firmware/target/arm/sandisk/sansa-e200/button-e200.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Barry Wardell
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 /* Taken from button-h10.c by Barry Wardell and reverse engineering by MrH. */
  23
  24 #include "system.h"
  25 #include "button.h"
  26 #include "backlight.h"
  27 #include "powermgmt.h"
  28
  29 #define WHEEL_REPEAT_VELOCITY       35 /* deg/s */
  30 #define WHEEL_SMOOTHING_VELOCITY    50 /* deg/s */
  31 #define WHEEL_FAST_ON_VELOCITY     350 /* deg/s */
  32 #define WHEEL_FAST_OFF_VELOCITY    150 /* deg/s */
  33 #define WHEEL_BASE_SENSITIVITY       2
  34 #define WHEELCLICKS_PER_ROTATION    48 /* wheelclicks per full rotation */
  35
  36 #ifndef BOOTLOADER
  37 /* Wheel */
  38 static int read_wheel_keycode(void);
  39 /* Buttons */
  40 static bool hold_button     = false;
  41 static bool hold_button_old = false;
  42 #define _button_hold() hold_button
  43 #else
  44 #define _button_hold() ((GPIOF_INPUT_VAL & 0x80) != 0)
  45 #endif /* BOOTLOADER */
  46 static int  int_btn         = BUTTON_NONE;
  47
  48 void button_init_device(void)
  49 {
  50     /* Enable all buttons */
  51     GPIO_CLEAR_BITWISE(GPIOF_OUTPUT_EN, 0xff);
  52     GPIO_SET_BITWISE(GPIOF_ENABLE, 0xff);
  53
  54     /* Scrollwheel light - enable control through GPIOG pin 7 and set timeout */
  55     GPIO_SET_BITWISE(GPIOG_OUTPUT_EN, 0x80);
  56     GPIO_SET_BITWISE(GPIOG_ENABLE, 0x80);
  57
  58 #ifndef BOOTLOADER
  59     /* Mask these before performing init ... because init has possibly
  60        occurred before */
  61     GPIO_CLEAR_BITWISE(GPIOF_INT_EN, 0xff);
  62     GPIO_CLEAR_BITWISE(GPIOH_INT_EN, 0xc0);
  63
  64     GPIO_CLEAR_BITWISE(GPIOH_OUTPUT_EN, 0xc0);
  65     GPIO_SET_BITWISE(GPIOH_ENABLE, 0xc0);
  66
  67     /* Read initial buttons */
  68     button_int();
  69
  70     /* Read initial wheel value (bit 6-7 of GPIOH) */
  71     read_wheel_keycode();
  72
  73     /* Enable button interrupts */
  74     GPIO_SET_BITWISE(GPIOF_INT_EN, 0xff);
  75     GPIO_SET_BITWISE(GPIOH_INT_EN, 0xc0);
  76
  77     CPU_INT_EN = HI_MASK;
  78     CPU_HI_INT_EN = GPIO1_MASK;
  79 #endif /* BOOTLOADER */
  80 }
  81
  82 bool button_hold(void)
  83 {
  84     return _button_hold();
  85 }
  86
  87 /* clickwheel */
  88 #ifndef BOOTLOADER
  89 static int read_wheel_keycode(void)
  90 {
  91     /* Read wheel
  92      * Bits 6 and 7 of GPIOH change as follows:
  93      * Clockwise rotation   01 -> 00 -> 10 -> 11
  94      * Counter-clockwise    11 -> 10 -> 00 -> 01
  95      *
  96      * This is equivalent to wheel_value of:
  97      * Clockwise rotation   0x40 -> 0x00 -> 0x80 -> 0xc0
  98      * Counter-clockwise    0xc0 -> 0x80 -> 0x00 -> 0x40
  99      */
 100     static const unsigned char wheel_tbl[2][4] =
 101     {
 102        /* 0x00  0x40  0x80  0xc0 */ /* Wheel value        */
 103         { 0x40, 0xc0, 0x00, 0x80 }, /* Clockwise rotation */
 104         { 0x80, 0x00, 0xc0, 0x40 }, /* Counter-clockwise  */
 105     };
 106
 107     static unsigned long prev_value;
 108
 109     int keycode = BUTTON_NONE;
 110
 111     unsigned long value = GPIOH_INPUT_VAL & 0xc0;
 112     GPIO_WRITE_BITWISE(GPIOH_INT_LEV, value ^ 0xc0, 0xc0);
 113     GPIOH_INT_CLR = GPIOH_INT_STAT & 0xc0;
 114
 115     if (!hold_button)
 116     {
