// SPDX-License-Identifier: GPL-2.0+
/*
 *  HID driver for UC-Logic devices not fully compliant with HID standard
 *
 *  Copyright (c) 2010-2014 Nikolai Kondrashov
 *  Copyright (c) 2013 Martin Rusko
 */

/*
 * 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.
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/timer.h>
#include "usbhid/usbhid.h"
#include "hid-uclogic-params.h"

#include "hid-ids.h"

/**
 * uclogic_inrange_timeout - handle pen in-range state timeout.
 * Emulate input events normally generated when pen goes out of range for
 * tablets which don't report that.
 *
 * @t:  The timer the timeout handler is attached to, stored in a struct
 *      uclogic_drvdata.
 */
static void uclogic_inrange_timeout(struct timer_list *t)
{
        struct uclogic_drvdata *drvdata = timer_container_of(drvdata, t,
                                                             inrange_timer);
        struct input_dev *input = drvdata->pen_input;

        if (input == NULL)
                return;
        input_report_abs(input, ABS_PRESSURE, 0);
        /* If BTN_TOUCH state is changing */
        if (test_bit(BTN_TOUCH, input->key)) {
                input_event(input, EV_MSC, MSC_SCAN,
                                /* Digitizer Tip Switch usage */
                                0xd0042);
                input_report_key(input, BTN_TOUCH, 0);
        }
        input_report_key(input, BTN_TOOL_PEN, 0);
        input_sync(input);
}

static const __u8 *uclogic_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                                        unsigned int *rsize)
{
        struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

        if (drvdata->desc_ptr != NULL) {
                *rsize = drvdata->desc_size;
                return drvdata->desc_ptr;
        }
        return rdesc;
}

/* Buttons considered valid tablet pad inputs. */
static const unsigned int uclogic_extra_input_mapping[] = {
        BTN_0,
        BTN_1,
        BTN_2,
        BTN_3,
        BTN_4,
        BTN_5,
        BTN_6,
        BTN_7,
        BTN_8,
        BTN_RIGHT,
        BTN_MIDDLE,
        BTN_SIDE,
        BTN_EXTRA,
        BTN_FORWARD,
        BTN_BACK,
        BTN_B,
        BTN_A,
        BTN_BASE,
        BTN_BASE2,
        BTN_X
};

static int uclogic_input_mapping(struct hid_device *hdev,
                                 struct hid_input *hi,
                                 struct hid_field *field,
                                 struct hid_usage *usage,
                                 unsigned long **bit,
                                 int *max)
{
        struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);
        struct uclogic_params *params = &drvdata->params;

        if (field->application == HID_GD_KEYPAD) {
                /*
                 * Remap input buttons to sensible ones that are not invalid.
                 * This only affects previous behavior for devices with more than ten or so buttons.
                 */
                const int key = (usage->hid & HID_USAGE) - 1;

                if (key < ARRAY_SIZE(uclogic_extra_input_mapping)) {
                        hid_map_usage(hi,
                                      usage,
                                      bit,
                                      max,
                                      EV_KEY,
                                      uclogic_extra_input_mapping[key]);
                        return 1;
                }
        } else if (field->application == HID_DG_PEN) {
                /* Discard invalid pen usages */
                if (params->pen.usage_invalid)
                        return -1;
        }

        /* Let hid-core decide what to do */
        return 0;
}

static int uclogic_input_configured(struct hid_device *hdev,
                struct hid_input *hi)
{
        struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);
        struct uclogic_params *params = &drvdata->params;
        const char *suffix = NULL;
        struct hid_field *field;
        size_t i;
        const struct uclogic_params_frame *frame;

        /* no report associated (HID_QUIRK_MULTI_INPUT not set) */
        if (!hi->report)
                return 0;

        /*
         * If this is the input corresponding to the pen report
         * in need of tweaking.
         */
        if (hi->report->id == params->pen.id) {
                /* Remember the input device so we can simulate events */
                drvdata->pen_input = hi->input;
        }

        /* If it's one of the frame devices */
        for (i = 0; i < ARRAY_SIZE(params->frame_list); i++) {
                frame = &params->frame_list[i];
                if (hi->report->id == frame->id) {
                        /* Assign custom suffix, if any */
                        suffix = frame->suffix;
                        /*
                         * Disable EV_MSC reports for touch ring interfaces to
                         * make the Wacom driver pickup touch ring extents
                         */
                        if (frame->touch_byte > 0)
                                __clear_bit(EV_MSC, hi->input->evbit);
                }
        }

        if (!suffix) {
                field = hi->report->field[0];

