// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2011 - 2015 UNISYS CORPORATION
 * All rights reserved.
 */

/*
 * This driver lives in a generic guest Linux partition, and registers to
 * receive keyboard and mouse channels from the visorbus driver.  It reads
 * inputs from such channels, and delivers it to the Linux OS in the
 * standard way the Linux expects for input drivers.
 */

#include <linux/fb.h>
#include <linux/input.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/uuid.h>
#include <linux/visorbus.h>

/* These defines identify mouse and keyboard activity which is specified by the
 * firmware to the host using the cmsimpleinput protocol.  @ingroup coretypes
 */
/* only motion; arg1=x, arg2=y */
#define INPUTACTION_XY_MOTION 1

/* arg1: 1=left,2=center,3=right */
#define INPUTACTION_MOUSE_BUTTON_DOWN 2
#define INPUTACTION_MOUSE_BUTTON_UP 3
#define INPUTACTION_MOUSE_BUTTON_CLICK 4
#define INPUTACTION_MOUSE_BUTTON_DCLICK 5

/* arg1: wheel rotation away from/toward user */
#define INPUTACTION_WHEEL_ROTATE_AWAY 6
#define INPUTACTION_WHEEL_ROTATE_TOWARD 7

/* arg1: scancode, as follows: If arg1 <= 0xff, it's a 1-byte scancode and arg1
 *       is that scancode. If arg1 > 0xff, it's a 2-byte scanecode, with the 1st
 *       byte in the low 8 bits, and the 2nd byte in the high 8 bits.
 *       E.g., the right ALT key would appear as x'38e0'.
 */
#define INPUTACTION_KEY_DOWN 64
#define INPUTACTION_KEY_UP 65
#define INPUTACTION_KEY_DOWN_UP 67

/* arg1: scancode (in same format as inputaction_keyDown); MUST refer to one of
 *       the locking keys, like capslock, numlock, or scrolllock.
 * arg2: 1 iff locking key should be in the LOCKED position (e.g., light is ON)
 */
#define INPUTACTION_SET_LOCKING_KEY_STATE 66

/* Keyboard channel {c73416d0-b0b8-44af-b304-9d2ae99f1b3d} */
#define VISOR_KEYBOARD_CHANNEL_GUID \
        GUID_INIT(0xc73416d0, 0xb0b8, 0x44af, \
                  0xb3, 0x4, 0x9d, 0x2a, 0xe9, 0x9f, 0x1b, 0x3d)
#define VISOR_KEYBOARD_CHANNEL_GUID_STR "c73416d0-b0b8-44af-b304-9d2ae99f1b3d"

/* Mouse channel {addf07d4-94a9-46e2-81c3-61abcdbdbd87} */
#define VISOR_MOUSE_CHANNEL_GUID \
        GUID_INIT(0xaddf07d4, 0x94a9, 0x46e2, \
                  0x81, 0xc3, 0x61, 0xab, 0xcd, 0xbd, 0xbd, 0x87)
#define VISOR_MOUSE_CHANNEL_GUID_STR "addf07d4-94a9-46e2-81c3-61abcdbdbd87"

#define PIXELS_ACROSS_DEFAULT 1024
#define PIXELS_DOWN_DEFAULT   768
#define KEYCODE_TABLE_BYTES   256

struct visor_inputactivity {
        u16 action;
        u16 arg1;
        u16 arg2;
        u16 arg3;
} __packed;

struct visor_inputreport {
        u64 seq_no;
        struct visor_inputactivity activity;
} __packed;

/* header of keyboard/mouse channels */
struct visor_input_channel_data {
        u32 n_input_reports;
        union {
                struct {
                        u16 x_res;
                        u16 y_res;
                } mouse;
                struct {
                        u32 flags;
                } keyboard;
        };
} __packed;

enum visorinput_dev_type {
        visorinput_keyboard,
        visorinput_mouse,
};

