summaryrefslogtreecommitdiffstats
path: root/firmware/target/arm/sandisk/sansa-e200/button-e200.c
blob: af68f32279e69685fbf628444861770ee284fba3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2006 by Barry Wardell
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/* Taken from button-h10.c by Barry Wardell and reverse engineering by MrH. */

#include "system.h"
#include "button.h"
#include "backlight.h"

#define WHEEL_REPEAT_INTERVAL   300000
#define WHEEL_FAST_ON_INTERVAL   20000
#define WHEEL_FAST_OFF_INTERVAL  60000

/* Clickwheel */
#ifndef BOOTLOADER
static unsigned int  old_wheel_value   = 0;
static unsigned int  wheel_repeat      = BUTTON_NONE;
static unsigned int  wheel_click_count = 0;
static unsigned int  wheel_delta       = 0;
static          int  wheel_fast_mode   = 0;
static unsigned long last_wheel_usec   = 0;
static unsigned long wheel_velocity    = 0;
static          long last_wheel_post   = 0;
static          long next_backlight_on = 0;
/* Buttons */
static bool hold_button     = false;
static bool hold_button_old = false;
#define _button_hold() hold_button
#else
#define _button_hold() ((GPIOF_INPUT_VAL & 0x80) != 0)
#endif /* BOOTLOADER */
static int  int_btn         = BUTTON_NONE;

void button_int(void);

void button_init_device(void)
{
    /* Enable all buttons */
    GPIOF_OUTPUT_EN &= ~0xff;
    GPIOF_ENABLE |= 0xff;

    /* Scrollwheel light - enable control through GPIOG pin 7 and set timeout */
    GPIOG_OUTPUT_EN |= 0x80;
    GPIOG_ENABLE = 0x80;

#ifndef BOOTLOADER
    /* Mask these before performing init ... because init has possibly
       occurred before */
    GPIOF_INT_EN &= ~0xff;
    GPIOH_INT_EN &= ~0xc0;

    /* Get current tick before enabling button interrupts */
    last_wheel_usec = USEC_TIMER;
    last_wheel_post = last_wheel_usec;

    GPIOH_ENABLE |= 0xc0;
    GPIOH_OUTPUT_EN &= ~0xc0;

    /* Read initial buttons */
    button_int();
    GPIOF_INT_CLR = 0xff;

    /* Read initial wheel value (bit 6-7 of GPIOH) */
    old_wheel_value = GPIOH_INPUT_VAL & 0xc0;
    GPIOH_INT_LEV = (GPIOH_INT_LEV & ~0xc0) | (old_wheel_value ^ 0xc0);
    GPIOH_INT_CLR = 0xc0;

    /* Enable button interrupts */
    GPIOF_INT_EN |= 0xff;
    GPIOH_INT_EN |= 0xc0;

    CPU_INT_EN = HI_MASK;
    CPU_HI_INT_EN = GPIO1_MASK;
#endif /* BOOTLOADER */
}

bool button_hold(void)
{
    return _button_hold();
}

/* clickwheel */
#ifndef BOOTLOADER
void clickwheel_int(void)
{
    /* Read wheel 
     * Bits 6 and 7 of GPIOH change as follows:
     * Clockwise rotation   01 -> 00 -> 10 -> 11
     * Counter-clockwise    11 -> 10 -> 00 -> 01
     *
     * This is equivalent to wheel_value of:
     * Clockwise rotation   0x40 -> 0x00 -> 0x80 -> 0xc0
     * Counter-clockwise    0xc0 -> 0x80 -> 0x00 -> 0x40
     */
    static const unsigned char wheel_tbl[2][4] =
    {
       /* 0x00  0x40  0x80  0xc0 */ /* Wheel value        */
        { 0x40, 0xc0, 0x00, 0x80 }, /* Clockwise rotation */
        { 0x80, 0x00, 0xc0, 0x40 }, /* Counter-clockwise  */ 
    };

    unsigned int wheel_value;

    wheel_value = GPIOH_INPUT_VAL & 0xc0;
    GPIOH_INT_LEV = (GPIOH_INT_LEV & ~0xc0) | (wheel_value ^ 0xc0);
    GPIOH_INT_CLR = GPIOH_INT_STAT & 0xc0;

    if (!hold_button)
    {
        unsigned int btn = BUTTON_NONE;

        if (old_wheel_value == wheel_tbl[0][wheel_value >> 6])
            btn = BUTTON_SCROLL_DOWN;
        else if (old_wheel_value == wheel_tbl[1][wheel_value >> 6])
            btn = BUTTON_SCROLL_UP;

        if (btn != BUTTON_NONE)
        {
            int repeat = 1; /* assume repeat */
            unsigned long usec = USEC_TIMER;
            unsigned v = (usec - last_wheel_usec) & 0x7fffffff;

