// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 *
 *  USB HIDBP Keyboard support
 */

/*
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

/*
 * Version Information
 */
#define DRIVER_VERSION ""
#define DRIVER_AUTHOR "Vojtech Pavlik <vojtech@ucw.cz>"
#define DRIVER_DESC "USB HID Boot Protocol keyboard driver"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

static const unsigned char usb_kbd_keycode[256] = {
          0,  0,  0,  0, 30, 48, 46, 32, 18, 33, 34, 35, 23, 36, 37, 38,
         50, 49, 24, 25, 16, 19, 31, 20, 22, 47, 17, 45, 21, 44,  2,  3,
          4,  5,  6,  7,  8,  9, 10, 11, 28,  1, 14, 15, 57, 12, 13, 26,
         27, 43, 43, 39, 40, 41, 51, 52, 53, 58, 59, 60, 61, 62, 63, 64,
         65, 66, 67, 68, 87, 88, 99, 70,119,110,102,104,111,107,109,106,
        105,108,103, 69, 98, 55, 74, 78, 96, 79, 80, 81, 75, 76, 77, 71,
         72, 73, 82, 83, 86,127,116,117,183,184,185,186,187,188,189,190,
        191,192,193,194,134,138,130,132,128,129,131,137,133,135,136,113,
        115,114,  0,  0,  0,121,  0, 89, 93,124, 92, 94, 95,  0,  0,  0,
        122,123, 90, 91, 85,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
          0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
          0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
          0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
          0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
         29, 42, 56,125, 97, 54,100,126,164,166,165,163,161,115,114,113,
        150,158,159,128,136,177,178,176,142,152,173,140
};


/**
 * struct usb_kbd - state of each attached keyboard
 * @dev:        input device associated with this keyboard
 * @usbdev:     usb device associated with this keyboard
 * @old:        data received in the past from the @irq URB representing which
 *              keys were pressed. By comparing with the current list of keys
 *              that are pressed, we are able to see key releases.
 * @irq:        URB for receiving a list of keys that are pressed when a
 *              new key is pressed or a key that was pressed is released.
 * @led:        URB for sending LEDs (e.g. numlock, ...)
 * @newleds:    data that will be sent with the @led URB representing which LEDs
 *              should be on
 * @name:       Name of the keyboard. @dev's name field points to this buffer
 * @phys:       Physical path of the keyboard. @dev's phys field points to this
 *              buffer
 * @new:        Buffer for the @irq URB
 * @cr:         Control request for @led URB
 * @leds:       Buffer for the @led URB
 * @new_dma:    DMA address for @irq URB
 * @leds_dma:   DMA address for @led URB
 * @leds_lock:  spinlock that protects @leds, @newleds, and @led_urb_submitted
 * @led_urb_submitted: indicates whether @led is in progress, i.e. it has been
 *              submitted and its completion handler has not returned yet
 *              without resubmitting @led
 */
struct usb_kbd {
        struct input_dev *dev;
        struct usb_device *usbdev;
        unsigned char old[8];
        struct urb *irq, *led;
        unsigned char newleds;
        char name[128];
        char phys[64];

        unsigned char *new;
        struct usb_ctrlrequest *cr;
        unsigned char *leds;
        dma_addr_t new_dma;
        dma_addr_t leds_dma;

        spinlock_t leds_lock;
        bool led_urb_submitted;

};

static void usb_kbd_irq(struct urb *urb)
{
        struct usb_kbd *kbd = urb->context;
        int i;

        switch (urb->status) {
        case 0:                 /* success */
                break;
        case -ECONNRESET:       /* unlink */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        /* -EPIPE:  should clear the halt */
        default:                /* error */
                goto resubmit;
        }

        for (i = 0; i < 8; i++)
                input_report_key(kbd->dev, usb_kbd_keycode[i + 224], (kbd->new[0] >> i) & 1);

        for (i = 2; i < 8; i++) {

                if (kbd->old[i] > 3 && memscan(kbd->new + 2, kbd->old[i], 6) == kbd->new + 8) {
                        if (usb_kbd_keycode[kbd->old[i]])
                                input_report_key(kbd->dev, usb_kbd_keycode[kbd->old[i]], 0);
                        else
                                hid_info(urb->dev,
                                         "Unknown key (scancode %#x) released.\n",
                                         kbd->old[i]);
                }