                switch (field->application) {
                case HID_GD_KEYBOARD:
                        suffix = "Keyboard";
                        break;
                case HID_GD_MOUSE:
                        suffix = "Mouse";
                        break;
                case HID_GD_KEYPAD:
                        suffix = "Pad";
                        break;
                case HID_DG_PEN:
                case HID_DG_DIGITIZER:
                        suffix = "Pen";
                        break;
                case HID_CP_CONSUMER_CONTROL:
                        suffix = "Consumer Control";
                        break;
                case HID_GD_SYSTEM_CONTROL:
                        suffix = "System Control";
                        break;
                }
        } else {
                hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
                                                 "%s %s", hdev->name, suffix);
                if (!hi->input->name)
                        return -ENOMEM;
        }

        return 0;
}

static int uclogic_probe(struct hid_device *hdev,
                const struct hid_device_id *id)
{
        int rc;
        struct uclogic_drvdata *drvdata = NULL;
        bool params_initialized = false;

        if (!hid_is_usb(hdev))
                return -EINVAL;

        /*
         * libinput requires the pad interface to be on a different node
         * than the pen, so use QUIRK_MULTI_INPUT for all tablets.
         */
        hdev->quirks |= HID_QUIRK_MULTI_INPUT;
        hdev->quirks |= HID_QUIRK_HIDINPUT_FORCE;

        /* Allocate and assign driver data */
        drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
        if (drvdata == NULL) {
                rc = -ENOMEM;
                goto failure;
        }
        timer_setup(&drvdata->inrange_timer, uclogic_inrange_timeout, 0);
        drvdata->re_state = U8_MAX;
        drvdata->quirks = id->driver_data;
        hid_set_drvdata(hdev, drvdata);

        /* Initialize the device and retrieve interface parameters */
        rc = uclogic_params_init(&drvdata->params, hdev);
        if (rc != 0) {
                hid_err(hdev, "failed probing parameters: %d\n", rc);
                goto failure;
        }
        params_initialized = true;
        hid_dbg(hdev, "parameters:\n");
        uclogic_params_hid_dbg(hdev, &drvdata->params);
        if (drvdata->params.invalid) {
                hid_info(hdev, "interface is invalid, ignoring\n");
                rc = -ENODEV;
                goto failure;
        }

        /* Generate replacement report descriptor */
        rc = uclogic_params_get_desc(&drvdata->params,
                                     &drvdata->desc_ptr,
                                     &drvdata->desc_size);
        if (rc) {
                hid_err(hdev,
                        "failed generating replacement report descriptor: %d\n",
                        rc);
                goto failure;
        }

        rc = hid_parse(hdev);
        if (rc) {
                hid_err(hdev, "parse failed\n");
                goto failure;
        }

        rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (rc) {
                hid_err(hdev, "hw start failed\n");
                goto failure;
        }

        return 0;
failure:
        /* Assume "remove" might not be called if "probe" failed */
        if (params_initialized)
                uclogic_params_cleanup(&drvdata->params);
        return rc;
}

static int uclogic_resume(struct hid_device *hdev)
{
        int rc;
        struct uclogic_params params;

        /* Re-initialize the device, but discard parameters */
        rc = uclogic_params_init(&params, hdev);
        if (rc != 0)
                hid_err(hdev, "failed to re-initialize the device\n");
        else
                uclogic_params_cleanup(&params);

        return rc;
}

/**
 * uclogic_exec_event_hook - if the received event is hooked schedules the
 * associated work.
 *
 * @p:          Tablet interface report parameters.
 * @event:      Raw event.
 * @size:       The size of event.
 *
 * Returns:
 *      Whether the event was hooked or not.
 */
static bool uclogic_exec_event_hook(struct uclogic_params *p, u8 *event, int size)
{
        struct uclogic_raw_event_hook *curr;

        if (!p->event_hooks)
                return false;

        list_for_each_entry(curr, &p->event_hooks->list, list) {
                if (curr->size == size && memcmp(curr->event, event, size) == 0) {
                        schedule_work(&curr->work);
                        return true;
                }
        }

        return false;
}

/**
 * uclogic_raw_event_pen - handle raw pen events (pen HID reports).
 *
 * @drvdata:    Driver data.
 * @data:       Report data buffer, can be modified.
 * @size:       Report data size, bytes.
 *
 * Returns:
 *      Negative value on error (stops event delivery), zero for success.
 */
static int uclogic_raw_event_pen(struct uclogic_drvdata *drvdata,
                                        u8 *data, int size)
{
        struct uclogic_params_pen *pen = &drvdata->params.pen;

        WARN_ON(drvdata == NULL);
        WARN_ON(data == NULL && size != 0);

        /* If in-range reports are inverted */
        if (pen->inrange ==
                UCLOGIC_PARAMS_PEN_INRANGE_INVERTED) {
                /* Invert the in-range bit */
                data[1] ^= 0x40;
        }
        /*
         * If report contains fragmented high-resolution pen
         * coordinates
         */
        if (size >= 10 && pen->fragmented_hires) {
                u8 pressure_low_byte;
                u8 pressure_high_byte;

