/*
 * Generic linux-input device driver for keyboard devices
 *
 * Copyright (c) 2001 Brian S. Julin
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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
 *
 * References:
 * HP-HIL Technical Reference Manual.  Hewlett Packard Product No. 45918A
 *
 */

#include <linux/hil.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/pci_ids.h>

#define PREFIX "HIL: "

MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
MODULE_DESCRIPTION("HIL keyboard/mouse driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("serio:ty03pr25id00ex*"); /* HIL keyboard */
MODULE_ALIAS("serio:ty03pr25id0Fex*"); /* HIL mouse */

#define HIL_PACKET_MAX_LENGTH 16

#define HIL_KBD_SET1_UPBIT 0x01
#define HIL_KBD_SET1_SHIFT 1
static unsigned int hil_kbd_set1[HIL_KEYCODES_SET1_TBLSIZE] __read_mostly =
        { HIL_KEYCODES_SET1 };

#define HIL_KBD_SET2_UPBIT 0x01
#define HIL_KBD_SET2_SHIFT 1
/* Set2 is user defined */

#define HIL_KBD_SET3_UPBIT 0x80
#define HIL_KBD_SET3_SHIFT 0
static unsigned int hil_kbd_set3[HIL_KEYCODES_SET3_TBLSIZE] __read_mostly =
        { HIL_KEYCODES_SET3 };

static const char hil_language[][16] = { HIL_LOCALE_MAP };

struct hil_dev {
        struct input_dev *dev;
        struct serio *serio;

        /* Input buffer and index for packets from HIL bus. */
        hil_packet data[HIL_PACKET_MAX_LENGTH];
        int idx4; /* four counts per packet */

        /* Raw device info records from HIL bus, see hil.h for fields. */
        char    idd[HIL_PACKET_MAX_LENGTH];     /* DID byte and IDD record */
        char    rsc[HIL_PACKET_MAX_LENGTH];     /* RSC record */
        char    exd[HIL_PACKET_MAX_LENGTH];     /* EXD record */
        char    rnm[HIL_PACKET_MAX_LENGTH + 1]; /* RNM record + NULL term. */

        struct completion cmd_done;

        bool is_pointer;
        /* Extra device details needed for pointing devices. */
        unsigned int nbtn, naxes;
        unsigned int btnmap[7];
};

static bool hil_dev_is_command_response(hil_packet p)
{
        if ((p & ~HIL_CMDCT_POL) == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
                return false;

        if ((p & ~HIL_CMDCT_RPL) == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_RPL))
                return false;

        return true;
}

static void hil_dev_handle_command_response(struct hil_dev *dev)
{
        hil_packet p;
        char *buf;
        int i, idx;

        idx = dev->idx4 / 4;
        p = dev->data[idx - 1];

        switch (p & HIL_PKT_DATA_MASK) {
        case HIL_CMD_IDD:
                buf = dev->idd;
                break;

        case HIL_CMD_RSC:
                buf = dev->rsc;
                break;

        case HIL_CMD_EXD:
                buf = dev->exd;
                break;

        case HIL_CMD_RNM:
                dev->rnm[HIL_PACKET_MAX_LENGTH] = 0;
                buf = dev->rnm;
                break;

        default:
                /* These occur when device isn't present */
                if (p != (HIL_ERR_INT | HIL_PKT_CMD)) {
                        /* Anything else we'd like to know about. */
                        printk(KERN_WARNING PREFIX "Device sent unknown record %x\n", p);
                }
                goto out;
        }

        for (i = 0; i < idx; i++)
                buf[i] = dev->data[i] & HIL_PKT_DATA_MASK;
        for (; i < HIL_PACKET_MAX_LENGTH; i++)
                buf[i] = 0;
 out:
        complete(&dev->cmd_done);
}

static void hil_dev_handle_kbd_events(struct hil_dev *kbd)
{
        struct input_dev *dev = kbd->dev;
        int idx = kbd->idx4 / 4;
        int i;

