/*
 *
 * BRIEF MODULE DESCRIPTION
 *      Qtronix 990P infrared keyboard driver.
 *
 *
 * Copyright 2001 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *              ppopov@mvista.com or source@mvista.com
 *
 *
 *  The bottom portion of this driver was take from 
 *  pc_keyb.c  Please see that file for copyrights.
 *
 *  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 PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>

/* 
 * NOTE:  
 *
 *      This driver has only been tested with the Consumer IR
 *      port of the ITE 8172 system controller.
 *
 *      You do not need this driver if you are using the ps/2 or
 *      USB adapter that the keyboard ships with.  You only need 
 *      this driver if your board has a IR port and the keyboard
 *      data is being sent directly to the IR.  In that case,
 *      you also need some low-level IR support. See it8172_cir.c.
 *      
 */

#ifdef CONFIG_QTRONIX_KEYBOARD

#include <linux/module.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>

#include <asm/it8172/it8172.h>
#include <asm/it8172/it8172_int.h>
#include <asm/it8172/it8172_cir.h>

#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/mm.h>
#include <linux/signal.h>
#include <linux/init.h>
#include <linux/kbd_ll.h>
#include <linux/delay.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/kbd_kern.h>
#include <linux/smp_lock.h>
#include <asm/io.h>
#include <linux/pc_keyb.h>

#include <asm/keyboard.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/system.h>

#define leading1 0
#define leading2 0xF

#define KBD_CIR_PORT 0
#define AUX_RECONNECT 170 /* scancode when ps2 device is plugged (back) in */

static int data_index;
struct cir_port *cir;
static unsigned char kbdbytes[5];
static unsigned char cir_data[32]; /* we only need 16 chars */

static void kbd_int_handler(int irq, void *dev_id, struct pt_regs *regs);
static int handle_data(unsigned char *p_data);
static inline void handle_mouse_event(unsigned char scancode);
static inline void handle_keyboard_event(unsigned char scancode, int down);
static int __init psaux_init(void);

static struct aux_queue *queue; /* Mouse data buffer. */
static int aux_count = 0;

/*
 * Keys accessed through the 'Fn' key
 * The Fn key does not produce a key-up sequence. So, the first
 * time the user presses it, it will be key-down event. The key
 * stays down until the user presses it again.
 */
#define NUM_FN_KEYS 56
static unsigned char fn_keys[NUM_FN_KEYS] = {
        0,0,0,0,0,0,0,0,        /* 0 7   */
        8,9,10,93,0,0,0,0,      /* 8 15  */
        0,0,0,0,0,0,0,5,        /* 16 23 */
        6,7,91,0,0,0,0,0,       /* 24 31 */
        0,0,0,0,0,2,3,4,        /* 32 39 */
        92,0,0,0,0,0,0,0,       /* 40 47 */
        0,0,0,0,11,0,94,95        /* 48 55 */

};

void __init init_qtronix_990P_kbd(void)
{
        int retval;

        cir = (struct cir_port *)kmalloc(sizeof(struct cir_port), GFP_KERNEL);
        if (!cir) {
                printk("Unable to initialize Qtronix keyboard\n");
                return;
        }

        /* 
         * revisit
         * this should be programmable, somehow by the, by the user.
         */
        cir->port = KBD_CIR_PORT;
        cir->baud_rate = 0x1d;
        cir->rdwos = 0;
        cir->rxdcr = 0x3;
        cir->hcfs = 0;
        cir->fifo_tl = 0;
        cir->cfq = 0x1d;
        cir_port_init(cir);

        retval = request_irq(IT8172_CIR0_IRQ, kbd_int_handler, 
                        (unsigned long )(SA_INTERRUPT|SA_SHIRQ), 
                        (const char *)"Qtronix IR Keyboard", (void *)cir);

        if (retval) {
                printk("unable to allocate cir %d irq %d\n", 
                                cir->port, IT8172_CIR0_IRQ);
        }
#ifdef CONFIG_PSMOUSE
        psaux_init();
#endif
}

static inline unsigned char BitReverse(unsigned short key)
{
        unsigned char rkey = 0;
        rkey |= (key & 0x1) << 7;
        rkey |= (key & 0x2) << 5;
        rkey |= (key & 0x4) << 3;
        rkey |= (key & 0x8) << 1;
        rkey |= (key & 0x10) >> 1;
        rkey |= (key & 0x20) >> 3;
        rkey |= (key & 0x40) >> 5;
        rkey |= (key & 0x80) >> 7;
        return rkey;

