// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID driver for some ITE "special" devices
 * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
 */

#include <linux/device.h>
#include <linux/input.h>
#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

#define QUIRK_TOUCHPAD_ON_OFF_REPORT            BIT(0)

static const __u8 *ite_report_fixup(struct hid_device *hdev, __u8 *rdesc, unsigned int *rsize)
{
        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);

        if (quirks & QUIRK_TOUCHPAD_ON_OFF_REPORT) {
                /* For Acer Aspire Switch 10 SW5-012 keyboard-dock */
                if (*rsize == 188 && rdesc[162] == 0x81 && rdesc[163] == 0x02) {
                        hid_info(hdev, "Fixing up Acer Sw5-012 ITE keyboard report descriptor\n");
                        rdesc[163] = HID_MAIN_ITEM_RELATIVE;
                }
                /* For Acer One S1002/S1003 keyboard-dock */
                if (*rsize == 188 && rdesc[185] == 0x81 && rdesc[186] == 0x02) {
                        hid_info(hdev, "Fixing up Acer S1002/S1003 ITE keyboard report descriptor\n");
                        rdesc[186] = HID_MAIN_ITEM_RELATIVE;
                }
                /* For Acer Aspire Switch 10E (SW3-016) keyboard-dock */
                if (*rsize == 210 && rdesc[184] == 0x81 && rdesc[185] == 0x02) {
                        hid_info(hdev, "Fixing up Acer Aspire Switch 10E (SW3-016) ITE keyboard report descriptor\n");
                        rdesc[185] = HID_MAIN_ITEM_RELATIVE;
                }
        }

        return rdesc;
}

static int ite_input_mapping(struct hid_device *hdev,
                struct hid_input *hi, struct hid_field *field,
                struct hid_usage *usage, unsigned long **bit,
                int *max)
{

        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);

        if ((quirks & QUIRK_TOUCHPAD_ON_OFF_REPORT) &&
            (usage->hid & HID_USAGE_PAGE) == 0x00880000) {
                if (usage->hid == 0x00880078) {
                        /* Touchpad on, userspace expects F22 for this */
                        hid_map_usage_clear(hi, usage, bit, max, EV_KEY, KEY_F22);
                        return 1;
                }
                if (usage->hid == 0x00880079) {
                        /* Touchpad off, userspace expects F23 for this */
                        hid_map_usage_clear(hi, usage, bit, max, EV_KEY, KEY_F23);
                        return 1;
                }
                return -1;
        }

        return 0;
}

static int ite_event(struct hid_device *hdev, struct hid_field *field,
                     struct hid_usage *usage, __s32 value)
{
        struct input_dev *input;

        if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput)
                return 0;

        input = field->hidinput->input;

        /*
         * The ITE8595 always reports 0 as value for the rfkill button. Luckily
         * it is the only button in its report, and it sends a report on
         * release only, so receiving a report means the button was pressed.
         */
        if (usage->hid == HID_GD_RFKILL_BTN) {
                input_event(input, EV_KEY, KEY_RFKILL, 1);
                input_sync(input);
                input_event(input, EV_KEY, KEY_RFKILL, 0);
                input_sync(input);
                return 1;
        }

        return 0;
}

static int ite_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        int ret;

        hid_set_drvdata(hdev, (void *)id->driver_data);

        ret = hid_open_report(hdev);
        if (ret)
                return ret;

        return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
}

static const struct hid_device_id ite_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_ITE, USB_DEVICE_ID_ITE8595) },
        { HID_USB_DEVICE(USB_VENDOR_ID_258A, USB_DEVICE_ID_258A_6A88) },
        /* ITE8595 USB kbd ctlr, with Synaptics touchpad connected to it. */
        { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
                     USB_VENDOR_ID_SYNAPTICS,
                     USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_012),
          .driver_data = QUIRK_TOUCHPAD_ON_OFF_REPORT },
        /* ITE8910 USB kbd ctlr, with Synaptics touchpad connected to it. */
        { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
                     USB_VENDOR_ID_SYNAPTICS,
                     USB_DEVICE_ID_SYNAPTICS_ACER_ONE_S1002),
          .driver_data = QUIRK_TOUCHPAD_ON_OFF_REPORT },
        /* ITE8910 USB kbd ctlr, with Synaptics touchpad connected to it. */
        { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
                     USB_VENDOR_ID_SYNAPTICS,
                     USB_DEVICE_ID_SYNAPTICS_ACER_ONE_S1003),
          .driver_data = QUIRK_TOUCHPAD_ON_OFF_REPORT },
        /* ITE8910 USB kbd ctlr, with Synaptics touchpad connected to it. */
        { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
                     USB_VENDOR_ID_SYNAPTICS,
                     USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_017),
          .driver_data = QUIRK_TOUCHPAD_ON_OFF_REPORT },
        { }
};
MODULE_DEVICE_TABLE(hid, ite_devices);

static struct hid_driver ite_driver = {
        .name = "itetech",
        .id_table = ite_devices,
        .probe = ite_probe,
        .report_fixup = ite_report_fixup,
        .input_mapping = ite_input_mapping,
        .event = ite_event,
};
module_hid_driver(ite_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("HID driver for some ITE \"special\" devices");
MODULE_LICENSE("GPL");