// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * USB Synaptics device driver
 *
 *  Copyright (c) 2002 Rob Miller (rob@inpharmatica . co . uk)
 *  Copyright (c) 2003 Ron Lee (ron@debian.org)
 *      cPad driver for kernel 2.4
 *
 *  Copyright (c) 2004 Jan Steinhoff (cpad@jan-steinhoff . de)
 *  Copyright (c) 2004 Ron Lee (ron@debian.org)
 *      rewritten for kernel 2.6
 *
 *  cPad display character device part is not included. It can be found at
 *  http://jan-steinhoff.de/linux/synaptics-usb.html
 *
 * Bases on:    usb_skeleton.c v2.2 by Greg Kroah-Hartman
 *              drivers/hid/usbhid/usbmouse.c by Vojtech Pavlik
 *              drivers/input/mouse/synaptics.c by Peter Osterlund
 *
 * Trademarks are the property of their respective owners.
 */

/*
 * There are three different types of Synaptics USB devices: Touchpads,
 * touchsticks (or trackpoints), and touchscreens. Touchpads are well supported
 * by this driver, touchstick support has not been tested much yet, and
 * touchscreens have not been tested at all.
 *
 * Up to three alternate settings are possible:
 *      setting 0: one int endpoint for relative movement (used by usbhid.ko)
 *      setting 1: one int endpoint for absolute finger position
 *      setting 2 (cPad only): one int endpoint for absolute finger position and
 *                 two bulk endpoints for the display (in/out)
 * This driver uses setting 1.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <linux/input.h>
#include <linux/usb/input.h>

#define USB_VENDOR_ID_SYNAPTICS 0x06cb
#define USB_DEVICE_ID_SYNAPTICS_TP      0x0001  /* Synaptics USB TouchPad */
#define USB_DEVICE_ID_SYNAPTICS_INT_TP  0x0002  /* Integrated USB TouchPad */
#define USB_DEVICE_ID_SYNAPTICS_CPAD    0x0003  /* Synaptics cPad */
#define USB_DEVICE_ID_SYNAPTICS_TS      0x0006  /* Synaptics TouchScreen */
#define USB_DEVICE_ID_SYNAPTICS_STICK   0x0007  /* Synaptics USB Styk */
#define USB_DEVICE_ID_SYNAPTICS_WP      0x0008  /* Synaptics USB WheelPad */
#define USB_DEVICE_ID_SYNAPTICS_COMP_TP 0x0009  /* Composite USB TouchPad */
#define USB_DEVICE_ID_SYNAPTICS_WTP     0x0010  /* Wireless TouchPad */
#define USB_DEVICE_ID_SYNAPTICS_DPAD    0x0013  /* DisplayPad */

#define SYNUSB_TOUCHPAD                 (1 << 0)
#define SYNUSB_STICK                    (1 << 1)
#define SYNUSB_TOUCHSCREEN              (1 << 2)
#define SYNUSB_AUXDISPLAY               (1 << 3) /* For cPad */
#define SYNUSB_COMBO                    (1 << 4) /* Composite device (TP + stick) */
#define SYNUSB_IO_ALWAYS                (1 << 5)

#define USB_DEVICE_SYNAPTICS(prod, kind)                \
        USB_DEVICE(USB_VENDOR_ID_SYNAPTICS,             \
                   USB_DEVICE_ID_SYNAPTICS_##prod),     \
        .driver_info = (kind),

#define SYNUSB_RECV_SIZE        8

#define XMIN_NOMINAL            1472
#define XMAX_NOMINAL            5472
#define YMIN_NOMINAL            1408
#define YMAX_NOMINAL            4448

struct synusb {
        struct usb_device *udev;
        struct usb_interface *intf;
        struct urb *urb;
        unsigned char *data;

        /* serialize access to open/suspend */
        struct mutex pm_mutex;
        bool is_open;