}


static inline u_int8_t UpperByte(u_int8_t data)
{
        return (data >> 4);
}


static inline u_int8_t LowerByte(u_int8_t data)
{
        return (data & 0xF);
}


int CheckSumOk(u_int8_t byte1, u_int8_t byte2, 
                u_int8_t byte3, u_int8_t byte4, u_int8_t byte5)
{
        u_int8_t CheckSum;

        CheckSum = (byte1 & 0x0F) + byte2 + byte3 + byte4 + byte5;
        if ( LowerByte(UpperByte(CheckSum) + LowerByte(CheckSum)) != UpperByte(byte1) )
                return 0;
        else
                return 1;
}


static void kbd_int_handler(int irq, void *dev_id, struct pt_regs *regs)
{
        struct cir_port *cir;
        int j;
        unsigned char int_status;

        cir = (struct cir_port *)dev_id;
        int_status = get_int_status(cir);;
        if (int_status & 0x4) {
                clear_fifo(cir);
                return;
        }

        while (cir_get_rx_count(cir)) {

                cir_data[data_index] = cir_read_data(cir);

                if (data_index == 0) {/* expecting first byte */
                        if (cir_data[data_index] != leading1) {
                                //printk("!leading byte %x\n", cir_data[data_index]);
                                set_rx_active(cir);
                                clear_fifo(cir);
                                continue;
                        }
                }
                if (data_index == 1) {
                        if ((cir_data[data_index] & 0xf) != leading2) {
                                set_rx_active(cir);
                                data_index = 0; /* start over */
                                clear_fifo(cir);
                                continue;
                        }
                }

                if ( (cir_data[data_index] == 0xff)) { /* last byte */
                        //printk("data_index %d\n", data_index);
                        set_rx_active(cir);
#if 0
                        for (j=0; j<=data_index; j++) {
                                printk("rx_data %d:  %x\n", j, cir_data[j]);
                        }
#endif
                        data_index = 0;
                        handle_data(cir_data);
                        return;
                }
                else if (data_index>16) {
                        set_rx_active(cir);
#if 0
                        printk("warning: data_index %d\n", data_index);
                        for (j=0; j<=data_index; j++) {
                                printk("rx_data %d:  %x\n", j, cir_data[j]);
                        }
#endif
                        data_index = 0;
                        clear_fifo(cir);
                        return;
                }
                data_index++;
        }
}


#define NUM_KBD_BYTES 5
static int handle_data(unsigned char *p_data)
{
        u_int32_t bit_bucket;
        u_int32_t i, j;
        u_int32_t got_bits, next_byte;
        int down = 0;

        /* Reorganize the bit stream */
        for (i=0; i<16; i++)
                p_data[i] = BitReverse(~p_data[i]);

        /* 
         * We've already previously checked that p_data[0]
         * is equal to leading1 and that (p_data[1] & 0xf)
         * is equal to leading2. These twelve bits are the
         * leader code.  We can now throw them away (the 12
         * bits) and continue parsing the stream.
         */
        bit_bucket = p_data[1] << 12;
        got_bits = 4;
        next_byte = 2;

        /* 
         * Process four bits at a time
         */
        for (i=0; i<NUM_KBD_BYTES; i++) {

                kbdbytes[i]=0;

                for (j=0; j<8; j++) /* 8 bits per byte */
                {
                        if (got_bits < 4) {
                                bit_bucket |= (p_data[next_byte++] << (8 - got_bits));
                                got_bits += 8;
                        }