                if (kbd->new[i] > 3 && memscan(kbd->old + 2, kbd->new[i], 6) == kbd->old + 8) {
                        if (usb_kbd_keycode[kbd->new[i]])
                                input_report_key(kbd->dev, usb_kbd_keycode[kbd->new[i]], 1);
                        else
                                hid_info(urb->dev,
                                         "Unknown key (scancode %#x) pressed.\n",
                                         kbd->new[i]);
                }
        }

        input_sync(kbd->dev);

        memcpy(kbd->old, kbd->new, 8);

resubmit:
        i = usb_submit_urb (urb, GFP_ATOMIC);
        if (i)
                hid_err(urb->dev, "can't resubmit intr, %s-%s/input0, status %d",
                        kbd->usbdev->bus->bus_name,
                        kbd->usbdev->devpath, i);
}

static int usb_kbd_event(struct input_dev *dev, unsigned int type,
                         unsigned int code, int value)
{
        unsigned long flags;
        struct usb_kbd *kbd = input_get_drvdata(dev);

        if (type != EV_LED)
                return -1;

        spin_lock_irqsave(&kbd->leds_lock, flags);
        kbd->newleds = (!!test_bit(LED_KANA,    dev->led) << 4) | (!!test_bit(LED_COMPOSE, dev->led) << 3) |
                       (!!test_bit(LED_SCROLLL, dev->led) << 2) | (!!test_bit(LED_CAPSL,   dev->led) << 1) |
                       (!!test_bit(LED_NUML,    dev->led));

        if (kbd->led_urb_submitted){
                spin_unlock_irqrestore(&kbd->leds_lock, flags);
                return 0;
        }

        if (*(kbd->leds) == kbd->newleds){
                spin_unlock_irqrestore(&kbd->leds_lock, flags);
                return 0;
        }

        *(kbd->leds) = kbd->newleds;

        kbd->led->dev = kbd->usbdev;
        if (usb_submit_urb(kbd->led, GFP_ATOMIC))
                pr_err("usb_submit_urb(leds) failed\n");
        else
                kbd->led_urb_submitted = true;

        spin_unlock_irqrestore(&kbd->leds_lock, flags);

        return 0;
}

static void usb_kbd_led(struct urb *urb)
{
        unsigned long flags;
        struct usb_kbd *kbd = urb->context;

        if (urb->status)
                hid_warn(urb->dev, "led urb status %d received\n",
                         urb->status);

        spin_lock_irqsave(&kbd->leds_lock, flags);

        if (*(kbd->leds) == kbd->newleds){
                kbd->led_urb_submitted = false;
                spin_unlock_irqrestore(&kbd->leds_lock, flags);
                return;
        }

        *(kbd->leds) = kbd->newleds;

        kbd->led->dev = kbd->usbdev;
        if (usb_submit_urb(kbd->led, GFP_ATOMIC)){
                hid_err(urb->dev, "usb_submit_urb(leds) failed\n");
                kbd->led_urb_submitted = false;
        }
        spin_unlock_irqrestore(&kbd->leds_lock, flags);

}

static int usb_kbd_open(struct input_dev *dev)
{
        struct usb_kbd *kbd = input_get_drvdata(dev);

        kbd->irq->dev = kbd->usbdev;
        if (usb_submit_urb(kbd->irq, GFP_KERNEL))
                return -EIO;

        return 0;
}

static void usb_kbd_close(struct input_dev *dev)
{
        struct usb_kbd *kbd = input_get_drvdata(dev);

        usb_kill_urb(kbd->irq);
}

static int usb_kbd_alloc_mem(struct usb_device *dev, struct usb_kbd *kbd)
{
        if (!(kbd->irq = usb_alloc_urb(0, GFP_KERNEL)))
                return -1;
        if (!(kbd->led = usb_alloc_urb(0, GFP_KERNEL)))
                return -1;
        if (!(kbd->new = usb_alloc_coherent(dev, 8, GFP_KERNEL, &kbd->new_dma)))
                return -1;
        if (!(kbd->cr = kmalloc_obj(struct usb_ctrlrequest)))
                return -1;
        if (!(kbd->leds = usb_alloc_coherent(dev, 1, GFP_KERNEL, &kbd->leds_dma)))
                return -1;

        return 0;
}

static void usb_kbd_free_mem(struct usb_device *dev, struct usb_kbd *kbd)
{
        usb_free_urb(kbd->irq);
        usb_free_urb(kbd->led);
        usb_free_coherent(dev, 8, kbd->new, kbd->new_dma);
        kfree(kbd->cr);
        usb_free_coherent(dev, 1, kbd->leds, kbd->leds_dma);
}