        /* input device related data structures */
        struct input_dev *input;
        char name[128];
        char phys[64];

        /* characteristics of the device */
        unsigned long flags;
};

static void synusb_report_buttons(struct synusb *synusb)
{
        struct input_dev *input_dev = synusb->input;

        input_report_key(input_dev, BTN_LEFT, synusb->data[1] & 0x04);
        input_report_key(input_dev, BTN_RIGHT, synusb->data[1] & 0x01);
        input_report_key(input_dev, BTN_MIDDLE, synusb->data[1] & 0x02);
}

static void synusb_report_stick(struct synusb *synusb)
{
        struct input_dev *input_dev = synusb->input;
        int x, y;
        unsigned int pressure;

        pressure = synusb->data[6];
        x = (s16)(be16_to_cpup((__be16 *)&synusb->data[2]) << 3) >> 7;
        y = (s16)(be16_to_cpup((__be16 *)&synusb->data[4]) << 3) >> 7;

        if (pressure > 0) {
                input_report_rel(input_dev, REL_X, x);
                input_report_rel(input_dev, REL_Y, -y);
        }

        input_report_abs(input_dev, ABS_PRESSURE, pressure);

        synusb_report_buttons(synusb);

        input_sync(input_dev);
}

static void synusb_report_touchpad(struct synusb *synusb)
{
        struct input_dev *input_dev = synusb->input;
        unsigned int num_fingers, tool_width;
        unsigned int x, y;
        unsigned int pressure, w;

        pressure = synusb->data[6];
        x = be16_to_cpup((__be16 *)&synusb->data[2]);
        y = be16_to_cpup((__be16 *)&synusb->data[4]);
        w = synusb->data[0] & 0x0f;

        if (pressure > 0) {
                num_fingers = 1;
                tool_width = 5;
                switch (w) {
                case 0 ... 1:
                        num_fingers = 2 + w;
                        break;

                case 2:                 /* pen, pretend its a finger */
                        break;

                case 4 ... 15:
                        tool_width = w;
                        break;
                }
        } else {
                num_fingers = 0;
                tool_width = 0;
        }

        /*
         * Post events
         * BTN_TOUCH has to be first as mousedev relies on it when doing
         * absolute -> relative conversion
         */

        if (pressure > 30)
                input_report_key(input_dev, BTN_TOUCH, 1);
        if (pressure < 25)
                input_report_key(input_dev, BTN_TOUCH, 0);

        if (num_fingers > 0) {
                input_report_abs(input_dev, ABS_X, x);
                input_report_abs(input_dev, ABS_Y,
                                 YMAX_NOMINAL + YMIN_NOMINAL - y);
        }

        input_report_abs(input_dev, ABS_PRESSURE, pressure);
        input_report_abs(input_dev, ABS_TOOL_WIDTH, tool_width);

        input_report_key(input_dev, BTN_TOOL_FINGER, num_fingers == 1);
        input_report_key(input_dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
        input_report_key(input_dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);

        synusb_report_buttons(synusb);
        if (synusb->flags & SYNUSB_AUXDISPLAY)
                input_report_key(input_dev, BTN_MIDDLE, synusb->data[1] & 0x08);

        input_sync(input_dev);
}

static void synusb_irq(struct urb *urb)
{
        struct synusb *synusb = urb->context;
        int error;

        /* Check our status in case we need to bail out early. */
        switch (urb->status) {
        case 0:
                usb_mark_last_busy(synusb->udev);
                break;

