/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id: $
*
* Copyright (C) 2011 by Tomasz Moń
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/

#include <stdio.h>
#include "config.h"
#include "system.h"
#include "kernel.h"
#include "logf.h"
#include "avr-sansaconnect.h"
#include "uart-target.h"
#include "button.h"
#include "backlight.h"
#include "powermgmt.h"
#include "aic3x.h"

//#define BUTTON_DEBUG

#ifdef BUTTON_DEBUG
#include "lcd-target.h"
#include "lcd.h"
#include "font.h"
#include "common.h"
#endif

#ifdef BUTTON_DEBUG
#define dbgprintf DEBUGF
#else
#define dbgprintf(...)
#endif

#define CMD_SYNC        0xAA
#define CMD_CLOSE       0xCC
#define CMD_LCM_POWER   0xC9
#define LCM_POWER_OFF   0x00
#define LCM_POWER_ON    0x01
#define LCM_POWER_SLEEP 0x02
#define LCM_POWER_WAKE  0x03
#define LCM_REPOWER_ON  0x04

#define CMD_STATE       0xBB
#define CMD_VER         0xBC
#define CMD_WHEEL_EN    0xD0
#define CMD_SET_INTCHRG 0xD1
#define CMD_CODEC_RESET 0xD7
#define CMD_FILL        0xFF

#define CMD_SYS_CTRL 0xDA
#define SYS_CTRL_POWEROFF 0x00

/* protects spi avr commands from concurrent access */
static struct mutex avr_mtx;

/* buttons thread */
#define BTN_INTERRUPT 1
static int btn = 0;
static bool hold_switch;
#ifndef BOOTLOADER
static long btn_stack[DEFAULT_STACK_SIZE/sizeof(long)];
static const char btn_thread_name[] = "buttons";
static struct event_queue btn_queue;
#endif

static inline unsigned short be2short(unsigned char* buf)
{
   return (unsigned short)((buf[0] << 8) | buf[1]);
}

#define BUTTON_DIRECT_MASK (BUTTON_LEFT | BUTTON_UP | BUTTON_RIGHT | BUTTON_DOWN | BUTTON_SELECT | BUTTON_VOL_UP | BUTTON_VOL_DOWN | BUTTON_NEXT | BUTTON_PREV)

#ifndef BOOTLOADER
static void handle_wheel(unsigned char wheel)
{
    static int key = 0;
    static unsigned char velocity = 0;
    static unsigned long wheel_delta = 1ul << 24;
    static unsigned char wheel_prev = 0;
    static long nextbacklight_hw_on = 0;
    static int prev_key = -1;
    static int prev_key_post = 0;

    if (TIME_AFTER(current_tick, nextbacklight_hw_on))
    {
        backlight_on();
        reset_poweroff_timer();
        nextbacklight_hw_on = current_tick + HZ/4;
    }

    if (wheel_prev < wheel)
    {
        key = BUTTON_SCROLL_FWD;
        velocity = wheel - wheel_prev;
    }
    else if (wheel_prev > wheel)
    {
        key = BUTTON_SCROLL_BACK;
        velocity = wheel_prev - wheel;
    }

    if (prev_key != key && velocity < 2 /* filter "rewinds" */)
    {
        /* direction reversal */
        prev_key = key;
        wheel_delta = 1ul << 24;
        return;
    }

    /* TODO: take velocity into account */
    if (queue_empty(&button_queue))
    {
        if (prev_key_post == key)
        {
            key |= BUTTON_REPEAT;
        }

        /* Post directly, don't update btn as avr doesn't give
           interrupt on scroll stop */
        queue_post(&button_queue, key, wheel_delta);

        wheel_delta = 1ul << 24;

        prev_key_post = key;
    }
    else
    {
        /* skipped post - increment delta and limit to 7 bits */
        wheel_delta += 1ul << 24;

        if (wheel_delta > (0x7ful << 24))
            wheel_delta = 0x7ful << 24;
    }

    wheel_prev = wheel;

    prev_key = key;
}
#endif

/* buf must be 11-byte array of byte (reply from avr_hid_get_state() */
static void parse_button_state(unsigned char *buf)
{
    unsigned short main_btns_state = be2short(&buf[4]);
#ifdef BUTTON_DEBUG
    unsigned short main_btns_changed = be2short(&buf[6]);
#endif

    /* make sure other bits doesn't conflict with our "free bits" buttons */
    main_btns_state &= BUTTON_DIRECT_MASK;

    if (buf[3] & 0x01) /* is power button pressed? */
    {
        main_btns_state |= BUTTON_POWER;
    }

    btn = main_btns_state;

#ifndef BOOTLOADER
    /* check if stored hold_switch state changed (prevents lost changes) */
    if ((buf[3] & 0x20) /* hold change notification */ ||
        (hold_switch != ((buf[3] & 0x02) >> 1)))
    {
#endif
        hold_switch = (buf[3] & 0x02) >> 1;
#ifdef BUTTON_DEBUG
        dbgprintf("HOLD changed (%d)", hold_switch);
#endif
#ifndef BOOTLOADER
        backlight_hold_changed(hold_switch);
    }
#endif
#ifndef BOOTLOADER
    if ((hold_switch == false) && (buf[3] & 0x80)) /* scrollwheel change */
    {
        handle_wheel(buf[2]);
    }
#endif

