LXR linux/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
  39struct 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
  48static 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 */
  64static int sp_idx;
  65static u16 last, tries;
  66static int irq;
  67
  68/*
  69 * Pen sampling frequency (Hz) in continuous mode.
  70 */
  71static int cont_rate = 200;
  72module_param(cont_rate, int, 0);
  73MODULE_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 */
  81static int pen_int;
  82module_param(pen_int, int, 0);
  83MODULE_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 */
  90static int pressure;
  91module_param(pressure, int, 0);
  92MODULE_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 */
  99static int ac97_touch_slot = 5;
 100module_param(ac97_touch_slot, int, 0);
 101MODULE_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
 106static 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
 114static 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
 125static 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);
 173up:
 174        return RC_PENDOWN | RC_AGAIN;
 175}
 176
 177static 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
 250out:
 251        return ret;
 252}
 253
 254static 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
 264static 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
 272static 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
 282static 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
 289static 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
 297static struct platform_driver mainstone_wm97xx_driver = {
 298        .probe = mainstone_wm97xx_probe,
 299        .remove = mainstone_wm97xx_remove,
 300        .driver = {
 301                .name = "wm97xx-touch",
 302        },
 303};
 304module_platform_driver(mainstone_wm97xx_driver);
 305
 306/* Module information */
 307MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 308MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 309MODULE_LICENSE("GPL");
 310