/*
 * This is the private data that we store for each device. A pointer to this
 * struct is maintained via dev_get_drvdata() / dev_set_drvdata() for each
 * struct device.
 */
struct visorinput_devdata {
        struct visor_device *dev;
        /* lock for dev */
        struct mutex lock_visor_dev;
        struct input_dev *visorinput_dev;
        bool paused;
        bool interrupts_enabled;
        /* size of following array */
        unsigned int keycode_table_bytes;
        /* for keyboard devices: visorkbd_keycode[] + visorkbd_ext_keycode[] */
        unsigned char keycode_table[];
};

static const guid_t visor_keyboard_channel_guid = VISOR_KEYBOARD_CHANNEL_GUID;
static const guid_t visor_mouse_channel_guid = VISOR_MOUSE_CHANNEL_GUID;

/*
 * Borrowed from drivers/input/keyboard/atakbd.c
 * This maps 1-byte scancodes to keycodes.
 */
static const unsigned char visorkbd_keycode[KEYCODE_TABLE_BYTES] = {
        /* American layout */
        [0] = KEY_GRAVE,
        [1] = KEY_ESC,
        [2] = KEY_1,
        [3] = KEY_2,
        [4] = KEY_3,
        [5] = KEY_4,
        [6] = KEY_5,
        [7] = KEY_6,
        [8] = KEY_7,
        [9] = KEY_8,
        [10] = KEY_9,
        [11] = KEY_0,
        [12] = KEY_MINUS,
        [13] = KEY_EQUAL,
        [14] = KEY_BACKSPACE,
        [15] = KEY_TAB,
        [16] = KEY_Q,
        [17] = KEY_W,
        [18] = KEY_E,
        [19] = KEY_R,
        [20] = KEY_T,
        [21] = KEY_Y,
        [22] = KEY_U,
        [23] = KEY_I,
        [24] = KEY_O,
        [25] = KEY_P,
        [26] = KEY_LEFTBRACE,
        [27] = KEY_RIGHTBRACE,
        [28] = KEY_ENTER,
        [29] = KEY_LEFTCTRL,
        [30] = KEY_A,
        [31] = KEY_S,
        [32] = KEY_D,
        [33] = KEY_F,
        [34] = KEY_G,
        [35] = KEY_H,
        [36] = KEY_J,
        [37] = KEY_K,
        [38] = KEY_L,
        [39] = KEY_SEMICOLON,
        [40] = KEY_APOSTROPHE,
        [41] = KEY_GRAVE,
        [42] = KEY_LEFTSHIFT,
        [43] = KEY_BACKSLASH,
        [44] = KEY_Z,
        [45] = KEY_X,
        [46] = KEY_C,
        [47] = KEY_V,
        [48] = KEY_B,
        [49] = KEY_N,
        [50] = KEY_M,
        [51] = KEY_COMMA,
        [52] = KEY_DOT,
        [53] = KEY_SLASH,
        [54] = KEY_RIGHTSHIFT,
        [55] = KEY_KPASTERISK,
        [56] = KEY_LEFTALT,
        [57] = KEY_SPACE,
        [58] = KEY_CAPSLOCK,
        [59] = KEY_F1,
        [60] = KEY_F2,
        [61] = KEY_F3,
        [62] = KEY_F4,
        [63] = KEY_F5,
        [64] = KEY_F6,
        [65] = KEY_F7,
        [66] = KEY_F8,
        [67] = KEY_F9,
        [68] = KEY_F10,
        [69] = KEY_NUMLOCK,
        [70] = KEY_SCROLLLOCK,
        [71] = KEY_KP7,
        [72] = KEY_KP8,
        [73] = KEY_KP9,
        [74] = KEY_KPMINUS,
        [75] = KEY_KP4,
        [76] = KEY_KP5,
        [77] = KEY_KP6,
        [78] = KEY_KPPLUS,
        [79] = KEY_KP1,
        [80] = KEY_KP2,
        [81] = KEY_KP3,
        [82] = KEY_KP0,
        [83] = KEY_KPDOT,
        /* enables UK backslash+pipe key and FR lessthan+greaterthan key */
        [86] = KEY_102ND,
        [87] = KEY_F11,
        [88] = KEY_F12,
        [90] = KEY_KPLEFTPAREN,
        [91] = KEY_KPRIGHTPAREN,
        [92] = KEY_KPASTERISK,
        [93] = KEY_KPASTERISK,
        [94] = KEY_KPPLUS,
        [95] = KEY_HELP,
        [96] = KEY_KPENTER,
        [97] = KEY_RIGHTCTRL,
        [98] = KEY_KPSLASH,
        [99] = KEY_KPLEFTPAREN,
        [100] = KEY_KPRIGHTPAREN,
        [101] = KEY_KPSLASH,
        [102] = KEY_HOME,
        [103] = KEY_UP,
        [104] = KEY_PAGEUP,
        [105] = KEY_LEFT,
        [106] = KEY_RIGHT,
        [107] = KEY_END,
        [108] = KEY_DOWN,
        [109] = KEY_PAGEDOWN,
        [110] = KEY_INSERT,
        [111] = KEY_DELETE,
        [112] = KEY_MACRO,
        [113] = KEY_MUTE
};