                        if ((bit_bucket & 0xF000) == 0x8000) { 
                                /* Convert 1000b to 1 */
                                kbdbytes[i] = 0x80 | (kbdbytes[i] >> 1);
                                got_bits -= 4;
                                bit_bucket = bit_bucket << 4;
                        }
                        else if ((bit_bucket & 0xC000) == 0x8000) {
                                /* Convert 10b to 0 */
                                kbdbytes[i] =  kbdbytes[i] >> 1;
                                got_bits -= 2;
                                bit_bucket = bit_bucket << 2;
                        }
                        else {
                                /* bad serial stream */
                                return 1;
                        }

                        if (next_byte > 16) {
                                //printk("error: too many bytes\n");
                                return 1;
                        }
                }
        }


        if (!CheckSumOk(kbdbytes[0], kbdbytes[1], 
                                kbdbytes[2], kbdbytes[3], kbdbytes[4])) {
                //printk("checksum failed\n");
                return 1;
        }

        if (kbdbytes[1] & 0x08) {
                //printk("m: %x %x %x\n", kbdbytes[1], kbdbytes[2], kbdbytes[3]);
                handle_mouse_event(kbdbytes[1]);
                handle_mouse_event(kbdbytes[2]);
                handle_mouse_event(kbdbytes[3]);
        }
        else {
                if (kbdbytes[2] == 0) down = 1;
#if 0
                if (down)
                        printk("down %d\n", kbdbytes[3]);
                else
                        printk("up %d\n", kbdbytes[3]);
#endif
                handle_keyboard_event(kbdbytes[3], down);
        }
        return 0;
}


spinlock_t kbd_controller_lock = SPIN_LOCK_UNLOCKED;
static unsigned char handle_kbd_event(void);


int kbd_setkeycode(unsigned int scancode, unsigned int keycode)
{
        printk("kbd_setkeycode scancode %x keycode %x\n", scancode, keycode);
        return 0;
}

int kbd_getkeycode(unsigned int scancode)
{
        return scancode;
}


int kbd_translate(unsigned char scancode, unsigned char *keycode,
                    char raw_mode)
{
        static int prev_scancode = 0;

        if (scancode == 0x00 || scancode == 0xff) {
                prev_scancode = 0;
                return 0;
        }

        /* todo */
        if (!prev_scancode && scancode == 160) { /* Fn key down */
                //printk("Fn key down\n");
                prev_scancode = 160;
                return 0;
        }
        else if (prev_scancode && scancode == 160) { /* Fn key up */
                //printk("Fn key up\n");
                prev_scancode = 0;
                return 0;
        }

        /* todo */
        if (prev_scancode == 160) {
                if (scancode <= NUM_FN_KEYS) {
                        *keycode = fn_keys[scancode];
                        //printk("fn keycode %d\n", *keycode);
                }
                else
                        return 0;
        } 
        else if (scancode <= 127) {
                *keycode = scancode;
        }
        else
                return 0;


        return 1;
}

char kbd_unexpected_up(unsigned char keycode)
{
        //printk("kbd_unexpected_up\n");
        return 0;
}

static unsigned char kbd_exists = 1;

static inline void handle_keyboard_event(unsigned char scancode, int down)
{
        kbd_exists = 1;
        handle_scancode(scancode, down);
        tasklet_schedule(&keyboard_tasklet);
}       


void kbd_leds(unsigned char leds)
{
}

/* dummy */
void kbd_init_hw(void)
{
}



static inline void handle_mouse_event(unsigned char scancode)
{
        if(scancode == AUX_RECONNECT){
                queue->head = queue->tail = 0;  /* Flush input queue */
        //      __aux_write_ack(AUX_ENABLE_DEV);  /* ping the mouse :) */
                return;
        }

        add_mouse_randomness(scancode);
        if (aux_count) {
                int head = queue->head;