                /* Lift pressure bytes */
                pressure_low_byte = data[6];
                pressure_high_byte = data[7];
                /*
                 * Move Y coord to make space for high-order X
                 * coord byte
                 */
                data[6] = data[5];
                data[5] = data[4];
                /* Move high-order X coord byte */
                data[4] = data[8];
                /* Move high-order Y coord byte */
                data[7] = data[9];
                /* Place pressure bytes */
                data[8] = pressure_low_byte;
                data[9] = pressure_high_byte;
        }
        if (size == 12 && pen->fragmented_hires2) {
                // 00 00 when on the left side, 01 00 in the right
                // we move these to the end of the x coord (u16) to create a correct x coord (u32)
                u8 lsb_low_byte = data[10];
                u8 lsb_high_byte = data[11];

                // shift everything right by 2 bytes, to make space for the moved lsb
                data[11] = data[9];
                data[10] = data[8];
                data[9] = data[7];
                data[8] = data[6];
                data[7] = data[5];
                data[6] = data[4];

                data[4] = lsb_low_byte;
                data[5] = lsb_high_byte;
        }
        /* If we need to emulate in-range detection */
        if (pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE) {
                /* Set in-range bit */
                data[1] |= 0x40;
                /* (Re-)start in-range timeout */
                mod_timer(&drvdata->inrange_timer,
                                jiffies + msecs_to_jiffies(100));
        }
        /* If we report tilt and Y direction is flipped */
        if (size >= 12 && pen->tilt_y_flipped)
                data[11] = -data[11];

        return 0;
}

/**
 * uclogic_raw_event_frame - handle raw frame events (frame HID reports).
 *
 * @drvdata:    Driver data.
 * @frame:      The parameters of the frame controls to handle.
 * @data:       Report data buffer, can be modified.
 * @size:       Report data size, bytes.
 *
 * Returns:
 *      Negative value on error (stops event delivery), zero for success.
 */
static int uclogic_raw_event_frame(
                struct uclogic_drvdata *drvdata,
                const struct uclogic_params_frame *frame,
                u8 *data, int size)
{
        WARN_ON(drvdata == NULL);
        WARN_ON(data == NULL && size != 0);

        /* If need to, and can, set pad device ID for Wacom drivers */
        if (frame->dev_id_byte > 0 && frame->dev_id_byte < size) {
                /* If we also have a touch ring and the finger left it */
                if (frame->touch_byte > 0 && frame->touch_byte < size &&
                    data[frame->touch_byte] == 0) {
                        data[frame->dev_id_byte] = 0;
                } else {
                        data[frame->dev_id_byte] = 0xf;
                }
        }

        /* If need to, and can, read rotary encoder state change */
        if (frame->re_lsb > 0 && frame->re_lsb / 8 < size) {
                unsigned int byte = frame->re_lsb / 8;
                unsigned int bit = frame->re_lsb % 8;

                u8 change;
                u8 prev_state = drvdata->re_state;
                /* Read Gray-coded state */
                u8 state = (data[byte] >> bit) & 0x3;
                /* Encode state change into 2-bit signed integer */
                if ((prev_state == 1 && state == 0) ||
                    (prev_state == 2 && state == 3)) {
                        change = 1;
                } else if ((prev_state == 2 && state == 0) ||
                           (prev_state == 1 && state == 3)) {
                        change = 3;
                } else {
                        change = 0;
                }
                /* Write change */
                data[byte] = (data[byte] & ~((u8)3 << bit)) |
                                (change << bit);
                /* Remember state */
                drvdata->re_state = state;
        }

        /* If need to, and can, transform the touch ring reports */
        if (frame->touch_byte > 0 && frame->touch_byte < size) {
                __s8 value = data[frame->touch_byte];

                if (value != 0) {
                        if (frame->touch_flip_at != 0) {
                                value = frame->touch_flip_at - value;
                                if (value <= 0)
                                        value = frame->touch_max + value;
                        }
                        data[frame->touch_byte] = value - 1;
                }
        }

        /* If need to, and can, transform the bitmap dial reports */
        if (frame->bitmap_dial_byte > 0 && frame->bitmap_dial_byte < size) {
                switch (data[frame->bitmap_dial_byte]) {
                case 2:
                        data[frame->bitmap_dial_byte] = -1;
                        break;

                /* Everything below here is for tablets that shove multiple dials into 1 byte */
                case 16:
                        data[frame->bitmap_dial_byte] = 0;
                        data[frame->bitmap_second_dial_destination_byte] = 1;
                        break;

                case 32:
                        data[frame->bitmap_dial_byte] = 0;
                        data[frame->bitmap_second_dial_destination_byte] = -1;
                        break;
                }
        }

        return 0;
}

static int uclogic_raw_event(struct hid_device *hdev,
                                struct hid_report *report,
                                u8 *data, int size)
{
        unsigned int report_id = report->id;
        struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);
        struct uclogic_params *params = &drvdata->params;
        struct uclogic_params_pen_subreport *subreport;
        struct uclogic_params_pen_subreport *subreport_list_end;
        size_t i;