        switch (kbd->data[0] & HIL_POL_CHARTYPE_MASK) {
        case HIL_POL_CHARTYPE_NONE:
                return;

        case HIL_POL_CHARTYPE_ASCII:
                for (i = 1; i < idx - 1; i++)
                        input_report_key(dev, kbd->data[i] & 0x7f, 1);
                break;

        case HIL_POL_CHARTYPE_RSVD1:
        case HIL_POL_CHARTYPE_RSVD2:
        case HIL_POL_CHARTYPE_BINARY:
                for (i = 1; i < idx - 1; i++)
                        input_report_key(dev, kbd->data[i], 1);
                break;

        case HIL_POL_CHARTYPE_SET1:
                for (i = 1; i < idx - 1; i++) {
                        unsigned int key = kbd->data[i];
                        int up = key & HIL_KBD_SET1_UPBIT;

                        key &= (~HIL_KBD_SET1_UPBIT & 0xff);
                        key = hil_kbd_set1[key >> HIL_KBD_SET1_SHIFT];
                        input_report_key(dev, key, !up);
                }
                break;

        case HIL_POL_CHARTYPE_SET2:
                for (i = 1; i < idx - 1; i++) {
                        unsigned int key = kbd->data[i];
                        int up = key & HIL_KBD_SET2_UPBIT;

                        key &= (~HIL_KBD_SET1_UPBIT & 0xff);
                        key = key >> HIL_KBD_SET2_SHIFT;
                        input_report_key(dev, key, !up);
                }
                break;

        case HIL_POL_CHARTYPE_SET3:
                for (i = 1; i < idx - 1; i++) {
                        unsigned int key = kbd->data[i];
                        int up = key & HIL_KBD_SET3_UPBIT;

                        key &= (~HIL_KBD_SET1_UPBIT & 0xff);
                        key = hil_kbd_set3[key >> HIL_KBD_SET3_SHIFT];
                        input_report_key(dev, key, !up);
                }
                break;
        }

        input_sync(dev);
}

static void hil_dev_handle_ptr_events(struct hil_dev *ptr)
{
        struct input_dev *dev = ptr->dev;
        int idx = ptr->idx4 / 4;
        hil_packet p = ptr->data[idx - 1];
        int i, cnt, laxis;
        bool absdev, ax16;

        if ((p & HIL_CMDCT_POL) != idx - 1) {
                printk(KERN_WARNING PREFIX
                        "Malformed poll packet %x (idx = %i)\n", p, idx);
                return;
        }

        i = (p & HIL_POL_AXIS_ALT) ? 3 : 0;
        laxis = (p & HIL_POL_NUM_AXES_MASK) + i;

        ax16 = ptr->idd[1] & HIL_IDD_HEADER_16BIT; /* 8 or 16bit resolution */
        absdev = ptr->idd[1] & HIL_IDD_HEADER_ABS;

        for (cnt = 1; i < laxis; i++) {
                unsigned int lo, hi, val;

                lo = ptr->data[cnt++] & HIL_PKT_DATA_MASK;
                hi = ax16 ? (ptr->data[cnt++] & HIL_PKT_DATA_MASK) : 0;

                if (absdev) {
                        val = lo + (hi << 8);
#ifdef TABLET_AUTOADJUST
                        if (val < input_abs_get_min(dev, ABS_X + i))
                                input_abs_set_min(dev, ABS_X + i, val);
                        if (val > input_abs_get_max(dev, ABS_X + i))
                                input_abs_set_max(dev, ABS_X + i, val);
#endif
                        if (i % 3)
                                val = input_abs_get_max(dev, ABS_X + i) - val;
                        input_report_abs(dev, ABS_X + i, val);
                } else {
                        val = (int) (((int8_t) lo) | ((int8_t) hi << 8));
                        if (i % 3)
                                val *= -1;
                        input_report_rel(dev, REL_X + i, val);
                }
        }

        while (cnt < idx - 1) {
                unsigned int btn = ptr->data[cnt++];
                int up = btn & 1;

