/*
 *  Copyright (c) 2001 "Crazy" James Simmons jsimmons@transvirtual.com
 *
 *  Sponsored by Transvirtual Technology.
 *
 *  Derived from the code in h3600_ts.[ch] by Charles Flynn
 */

/*
 * Driver for the h3600 Touch Screen and other Atmel controlled devices.
 */

/*
 * 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so by
 * e-mail - mail your message to <jsimmons@transvirtual.com>.
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>
#include <linux/delay.h>

/* SA1100 serial defines */
#include <mach/hardware.h>
#include <mach/irqs.h>

#define DRIVER_DESC     "H3600 touchscreen driver"

MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

/* The start and end of frame characters SOF and EOF */
#define CHAR_SOF                0x02
#define CHAR_EOF                0x03
#define FRAME_OVERHEAD          3       /* CHAR_SOF,CHAR_EOF,LENGTH = 3 */

/*
        Atmel events and response IDs contained in frame.
        Programmer has no control over these numbers.
        TODO there are holes - specifically  1,7,0x0a
*/
#define VERSION_ID              0       /* Get Version (request/response) */
#define KEYBD_ID                2       /* Keyboard (event) */
#define TOUCHS_ID               3       /* Touch Screen (event)*/
#define EEPROM_READ_ID          4       /* (request/response) */
#define EEPROM_WRITE_ID         5       /* (request/response) */
#define THERMAL_ID              6       /* (request/response) */
#define NOTIFY_LED_ID           8       /* (request/response) */
#define BATTERY_ID              9       /* (request/response) */
#define SPI_READ_ID             0x0b    /* ( request/response) */
#define SPI_WRITE_ID            0x0c    /* ( request/response) */
#define FLITE_ID                0x0d    /* backlight ( request/response) */
#define STX_ID                  0xa1    /* extension pack status (req/resp) */

#define MAX_ID                  14

#define H3600_MAX_LENGTH 16
#define H3600_KEY 0xf

#define H3600_SCANCODE_RECORD   1        /* 1 -> record button */
#define H3600_SCANCODE_CALENDAR 2        /* 2 -> calendar */
#define H3600_SCANCODE_CONTACTS 3        /* 3 -> contact */
#define H3600_SCANCODE_Q        4        /* 4 -> Q button */
#define H3600_SCANCODE_START    5        /* 5 -> start menu */
#define H3600_SCANCODE_UP       6        /* 6 -> up */
#define H3600_SCANCODE_RIGHT    7        /* 7 -> right */
#define H3600_SCANCODE_LEFT     8        /* 8 -> left */
#define H3600_SCANCODE_DOWN     9        /* 9 -> down */

/*
 * Per-touchscreen data.
 */
struct h3600_dev {
        struct input_dev *dev;
        struct serio *serio;
        unsigned char event;    /* event ID from packet */
        unsigned char chksum;
        unsigned char len;
        unsigned char idx;
        unsigned char buf[H3600_MAX_LENGTH];
        char phys[32];
};

static irqreturn_t action_button_handler(int irq, void *dev_id)
{
        int down = (GPLR & GPIO_BITSY_ACTION_BUTTON) ? 0 : 1;
        struct input_dev *dev = dev_id;

        input_report_key(dev, KEY_ENTER, down);
        input_sync(dev);

        return IRQ_HANDLED;
}

static irqreturn_t npower_button_handler(int irq, void *dev_id)
{
        int down = (GPLR & GPIO_BITSY_NPOWER_BUTTON) ? 0 : 1;
        struct input_dev *dev = dev_id;

        /*
         * This interrupt is only called when we release the key. So we have
         * to fake a key press.
         */
        input_report_key(dev, KEY_SUSPEND, 1);
        input_report_key(dev, KEY_SUSPEND, down);
        input_sync(dev);

        return IRQ_HANDLED;
}

#ifdef CONFIG_PM

static int flite_brightness = 25;

enum flite_pwr {
        FLITE_PWR_OFF = 0,
        FLITE_PWR_ON = 1
};

/*
 * h3600_flite_power: enables or disables power to frontlight, using last bright */
unsigned int h3600_flite_power(struct input_dev *dev, enum flite_pwr pwr)
{
        unsigned char brightness = (pwr == FLITE_PWR_OFF) ? 0 : flite_brightness;
        struct h3600_dev *ts = input_get_drvdata(dev);

        /* Must be in this order */
        serio_write(ts->serio, 1);
        serio_write(ts->serio, pwr);
        serio_write(ts->serio, brightness);

        return 0;
}

#endif

/*
 * This function translates the native event packets to linux input event
 * packets. Some packets coming from serial are not touchscreen related. In
 * this case we send them off to be processed elsewhere.
 */
static void h3600ts_process_packet(struct h3600_dev *ts)
{
        struct input_dev *dev = ts->dev;
        static int touched = 0;
        int key, down = 0;

        switch (ts->event) {
                /*
                   Buttons - returned as a single byte
                        7 6 5 4 3 2 1 0
                        S x x x N N N N

