// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Roccat Isku driver for Linux
 *
 * Copyright (c) 2011 Stefan Achatz <erazor_de@users.sourceforge.net>
 */

/*
 */

/*
 * Roccat Isku is a gamer keyboard with macro keys that can be configured in
 * 5 profiles.
 */

#include <linux/device.h>
#include <linux/input.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/hid-roccat.h>
#include "hid-ids.h"
#include "hid-roccat-common.h"
#include "hid-roccat-isku.h"

static void isku_profile_activated(struct isku_device *isku, uint new_profile)
{
        isku->actual_profile = new_profile;
}

static int isku_receive(struct usb_device *usb_dev, uint command,
                void *buf, uint size)
{
        return roccat_common2_receive(usb_dev, command, buf, size);
}

static int isku_get_actual_profile(struct usb_device *usb_dev)
{
        struct isku_actual_profile buf;
        int retval;

        retval = isku_receive(usb_dev, ISKU_COMMAND_ACTUAL_PROFILE,
                        &buf, sizeof(struct isku_actual_profile));
        return retval ? retval : buf.actual_profile;
}

static int isku_set_actual_profile(struct usb_device *usb_dev, int new_profile)
{
        struct isku_actual_profile buf;

        buf.command = ISKU_COMMAND_ACTUAL_PROFILE;
        buf.size = sizeof(struct isku_actual_profile);
        buf.actual_profile = new_profile;
        return roccat_common2_send_with_status(usb_dev,
                        ISKU_COMMAND_ACTUAL_PROFILE, &buf,
                        sizeof(struct isku_actual_profile));
}

static ssize_t isku_sysfs_show_actual_profile(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct isku_device *isku =
                        hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
        return sysfs_emit(buf, "%d\n", isku->actual_profile);
}

static ssize_t isku_sysfs_set_actual_profile(struct device *dev,
                struct device_attribute *attr, char const *buf, size_t size)
{
        struct isku_device *isku;
        struct usb_device *usb_dev;
        unsigned long profile;
        int retval;
        struct isku_roccat_report roccat_report;

        dev = dev->parent->parent;
        isku = hid_get_drvdata(dev_get_drvdata(dev));
        usb_dev = interface_to_usbdev(to_usb_interface(dev));

        retval = kstrtoul(buf, 10, &profile);
        if (retval)
                return retval;

        if (profile > 4)
                return -EINVAL;

        mutex_lock(&isku->isku_lock);

        retval = isku_set_actual_profile(usb_dev, profile);
        if (retval) {
                mutex_unlock(&isku->isku_lock);
                return retval;
        }

        isku_profile_activated(isku, profile);

        roccat_report.event = ISKU_REPORT_BUTTON_EVENT_PROFILE;
        roccat_report.data1 = profile + 1;
        roccat_report.data2 = 0;
        roccat_report.profile = profile + 1;
        roccat_report_event(isku->chrdev_minor, (uint8_t const *)&roccat_report);

        mutex_unlock(&isku->isku_lock);

        return size;
}
static DEVICE_ATTR(actual_profile, 0660, isku_sysfs_show_actual_profile,
                   isku_sysfs_set_actual_profile);

static struct attribute *isku_attrs[] = {
        &dev_attr_actual_profile.attr,
        NULL,
};

static ssize_t isku_sysfs_read(struct file *fp, struct kobject *kobj,
                char *buf, loff_t off, size_t count,
                size_t real_size, uint command)
{
        struct device *dev = kobj_to_dev(kobj)->parent->parent;
        struct isku_device *isku = hid_get_drvdata(dev_get_drvdata(dev));
        struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
        int retval;

        if (off >= real_size)
                return 0;

        if (off != 0 || count > real_size)
                return -EINVAL;

        mutex_lock(&isku->isku_lock);
        retval = isku_receive(usb_dev, command, buf, count);
        mutex_unlock(&isku->isku_lock);

        return retval ? retval : count;
}

static ssize_t isku_sysfs_write(struct file *fp, struct kobject *kobj,
                void const *buf, loff_t off, size_t count,
                size_t real_size, uint command)
{
        struct device *dev = kobj_to_dev(kobj)->parent->parent;
        struct isku_device *isku = hid_get_drvdata(dev_get_drvdata(dev));
        struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
        int retval;

        if (off != 0 || count > real_size)
                return -EINVAL;

        mutex_lock(&isku->isku_lock);
        retval = roccat_common2_send_with_status(usb_dev, command,
                        (void *)buf, count);
        mutex_unlock(&isku->isku_lock);

        return retval ? retval : count;
}

#define ISKU_SYSFS_W(thingy, THINGY) \
static ssize_t isku_sysfs_write_ ## thingy(struct file *fp, struct kobject *kobj, \
                const struct bin_attribute *attr, char *buf, \
                loff_t off, size_t count) \
{ \
        return isku_sysfs_write(fp, kobj, buf, off, count, \
                        ISKU_SIZE_ ## THINGY, ISKU_COMMAND_ ## THINGY); \
}