/*
 * This maps the <xx> in extended scancodes of the form "0xE0 <xx>" into
 * keycodes.
 */
static const unsigned char visorkbd_ext_keycode[KEYCODE_TABLE_BYTES] = {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,             /* 0x00 */
        0, 0, 0, 0, 0, 0, 0, 0,                                     /* 0x10 */
        0, 0, 0, 0, KEY_KPENTER, KEY_RIGHTCTRL, 0, 0,               /* 0x18 */
        0, 0, 0, 0, 0, 0, 0, 0,                                     /* 0x20 */
        KEY_RIGHTALT, 0, 0, 0, 0, 0, 0, 0,                          /* 0x28 */
        0, 0, 0, 0, 0, 0, 0, 0,                                     /* 0x30 */
        KEY_RIGHTALT /* AltGr */, 0, 0, 0, 0, 0, 0, 0,              /* 0x38 */
        0, 0, 0, 0, 0, 0, 0, KEY_HOME,                              /* 0x40 */
        KEY_UP, KEY_PAGEUP, 0, KEY_LEFT, 0, KEY_RIGHT, 0, KEY_END,  /* 0x48 */
        KEY_DOWN, KEY_PAGEDOWN, KEY_INSERT, KEY_DELETE, 0, 0, 0, 0, /* 0x50 */
        0, 0, 0, 0, 0, 0, 0, 0,                                     /* 0x58 */
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,             /* 0x60 */
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,             /* 0x70 */
};

static int visorinput_open(struct input_dev *visorinput_dev)
{
        struct visorinput_devdata *devdata = input_get_drvdata(visorinput_dev);

        if (!devdata) {
                dev_err(&visorinput_dev->dev,
                        "%s input_get_drvdata(%p) returned NULL\n",
                        __func__, visorinput_dev);
                return -EINVAL;
        }
        dev_dbg(&visorinput_dev->dev, "%s opened\n", __func__);

        /*
         * If we're not paused, really enable interrupts. Regardless of whether
         * we are paused, set a flag indicating interrupts should be enabled so
         * when we resume, interrupts will really be enabled.
         */
        mutex_lock(&devdata->lock_visor_dev);
        devdata->interrupts_enabled = true;
        if (devdata->paused)
                goto out_unlock;
        visorbus_enable_channel_interrupts(devdata->dev);

out_unlock:
        mutex_unlock(&devdata->lock_visor_dev);
        return 0;
}

static void visorinput_close(struct input_dev *visorinput_dev)
{
        struct visorinput_devdata *devdata = input_get_drvdata(visorinput_dev);

        if (!devdata) {
                dev_err(&visorinput_dev->dev,
                        "%s input_get_drvdata(%p) returned NULL\n",
                        __func__, visorinput_dev);
                return;
        }
        dev_dbg(&visorinput_dev->dev, "%s closed\n", __func__);