static int usb_kbd_probe(struct usb_interface *iface,
                         const struct usb_device_id *id)
{
        struct usb_device *dev = interface_to_usbdev(iface);
        struct usb_host_interface *interface;
        struct usb_endpoint_descriptor *endpoint;
        struct usb_kbd *kbd;
        struct input_dev *input_dev;
        int i, pipe, maxp;
        int error = -ENOMEM;

        interface = iface->cur_altsetting;

        if (interface->desc.bNumEndpoints != 1)
                return -ENODEV;

        endpoint = &interface->endpoint[0].desc;
        if (!usb_endpoint_is_int_in(endpoint))
                return -ENODEV;

        pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
        maxp = usb_maxpacket(dev, pipe);

        kbd = kzalloc_obj(struct usb_kbd);
        input_dev = input_allocate_device();
        if (!kbd || !input_dev)
                goto fail1;

        if (usb_kbd_alloc_mem(dev, kbd))
                goto fail2;

        kbd->usbdev = dev;
        kbd->dev = input_dev;
        spin_lock_init(&kbd->leds_lock);

        if (dev->manufacturer)
                strscpy(kbd->name, dev->manufacturer, sizeof(kbd->name));

        if (dev->product) {
                if (dev->manufacturer)
                        strlcat(kbd->name, " ", sizeof(kbd->name));
                strlcat(kbd->name, dev->product, sizeof(kbd->name));
        }

        if (!strlen(kbd->name))
                snprintf(kbd->name, sizeof(kbd->name),
                         "USB HIDBP Keyboard %04x:%04x",
                         le16_to_cpu(dev->descriptor.idVendor),
                         le16_to_cpu(dev->descriptor.idProduct));

        usb_make_path(dev, kbd->phys, sizeof(kbd->phys));
        strlcat(kbd->phys, "/input0", sizeof(kbd->phys));

        input_dev->name = kbd->name;
        input_dev->phys = kbd->phys;
        usb_to_input_id(dev, &input_dev->id);
        input_dev->dev.parent = &iface->dev;

        input_set_drvdata(input_dev, kbd);

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

        for (i = 0; i < 255; i++)
                set_bit(usb_kbd_keycode[i], input_dev->keybit);
        clear_bit(0, input_dev->keybit);

        input_dev->event = usb_kbd_event;
        input_dev->open = usb_kbd_open;
        input_dev->close = usb_kbd_close;

        usb_fill_int_urb(kbd->irq, dev, pipe,
                         kbd->new, (maxp > 8 ? 8 : maxp),
                         usb_kbd_irq, kbd, endpoint->bInterval);
        kbd->irq->transfer_dma = kbd->new_dma;
        kbd->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        kbd->cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
        kbd->cr->bRequest = 0x09;
        kbd->cr->wValue = cpu_to_le16(0x200);
        kbd->cr->wIndex = cpu_to_le16(interface->desc.bInterfaceNumber);
        kbd->cr->wLength = cpu_to_le16(1);

        usb_fill_control_urb(kbd->led, dev, usb_sndctrlpipe(dev, 0),
                             (void *) kbd->cr, kbd->leds, 1,
                             usb_kbd_led, kbd);
        kbd->led->transfer_dma = kbd->leds_dma;
        kbd->led->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        error = input_register_device(kbd->dev);
        if (error)
                goto fail2;

        usb_set_intfdata(iface, kbd);
        device_set_wakeup_enable(&dev->dev, 1);
        return 0;

fail2:
        usb_kbd_free_mem(dev, kbd);
fail1:
        input_free_device(input_dev);
        kfree(kbd);
        return error;
}

static void usb_kbd_disconnect(struct usb_interface *intf)
{
        struct usb_kbd *kbd = usb_get_intfdata (intf);

        usb_set_intfdata(intf, NULL);
        if (kbd) {
                usb_kill_urb(kbd->irq);
                input_unregister_device(kbd->dev);
                usb_kill_urb(kbd->led);
                usb_kbd_free_mem(interface_to_usbdev(intf), kbd);
                kfree(kbd);
        }
}

static const struct usb_device_id usb_kbd_id_table[] = {
        { USB_INTERFACE_INFO(USB_INTERFACE_CLASS_HID, USB_INTERFACE_SUBCLASS_BOOT,
                USB_INTERFACE_PROTOCOL_KEYBOARD) },
        { }                                             /* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, usb_kbd_id_table);

static struct usb_driver usb_kbd_driver = {
        .name =         "usbkbd",
        .probe =        usb_kbd_probe,
        .disconnect =   usb_kbd_disconnect,
        .id_table =     usb_kbd_id_table,
};

module_usb_driver(usb_kbd_driver);