#ifdef BUTTON_DEBUG
    if (buf[3] & 0x10) /* power button change */
    {
        /* power button state has changed */
        main_btns_changed |= BUTTON_POWER;
    }

    if (btn & BUTTON_LEFT)        dbgprintf("LEFT");
    if (btn & BUTTON_UP)          dbgprintf("UP");
    if (btn & BUTTON_RIGHT)       dbgprintf("RIGHT");
    if (btn & BUTTON_DOWN)        dbgprintf("DOWN");
    if (btn & BUTTON_SELECT)      dbgprintf("SELECT");
    if (btn & BUTTON_VOL_UP)      dbgprintf("VOL UP");
    if (btn & BUTTON_VOL_DOWN)    dbgprintf("VOL DOWN");
    if (btn & BUTTON_NEXT)        dbgprintf("NEXT");
    if (btn & BUTTON_PREV)        dbgprintf("PREV");
    if (btn & BUTTON_POWER)       dbgprintf("POWER");
    if (btn & BUTTON_HOLD)        dbgprintf("HOLD");
    if (btn & BUTTON_SCROLL_FWD)  dbgprintf("SCROLL FWD");
    if (btn & BUTTON_SCROLL_BACK) dbgprintf("SCROLL BACK");
#endif
}

static void spi_txrx(unsigned char *buf_tx, unsigned char *buf_rx, int n)
{
    int i;
    unsigned short rxdata;

    mutex_lock(&avr_mtx);

    bitset16(&IO_CLK_MOD2, CLK_MOD2_SIF1);
    IO_SERIAL1_TX_ENABLE = 0x0001;

    for (i = 0; i<n; i++)
    {
        IO_SERIAL1_TX_DATA = buf_tx[i];

        /* 100 us wait for AVR */
        udelay(100);

        do
        {
            rxdata = IO_SERIAL1_RX_DATA;
        } while (rxdata & (1<<8));

        if (buf_rx != NULL)
            buf_rx[i] = rxdata & 0xFF;

        /* 100 us wait to give AVR time to process data */
        udelay(100);
    }

    IO_SERIAL1_TX_ENABLE = 0;
    bitclr16(&IO_CLK_MOD2, CLK_MOD2_SIF1);

    mutex_unlock(&avr_mtx);
}

void avr_hid_sync(void)
{
    int i;
    unsigned char prg[4] = {CMD_SYNC, CMD_VER, CMD_FILL, CMD_CLOSE};

    /* Send SYNC three times */
    for (i = 0; i<3; i++)
    {
        spi_txrx(prg, NULL, sizeof(prg));
    }
}

void avr_hid_init(void)
{
    /*
       setup alternate GIO functions:
       GIO29 - SIF1 Enable (Directly connected to AVR's SS)
       GIO30 - SIF1 Clock
       GIO31 - SIF1 Data In
       GIO32 - SIF1 Data Out
    */
    IO_GIO_FSEL2 = (IO_GIO_FSEL2 & 0x00FF) | 0xAA00;
    /* GIO29, GIO30 - outputs, GIO31 - input */
    IO_GIO_DIR1 = (IO_GIO_DIR1 & ~((1 << 13) | (1 << 14))) | (1 << 15);
    /* GIO32 - output */
    bitclr16(&IO_GIO_DIR2, (1 << 0));

    /* RATE = 219 (0xDB) -> 200 kHz */
    IO_SERIAL1_MODE = 0x6DB;

    mutex_init(&avr_mtx);
}

/* defined in powermgmt-sansaconnect.c */
void set_battery_level(unsigned int level);

static void avr_hid_get_state(void)
{
    static unsigned char cmd[11] = {CMD_SYNC, CMD_STATE,
      CMD_FILL, CMD_FILL, CMD_FILL, CMD_FILL, CMD_FILL, CMD_FILL, CMD_FILL, CMD_FILL,
      CMD_CLOSE};

    static unsigned char buf[11];
    static unsigned char cmd_empty[1] = {0xCC};

    spi_txrx(cmd, buf, sizeof(cmd));