        /*
         * If we're not paused, really disable interrupts. Regardless of
         * whether we are paused, set a flag indicating interrupts should be
         * disabled so when we resume we will not re-enable them.
         */
        mutex_lock(&devdata->lock_visor_dev);
        devdata->interrupts_enabled = false;
        if (devdata->paused)
                goto out_unlock;
        visorbus_disable_channel_interrupts(devdata->dev);

out_unlock:
        mutex_unlock(&devdata->lock_visor_dev);
}

/*
 * setup_client_keyboard() initializes and returns a Linux input node that we
 * can use to deliver keyboard inputs to Linux.  We of course do this when we
 * see keyboard inputs coming in on a keyboard channel.
 */
static struct input_dev *setup_client_keyboard(void *devdata,
                                               unsigned char *keycode_table)

{
        int i;
        struct input_dev *visorinput_dev = input_allocate_device();

        if (!visorinput_dev)
                return NULL;

        visorinput_dev->name = "visor Keyboard";
        visorinput_dev->phys = "visorkbd:input0";
        visorinput_dev->id.bustype = BUS_VIRTUAL;
        visorinput_dev->id.vendor = 0x0001;
        visorinput_dev->id.product = 0x0001;
        visorinput_dev->id.version = 0x0100;

        visorinput_dev->evbit[0] = BIT_MASK(EV_KEY) |
                                   BIT_MASK(EV_REP) |
                                   BIT_MASK(EV_LED);
        visorinput_dev->ledbit[0] = BIT_MASK(LED_CAPSL) |
                                    BIT_MASK(LED_SCROLLL) |
                                    BIT_MASK(LED_NUML);
        visorinput_dev->keycode = keycode_table;
        /* sizeof(unsigned char) */
        visorinput_dev->keycodesize = 1;
        visorinput_dev->keycodemax = KEYCODE_TABLE_BYTES;

        for (i = 1; i < visorinput_dev->keycodemax; i++)
                set_bit(keycode_table[i], visorinput_dev->keybit);
        for (i = 1; i < visorinput_dev->keycodemax; i++)
                set_bit(keycode_table[i + KEYCODE_TABLE_BYTES],
                        visorinput_dev->keybit);

        visorinput_dev->open = visorinput_open;
        visorinput_dev->close = visorinput_close;
        /* pre input_register! */
        input_set_drvdata(visorinput_dev, devdata);

        return visorinput_dev;
}

static struct input_dev *setup_client_mouse(void *devdata, unsigned int xres,
                                            unsigned int yres)
{
        struct input_dev *visorinput_dev = input_allocate_device();

        if (!visorinput_dev)
                return NULL;

        visorinput_dev->name = "visor Mouse";
        visorinput_dev->phys = "visormou:input0";
        visorinput_dev->id.bustype = BUS_VIRTUAL;
        visorinput_dev->id.vendor = 0x0001;
        visorinput_dev->id.product = 0x0002;
        visorinput_dev->id.version = 0x0100;

        visorinput_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
        set_bit(BTN_LEFT, visorinput_dev->keybit);
        set_bit(BTN_RIGHT, visorinput_dev->keybit);
        set_bit(BTN_MIDDLE, visorinput_dev->keybit);

        if (xres == 0)
                xres = PIXELS_ACROSS_DEFAULT;
        if (yres == 0)
                yres = PIXELS_DOWN_DEFAULT;
        input_set_abs_params(visorinput_dev, ABS_X, 0, xres, 0, 0);
        input_set_abs_params(visorinput_dev, ABS_Y, 0, yres, 0, 0);

        visorinput_dev->open = visorinput_open;
        visorinput_dev->close = visorinput_close;
        /* pre input_register! */
        input_set_drvdata(visorinput_dev, devdata);
        input_set_capability(visorinput_dev, EV_REL, REL_WHEEL);

        return visorinput_dev;
}

static struct visorinput_devdata *devdata_create(struct visor_device *dev,
                                                 enum visorinput_dev_type dtype)
{
        struct visorinput_devdata *devdata = NULL;
        unsigned int extra_bytes = 0;
        unsigned int size, xres, yres, err;
        struct visor_input_channel_data data;

        if (dtype == visorinput_keyboard)
                /* allocate room for devdata->keycode_table, filled in below */
                extra_bytes = KEYCODE_TABLE_BYTES * 2;
        devdata = kzalloc(sizeof(*devdata) + extra_bytes, GFP_KERNEL);
        if (!devdata)
                return NULL;
        mutex_init(&devdata->lock_visor_dev);
        mutex_lock(&devdata->lock_visor_dev);
        devdata->dev = dev;

