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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * zylonite-wm97xx.c  --  Zylonite Continuous Touch screen driver
   4 *
   5 * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
   6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7 * Parts Copyright : Ian Molton <spyro@f2s.com>
   8 *                   Andrew Zabolotny <zap@homelink.ru>
   9 *
  10 * Notes:
  11 *     This is a wm97xx extended touch driver supporting interrupt driven
  12 *     and continuous operation on Marvell Zylonite development systems
  13 *     (which have a WM9713 on board).
  14 */
  15
  16#include <linux/module.h>
  17#include <linux/moduleparam.h>
  18#include <linux/kernel.h>
  19#include <linux/delay.h>
  20#include <linux/gpio.h>
  21#include <linux/irq.h>
  22#include <linux/interrupt.h>
  23#include <linux/io.h>
  24#include <linux/wm97xx.h>
  25
  26#include <mach/hardware.h>
  27#include <mach/mfp.h>
  28#include <mach/regs-ac97.h>
  29
  30struct continuous {
  31        u16 id;    /* codec id */
  32        u8 code;   /* continuous code */
  33        u8 reads;  /* number of coord reads per read cycle */
  34        u32 speed; /* number of coords per second */
  35};
  36
  37#define WM_READS(sp) ((sp / HZ) + 1)
  38
  39static const struct continuous cinfo[] = {
  40        { WM9713_ID2, 0, WM_READS(94),  94  },
  41        { WM9713_ID2, 1, WM_READS(120), 120 },
  42        { WM9713_ID2, 2, WM_READS(154), 154 },
  43        { WM9713_ID2, 3, WM_READS(188), 188 },
  44};
  45
  46/* continuous speed index */
  47static int sp_idx;
  48
  49/*
  50 * Pen sampling frequency (Hz) in continuous mode.
  51 */
  52static int cont_rate = 200;
  53module_param(cont_rate, int, 0);
  54MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  55
  56/*
  57 * Pressure readback.
  58 *
  59 * Set to 1 to read back pen down pressure
  60 */
  61static int pressure;
  62module_param(pressure, int, 0);
  63MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  64
  65/*
  66 * AC97 touch data slot.
  67 *
  68 * Touch screen readback data ac97 slot
  69 */
  70static int ac97_touch_slot = 5;
  71module_param(ac97_touch_slot, int, 0);
  72MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  73
  74
  75/* flush AC97 slot 5 FIFO machines */
  76static void wm97xx_acc_pen_up(struct wm97xx *wm)
  77{
  78        int i;
  79
  80        msleep(1);
  81
  82        for (i = 0; i < 16; i++)
  83                MODR;
  84}
  85
  86static int wm97xx_acc_pen_down(struct wm97xx *wm)
  87{
  88        u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
  89        int reads = 0;
  90        static u16 last, tries;
  91
  92        /* When the AC97 queue has been drained we need to allow time
  93         * to buffer up samples otherwise we end up spinning polling
  94         * for samples.  The controller can't have a suitably low
  95         * threshold set to use the notifications it gives.
  96         */
  97        msleep(1);
  98
  99        if (tries > 5) {
 100                tries = 0;
 101                return RC_PENUP;
 102        }
 103
 104        x = MODR;
 105        if (x == last) {
 106                tries++;
 107                return RC_AGAIN;
 108        }
 109        last = x;
 110        do {
 111                if (reads)
 112                        x = MODR;
 113                y = MODR;
 114                if (pressure)
 115                        p = MODR;
 116
 117                dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 118                        x, y, p);
 119
 120                /* are samples valid */
 121                if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 122                    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 123                    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 124                        goto up;
 125
 126                /* coordinate is good */
 127                tries = 0;
 128                input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 129                input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 130                input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 131                input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 132                input_sync(wm->input_dev);
 133                reads++;
 134        } while (reads < cinfo[sp_idx].reads);
 135up:
 136        return RC_PENDOWN | RC_AGAIN;
 137}
 138
 139static int wm97xx_acc_startup(struct wm97xx *wm)
 140{
 141        int idx;
 142
 143        /* check we have a codec */
 144        if (wm->ac97 == NULL)
 145                return -ENODEV;
 146
 147        /* Go you big red fire engine */
 148        for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 149                if (wm->id != cinfo[idx].id)
 150                        continue;
 151                sp_idx = idx;
 152                if (cont_rate <= cinfo[idx].speed)
 153                        break;
 154        }
 155        wm->acc_rate = cinfo[sp_idx].code;
 156        wm->acc_slot = ac97_touch_slot;
 157        dev_info(wm->dev,
 158                 "zylonite accelerated touchscreen driver, %d samples/sec\n",
 159                 cinfo[sp_idx].speed);
 160
 161        return 0;
 162}
 163
 164static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 165{
 166        if (enable)
 167                enable_irq(wm->pen_irq);
 168        else
 169                disable_irq_nosync(wm->pen_irq);
 170}
 171
 172static struct wm97xx_mach_ops zylonite_mach_ops = {
 173        .acc_enabled    = 1,
 174        .acc_pen_up     = wm97xx_acc_pen_up,
 175        .acc_pen_down   = wm97xx_acc_pen_down,
 176        .acc_startup    = wm97xx_acc_startup,
 177        .irq_enable     = wm97xx_irq_enable,
 178        .irq_gpio       = WM97XX_GPIO_2,
 179};
 180
 181static int zylonite_wm97xx_probe(struct platform_device *pdev)
 182{
 183        struct wm97xx *wm = platform_get_drvdata(pdev);
 184        int gpio_touch_irq;
 185
 186        if (cpu_is_pxa320())
 187                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
 188        else
 189                gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
 190
 191        wm->pen_irq = gpio_to_irq(gpio_touch_irq);
 192        irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 193
 194        wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 195                           WM97XX_GPIO_POL_HIGH,
 196                           WM97XX_GPIO_STICKY,
 197                           WM97XX_GPIO_WAKE);
 198        wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 199                           WM97XX_GPIO_POL_HIGH,
 200                           WM97XX_GPIO_NOTSTICKY,
 201                           WM97XX_GPIO_NOWAKE);
 202
 203        return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
 204}
 205
 206static int zylonite_wm97xx_remove(struct platform_device *pdev)
 207{
 208        struct wm97xx *wm = platform_get_drvdata(pdev);
 209
 210        wm97xx_unregister_mach_ops(wm);
 211
 212        return 0;
 213}
 214
 215static struct platform_driver zylonite_wm97xx_driver = {
 216        .probe  = zylonite_wm97xx_probe,
 217        .remove = zylonite_wm97xx_remove,
 218        .driver = {
 219                .name   = "wm97xx-touch",
 220        },
 221};
 222module_platform_driver(zylonite_wm97xx_driver);
 223
 224/* Module information */
 225MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 226MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 227MODULE_LICENSE("GPL");
 228