LXR linux/drivers/input/touchscreen/zylonite-wm97xx.c

   1/*
   2 * zylonite-wm97xx.c  --  Zylonite Continuous Touch screen driver
   3 *
   4 * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
   5 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   6 * Parts Copyright : Ian Molton <spyro@f2s.com>
   7 *                   Andrew Zabolotny <zap@homelink.ru>
   8 *
   9 *  This program is free software; you can redistribute  it and/or modify it
  10 *  under  the terms of  the GNU General  Public License as published by the
  11 *  Free Software Foundation;  either version 2 of the  License, or (at your
  12 *  option) any later version.
  13 *
  14 * Notes:
  15 *     This is a wm97xx extended touch driver supporting interrupt driven
  16 *     and continuous operation on Marvell Zylonite development systems
  17 *     (which have a WM9713 on board).
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/moduleparam.h>
  22#include <linux/kernel.h>
  23#include <linux/delay.h>
  24#include <linux/gpio.h>
  25#include <linux/irq.h>
  26#include <linux/interrupt.h>
  27#include <linux/io.h>
  28#include <linux/wm97xx.h>
  29
  30#include <mach/hardware.h>
  31#include <mach/mfp.h>
  32#include <mach/regs-ac97.h>
  33
  34struct continuous {
  35        u16 id;    /* codec id */
  36        u8 code;   /* continuous code */
  37        u8 reads;  /* number of coord reads per read cycle */
  38        u32 speed; /* number of coords per second */
  39};
  40
  41#define WM_READS(sp) ((sp / HZ) + 1)
  42
  43static const struct continuous cinfo[] = {
  44        { WM9713_ID2, 0, WM_READS(94),  94  },
  45        { WM9713_ID2, 1, WM_READS(120), 120 },
  46        { WM9713_ID2, 2, WM_READS(154), 154 },
  47        { WM9713_ID2, 3, WM_READS(188), 188 },
  48};
  49
  50/* continuous speed index */
  51static int sp_idx;
  52
  53/*
  54 * Pen sampling frequency (Hz) in continuous mode.
  55 */
  56static int cont_rate = 200;
  57module_param(cont_rate, int, 0);
  58MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  59
  60/*
  61 * Pressure readback.
  62 *
  63 * Set to 1 to read back pen down pressure
  64 */
  65static int pressure;
  66module_param(pressure, int, 0);
  67MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  68
  69/*
  70 * AC97 touch data slot.
  71 *
  72 * Touch screen readback data ac97 slot
  73 */
  74static int ac97_touch_slot = 5;
  75module_param(ac97_touch_slot, int, 0);
  76MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  77
  78
  79/* flush AC97 slot 5 FIFO machines */
  80static void wm97xx_acc_pen_up(struct wm97xx *wm)
  81{
  82        int i;
  83
  84        msleep(1);
  85
  86        for (i = 0; i < 16; i++)
  87                MODR;
  88}
  89
  90static int wm97xx_acc_pen_down(struct wm97xx *wm)
  91{
  92        u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
  93        int reads = 0;
  94        static u16 last, tries;
  95
  96        /* When the AC97 queue has been drained we need to allow time
  97         * to buffer up samples otherwise we end up spinning polling
  98         * for samples.  The controller can't have a suitably low
  99         * threshold set to use the notifications it gives.
 100         */
 101        msleep(1);
 102
 103        if (tries > 5) {
 104                tries = 0;
 105                return RC_PENUP;
 106        }
 107
 108        x = MODR;
 109        if (x == last) {
 110                tries++;
 111                return RC_AGAIN;
 112        }
 113        last = x;
 114        do {
 115                if (reads)
 116                        x = MODR;
 117                y = MODR;
 118                if (pressure)
 119                        p = MODR;
 120
 121                dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 122                        x, y, p);
 123
 124                /* are samples valid */
 125                if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 126                    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 127                    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 128                        goto up;
 129
 130                /* coordinate is good */
 131                tries = 0;
 132                input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 133                input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 134                input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 135                input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 136                input_sync(wm->input_dev);
 137                reads++;
 138        } while (reads < cinfo[sp_idx].reads);
 139up:
 140        return RC_PENDOWN | RC_AGAIN;
 141}
 142
 143static int wm97xx_acc_startup(struct wm97xx *wm)
 144{
 145        int idx;
 146
 147        /* check we have a codec */
 148        if (wm->ac97 == NULL)
 149                return -ENODEV;
 150
 151        /* Go you big red fire engine */
 152        for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 153                if (wm->id != cinfo[idx].id)
 154                        continue;
 155                sp_idx = idx;
 156                if (cont_rate <= cinfo[idx].speed)
 157                        break;
 158        }
 159        wm->acc_rate = cinfo[sp_idx].code;
 160        wm->acc_slot = ac97_touch_slot;
 161        dev_info(wm->dev,
 162                 "zylonite accelerated touchscreen driver, %d samples/sec\n",
 163                 cinfo[sp_idx].speed);
 164
 165        return 0;
 166}
 167
 168static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 169{
 170        if (enable)
 171                enable_irq(wm->pen_irq);
 172        else
 173                disable_irq_nosync(wm->pen_irq);
 174}
 175
 176static struct wm97xx_mach_ops zylonite_mach_ops = {
 177        .acc_enabled    = 1,
 178        .acc_pen_up     = wm97xx_acc_pen_up,
 179        .acc_pen_down   = wm97xx_acc_pen_down,
 180        .acc_startup    = wm97xx_acc_startup,
 181        .irq_enable     = wm97xx_irq_enable,
 182        .irq_gpio       = WM97XX_GPIO_2,
 183};
 184
 185static int zylonite_wm97xx_probe(struct platform_device *pdev)
 186{
 187        struct wm97xx *wm = platform_get_drvdata(pdev);
 188        int gpio_touch_irq;
 189
 190        if (cpu_is_pxa320())
 191                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
 192        else
 193                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
 194
 195        wm->pen_irq = gpio_to_irq(gpio_touch_irq);
 196        irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 197
 198        wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 199                           WM97XX_GPIO_POL_HIGH,
 200                           WM97XX_GPIO_STICKY,
 201                           WM97XX_GPIO_WAKE);
 202        wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 203                           WM97XX_GPIO_POL_HIGH,
 204                           WM97XX_GPIO_NOTSTICKY,
 205                           WM97XX_GPIO_NOWAKE);
 206
 207        return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
 208}
 209
 210static int zylonite_wm97xx_remove(struct platform_device *pdev)
 211{
 212        struct wm97xx *wm = platform_get_drvdata(pdev);
 213
 214        wm97xx_unregister_mach_ops(wm);
 215
 216        return 0;
 217}
 218
 219static struct platform_driver zylonite_wm97xx_driver = {
 220        .probe  = zylonite_wm97xx_probe,
 221        .remove = zylonite_wm97xx_remove,
 222        .driver = {
 223                .name   = "wm97xx-touch",
 224        },
 225};
 226module_platform_driver(zylonite_wm97xx_driver);
 227
 228/* Module information */
 229MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 230MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 231MODULE_LICENSE("GPL");
 232