        /*
         * visorinput_open() can be called as soon as input_register_device()
         * happens, and that will enable channel interrupts.  Setting paused
         * prevents us from getting into visorinput_channel_interrupt() prior
         * to the device structure being totally initialized.
         */
        devdata->paused = true;

        /*
         * This is an input device in a client guest partition, so we need to
         * create whatever input nodes are necessary to deliver our inputs to
         * the guest OS.
         */
        switch (dtype) {
        case visorinput_keyboard:
                devdata->keycode_table_bytes = extra_bytes;
                memcpy(devdata->keycode_table, visorkbd_keycode,
                       KEYCODE_TABLE_BYTES);
                memcpy(devdata->keycode_table + KEYCODE_TABLE_BYTES,
                       visorkbd_ext_keycode, KEYCODE_TABLE_BYTES);
                devdata->visorinput_dev = setup_client_keyboard
                        (devdata, devdata->keycode_table);
                if (!devdata->visorinput_dev)
                        goto cleanups_register;
                break;
        case visorinput_mouse:
                size = sizeof(struct visor_input_channel_data);
                err = visorbus_read_channel(dev, sizeof(struct channel_header),
                                            &data, size);
                if (err)
                        goto cleanups_register;
                xres = data.mouse.x_res;
                yres = data.mouse.y_res;
                devdata->visorinput_dev = setup_client_mouse(devdata, xres,
                                                             yres);
                if (!devdata->visorinput_dev)
                        goto cleanups_register;
                break;
        default:
                /* No other input devices supported */
                break;
        }

        dev_set_drvdata(&dev->device, devdata);
        mutex_unlock(&devdata->lock_visor_dev);

        /*
         * Device struct is completely set up now, with the exception of
         * visorinput_dev being registered. We need to unlock before we
         * register the device, because this can cause an on-stack call of
         * visorinput_open(), which would deadlock if we had the lock.
         */
        if (input_register_device(devdata->visorinput_dev)) {
                input_free_device(devdata->visorinput_dev);
                goto err_kfree_devdata;
        }

        mutex_lock(&devdata->lock_visor_dev);
        /*
         * Establish calls to visorinput_channel_interrupt() if that is the
         * desired state that we've kept track of in interrupts_enabled while
         * the device was being created.
         */
        devdata->paused = false;
        if (devdata->interrupts_enabled)
                visorbus_enable_channel_interrupts(dev);
        mutex_unlock(&devdata->lock_visor_dev);

        return devdata;

cleanups_register:
        mutex_unlock(&devdata->lock_visor_dev);
err_kfree_devdata:
        kfree(devdata);
        return NULL;
}

static int visorinput_probe(struct visor_device *dev)
{
        const guid_t *guid;
        enum visorinput_dev_type dtype;

        guid = visorchannel_get_guid(dev->visorchannel);
        if (guid_equal(guid, &visor_mouse_channel_guid))
                dtype = visorinput_mouse;
        else if (guid_equal(guid, &visor_keyboard_channel_guid))
                dtype = visorinput_keyboard;
        else
                return -ENODEV;
        visorbus_disable_channel_interrupts(dev);
        if (!devdata_create(dev, dtype))
                return -ENOMEM;
        return 0;
}

static void unregister_client_input(struct input_dev *visorinput_dev)
{
        if (visorinput_dev)
                input_unregister_device(visorinput_dev);
}

static void visorinput_remove(struct visor_device *dev)
{
        struct visorinput_devdata *devdata = dev_get_drvdata(&dev->device);

        if (!devdata)
                return;

        mutex_lock(&devdata->lock_visor_dev);
        visorbus_disable_channel_interrupts(dev);

