firmware/target/arm/imx31/gigabeat-s/button-imx31.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Linus Nielsen Feltzing
  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 #include "config.h"
  23 #include "cpu.h"
  24 #include "system.h"
  25 #include "button.h"
  26 #include "backlight.h"
  27 #include "system.h"
  28 #include "backlight-target.h"
  29 #include "avic-imx31.h"
  30 #include "clkctl-imx31.h"
  31 #include "mc13783.h"
  32
  33 /* Most code in here is taken from the Linux BSP provided by Freescale
  34  * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved. */
  35 #ifdef HAVE_HEADPHONE_DETECTION
  36 static bool headphones_detect = false;
  37 #endif
  38 static uint32_t int_btn     = BUTTON_NONE;
  39 static bool hold_button     = false;
  40 #ifdef BOOTLOADER
  41 static bool initialized     = false;
  42 #else
  43 static bool hold_button_old = false;
  44 #endif
  45 #define _button_hold() (GPIO3_DR & 0x10)
  46
  47 static __attribute__((interrupt("IRQ"))) void KPP_HANDLER(void)
  48 {
  49     static const struct key_mask_shift
  50     {
  51         uint8_t mask;
  52         uint8_t shift;
  53     } kms[3] =
  54     {
  55         { 0x1f, 0 }, /* BUTTON_LEFT...BUTTON_SELECT */
  56         { 0x03, 5 }, /* BUTTON_BACK...BUTTON_MENU   */
  57         { 0x1f, 7 }, /* BUTTON_VOL_UP...BUTTON_NEXT */
  58     };
  59
  60     int col;
  61     /* Power button is handled separately on PMIC */
  62     int button = int_btn & BUTTON_POWER;
  63
  64     int oldlevel = disable_irq_save();
  65
  66     /* 1. Disable both (depress and release) keypad interrupts. */
  67     KPP_KPSR &= ~(KPP_KPSR_KRIE | KPP_KPSR_KDIE);
  68
  69     for (col = 0; col < 3; col++) /* Col */
  70     {
  71         /* 2. Write 1s to KPDR[10:8] setting column data to 1s */
  72         KPP_KPDR |= (0x7 << 8);
  73
  74         /* 3. Configure columns as totem pole outputs(for quick
  75          * discharging of keypad capacitance) */
  76         KPP_KPCR &= ~(0x7 << 8);
  77
  78         /* Give the columns time to discharge */
  79         udelay(2);
  80
  81         /* 4. Configure columns as open-drain */
  82         KPP_KPCR |= (0x7 << 8);
  83
  84         /* 5. Write a single column to 0, others to 1.
  85          * 6. Sample row inputs and save data. Multiple key presses
  86          *    can be detected on a single column.
  87          * 7. Repeat steps 2 - 6 for remaining columns. */
  88
  89         /* Col bit starts at 8th bit in KPDR */
  90         KPP_KPDR &= ~(0x100 << col);
  91
  92         /* Delay added to avoid propagating the 0 from column to row
  93          * when scanning. */
  94         udelay(2);
  95
  96         /* Read row input */
  97         button |= (~KPP_KPDR & kms[col].mask) << kms[col].shift;
  98     }
  99
 100     /* 8. Return all columns to 0 in preparation for standby mode. */
 101     KPP_KPDR &= ~(0x7 << 8);
 102
 103     /* 9. Clear KPKD and KPKR status bit(s) by writing to a .1.,
 104      *    set the KPKR synchronizer chain by writing "1" to KRSS register,
 105      *    clear the KPKD synchronizer chain by writing "1" to KDSC register */
 106     KPP_KPSR = KPP_KPSR_KRSS | KPP_KPSR_KDSC | KPP_KPSR_KPKR | KPP_KPSR_KPKD;
 107
 108     /* 10. Re-enable the appropriate keypad interrupt(s) so that the KDIE
 109      *     detects a key hold condition, or the KRIE detects a key-release
 110      *     event. */
 111     if ((button & ~BUTTON_POWER) != BUTTON_NONE)
 112         KPP_KPSR |= KPP_KPSR_KRIE;
 113     else
 114         KPP_KPSR |= KPP_KPSR_KDIE;
 115
 116     restore_irq(oldlevel);
 117
 118     int_btn = button;
 119 }
 120
 121 bool button_hold(void)
 122 {
 123     return _button_hold();
 124 }
 125
 126 int button_read_device(void)
 127 {
 128     /* Simple poll of GPIO status */
 129     hold_button = _button_hold();
 130
 131 #ifndef BOOTLOADER
 132     /* Backlight hold handling */
 133     if (hold_button != hold_button_old)
 134     {
 135         hold_button_old = hold_button;
 136         backlight_hold_changed(hold_button);
 137     }
 138 #endif
 139
 140     /* Enable the keypad interrupt to cause it to fire if a key is down.