                btn &= 0xfe;
                if (btn == 0x8e)
                        continue; /* TODO: proximity == touch? */
                if (btn > 0x8c || btn < 0x80)
                        continue;
                btn = (btn - 0x80) >> 1;
                btn = ptr->btnmap[btn];
                input_report_key(dev, btn, !up);
        }

        input_sync(dev);
}

static void hil_dev_process_err(struct hil_dev *dev)
{
        printk(KERN_WARNING PREFIX "errored HIL packet\n");
        dev->idx4 = 0;
        complete(&dev->cmd_done); /* just in case somebody is waiting */
}

static irqreturn_t hil_dev_interrupt(struct serio *serio,
                                unsigned char data, unsigned int flags)
{
        struct hil_dev *dev;
        hil_packet packet;
        int idx;

        dev = serio_get_drvdata(serio);
        BUG_ON(dev == NULL);

        if (dev->idx4 >= HIL_PACKET_MAX_LENGTH * sizeof(hil_packet)) {
                hil_dev_process_err(dev);
                goto out;
        }

        idx = dev->idx4 / 4;
        if (!(dev->idx4 % 4))
                dev->data[idx] = 0;
        packet = dev->data[idx];
        packet |= ((hil_packet)data) << ((3 - (dev->idx4 % 4)) * 8);
        dev->data[idx] = packet;

        /* Records of N 4-byte hil_packets must terminate with a command. */
        if ((++dev->idx4 % 4) == 0) {
                if ((packet & 0xffff0000) != HIL_ERR_INT) {
                        hil_dev_process_err(dev);
                } else if (packet & HIL_PKT_CMD) {
                        if (hil_dev_is_command_response(packet))
                                hil_dev_handle_command_response(dev);
                        else if (dev->is_pointer)
                                hil_dev_handle_ptr_events(dev);
                        else
                                hil_dev_handle_kbd_events(dev);
                        dev->idx4 = 0;
                }
        }
 out:
        return IRQ_HANDLED;
}

static void hil_dev_disconnect(struct serio *serio)
{
        struct hil_dev *dev = serio_get_drvdata(serio);

        BUG_ON(dev == NULL);

        serio_close(serio);
        input_unregister_device(dev->dev);
        serio_set_drvdata(serio, NULL);
        kfree(dev);
}

static void hil_dev_keyboard_setup(struct hil_dev *kbd)
{
        struct input_dev *input_dev = kbd->dev;
        uint8_t did = kbd->idd[0];
        int i;

        input_dev->evbit[0]     = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
        input_dev->ledbit[0]    = BIT_MASK(LED_NUML) | BIT_MASK(LED_CAPSL) |
                                  BIT_MASK(LED_SCROLLL);

        for (i = 0; i < 128; i++) {
                __set_bit(hil_kbd_set1[i], input_dev->keybit);
                __set_bit(hil_kbd_set3[i], input_dev->keybit);
        }
        __clear_bit(KEY_RESERVED, input_dev->keybit);

        input_dev->keycodemax   = HIL_KEYCODES_SET1_TBLSIZE;
        input_dev->keycodesize  = sizeof(hil_kbd_set1[0]);
        input_dev->keycode      = hil_kbd_set1;

        input_dev->name = strlen(kbd->rnm) ? kbd->rnm : "HIL keyboard";
        input_dev->phys = "hpkbd/input0";

        printk(KERN_INFO PREFIX "HIL keyboard found (did = 0x%02x, lang = %s)\n",
                did, hil_language[did & HIL_IDD_DID_TYPE_KB_LANG_MASK]);
}

static void hil_dev_pointer_setup(struct hil_dev *ptr)
{
        struct input_dev *input_dev = ptr->dev;
        uint8_t did = ptr->idd[0];
        uint8_t *idd = ptr->idd + 1;
        unsigned int naxsets = HIL_IDD_NUM_AXSETS(*idd);
        unsigned int i, btntype;
        const char *txt;