                   S       switch state ( 0=pressed 1=released)
                   x       Unused.
                   NNNN    switch number 0-15

                   Note: This is true for non interrupt generated key events.
                */
                case KEYBD_ID:
                        down = (ts->buf[0] & 0x80) ? 0 : 1;

                        switch (ts->buf[0] & 0x7f) {
                                case H3600_SCANCODE_RECORD:
                                        key = KEY_RECORD;
                                        break;
                                case H3600_SCANCODE_CALENDAR:
                                        key = KEY_PROG1;
                                        break;
                                case H3600_SCANCODE_CONTACTS:
                                        key = KEY_PROG2;
                                        break;
                                case H3600_SCANCODE_Q:
                                        key = KEY_Q;
                                        break;
                                case H3600_SCANCODE_START:
                                        key = KEY_PROG3;
                                        break;
                                case H3600_SCANCODE_UP:
                                        key = KEY_UP;
                                        break;
                                case H3600_SCANCODE_RIGHT:
                                        key = KEY_RIGHT;
                                        break;
                                case H3600_SCANCODE_LEFT:
                                        key = KEY_LEFT;
                                        break;
                                case H3600_SCANCODE_DOWN:
                                        key = KEY_DOWN;
                                        break;
                                default:
                                        key = 0;
                        }
                        if (key)
                                input_report_key(dev, key, down);
                        break;
                /*
                 * Native touchscreen event data is formatted as shown below:-
                 *
                 *      +-------+-------+-------+-------+
                 *      | Xmsb  | Xlsb  | Ymsb  | Ylsb  |
                 *      +-------+-------+-------+-------+
                 *       byte 0    1       2       3
                 */
                case TOUCHS_ID:
                        if (!touched) {
                                input_report_key(dev, BTN_TOUCH, 1);
                                touched = 1;
                        }

                        if (ts->len) {
                                unsigned short x, y;

                                x = ts->buf[0]; x <<= 8; x += ts->buf[1];
                                y = ts->buf[2]; y <<= 8; y += ts->buf[3];

                                input_report_abs(dev, ABS_X, x);
                                input_report_abs(dev, ABS_Y, y);
                        } else {
                                input_report_key(dev, BTN_TOUCH, 0);
                                touched = 0;
                        }
                        break;
                default:
                        /* Send a non input event elsewhere */
                        break;
        }

        input_sync(dev);
}

/*
 * h3600ts_event() handles events from the input module.
 */
static int h3600ts_event(struct input_dev *dev, unsigned int type,
                         unsigned int code, int value)
{
#if 0
        struct h3600_dev *ts = input_get_drvdata(dev);

        switch (type) {
                case EV_LED: {
                //      serio_write(ts->serio, SOME_CMD);
                        return 0;
                }
        }
        return -1;
#endif
        return 0;
}

/*
        Frame format
  byte    1       2               3              len + 4
        +-------+---------------+---------------+--=------------+
        |SOF    |id     |len    | len bytes     | Chksum        |
        +-------+---------------+---------------+--=------------+
  bit   0     7  8    11 12   15 16

        +-------+---------------+-------+
        |SOF    |id     |0      |Chksum | - Note Chksum does not include SOF
        +-------+---------------+-------+
  bit   0     7  8    11 12   15 16

*/

static int state;

/* decode States  */
#define STATE_SOF       0       /* start of FRAME */
#define STATE_ID        1       /* state where we decode the ID & len */
#define STATE_DATA      2       /* state where we decode data */
#define STATE_EOF       3       /* state where we decode checksum or EOF */

static irqreturn_t h3600ts_interrupt(struct serio *serio, unsigned char data,
                                     unsigned int flags)
{
        struct h3600_dev *ts = serio_get_drvdata(serio);

        /*
         * We have a new frame coming in.
         */
        switch (state) {
                case STATE_SOF:
                        if (data == CHAR_SOF)
                                state = STATE_ID;
                        break;
                case STATE_ID:
                        ts->event = (data & 0xf0) >> 4;
                        ts->len = (data & 0xf);
                        ts->idx = 0;
                        if (ts->event >= MAX_ID) {
                                state = STATE_SOF;
                                break;
                        }
                        ts->chksum = data;
                        state = (ts->len > 0) ? STATE_DATA : STATE_EOF;
                        break;
                case STATE_DATA:
                        ts->chksum += data;
                        ts->buf[ts->idx]= data;
                        if (++ts->idx == ts->len)
                                state = STATE_EOF;
                        break;
                case STATE_EOF:
                        state = STATE_SOF;
                        if (data == CHAR_EOF || data == ts->chksum)
                                h3600ts_process_packet(ts);
                        break;
                default:
                        printk("Error3\n");
                        break;
        }