        /*
         * due to above, at this time no thread of execution will be in
         * visorinput_channel_interrupt()
         */

        dev_set_drvdata(&dev->device, NULL);
        mutex_unlock(&devdata->lock_visor_dev);

        unregister_client_input(devdata->visorinput_dev);
        kfree(devdata);
}

/*
 * Make it so the current locking state of the locking key indicated by
 * <keycode> is as indicated by <desired_state> (1=locked, 0=unlocked).
 */
static void handle_locking_key(struct input_dev *visorinput_dev, int keycode,
                               int desired_state)
{
        int led;

        switch (keycode) {
        case KEY_CAPSLOCK:
                led = LED_CAPSL;
                break;
        case KEY_SCROLLLOCK:
                led = LED_SCROLLL;
                break;
        case KEY_NUMLOCK:
                led = LED_NUML;
                break;
        default:
                return;
        }
        if (test_bit(led, visorinput_dev->led) != desired_state) {
                input_report_key(visorinput_dev, keycode, 1);
                input_sync(visorinput_dev);
                input_report_key(visorinput_dev, keycode, 0);
                input_sync(visorinput_dev);
                __change_bit(led, visorinput_dev->led);
        }
}

/*
 * <scancode> is either a 1-byte scancode, or an extended 16-bit scancode with
 * 0xE0 in the low byte and the extended scancode value in the next higher byte.
 */
static int scancode_to_keycode(int scancode)
{
        if (scancode > 0xff)
                return visorkbd_ext_keycode[(scancode >> 8) & 0xff];

        return visorkbd_keycode[scancode];
}

static int calc_button(int x)
{
        switch (x) {
        case 1:
                return BTN_LEFT;
        case 2:
                return BTN_MIDDLE;
        case 3:
                return BTN_RIGHT;
        default:
                return -EINVAL;
        }
}

/*
 * This is used only when this driver is active as an input driver in the
 * client guest partition.  It is called periodically so we can obtain inputs
 * from the channel, and deliver them to the guest OS.
 */
static void visorinput_channel_interrupt(struct visor_device *dev)
{
        struct visor_inputreport r;
        int scancode, keycode;
        struct input_dev *visorinput_dev;
        int xmotion, ymotion, button;
        int i;
        struct visorinput_devdata *devdata = dev_get_drvdata(&dev->device);

        if (!devdata)
                return;

        visorinput_dev = devdata->visorinput_dev;

        while (!visorchannel_signalremove(dev->visorchannel, 0, &r)) {
                scancode = r.activity.arg1;
                keycode = scancode_to_keycode(scancode);
                switch (r.activity.action) {
                case INPUTACTION_KEY_DOWN:
                        input_report_key(visorinput_dev, keycode, 1);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_KEY_UP:
                        input_report_key(visorinput_dev, keycode, 0);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_KEY_DOWN_UP:
                        input_report_key(visorinput_dev, keycode, 1);
                        input_sync(visorinput_dev);
                        input_report_key(visorinput_dev, keycode, 0);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_SET_LOCKING_KEY_STATE:
                        handle_locking_key(visorinput_dev, keycode,
                                           r.activity.arg2);
                        break;
                case INPUTACTION_XY_MOTION:
                        xmotion = r.activity.arg1;
                        ymotion = r.activity.arg2;
                        input_report_abs(visorinput_dev, ABS_X, xmotion);
                        input_report_abs(visorinput_dev, ABS_Y, ymotion);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_MOUSE_BUTTON_DOWN:
                        button = calc_button(r.activity.arg1);
                        if (button < 0)
                                break;
                        input_report_key(visorinput_dev, button, 1);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_MOUSE_BUTTON_UP:
                        button = calc_button(r.activity.arg1);
                        if (button < 0)
                                break;
                        input_report_key(visorinput_dev, button, 0);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_MOUSE_BUTTON_CLICK:
                        button = calc_button(r.activity.arg1);
                        if (button < 0)
                                break;
                        input_report_key(visorinput_dev, button, 1);
                        input_sync(visorinput_dev);
                        input_report_key(visorinput_dev, button, 0);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_MOUSE_BUTTON_DCLICK:
                        button = calc_button(r.activity.arg1);
                        if (button < 0)
                                break;
                        for (i = 0; i < 2; i++) {
                                input_report_key(visorinput_dev, button, 1);
                                input_sync(visorinput_dev);
                                input_report_key(visorinput_dev, button, 0);
                                input_sync(visorinput_dev);
                        }
                        break;
                case INPUTACTION_WHEEL_ROTATE_AWAY:
                        input_report_rel(visorinput_dev, REL_WHEEL, 1);
                        input_sync(visorinput_dev);
                        break;
                case INPUTACTION_WHEEL_ROTATE_TOWARD:
                        input_report_rel(visorinput_dev, REL_WHEEL, -1);
                        input_sync(visorinput_dev);
                        break;
                default:
                        /* Unsupported input action */
                        break;
                }
        }
}