        ptr->naxes = HIL_IDD_NUM_AXES_PER_SET(*idd);

        switch (did & HIL_IDD_DID_TYPE_MASK) {
        case HIL_IDD_DID_TYPE_REL:
                input_dev->evbit[0] = BIT_MASK(EV_REL);

                for (i = 0; i < ptr->naxes; i++)
                        __set_bit(REL_X + i, input_dev->relbit);

                for (i = 3; naxsets > 1 && i < ptr->naxes + 3; i++)
                        __set_bit(REL_X + i, input_dev->relbit);

                txt = "relative";
                break;

        case HIL_IDD_DID_TYPE_ABS:
                input_dev->evbit[0] = BIT_MASK(EV_ABS);

                for (i = 0; i < ptr->naxes; i++)
                        input_set_abs_params(input_dev, ABS_X + i,
                                        0, HIL_IDD_AXIS_MAX(idd, i), 0, 0);

                for (i = 3; naxsets > 1 && i < ptr->naxes + 3; i++)
                        input_set_abs_params(input_dev, ABS_X + i,
                                        0, HIL_IDD_AXIS_MAX(idd, i - 3), 0, 0);

#ifdef TABLET_AUTOADJUST
                for (i = 0; i < ABS_MAX; i++) {
                        int diff = input_abs_get_max(input_dev, ABS_X + i) / 10;
                        input_abs_set_min(input_dev, ABS_X + i,
                                input_abs_get_min(input_dev, ABS_X + i) + diff);
                        input_abs_set_max(input_dev, ABS_X + i,
                                input_abs_get_max(input_dev, ABS_X + i) - diff);
                }
#endif

                txt = "absolute";
                break;

        default:
                BUG();
        }

        ptr->nbtn = HIL_IDD_NUM_BUTTONS(idd);
        if (ptr->nbtn)
                input_dev->evbit[0] |= BIT_MASK(EV_KEY);

        btntype = BTN_MISC;
        if ((did & HIL_IDD_DID_ABS_TABLET_MASK) == HIL_IDD_DID_ABS_TABLET)
#ifdef TABLET_SIMULATES_MOUSE
                btntype = BTN_TOUCH;
#else
                btntype = BTN_DIGI;
#endif
        if ((did & HIL_IDD_DID_ABS_TSCREEN_MASK) == HIL_IDD_DID_ABS_TSCREEN)
                btntype = BTN_TOUCH;

        if ((did & HIL_IDD_DID_REL_MOUSE_MASK) == HIL_IDD_DID_REL_MOUSE)
                btntype = BTN_MOUSE;

        for (i = 0; i < ptr->nbtn; i++) {
                __set_bit(btntype | i, input_dev->keybit);
                ptr->btnmap[i] = btntype | i;
        }

        if (btntype == BTN_MOUSE) {
                /* Swap buttons 2 and 3 */
                ptr->btnmap[1] = BTN_MIDDLE;
                ptr->btnmap[2] = BTN_RIGHT;
        }

        input_dev->name = strlen(ptr->rnm) ? ptr->rnm : "HIL pointer device";

        printk(KERN_INFO PREFIX
                "HIL pointer device found (did: 0x%02x, axis: %s)\n",
                did, txt);
        printk(KERN_INFO PREFIX
                "HIL pointer has %i buttons and %i sets of %i axes\n",
                ptr->nbtn, naxsets, ptr->naxes);
}

static int hil_dev_connect(struct serio *serio, struct serio_driver *drv)
{
        struct hil_dev *dev;
        struct input_dev *input_dev;
        uint8_t did, *idd;
        int error;

        dev = kzalloc_obj(*dev);
        input_dev = input_allocate_device();
        if (!dev || !input_dev) {
                error = -ENOMEM;
                goto bail0;
        }

        dev->serio = serio;
        dev->dev = input_dev;

        error = serio_open(serio, drv);
        if (error)
                goto bail0;

        serio_set_drvdata(serio, dev);