 117         unsigned long prev = prev_value;
 118         int scroll = value >> 6;
 119
 120         if (prev == wheel_tbl[0][scroll])
 121             keycode = BUTTON_SCROLL_FWD;
 122         else if (prev == wheel_tbl[1][scroll])
 123             keycode = BUTTON_SCROLL_BACK;
 124     }
 125
 126     prev_value = value;
 127
 128     return keycode;
 129 }
 130
 131 void clickwheel_int(void)
 132 {
 133     static int prev_keycode = BUTTON_NONE;
 134     static int prev_keypost = BUTTON_NONE;
 135     static int count = 0;
 136     static int fast_mode = 0;
 137     static long next_backlight_on = 0;
 138
 139     static unsigned long prev_usec[WHEEL_BASE_SENSITIVITY] = { 0 };
 140     static unsigned long delta = 1ul << 24;
 141     static unsigned long velocity = 0; /* Velocity smoothed or unsmoothed */
 142
 143     unsigned long usec = USEC_TIMER;
 144     unsigned long v; /* Raw velocity */
 145
 146     int keycode = read_wheel_keycode();
 147
 148     if (keycode == BUTTON_NONE)
 149         return;
 150
 151     /* Spurious wheel "reversals" are not uncommon. Resetting also helps
 152      * cover them up. As such, prev_keypost is also not reset or else false
 153      * non-repeats are generated when it happens. */
 154     if (keycode != prev_keycode)
 155     {
 156         /* Direction reversals reset state */
 157         unsigned long usec_back = 360000000ul /
 158                         (WHEEL_REPEAT_VELOCITY*WHEELCLICKS_PER_ROTATION);
 159         prev_keycode = keycode;
 160         count = 0;
 161         fast_mode = 0;
 162         prev_usec[0] = usec - usec_back;
 163         prev_usec[1] = prev_usec[0] - usec_back;
 164         delta = 1ul << 24;
 165         velocity = 0;
 166     }
 167
 168     if (TIME_AFTER(current_tick, next_backlight_on))
 169     {
 170         /* Poke backlight to turn it on or maintain it no more often
 171          * than every 1/4 second */
 172         next_backlight_on = current_tick + HZ/4;
 173         backlight_on();
 174         buttonlight_on();
 175         reset_poweroff_timer();
 176     }
 177
 178     /* Calculate deg/s based upon interval and number of clicks in that
 179      * interval - FIR moving average */
 180     v = usec - prev_usec[1];
 181
 182     if ((long)v <= 0)
 183     {
 184         /* timer wrapped (no activity for awhile), skip acceleration */
 185         v = 0;
 186         delta = 1ul << 24;
 187     }
 188     else
 189     {
 190         /* Check overflow below */
 191         if (v > 0xfffffffful / WHEELCLICKS_PER_ROTATION)
 192             v = 0xfffffffful / WHEELCLICKS_PER_ROTATION;
 193
 194         v = 360000000ul*WHEEL_BASE_SENSITIVITY / (v*WHEELCLICKS_PER_ROTATION);
 195
 196         if (v > 0xfffffful)
 197             v = 0xfffffful; /* limit to 24 bits */
 198     }
 199
 200     prev_usec[1] = prev_usec[0];
 201     prev_usec[0] = usec;
 202
 203     if (v < WHEEL_SMOOTHING_VELOCITY)
 204     {
 205         /* Very slow - no smoothing */
 206         velocity = v;
 207         /* Ensure backlight never gets stuck for an extended period if tick
 208          * wrapped such that next poke is very far ahead */
 209         next_backlight_on = current_tick - 1;
 210     }
 211     else
 212     {
 213         /* Some velocity filtering to smooth things out */