static int visorinput_pause(struct visor_device *dev,
                            visorbus_state_complete_func complete_func)
{
        int rc;
        struct visorinput_devdata *devdata = dev_get_drvdata(&dev->device);

        if (!devdata) {
                rc = -ENODEV;
                goto out;
        }

        mutex_lock(&devdata->lock_visor_dev);
        if (devdata->paused) {
                rc = -EBUSY;
                goto out_locked;
        }
        if (devdata->interrupts_enabled)
                visorbus_disable_channel_interrupts(dev);

        /*
         * due to above, at this time no thread of execution will be in
         * visorinput_channel_interrupt()
         */
        devdata->paused = true;
        complete_func(dev, 0);
        rc = 0;
out_locked:
        mutex_unlock(&devdata->lock_visor_dev);
out:
        return rc;
}

static int visorinput_resume(struct visor_device *dev,
                             visorbus_state_complete_func complete_func)
{
        int rc;
        struct visorinput_devdata *devdata = dev_get_drvdata(&dev->device);

        if (!devdata) {
                rc = -ENODEV;
                goto out;
        }
        mutex_lock(&devdata->lock_visor_dev);
        if (!devdata->paused) {
                rc = -EBUSY;
                goto out_locked;
        }
        devdata->paused = false;
        complete_func(dev, 0);

        /*
         * Re-establish calls to visorinput_channel_interrupt() if that is the
         * desired state that we've kept track of in interrupts_enabled while
         * the device was paused.
         */
        if (devdata->interrupts_enabled)
                visorbus_enable_channel_interrupts(dev);

        rc = 0;
out_locked:
        mutex_unlock(&devdata->lock_visor_dev);
out:
        return rc;
}

/* GUIDS for all channel types supported by this driver. */
static struct visor_channeltype_descriptor visorinput_channel_types[] = {
        { VISOR_KEYBOARD_CHANNEL_GUID, "keyboard",
          sizeof(struct channel_header), 0 },
        { VISOR_MOUSE_CHANNEL_GUID, "mouse", sizeof(struct channel_header), 0 },
        {}
};

static struct visor_driver visorinput_driver = {
        .name = "visorinput",
        .owner = THIS_MODULE,
        .channel_types = visorinput_channel_types,
        .probe = visorinput_probe,
        .remove = visorinput_remove,
        .channel_interrupt = visorinput_channel_interrupt,
        .pause = visorinput_pause,
        .resume = visorinput_resume,
};

module_driver(visorinput_driver, visorbus_register_visor_driver,
              visorbus_unregister_visor_driver);

MODULE_DEVICE_TABLE(visorbus, visorinput_channel_types);

MODULE_AUTHOR("Unisys");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("s-Par human input driver for virtual keyboard/mouse");

MODULE_ALIAS("visorbus:" VISOR_MOUSE_CHANNEL_GUID_STR);
MODULE_ALIAS("visorbus:" VISOR_KEYBOARD_CHANNEL_GUID_STR);