        /* Do not handle anything but input reports */
        if (report->type != HID_INPUT_REPORT)
                return 0;

        if (uclogic_exec_event_hook(params, data, size))
                return 0;

        while (true) {
                /* Tweak pen reports, if necessary */
                if ((report_id == params->pen.id) && (size >= 2)) {
                        subreport_list_end =
                                params->pen.subreport_list +
                                ARRAY_SIZE(params->pen.subreport_list);
                        /* Try to match a subreport */
                        for (subreport = params->pen.subreport_list;
                             subreport < subreport_list_end; subreport++) {
                                if (subreport->value != 0 &&
                                    subreport->value == data[1]) {
                                        break;
                                }
                        }
                        /* If a subreport matched */
                        if (subreport < subreport_list_end) {
                                /* Change to subreport ID, and restart */
                                report_id = data[0] = subreport->id;
                                continue;
                        } else {
                                return uclogic_raw_event_pen(drvdata, data, size);
                        }
                }

                /* Tweak frame control reports, if necessary */
                for (i = 0; i < ARRAY_SIZE(params->frame_list); i++) {
                        if (report_id == params->frame_list[i].id) {
                                return uclogic_raw_event_frame(
                                        drvdata, &params->frame_list[i],
                                        data, size);
                        }
                }

                break;
        }

        return 0;
}

static void uclogic_remove(struct hid_device *hdev)
{
        struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);

        timer_delete_sync(&drvdata->inrange_timer);
        hid_hw_stop(hdev);
        kfree(drvdata->desc_ptr);
        uclogic_params_cleanup(&drvdata->params);
}

static const struct hid_device_id uclogic_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_PF1209) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_WP4030U) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_WP5540U) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_WP8060U) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_WP1062) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_WIRELESS_TABLET_TWHL850) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_TABLET_TWHA60) },
        { HID_USB_DEVICE(USB_VENDOR_ID_HUION,
                                USB_DEVICE_ID_HUION_TABLET) },
        { HID_USB_DEVICE(USB_VENDOR_ID_HUION,
                                USB_DEVICE_ID_HUION_TABLET2) },
        { HID_USB_DEVICE(USB_VENDOR_ID_TRUST,
                                USB_DEVICE_ID_TRUST_PANORA_TABLET) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_HUION_TABLET) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_YIYNOVA_TABLET) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_81) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_45) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_47) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC,
                                USB_DEVICE_ID_UCLOGIC_DRAWIMAGE_G3) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGTIZER,
                                USB_DEVICE_ID_UGTIZER_TABLET_GP0610) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGTIZER,
                                USB_DEVICE_ID_UGTIZER_TABLET_GT5040) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_PARBLO_A610_PRO) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_TABLET_G5) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_TABLET_EX07S) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_TABLET_RAINBOW_CV720) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_G540) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_G640) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO01) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO01_V2) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO_L) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO_PRO_MW),
                .driver_data = UCLOGIC_MOUSE_FRAME_QUIRK | UCLOGIC_BATTERY_QUIRK },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO_PRO_S) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO_PRO_SW),
                .driver_data = UCLOGIC_MOUSE_FRAME_QUIRK | UCLOGIC_BATTERY_QUIRK },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_STAR06) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_22R_PRO) },
        { HID_USB_DEVICE(USB_VENDOR_ID_UGEE,
                                USB_DEVICE_ID_UGEE_XPPEN_TABLET_24_PRO) },
        { }
};
MODULE_DEVICE_TABLE(hid, uclogic_devices);

static struct hid_driver uclogic_driver = {
        .name = "uclogic",
        .id_table = uclogic_devices,
        .probe = uclogic_probe,
        .remove = uclogic_remove,
        .report_fixup = uclogic_report_fixup,
        .raw_event = uclogic_raw_event,
        .input_mapping = uclogic_input_mapping,
        .input_configured = uclogic_input_configured,
        .resume           = pm_ptr(uclogic_resume),
        .reset_resume     = pm_ptr(uclogic_resume),
};
module_hid_driver(uclogic_driver);

MODULE_AUTHOR("Martin Rusko");
MODULE_AUTHOR("Nikolai Kondrashov");
MODULE_DESCRIPTION("HID driver for UC-Logic devices not fully compliant with HID standard");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("HID driver for UC-Logic devices not fully compliant with HID standard");

#ifdef CONFIG_HID_KUNIT_TEST
#include "hid-uclogic-core-test.c"
#endif