                queue->buf[head] = scancode;
                head = (head + 1) & (AUX_BUF_SIZE-1);
                if (head != queue->tail) {
                        queue->head = head;
                        kill_fasync(&queue->fasync, SIGIO, POLL_IN);
                        wake_up_interruptible(&queue->proc_list);
                }
        }
}

static unsigned char get_from_queue(void)
{
        unsigned char result;
        unsigned long flags;

        spin_lock_irqsave(&kbd_controller_lock, flags);
        result = queue->buf[queue->tail];
        queue->tail = (queue->tail + 1) & (AUX_BUF_SIZE-1);
        spin_unlock_irqrestore(&kbd_controller_lock, flags);
        return result;
}


static inline int queue_empty(void)
{
        return queue->head == queue->tail;
}

static int fasync_aux(int fd, struct file *filp, int on)
{
        int retval;

        //printk("fasync_aux\n");
        retval = fasync_helper(fd, filp, on, &queue->fasync);
        if (retval < 0)
                return retval;
        return 0;
}


/*
 * Random magic cookie for the aux device
 */
#define AUX_DEV ((void *)queue)

static int release_aux(struct inode * inode, struct file * file)
{
        lock_kernel();
        fasync_aux(-1, file, 0);
        aux_count--;
        unlock_kernel();
        return 0;
}

static int open_aux(struct inode * inode, struct file * file)
{
        if (aux_count++) {
                return 0;
        }
        queue->head = queue->tail = 0;          /* Flush input queue */
        return 0;
}

/*
 * Put bytes from input queue to buffer.
 */

static ssize_t read_aux(struct file * file, char * buffer,
                        size_t count, loff_t *ppos)
{
        DECLARE_WAITQUEUE(wait, current);
        ssize_t i = count;
        unsigned char c;

        if (queue_empty()) {
                if (file->f_flags & O_NONBLOCK)
                        return -EAGAIN;
                add_wait_queue(&queue->proc_list, &wait);
repeat:
                set_current_state(TASK_INTERRUPTIBLE);
                if (queue_empty() && !signal_pending(current)) {
                        schedule();
                        goto repeat;
                }
                current->state = TASK_RUNNING;
                remove_wait_queue(&queue->proc_list, &wait);
        }
        while (i > 0 && !queue_empty()) {
                c = get_from_queue();
                put_user(c, buffer++);
                i--;
        }
        if (count-i) {
                file->f_dentry->d_inode->i_atime = CURRENT_TIME;
                return count-i;
        }
        if (signal_pending(current))
                return -ERESTARTSYS;
        return 0;
}

/*
 * Write to the aux device.
 */

static ssize_t write_aux(struct file * file, const char * buffer,
                         size_t count, loff_t *ppos)
{
        /*
         * The ITE boards this was tested on did not have the
         * transmit wires connected.
         */
        return count;
}

static unsigned int aux_poll(struct file *file, poll_table * wait)
{
        poll_wait(file, &queue->proc_list, wait);
        if (!queue_empty())
                return POLLIN | POLLRDNORM;
        return 0;
}

struct file_operations psaux_fops = {
        read:           read_aux,
        write:          write_aux,
        poll:           aux_poll,
        open:           open_aux,
        release:        release_aux,
        fasync:         fasync_aux,
};

/*
 * Initialize driver.
 */
static struct miscdevice psaux_mouse = {
        PSMOUSE_MINOR, "psaux", &psaux_fops
};

static int __init psaux_init(void)
{
        int retval;

        retval = misc_register(&psaux_mouse);
        if(retval < 0)
                return retval;

        queue = (struct aux_queue *) kmalloc(sizeof(*queue), GFP_KERNEL);
        memset(queue, 0, sizeof(*queue));
        queue->head = queue->tail = 0;
        init_waitqueue_head(&queue->proc_list);

        return 0;
}
module_init(init_qtronix_990P_kbd);
#endif