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/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
  34 struct 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
  43 static 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 */
  51 static int sp_idx;
  52
  53 /*
  54  * Pen sampling frequency (Hz) in continuous mode.
  55  */
  56 static int cont_rate = 200;
  57 module_param(cont_rate, int, 0);
  58 MODULE_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  */
  65 static int pressure;
  66 module_param(pressure, int, 0);
  67 MODULE_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  */
  74 static int ac97_touch_slot = 5;
  75 module_param(ac97_touch_slot, int, 0);
  76 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  77
  78
  79 /* flush AC97 slot 5 FIFO machines */
  80 static 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
  90 static 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          * threashold 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                 /* are samples valid */
 122                 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X ||
 123                     (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y ||
 124                     (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES)
 125                         goto up;
 126
 127                 /* coordinate is good */
 128                 tries = 0;
 129                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 130                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 131                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 132                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 133                 input_sync(wm->input_dev);
 134                 reads++;
 135         } while (reads < cinfo[sp_idx].reads);
 136 up:
 137         return RC_PENDOWN | RC_AGAIN;
 138 }
 139
 140 static int wm97xx_acc_startup(struct wm97xx *wm)
 141 {
 142         int idx;
 143
 144         /* check we have a codec */
 145         if (wm->ac97 == NULL)
 146                 return -ENODEV;
 147
 148         /* Go you big red fire engine */
 149         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 150                 if (wm->id != cinfo[idx].id)
 151                         continue;
 152                 sp_idx = idx;
 153                 if (cont_rate <= cinfo[idx].speed)
 154                         break;
 155         }
 156         wm->acc_rate = cinfo[sp_idx].code;
 157         wm->acc_slot = ac97_touch_slot;
 158         dev_info(wm->dev,
 159                  "zylonite accelerated touchscreen driver, %d samples/sec\n",
 160                  cinfo[sp_idx].speed);
 161
 162         return 0;
 163 }
 164
 165 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 166 {
 167         if (enable)
 168                 enable_irq(wm->pen_irq);
 169         else
 170                 disable_irq_nosync(wm->pen_irq);
 171 }
 172
 173 static struct wm97xx_mach_ops zylonite_mach_ops = {
 174         .acc_enabled    = 1,
 175         .acc_pen_up     = wm97xx_acc_pen_up,
 176         .acc_pen_down   = wm97xx_acc_pen_down,
 177         .acc_startup    = wm97xx_acc_startup,
 178         .irq_enable     = wm97xx_irq_enable,
 179         .irq_gpio       = WM97XX_GPIO_2,
 180 };
 181
 182 static int zylonite_wm97xx_probe(struct platform_device *pdev)
 183 {
 184         struct wm97xx *wm = platform_get_drvdata(pdev);
 185         int gpio_touch_irq;
 186
 187         if (cpu_is_pxa320())
 188                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
 189         else
 190                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
 191
 192         wm->pen_irq = IRQ_GPIO(gpio_touch_irq);
 193         set_irq_type(IRQ_GPIO(gpio_touch_irq), IRQ_TYPE_EDGE_BOTH);
 194
 195         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 196                            WM97XX_GPIO_POL_HIGH,
 197                            WM97XX_GPIO_STICKY,
 198                            WM97XX_GPIO_WAKE);
 199         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 200                            WM97XX_GPIO_POL_HIGH,
 201                            WM97XX_GPIO_NOTSTICKY,
 202                            WM97XX_GPIO_NOWAKE);
 203
 204         return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
 205 }
 206
 207 static int zylonite_wm97xx_remove(struct platform_device *pdev)
 208 {
 209         struct wm97xx *wm = platform_get_drvdata(pdev);
 210
 211         wm97xx_unregister_mach_ops(wm);
 212
 213         return 0;
 214 }
 215
 216 static struct platform_driver zylonite_wm97xx_driver = {
 217         .probe  = zylonite_wm97xx_probe,
 218         .remove = zylonite_wm97xx_remove,
 219         .driver = {
 220                 .name   = "wm97xx-touch",
 221         },
 222 };
 223
 224 static int __init zylonite_wm97xx_init(void)
 225 {
 226         return platform_driver_register(&zylonite_wm97xx_driver);
 227 }
 228
 229 static void __exit zylonite_wm97xx_exit(void)
 230 {
 231         platform_driver_unregister(&zylonite_wm97xx_driver);
 232 }
 233
 234 module_init(zylonite_wm97xx_init);
 235 module_exit(zylonite_wm97xx_exit);
 236
 237 /* Module information */
 238 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 239 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 240 MODULE_LICENSE("GPL");