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/init.h>
  24#include <linux/delay.h>
  25#include <linux/gpio.h>
  26#include <linux/irq.h>
  27#include <linux/interrupt.h>
  28#include <linux/io.h>
  29#include <linux/wm97xx.h>
  30
  31#include <mach/hardware.h>
  32#include <mach/mfp.h>
  33#include <mach/regs-ac97.h>
  34
  35struct continuous {
  36        u16 id;    /* codec id */
  37        u8 code;   /* continuous code */
  38        u8 reads;  /* number of coord reads per read cycle */
  39        u32 speed; /* number of coords per second */
  40};
  41
  42#define WM_READS(sp) ((sp / HZ) + 1)
  43
  44static const struct continuous cinfo[] = {
  45        { WM9713_ID2, 0, WM_READS(94),  94  },
  46        { WM9713_ID2, 1, WM_READS(120), 120 },
  47        { WM9713_ID2, 2, WM_READS(154), 154 },
  48        { WM9713_ID2, 3, WM_READS(188), 188 },
  49};
  50
  51/* continuous speed index */
  52static int sp_idx;
  53
  54/*
  55 * Pen sampling frequency (Hz) in continuous mode.
  56 */
  57static int cont_rate = 200;
  58module_param(cont_rate, int, 0);
  59MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  60
  61/*
  62 * Pressure readback.
  63 *
  64 * Set to 1 to read back pen down pressure
  65 */
  66static int pressure;
  67module_param(pressure, int, 0);
  68MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  69
  70/*
  71 * AC97 touch data slot.
  72 *
  73 * Touch screen readback data ac97 slot
  74 */
  75static int ac97_touch_slot = 5;
  76module_param(ac97_touch_slot, int, 0);
  77MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  78
  79
  80/* flush AC97 slot 5 FIFO machines */
  81static void wm97xx_acc_pen_up(struct wm97xx *wm)
  82{
  83        int i;
  84
  85        msleep(1);
  86
  87        for (i = 0; i < 16; i++)
  88                MODR;
  89}
  90
  91static int wm97xx_acc_pen_down(struct wm97xx *wm)
  92{
  93        u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
  94        int reads = 0;
  95        static u16 last, tries;
  96
  97        /* When the AC97 queue has been drained we need to allow time
  98         * to buffer up samples otherwise we end up spinning polling
  99         * for samples.  The controller can't have a suitably low
 100         * threshold set to use the notifications it gives.
 101         */
 102        msleep(1);
 103
 104        if (tries > 5) {
 105                tries = 0;
 106                return RC_PENUP;
 107        }
 108
 109        x = MODR;
 110        if (x == last) {
 111                tries++;
 112                return RC_AGAIN;
 113        }
 114        last = x;
 115        do {
 116                if (reads)
 117                        x = MODR;
 118                y = MODR;
 119                if (pressure)
 120                        p = MODR;
 121
 122                dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 123                        x, y, p);
 124
 125                /* are samples valid */
 126                if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 127                    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 128                    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 129                        goto up;
 130
 131                /* coordinate is good */
 132                tries = 0;
 133                input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 134                input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 135                input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 136                input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 137                input_sync(wm->input_dev);
 138                reads++;
 139        } while (reads < cinfo[sp_idx].reads);
 140up:
 141        return RC_PENDOWN | RC_AGAIN;
 142}
 143
 144static int wm97xx_acc_startup(struct wm97xx *wm)
 145{
 146        int idx;
 147
 148        /* check we have a codec */
 149        if (wm->ac97 == NULL)
 150                return -ENODEV;
 151
 152        /* Go you big red fire engine */
 153        for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 154                if (wm->id != cinfo[idx].id)
 155                        continue;
 156                sp_idx = idx;
 157                if (cont_rate <= cinfo[idx].speed)
 158                        break;
 159        }
 160        wm->acc_rate = cinfo[sp_idx].code;
 161        wm->acc_slot = ac97_touch_slot;
 162        dev_info(wm->dev,
 163                 "zylonite accelerated touchscreen driver, %d samples/sec\n",
 164                 cinfo[sp_idx].speed);
 165
 166        return 0;
 167}
 168
 169static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 170{
 171        if (enable)
 172                enable_irq(wm->pen_irq);
 173        else
 174                disable_irq_nosync(wm->pen_irq);
 175}
 176
 177static struct wm97xx_mach_ops zylonite_mach_ops = {
 178        .acc_enabled    = 1,
 179        .acc_pen_up     = wm97xx_acc_pen_up,
 180        .acc_pen_down   = wm97xx_acc_pen_down,
 181        .acc_startup    = wm97xx_acc_startup,
 182        .irq_enable     = wm97xx_irq_enable,
 183        .irq_gpio       = WM97XX_GPIO_2,
 184};
 185
 186static int zylonite_wm97xx_probe(struct platform_device *pdev)
 187{
 188        struct wm97xx *wm = platform_get_drvdata(pdev);
 189        int gpio_touch_irq;
 190
 191        if (cpu_is_pxa320())
 192                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
 193        else
 194                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
 195
 196        wm->pen_irq = gpio_to_irq(gpio_touch_irq);
 197        irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 198
 199        wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 200                           WM97XX_GPIO_POL_HIGH,
 201                           WM97XX_GPIO_STICKY,
 202                           WM97XX_GPIO_WAKE);
 203        wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 204                           WM97XX_GPIO_POL_HIGH,
 205                           WM97XX_GPIO_NOTSTICKY,
 206                           WM97XX_GPIO_NOWAKE);
 207
 208        return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
 209}
 210
 211static int zylonite_wm97xx_remove(struct platform_device *pdev)
 212{
 213        struct wm97xx *wm = platform_get_drvdata(pdev);
 214
 215        wm97xx_unregister_mach_ops(wm);
 216
 217        return 0;
 218}
 219
 220static struct platform_driver zylonite_wm97xx_driver = {
 221        .probe  = zylonite_wm97xx_probe,
 222        .remove = zylonite_wm97xx_remove,
 223        .driver = {
 224                .name   = "wm97xx-touch",
 225        },
 226};
 227module_platform_driver(zylonite_wm97xx_driver);
 228
 229/* Module information */
 230MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 231MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 232MODULE_LICENSE("GPL");
 233