            /* wheel velocity in 0.24 fixed point - clicks/uS */

            /* velocity cap to 18 bits to allow up to x16 scaling */
            v = (v < 0x40) ? 0xffffff / 0x40 : 0xffffff / v;

            /* some velocity filtering to smooth things out */
            wheel_velocity = (7*wheel_velocity + v) / 8;

            if (btn != wheel_repeat)
            {
                /* direction reversals nullify all fast mode states */
                wheel_repeat      = btn;
                repeat            =
                wheel_fast_mode   =
                wheel_velocity    =
                wheel_click_count = 0;
            }

            if (wheel_fast_mode != 0)
            {
                /* fast OFF happens immediately when velocity drops below
                   threshold */
                if (TIME_AFTER(usec,
                        last_wheel_usec + WHEEL_FAST_OFF_INTERVAL))
                {
                    /* moving out of fast mode */
                    wheel_fast_mode = 0;
                    /* reset velocity */
                    wheel_velocity = 0;
                    /* wheel_delta is always 1 in slow mode */
                    wheel_delta = 1;
                }
            }
            else
            {
                /* fast ON gets filtered to avoid inadvertent jumps to fast mode */
                if (repeat && wheel_velocity > 0xffffff/WHEEL_FAST_ON_INTERVAL)
                {
                    /* moving into fast mode */
                    wheel_fast_mode = 1 << 31;
                    wheel_click_count = 0;
                    wheel_velocity = 0xffffff/WHEEL_FAST_OFF_INTERVAL;
                }
                else if (++wheel_click_count < 2)
                {
                    btn = BUTTON_NONE;
                }

                /* wheel_delta is always 1 in slow mode */
                wheel_delta = 1;
            }

            if (TIME_AFTER(current_tick, next_backlight_on) ||
                v <= 0xffffff/(1000000/4))
            {
                /* poke backlight to turn it on or maintain it no more often
                   than every 1/4 second*/
                next_backlight_on = current_tick + HZ/4;
                backlight_on();
                button_backlight_on();
            }

            if (btn != BUTTON_NONE)
            {
                wheel_click_count = 0;

                /* generate repeats if quick enough */
                if (repeat && TIME_BEFORE(usec,
                        last_wheel_post + WHEEL_REPEAT_INTERVAL))
                    btn |= BUTTON_REPEAT;

                last_wheel_post = usec;

                if (queue_empty(&button_queue))
                {
                    queue_post(&button_queue, btn, wheel_fast_mode |
                               (wheel_delta << 24) | wheel_velocity);
                    /* message posted - reset delta */
                    wheel_delta = 1;
                }
                else
                {
                    /* skipped post - increment delta */
                    if (++wheel_delta > 0x7f)
                        wheel_delta = 0x7f;
                }
            }

            last_wheel_usec = usec;
        }
    }

    old_wheel_value = wheel_value;
}
#endif /* BOOTLOADER */

/* device buttons */
void button_int(void)
{
    unsigned char state;

    int_btn = BUTTON_NONE;

    state = GPIOF_INPUT_VAL & 0xff;

#ifndef BOOTLOADER
    GPIOF_INT_LEV = (GPIOF_INT_LEV & ~0xff) | (state ^ 0xff);
    GPIOF_INT_CLR = GPIOF_INT_STAT;

    hold_button = (state & 0x80) != 0;
#endif

    if (!_button_hold())
    {
        /* Read normal buttons */
        if ((state & 0x01) == 0) int_btn |= BUTTON_REC;
        if ((state & 0x02) == 0) int_btn |= BUTTON_DOWN;
        if ((state & 0x04) == 0) int_btn |= BUTTON_RIGHT;
        if ((state & 0x08) == 0) int_btn |= BUTTON_LEFT;
        if ((state & 0x10) == 0) int_btn |= BUTTON_SELECT; /* The centre button */
        if ((state & 0x20) == 0) int_btn |= BUTTON_UP; /* The "play" button */
        if ((state & 0x40) != 0) int_btn |= BUTTON_POWER;
    }
}

/*
 * Get button pressed from hardware
 */
int button_read_device(void)
{
#ifdef BOOTLOADER
    /* Read buttons directly in the bootloader */
    button_int();
#else
    /* light handling */
    if (hold_button != hold_button_old)
    {
        hold_button_old = hold_button;
        backlight_hold_changed(hold_button);
    }
#endif /* BOOTLOADER */

    /* The int_btn variable is set in the button interrupt handler */
    return int_btn;
}