#define ISKU_SYSFS_R(thingy, THINGY) \
static ssize_t isku_sysfs_read_ ## thingy(struct file *fp, struct kobject *kobj, \
                const struct bin_attribute *attr, char *buf, \
                loff_t off, size_t count) \
{ \
        return isku_sysfs_read(fp, kobj, buf, off, count, \
                        ISKU_SIZE_ ## THINGY, ISKU_COMMAND_ ## THINGY); \
}

#define ISKU_SYSFS_RW(thingy, THINGY) \
ISKU_SYSFS_R(thingy, THINGY) \
ISKU_SYSFS_W(thingy, THINGY)

#define ISKU_BIN_ATTR_RW(thingy, THINGY) \
ISKU_SYSFS_RW(thingy, THINGY); \
static const struct bin_attribute bin_attr_##thingy = { \
        .attr = { .name = #thingy, .mode = 0660 }, \
        .size = ISKU_SIZE_ ## THINGY, \
        .read = isku_sysfs_read_ ## thingy, \
        .write = isku_sysfs_write_ ## thingy \
}

#define ISKU_BIN_ATTR_R(thingy, THINGY) \
ISKU_SYSFS_R(thingy, THINGY); \
static const struct bin_attribute bin_attr_##thingy = { \
        .attr = { .name = #thingy, .mode = 0440 }, \
        .size = ISKU_SIZE_ ## THINGY, \
        .read = isku_sysfs_read_ ## thingy, \
}

#define ISKU_BIN_ATTR_W(thingy, THINGY) \
ISKU_SYSFS_W(thingy, THINGY); \
static const struct bin_attribute bin_attr_##thingy = { \
        .attr = { .name = #thingy, .mode = 0220 }, \
        .size = ISKU_SIZE_ ## THINGY, \
        .write = isku_sysfs_write_ ## thingy \
}

ISKU_BIN_ATTR_RW(macro, MACRO);
ISKU_BIN_ATTR_RW(keys_function, KEYS_FUNCTION);
ISKU_BIN_ATTR_RW(keys_easyzone, KEYS_EASYZONE);
ISKU_BIN_ATTR_RW(keys_media, KEYS_MEDIA);
ISKU_BIN_ATTR_RW(keys_thumbster, KEYS_THUMBSTER);
ISKU_BIN_ATTR_RW(keys_macro, KEYS_MACRO);
ISKU_BIN_ATTR_RW(keys_capslock, KEYS_CAPSLOCK);
ISKU_BIN_ATTR_RW(light, LIGHT);
ISKU_BIN_ATTR_RW(key_mask, KEY_MASK);
ISKU_BIN_ATTR_RW(last_set, LAST_SET);
ISKU_BIN_ATTR_W(talk, TALK);
ISKU_BIN_ATTR_W(talkfx, TALKFX);
ISKU_BIN_ATTR_W(control, CONTROL);
ISKU_BIN_ATTR_W(reset, RESET);
ISKU_BIN_ATTR_R(info, INFO);

static const struct bin_attribute *const isku_bin_attributes[] = {
        &bin_attr_macro,
        &bin_attr_keys_function,
        &bin_attr_keys_easyzone,
        &bin_attr_keys_media,
        &bin_attr_keys_thumbster,
        &bin_attr_keys_macro,
        &bin_attr_keys_capslock,
        &bin_attr_light,
        &bin_attr_key_mask,
        &bin_attr_last_set,
        &bin_attr_talk,
        &bin_attr_talkfx,
        &bin_attr_control,
        &bin_attr_reset,
        &bin_attr_info,
        NULL,
};

static const struct attribute_group isku_group = {
        .attrs = isku_attrs,
        .bin_attrs = isku_bin_attributes,
};

static const struct attribute_group *isku_groups[] = {
        &isku_group,
        NULL,
};

static const struct class isku_class = {
        .name = "isku",
        .dev_groups = isku_groups,
};

static int isku_init_isku_device_struct(struct usb_device *usb_dev,
                struct isku_device *isku)
{
        int retval;

        mutex_init(&isku->isku_lock);

        retval = isku_get_actual_profile(usb_dev);
        if (retval < 0)
                return retval;
        isku_profile_activated(isku, retval);

