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
  35 struct 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
  44 static 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 */
  52 static int sp_idx;
  53
  54 /*
  55  * Pen sampling frequency (Hz) in continuous mode.
  56  */
  57 static int cont_rate = 200;
  58 module_param(cont_rate, int, 0);
  59 MODULE_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  */
  66 static int pressure;
  67 module_param(pressure, int, 0);
  68 MODULE_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  */
  75 static int ac97_touch_slot = 5;
  76 module_param(ac97_touch_slot, int, 0);
  77 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  78
  79
  80 /* flush AC97 slot 5 FIFO machines */
  81 static 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
  91 static 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);
 140 up:
 141         return RC_PENDOWN | RC_AGAIN;
 142 }
 143
 144 static 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
 169 static 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
 177 static 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
 186 static 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
 211 static 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
 220 static struct platform_driver zylonite_wm97xx_driver = {
 221         .probe  = zylonite_wm97xx_probe,
 222         .remove = zylonite_wm97xx_remove,
 223         .driver = {
 224                 .name   = "wm97xx-touch",
 225         },
 226 };
 227 module_platform_driver(zylonite_wm97xx_driver);
 228
 229 /* Module information */
 230 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 231 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 232 MODULE_LICENSE("GPL");