        return IRQ_HANDLED;
}

/*
 * h3600ts_connect() is the routine that is called when someone adds a
 * new serio device that supports H3600 protocol and registers it as
 * an input device.
 */
static int h3600ts_connect(struct serio *serio, struct serio_driver *drv)
{
        struct h3600_dev *ts;
        struct input_dev *input_dev;
        int err;

        ts = kzalloc(sizeof(struct h3600_dev), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!ts || !input_dev) {
                err = -ENOMEM;
                goto fail1;
        }

        ts->serio = serio;
        ts->dev = input_dev;
        snprintf(ts->phys, sizeof(ts->phys), "%s/input0", serio->phys);

        input_dev->name = "H3600 TouchScreen";
        input_dev->phys = ts->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor = SERIO_H3600;
        input_dev->id.product = 0x0666;  /* FIXME !!! We can ask the hardware */
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = &serio->dev;

        input_set_drvdata(input_dev, ts);

        input_dev->event = h3600ts_event;

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) |
                BIT_MASK(EV_LED) | BIT_MASK(EV_PWR);
        input_dev->ledbit[0] = BIT_MASK(LED_SLEEP);
        input_set_abs_params(input_dev, ABS_X, 60, 985, 0, 0);
        input_set_abs_params(input_dev, ABS_Y, 35, 1024, 0, 0);

        set_bit(KEY_RECORD, input_dev->keybit);
        set_bit(KEY_Q, input_dev->keybit);
        set_bit(KEY_PROG1, input_dev->keybit);
        set_bit(KEY_PROG2, input_dev->keybit);
        set_bit(KEY_PROG3, input_dev->keybit);
        set_bit(KEY_UP, input_dev->keybit);
        set_bit(KEY_RIGHT, input_dev->keybit);
        set_bit(KEY_LEFT, input_dev->keybit);
        set_bit(KEY_DOWN, input_dev->keybit);
        set_bit(KEY_ENTER, input_dev->keybit);
        set_bit(KEY_SUSPEND, input_dev->keybit);
        set_bit(BTN_TOUCH, input_dev->keybit);

        /* Device specific stuff */
        set_GPIO_IRQ_edge(GPIO_BITSY_ACTION_BUTTON, GPIO_BOTH_EDGES);
        set_GPIO_IRQ_edge(GPIO_BITSY_NPOWER_BUTTON, GPIO_RISING_EDGE);

        if (request_irq(IRQ_GPIO_BITSY_ACTION_BUTTON, action_button_handler,
                        IRQF_SHARED, "h3600_action", ts->dev)) {
                printk(KERN_ERR "h3600ts.c: Could not allocate Action Button IRQ!\n");
                err = -EBUSY;
                goto fail1;
        }

        if (request_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, npower_button_handler,
                        IRQF_SHARED, "h3600_suspend", ts->dev)) {
                printk(KERN_ERR "h3600ts.c: Could not allocate Power Button IRQ!\n");
                err = -EBUSY;
                goto fail2;
        }

        serio_set_drvdata(serio, ts);

        err = serio_open(serio, drv);
        if (err)
                goto fail3;

        //h3600_flite_control(1, 25);     /* default brightness */
        err = input_register_device(ts->dev);
        if (err)
                goto fail4;

        return 0;

fail4:  serio_close(serio);
fail3:  serio_set_drvdata(serio, NULL);
        free_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, ts->dev);
fail2:  free_irq(IRQ_GPIO_BITSY_ACTION_BUTTON, ts->dev);
fail1:  input_free_device(input_dev);
        kfree(ts);
        return err;
}

/*
 * h3600ts_disconnect() is the opposite of h3600ts_connect()
 */

static void h3600ts_disconnect(struct serio *serio)
{
        struct h3600_dev *ts = serio_get_drvdata(serio);

        free_irq(IRQ_GPIO_BITSY_ACTION_BUTTON, ts->dev);
        free_irq(IRQ_GPIO_BITSY_NPOWER_BUTTON, ts->dev);
        input_get_device(ts->dev);
        input_unregister_device(ts->dev);
        serio_close(serio);
        serio_set_drvdata(serio, NULL);
        input_put_device(ts->dev);
        kfree(ts);
}

/*
 * The serio driver structure.
 */

static struct serio_device_id h3600ts_serio_ids[] = {
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_H3600,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, h3600ts_serio_ids);

static struct serio_driver h3600ts_drv = {
        .driver         = {
                .name   = "h3600ts",
        },
        .description    = DRIVER_DESC,
        .id_table       = h3600ts_serio_ids,
        .interrupt      = h3600ts_interrupt,
        .connect        = h3600ts_connect,
        .disconnect     = h3600ts_disconnect,
};

/*
 * The functions for inserting/removing us as a module.
 */

static int __init h3600ts_init(void)
{
        return serio_register_driver(&h3600ts_drv);
}

static void __exit h3600ts_exit(void)
{
        serio_unregister_driver(&h3600ts_drv);
}

module_init(h3600ts_init);
module_exit(h3600ts_exit);