        /* Device went away so don't keep trying to read from it. */
        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
                return;

        default:
                goto resubmit;
                break;
        }

        if (synusb->flags & SYNUSB_STICK)
                synusb_report_stick(synusb);
        else
                synusb_report_touchpad(synusb);

resubmit:
        error = usb_submit_urb(urb, GFP_ATOMIC);
        if (error && error != -EPERM)
                dev_err(&synusb->intf->dev,
                        "%s - usb_submit_urb failed with result: %d",
                        __func__, error);
}

static struct usb_endpoint_descriptor *
synusb_get_in_endpoint(struct usb_host_interface *iface)
{

        struct usb_endpoint_descriptor *endpoint;
        int i;

        for (i = 0; i < iface->desc.bNumEndpoints; ++i) {
                endpoint = &iface->endpoint[i].desc;

                if (usb_endpoint_is_int_in(endpoint)) {
                        /* we found our interrupt in endpoint */
                        return endpoint;
                }
        }

        return NULL;
}

static int synusb_open(struct input_dev *dev)
{
        struct synusb *synusb = input_get_drvdata(dev);
        int retval;

        retval = usb_autopm_get_interface(synusb->intf);
        if (retval) {
                dev_err(&synusb->intf->dev,
                        "%s - usb_autopm_get_interface failed, error: %d\n",
                        __func__, retval);
                return retval;
        }

        mutex_lock(&synusb->pm_mutex);
        retval = usb_submit_urb(synusb->urb, GFP_KERNEL);
        if (retval) {
                dev_err(&synusb->intf->dev,
                        "%s - usb_submit_urb failed, error: %d\n",
                        __func__, retval);
                retval = -EIO;
                goto out;
        }

        synusb->intf->needs_remote_wakeup = 1;
        synusb->is_open = true;

out:
        mutex_unlock(&synusb->pm_mutex);
        usb_autopm_put_interface(synusb->intf);
        return retval;
}

static void synusb_close(struct input_dev *dev)
{
        struct synusb *synusb = input_get_drvdata(dev);
        int autopm_error;

        autopm_error = usb_autopm_get_interface(synusb->intf);

        mutex_lock(&synusb->pm_mutex);
        usb_kill_urb(synusb->urb);
        synusb->intf->needs_remote_wakeup = 0;
        synusb->is_open = false;
        mutex_unlock(&synusb->pm_mutex);

        if (!autopm_error)
                usb_autopm_put_interface(synusb->intf);
}

static int synusb_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(intf);
        struct usb_endpoint_descriptor *ep;
        struct synusb *synusb;
        struct input_dev *input_dev;
        unsigned int intf_num = intf->cur_altsetting->desc.bInterfaceNumber;
        unsigned int altsetting = min(intf->num_altsetting, 1U);
        int error;

        error = usb_set_interface(udev, intf_num, altsetting);
        if (error) {
                dev_err(&udev->dev,
                        "Can not set alternate setting to %i, error: %i",
                        altsetting, error);
                return error;
        }

        ep = synusb_get_in_endpoint(intf->cur_altsetting);
        if (!ep)
                return -ENODEV;

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

        synusb->udev = udev;
        synusb->intf = intf;
        synusb->input = input_dev;
        mutex_init(&synusb->pm_mutex);

        synusb->flags = id->driver_info;
        if (synusb->flags & SYNUSB_COMBO) {
                /*
                 * This is a combo device, we need to set proper
                 * capability, depending on the interface.
                 */
                synusb->flags |= intf_num == 1 ?
                                        SYNUSB_STICK : SYNUSB_TOUCHPAD;
        }

        synusb->urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!synusb->urb) {
                error = -ENOMEM;
                goto err_free_mem;
        }

        synusb->data = usb_alloc_coherent(udev, SYNUSB_RECV_SIZE, GFP_KERNEL,
                                          &synusb->urb->transfer_dma);
        if (!synusb->data) {
                error = -ENOMEM;
                goto err_free_urb;
        }

        usb_fill_int_urb(synusb->urb, udev,
                         usb_rcvintpipe(udev, ep->bEndpointAddress),
                         synusb->data, SYNUSB_RECV_SIZE,
                         synusb_irq, synusb,
                         ep->bInterval);
        synusb->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        if (udev->manufacturer)
                strscpy(synusb->name, udev->manufacturer,
                        sizeof(synusb->name));