    /*
     *  buf[8] contains some battery/charger related information (unknown)
     *  buf[9] contains battery level in percents (0-100)
     */
    set_battery_level((unsigned int)buf[9]);

    spi_txrx(cmd_empty, NULL, 1); /* request interrupt on button press */

    parse_button_state(buf);
}

static void avr_hid_enable_wheel(void)
{
    unsigned char wheel_en[4] = {CMD_SYNC, CMD_WHEEL_EN, 0x01, CMD_CLOSE};

    spi_txrx(wheel_en, NULL, sizeof(wheel_en));
}

/* command that is sent by "hidtool -J 1" issued on every OF boot */
void avr_hid_enable_charger(void)
{
    unsigned char charger_en[4] = {CMD_SYNC, CMD_SET_INTCHRG, 0x01, CMD_CLOSE};

    spi_txrx(charger_en, NULL, sizeof(charger_en));
}

void avr_hid_lcm_sleep(void)
{
    unsigned char lcm_sleep[4] = {CMD_SYNC, CMD_LCM_POWER, LCM_POWER_SLEEP, CMD_CLOSE};

    spi_txrx(lcm_sleep, NULL, sizeof(lcm_sleep));
}


void avr_hid_lcm_wake(void)
{
    unsigned char lcm_wake[4] = {CMD_SYNC, CMD_LCM_POWER, LCM_POWER_WAKE, CMD_CLOSE};

    spi_txrx(lcm_wake, NULL, sizeof(lcm_wake));
}

void avr_hid_lcm_power_on(void)
{
    unsigned char lcm_power_on[4] = {CMD_SYNC, CMD_LCM_POWER, LCM_POWER_ON, CMD_CLOSE};

    spi_txrx(lcm_power_on, NULL, sizeof(lcm_power_on));
}

void avr_hid_lcm_power_off(void)
{
    unsigned char lcm_power_off[4] = {CMD_SYNC, CMD_LCM_POWER, LCM_POWER_OFF, CMD_CLOSE};

    spi_txrx(lcm_power_off, NULL, sizeof(lcm_power_off));
}

void avr_hid_reset_codec(void)
{
    unsigned char codec_reset[4] = {CMD_SYNC, CMD_CODEC_RESET, CMD_CLOSE, CMD_FILL};

    spi_txrx(codec_reset, NULL, sizeof(codec_reset));
}

void avr_hid_power_off(void)
{
    unsigned char prg[4] = {CMD_SYNC, CMD_SYS_CTRL, SYS_CTRL_POWEROFF, CMD_CLOSE};

    spi_txrx(prg, NULL, sizeof(prg));
}

#ifndef BOOTLOADER
void btn_thread(void)
{
    struct queue_event ev;

    while (1)
    {
        queue_wait(&btn_queue, &ev);
        
        /* Ignore all messages except BTN_INTERRUPT */
        if (ev.id != BTN_INTERRUPT)
            continue;

        /* Enable back button interrupt */
        IO_INTC_EINT1 |= INTR_EINT1_EXT0;

        /* Read buttons state */
        avr_hid_get_state();

        yield();

        if (queue_empty(&btn_queue) && ((IO_GIO_BITSET0 & 0x1) == 0))
        {
            /* for some reason we have lost next interrupt */
            queue_post(&btn_queue, BTN_INTERRUPT, 0);
        }
    }
}

void GIO0(void) __attribute__ ((section(".icode")));
void GIO0(void)
{
    /* Clear interrupt */
    IO_INTC_IRQ1 = (1 << 5);
    /* Disable interrupt */
    IO_INTC_EINT1 &= ~INTR_EINT1_EXT0;

    /* interrupt will be enabled back after button read */
    queue_post(&btn_queue, BTN_INTERRUPT, 0);
}

static int headphones_inserted_callback(struct timeout *tmo)
{
    (void)tmo;

    if (IO_GIO_BITSET0 & 0x04)
    {
        aic3x_switch_output(false);
    }
    else
    {
        aic3x_switch_output(true);
    }

    return 0;
}

void GIO2(void) __attribute__ ((section(".icode")));
void GIO2(void)
{
    static struct timeout headphones_oneshot;

    /* Clear interrupt */
    IO_INTC_IRQ1 = (1 << 7);

    timeout_register(&headphones_oneshot, headphones_inserted_callback,
                     HZ/2, 0);
}
#endif

void button_init_device(void)
{
    btn = 0;
    hold_switch = false;
#ifndef BOOTLOADER
    queue_init(&btn_queue, true);
    create_thread(btn_thread, btn_stack, sizeof(btn_stack), 0,
                  btn_thread_name IF_PRIO(, PRIORITY_USER_INTERFACE)
                  IF_COP(, CPU));
#endif
    IO_GIO_DIR0 |= 0x01; /* Set GIO0 as input */

    /* Enable wheel */
    avr_hid_enable_wheel();
    /* Read button status and tell avr we want interrupt on next change */
    avr_hid_get_state();

#ifndef BOOTLOADER
    IO_GIO_IRQPORT |= 0x05; /* Enable GIO0/GIO2 external interrupt */
    IO_GIO_INV0 &= ~0x05; /* Clear INV for GIO0/GIO2 */
    /* falling edge detection on GIO0, any edge on GIO2 */
    IO_GIO_IRQEDGE = (IO_GIO_IRQEDGE & ~0x01) | 0x04;

    /* Enable GIO0 and GIO2 interrupts */
    IO_INTC_EINT1 |= INTR_EINT1_EXT0 | INTR_EINT1_EXT2;
#endif
}

int button_read_device(void)
{
    if(hold_switch)
        return 0;
    else
        return btn;
}

bool button_hold(void)
{
    return hold_switch;
}

void lcd_enable(bool on)
{
    (void)on;
}