 214         velocity = (7*velocity + v) / 8;
 215     }
 216
 217     if (fast_mode != 0)
 218     {
 219         /* Fast OFF happens immediately when velocity drops below
 220            threshold */
 221         if (v < WHEEL_FAST_OFF_VELOCITY)
 222         {
 223             fast_mode = 0; /* moving out of fast mode */
 224             velocity = v;
 225
 226             /* delta is always 1 in slow mode */
 227             delta = 1ul << 24;
 228         }
 229     }
 230     else
 231     {
 232         /* Fast ON gets filtered to avoid inadvertent jumps to fast mode */
 233         if (velocity >= WHEEL_FAST_ON_VELOCITY)
 234             fast_mode = 1; /* moving into fast mode */
 235
 236         /* delta is always 1 in slow mode */
 237         delta = 1ul << 24;
 238     }
 239
 240     count += fast_mode + 1;
 241     if (count < WHEEL_BASE_SENSITIVITY)
 242         return;
 243
 244     count = 0;
 245
 246     if (queue_empty(&button_queue))
 247     {
 248         /* Post wheel keycode with wheel data */
 249         int key = keycode;
 250
 251         if (v >= WHEEL_REPEAT_VELOCITY && prev_keypost == key)
 252         {
 253             /* Quick enough and same key is being posted more than once in a
 254              * row - generate repeats - use unsmoothed v */
 255             key |= BUTTON_REPEAT;
 256         }
 257
 258         prev_keypost = keycode;
 259
 260         queue_post(&button_queue, key, (fast_mode << 31) | delta | velocity);
 261         /* Message posted - reset delta */
 262         delta = 1ul << 24;
 263     }
 264     else
 265     {
 266         /* Skipped post - increment delta and limit to 7 bits */
 267         delta += 1ul << 24;
 268
 269         if (delta > (0x7ful << 24))
 270             delta = 0x7ful << 24;
 271     }
 272 }
 273 #endif /* BOOTLOADER */
 274
 275 /* device buttons */
 276 void button_int(void)
 277 {
 278     unsigned long state = GPIOF_INPUT_VAL & 0xff;
 279
 280 #ifndef BOOTLOADER
 281     unsigned long status = GPIOF_INT_STAT;
 282
 283     GPIO_WRITE_BITWISE(GPIOF_INT_LEV, state ^ 0xff, 0xff);
 284     GPIOF_INT_CLR = status;
 285
 286     hold_button = (state & 0x80) != 0;
 287 #endif
 288
 289     int_btn = BUTTON_NONE;
 290
 291     if (!_button_hold())
 292     {
 293         /* Read normal buttons */
 294         if ((state & 0x01) == 0) int_btn |= BUTTON_REC;
 295         if ((state & 0x02) == 0) int_btn |= BUTTON_DOWN;
 296         if ((state & 0x04) == 0) int_btn |= BUTTON_RIGHT;
 297         if ((state & 0x08) == 0) int_btn |= BUTTON_LEFT;
 298         if ((state & 0x10) == 0) int_btn |= BUTTON_SELECT; /* The centre button */
 299         if ((state & 0x20) == 0) int_btn |= BUTTON_UP; /* The "play" button */
 300         if ((state & 0x40) != 0) int_btn |= BUTTON_POWER;
 301     }
 302 }
 303
 304 /*
 305  * Get button pressed from hardware
 306  */
 307 int button_read_device(void)
 308 {
 309 #ifdef BOOTLOADER
 310     /* Read buttons directly in the bootloader */
 311     button_int();
 312 #else
 313     /* light handling */
 314     if (hold_button != hold_button_old)
 315     {
 316         hold_button_old = hold_button;
 317         backlight_hold_changed(hold_button);
 318     }
 319 #endif /* BOOTLOADER */
 320
 321     /* The int_btn variable is set in the button interrupt handler */
 322     return int_btn;
 323 }