) {
 226                 case WM9705_ID2:
 227                         break;
 228                 case WM9712_ID2:
 229                 case WM9713_ID2:
 230                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
 231                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 232                                            WM97XX_GPIO_POL_HIGH,
 233                                            WM97XX_GPIO_STICKY,
 234                                            WM97XX_GPIO_WAKE);
 235                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 236                                            WM97XX_GPIO_POL_HIGH,
 237                                            WM97XX_GPIO_NOTSTICKY,
 238                                            WM97XX_GPIO_NOWAKE);
 239                         break;
 240                 default:
 241                         dev_err(wm->dev,
 242                                 "pen down irq not supported on this device\n");
 243                         pen_int = 0;
 244                         break;
 245                 }
 246         }
 247
 248 out:
 249         return ret;
 250 }
 251
 252 static void wm97xx_acc_shutdown(struct wm97xx *wm)
 253 {
 254         /* codec specific deconfig */
 255         if (pen_int) {
 256                 if (irq)
 257                         gpio_free(irq);
 258                 wm->pen_irq = 0;
 259         }
 260 }
 261
 262 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 263 {
 264         if (enable)
 265                 enable_irq(wm->pen_irq);
 266         else
 267                 disable_irq_nosync(wm->pen_irq);
 268 }
 269
 270 static struct wm97xx_mach_ops mainstone_mach_ops = {
 271         .acc_enabled = 1,
 272         .acc_pen_up = wm97xx_acc_pen_up,
 273         .acc_pen_down = wm97xx_acc_pen_down,
 274         .acc_startup = wm97xx_acc_startup,
 275         .acc_shutdown = wm97xx_acc_shutdown,
 276         .irq_enable = wm97xx_irq_enable,
 277         .irq_gpio = WM97XX_GPIO_2,
 278 };
 279
 280 static int mainstone_wm97xx_probe(struct platform_device *pdev)
 281 {
 282         struct wm97xx *wm = platform_get_drvdata(pdev);
 283
 284         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
 285 }
 286
 287 static int mainstone_wm97xx_remove(struct platform_device *pdev)
 288 {
 289         struct wm97xx *wm = platform_get_drvdata(pdev);
 290
 291         wm97xx_unregister_mach_ops(wm);
 292         return 0;
 293 }
 294
 295 static struct platform_driver mainstone_wm97xx_driver = {
 296         .probe = mainstone_wm97xx_probe,
 297         .remove = mainstone_wm97xx_remove,
 298         .driver = {
 299                 .name = "wm97xx-touch",
 300         },
 301 };
 302
 303 static int __init mainstone_wm97xx_init(void)
 304 {
 305         return platform_driver_register(&mainstone_wm97xx_driver);
 306 }
 307
 308 static void __exit mainstone_wm97xx_exit(void)
 309 {
 310         platform_driver_unregister(&mainstone_wm97xx_driver);
 311 }
 312
 313 module_init(mainstone_wm97xx_init);
 314 module_exit(mainstone_wm97xx_exit);
 315
 316 /* Module information */
 317 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 318 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 319 MODULE_LICENSE("GPL");