        /* Get device info.  MLC driver supplies devid/status/etc. */
        init_completion(&dev->cmd_done);
        serio_write(serio, 0);
        serio_write(serio, 0);
        serio_write(serio, HIL_PKT_CMD >> 8);
        serio_write(serio, HIL_CMD_IDD);
        error = wait_for_completion_killable(&dev->cmd_done);
        if (error)
                goto bail1;

        reinit_completion(&dev->cmd_done);
        serio_write(serio, 0);
        serio_write(serio, 0);
        serio_write(serio, HIL_PKT_CMD >> 8);
        serio_write(serio, HIL_CMD_RSC);
        error = wait_for_completion_killable(&dev->cmd_done);
        if (error)
                goto bail1;

        reinit_completion(&dev->cmd_done);
        serio_write(serio, 0);
        serio_write(serio, 0);
        serio_write(serio, HIL_PKT_CMD >> 8);
        serio_write(serio, HIL_CMD_RNM);
        error = wait_for_completion_killable(&dev->cmd_done);
        if (error)
                goto bail1;

        reinit_completion(&dev->cmd_done);
        serio_write(serio, 0);
        serio_write(serio, 0);
        serio_write(serio, HIL_PKT_CMD >> 8);
        serio_write(serio, HIL_CMD_EXD);
        error = wait_for_completion_killable(&dev->cmd_done);
        if (error)
                goto bail1;

        did = dev->idd[0];
        idd = dev->idd + 1;

        switch (did & HIL_IDD_DID_TYPE_MASK) {
        case HIL_IDD_DID_TYPE_KB_INTEGRAL:
        case HIL_IDD_DID_TYPE_KB_ITF:
        case HIL_IDD_DID_TYPE_KB_RSVD:
        case HIL_IDD_DID_TYPE_CHAR:
                if (HIL_IDD_NUM_BUTTONS(idd) ||
                    HIL_IDD_NUM_AXES_PER_SET(*idd)) {
                        printk(KERN_INFO PREFIX
                                "combo devices are not supported.\n");
                        error = -EINVAL;
                        goto bail1;
                }

                dev->is_pointer = false;
                hil_dev_keyboard_setup(dev);
                break;

        case HIL_IDD_DID_TYPE_REL:
        case HIL_IDD_DID_TYPE_ABS:
                dev->is_pointer = true;
                hil_dev_pointer_setup(dev);
                break;

        default:
                goto bail1;
        }

        input_dev->id.bustype   = BUS_HIL;
        input_dev->id.vendor    = PCI_VENDOR_ID_HP;
        input_dev->id.product   = 0x0001; /* TODO: get from kbd->rsc */
        input_dev->id.version   = 0x0100; /* TODO: get from kbd->rsc */
        input_dev->dev.parent   = &serio->dev;

        if (!dev->is_pointer) {
                serio_write(serio, 0);
                serio_write(serio, 0);
                serio_write(serio, HIL_PKT_CMD >> 8);
                /* Enable Keyswitch Autorepeat 1 */
                serio_write(serio, HIL_CMD_EK1);
                /* No need to wait for completion */
        }

        error = input_register_device(input_dev);
        if (error)
                goto bail1;

        return 0;

 bail1:
        serio_close(serio);
        serio_set_drvdata(serio, NULL);
 bail0:
        input_free_device(input_dev);
        kfree(dev);
        return error;
}

static const struct serio_device_id hil_dev_ids[] = {
        {
                .type = SERIO_HIL_MLC,
                .proto = SERIO_HIL,
                .id = SERIO_ANY,
                .extra = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, hil_dev_ids);

static struct serio_driver hil_serio_drv = {
        .driver         = {
                .name   = "hil_dev",
        },
        .description    = "HP HIL keyboard/mouse/tablet driver",
        .id_table       = hil_dev_ids,
        .connect        = hil_dev_connect,
        .disconnect     = hil_dev_disconnect,
        .interrupt      = hil_dev_interrupt
};

module_serio_driver(hil_serio_drv);