        if (udev->product) {
                if (udev->manufacturer)
                        strlcat(synusb->name, " ", sizeof(synusb->name));
                strlcat(synusb->name, udev->product, sizeof(synusb->name));
        }

        if (!strlen(synusb->name))
                snprintf(synusb->name, sizeof(synusb->name),
                         "USB Synaptics Device %04x:%04x",
                         le16_to_cpu(udev->descriptor.idVendor),
                         le16_to_cpu(udev->descriptor.idProduct));

        if (synusb->flags & SYNUSB_STICK)
                strlcat(synusb->name, " (Stick)", sizeof(synusb->name));

        usb_make_path(udev, synusb->phys, sizeof(synusb->phys));
        strlcat(synusb->phys, "/input0", sizeof(synusb->phys));

        input_dev->name = synusb->name;
        input_dev->phys = synusb->phys;
        usb_to_input_id(udev, &input_dev->id);
        input_dev->dev.parent = &synusb->intf->dev;

        if (!(synusb->flags & SYNUSB_IO_ALWAYS)) {
                input_dev->open = synusb_open;
                input_dev->close = synusb_close;
        }

        input_set_drvdata(input_dev, synusb);

        __set_bit(EV_ABS, input_dev->evbit);
        __set_bit(EV_KEY, input_dev->evbit);

        if (synusb->flags & SYNUSB_STICK) {
                __set_bit(EV_REL, input_dev->evbit);
                __set_bit(REL_X, input_dev->relbit);
                __set_bit(REL_Y, input_dev->relbit);
                __set_bit(INPUT_PROP_POINTING_STICK, input_dev->propbit);
                input_set_abs_params(input_dev, ABS_PRESSURE, 0, 127, 0, 0);
        } else {
                input_set_abs_params(input_dev, ABS_X,
                                     XMIN_NOMINAL, XMAX_NOMINAL, 0, 0);
                input_set_abs_params(input_dev, ABS_Y,
                                     YMIN_NOMINAL, YMAX_NOMINAL, 0, 0);
                input_set_abs_params(input_dev, ABS_PRESSURE, 0, 255, 0, 0);
                input_set_abs_params(input_dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);
                __set_bit(BTN_TOUCH, input_dev->keybit);
                __set_bit(BTN_TOOL_FINGER, input_dev->keybit);
                __set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
                __set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
        }

        if (synusb->flags & SYNUSB_TOUCHSCREEN)
                __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
        else
                __set_bit(INPUT_PROP_POINTER, input_dev->propbit);

        __set_bit(BTN_LEFT, input_dev->keybit);
        __set_bit(BTN_RIGHT, input_dev->keybit);
        __set_bit(BTN_MIDDLE, input_dev->keybit);

        usb_set_intfdata(intf, synusb);

        if (synusb->flags & SYNUSB_IO_ALWAYS) {
                error = synusb_open(input_dev);
                if (error)
                        goto err_free_dma;
        }

        error = input_register_device(input_dev);
        if (error) {
                dev_err(&udev->dev,
                        "Failed to register input device, error %d\n",
                        error);
                goto err_stop_io;
        }

        return 0;

err_stop_io:
        if (synusb->flags & SYNUSB_IO_ALWAYS)
                synusb_close(synusb->input);
err_free_dma:
        usb_free_coherent(udev, SYNUSB_RECV_SIZE, synusb->data,
                          synusb->urb->transfer_dma);
err_free_urb:
        usb_free_urb(synusb->urb);
err_free_mem:
        input_free_device(input_dev);
        kfree(synusb);
        usb_set_intfdata(intf, NULL);

        return error;
}

static void synusb_disconnect(struct usb_interface *intf)
{
        struct synusb *synusb = usb_get_intfdata(intf);
        struct usb_device *udev = interface_to_usbdev(intf);