 141      * KPP_HANDLER will clear and disable it after the scan. If no key
 142      * is depressed then this bit will already be set in waiting for the
 143      * first key down event. */
 144     KPP_KPSR |= KPP_KPSR_KDIE;
 145
 146     /* If hold, ignore any pressed button */
 147     return hold_button ? BUTTON_NONE : int_btn;
 148 }
 149
 150 /* This is called from the mc13783 interrupt thread */
 151 void button_power_event(void)
 152 {
 153     bool pressed =
 154         (mc13783_read(MC13783_INTERRUPT_SENSE1) & MC13783_ONOFD1S) == 0;
 155
 156     /* Prevent KPP_HANDLER from changing things */
 157     int oldlevel = disable_irq_save();
 158
 159     if (pressed)
 160     {
 161         int_btn |= BUTTON_POWER;
 162     }
 163     else
 164     {
 165         int_btn &= ~BUTTON_POWER;
 166     }
 167
 168     restore_irq(oldlevel);
 169 }
 170
 171 #ifdef HAVE_HEADPHONE_DETECTION
 172 /* This is called from the mc13783 interrupt thread */
 173 void headphone_detect_event(void)
 174 {
 175     /* FIXME: Not really the correct method */
 176     headphones_detect =
 177         (mc13783_read(MC13783_INTERRUPT_SENSE1) & MC13783_ONOFD2S) == 0;
 178 }
 179
 180 bool headphones_inserted(void)
 181 {
 182     return headphones_detect;
 183 }
 184 #endif /* HAVE_HEADPHONE_DETECTION */
 185
 186 void button_init_device(void)
 187 {
 188 #ifdef BOOTLOADER
 189     /* Can be called more than once in the bootloader */
 190     if (initialized)
 191         return;
 192
 193     initialized = true;
 194 #endif
 195
 196     /* Enable keypad clock */
 197     imx31_clkctl_module_clock_gating(CG_KPP, CGM_ON_ALL);
 198
 199     /* 1. Enable number of rows in keypad (KPCR[4:0])
 200      *
 201      * Configure the rows/cols in KPP
 202      * LSB nybble in KPP is for 5 rows
 203      * MSB nybble in KPP is for 3 cols */
 204     KPP_KPCR |= 0x1f;
 205
 206     /* 2. Write 0's to KPDR[10:8] */
 207     KPP_KPDR &= ~(0x7 << 8);
 208
 209     /* 3. Configure the keypad columns as open-drain (KPCR[10:8]). */
 210     KPP_KPCR |= (0x7 << 8);
 211
 212     /* 4. Configure columns as output, rows as input (KDDR[10:8,4:0]) */
 213     KPP_KDDR = (KPP_KDDR | (0x7 << 8)) & ~0x1f;
 214
 215     /* 5. Clear the KPKD Status Flag and Synchronizer chain.
 216      * 6. Set the KDIE control bit bit. */
 217     KPP_KPSR = KPP_KPSR_KDIE | KPP_KPSR_KRSS | KPP_KPSR_KDSC | KPP_KPSR_KPKD;
 218
 219     /* KPP IRQ at priority 3 */
 220     avic_enable_int(KPP, IRQ, 3, KPP_HANDLER);
 221
 222     button_power_event();
 223     mc13783_enable_event(MC13783_ONOFD1_EVENT);
 224
 225 #ifdef HAVE_HEADPHONE_DETECTION
 226     headphone_detect_event();
 227     mc13783_enable_event(MC13783_ONOFD2_EVENT);
 228 #endif
 229 }
 230
 231 #ifdef BUTTON_DRIVER_CLOSE
 232 void button_close_device(void)
 233 {
 234     int oldlevel = disable_irq_save();
 235
 236     avic_disable_int(KPP);
 237     KPP_KPSR &= ~(KPP_KPSR_KRIE | KPP_KPSR_KDIE);
 238     int_btn = BUTTON_NONE;
 239
 240     restore_irq(oldlevel);
 241 }
 242 #endif /* BUTTON_DRIVER_CLOSE */