        if (synusb->flags & SYNUSB_IO_ALWAYS)
                synusb_close(synusb->input);

        input_unregister_device(synusb->input);

        usb_free_coherent(udev, SYNUSB_RECV_SIZE, synusb->data,
                          synusb->urb->transfer_dma);
        usb_free_urb(synusb->urb);
        kfree(synusb);

        usb_set_intfdata(intf, NULL);
}

static int synusb_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct synusb *synusb = usb_get_intfdata(intf);

        mutex_lock(&synusb->pm_mutex);
        usb_kill_urb(synusb->urb);
        mutex_unlock(&synusb->pm_mutex);

        return 0;
}

static int synusb_resume(struct usb_interface *intf)
{
        struct synusb *synusb = usb_get_intfdata(intf);
        int retval = 0;

        mutex_lock(&synusb->pm_mutex);

        if ((synusb->is_open || (synusb->flags & SYNUSB_IO_ALWAYS)) &&
            usb_submit_urb(synusb->urb, GFP_NOIO) < 0) {
                retval = -EIO;
        }

        mutex_unlock(&synusb->pm_mutex);

        return retval;
}

static int synusb_pre_reset(struct usb_interface *intf)
{
        struct synusb *synusb = usb_get_intfdata(intf);

        mutex_lock(&synusb->pm_mutex);
        usb_kill_urb(synusb->urb);

        return 0;
}

static int synusb_post_reset(struct usb_interface *intf)
{
        struct synusb *synusb = usb_get_intfdata(intf);
        int retval = 0;

        if ((synusb->is_open || (synusb->flags & SYNUSB_IO_ALWAYS)) &&
            usb_submit_urb(synusb->urb, GFP_NOIO) < 0) {
                retval = -EIO;
        }

        mutex_unlock(&synusb->pm_mutex);

        return retval;
}

static int synusb_reset_resume(struct usb_interface *intf)
{
        return synusb_resume(intf);
}

static const struct usb_device_id synusb_idtable[] = {
        { USB_DEVICE_SYNAPTICS(TP, SYNUSB_TOUCHPAD) },
        { USB_DEVICE_SYNAPTICS(INT_TP, SYNUSB_TOUCHPAD) },
        { USB_DEVICE_SYNAPTICS(CPAD,
                SYNUSB_TOUCHPAD | SYNUSB_AUXDISPLAY | SYNUSB_IO_ALWAYS) },
        { USB_DEVICE_SYNAPTICS(TS, SYNUSB_TOUCHSCREEN) },
        { USB_DEVICE_SYNAPTICS(STICK, SYNUSB_STICK) },
        { USB_DEVICE_SYNAPTICS(WP, SYNUSB_TOUCHPAD) },
        { USB_DEVICE_SYNAPTICS(COMP_TP, SYNUSB_COMBO) },
        { USB_DEVICE_SYNAPTICS(WTP, SYNUSB_TOUCHPAD) },
        { USB_DEVICE_SYNAPTICS(DPAD, SYNUSB_TOUCHPAD) },
        { }
};
MODULE_DEVICE_TABLE(usb, synusb_idtable);

static struct usb_driver synusb_driver = {
        .name           = "synaptics_usb",
        .probe          = synusb_probe,
        .disconnect     = synusb_disconnect,
        .id_table       = synusb_idtable,
        .suspend        = synusb_suspend,
        .resume         = synusb_resume,
        .pre_reset      = synusb_pre_reset,
        .post_reset     = synusb_post_reset,
        .reset_resume   = synusb_reset_resume,
        .supports_autosuspend = 1,
};

module_usb_driver(synusb_driver);

MODULE_AUTHOR("Rob Miller <rob@inpharmatica.co.uk>, "
              "Ron Lee <ron@debian.org>, "
              "Jan Steinhoff <cpad@jan-steinhoff.de>");
MODULE_DESCRIPTION("Synaptics USB device driver");
MODULE_LICENSE("GPL");