        return 0;
}

static int isku_init_specials(struct hid_device *hdev)
{
        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
        struct usb_device *usb_dev = interface_to_usbdev(intf);
        struct isku_device *isku;
        int retval;

        if (intf->cur_altsetting->desc.bInterfaceProtocol
                        != ISKU_USB_INTERFACE_PROTOCOL) {
                hid_set_drvdata(hdev, NULL);
                return 0;
        }

        isku = kzalloc_obj(*isku);
        if (!isku) {
                hid_err(hdev, "can't alloc device descriptor\n");
                return -ENOMEM;
        }
        hid_set_drvdata(hdev, isku);

        retval = isku_init_isku_device_struct(usb_dev, isku);
        if (retval) {
                hid_err(hdev, "couldn't init struct isku_device\n");
                goto exit_free;
        }

        retval = roccat_connect(&isku_class, hdev,
                        sizeof(struct isku_roccat_report));
        if (retval < 0) {
                hid_err(hdev, "couldn't init char dev\n");
        } else {
                isku->chrdev_minor = retval;
                isku->roccat_claimed = 1;
        }

        return 0;
exit_free:
        kfree(isku);
        return retval;
}

static void isku_remove_specials(struct hid_device *hdev)
{
        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
        struct isku_device *isku;

        if (intf->cur_altsetting->desc.bInterfaceProtocol
                        != ISKU_USB_INTERFACE_PROTOCOL)
                return;

        isku = hid_get_drvdata(hdev);
        if (isku->roccat_claimed)
                roccat_disconnect(isku->chrdev_minor);
        kfree(isku);
}

static int isku_probe(struct hid_device *hdev,
                const struct hid_device_id *id)
{
        int retval;

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

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

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

        retval = isku_init_specials(hdev);
        if (retval) {
                hid_err(hdev, "couldn't install keyboard\n");
                goto exit_stop;
        }

        return 0;

exit_stop:
        hid_hw_stop(hdev);
exit:
        return retval;
}

static void isku_remove(struct hid_device *hdev)
{
        isku_remove_specials(hdev);
        hid_hw_stop(hdev);
}

static void isku_keep_values_up_to_date(struct isku_device *isku,
                u8 const *data)
{
        struct isku_report_button const *button_report;

        switch (data[0]) {
        case ISKU_REPORT_NUMBER_BUTTON:
                button_report = (struct isku_report_button const *)data;
                switch (button_report->event) {
                case ISKU_REPORT_BUTTON_EVENT_PROFILE:
                        isku_profile_activated(isku, button_report->data1 - 1);
                        break;
                }
                break;
        }
}

static void isku_report_to_chrdev(struct isku_device const *isku,
                u8 const *data)
{
        struct isku_roccat_report roccat_report;
        struct isku_report_button const *button_report;

        if (data[0] != ISKU_REPORT_NUMBER_BUTTON)
                return;

        button_report = (struct isku_report_button const *)data;

        roccat_report.event = button_report->event;
        roccat_report.data1 = button_report->data1;
        roccat_report.data2 = button_report->data2;
        roccat_report.profile = isku->actual_profile + 1;
        roccat_report_event(isku->chrdev_minor,
                        (uint8_t const *)&roccat_report);
}

static int isku_raw_event(struct hid_device *hdev,
                struct hid_report *report, u8 *data, int size)
{
        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
        struct isku_device *isku = hid_get_drvdata(hdev);

        if (intf->cur_altsetting->desc.bInterfaceProtocol
                        != ISKU_USB_INTERFACE_PROTOCOL)
                return 0;

        if (isku == NULL)
                return 0;

        isku_keep_values_up_to_date(isku, data);

        if (isku->roccat_claimed)
                isku_report_to_chrdev(isku, data);

        return 0;
}

static const struct hid_device_id isku_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_ISKU) },
        { HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_ISKUFX) },
        { }
};

MODULE_DEVICE_TABLE(hid, isku_devices);

static struct hid_driver isku_driver = {
                .name = "isku",
                .id_table = isku_devices,
                .probe = isku_probe,
                .remove = isku_remove,
                .raw_event = isku_raw_event
};

static int __init isku_init(void)
{
        int retval;

        retval = class_register(&isku_class);
        if (retval)
                return retval;

        retval = hid_register_driver(&isku_driver);
        if (retval)
                class_unregister(&isku_class);
        return retval;
}

static void __exit isku_exit(void)
{
        hid_unregister_driver(&isku_driver);
        class_unregister(&isku_class);
}

module_init(isku_init);
module_exit(isku_exit);

MODULE_AUTHOR("Stefan Achatz");
MODULE_DESCRIPTION("USB Roccat Isku/FX driver");
MODULE_LICENSE("GPL v2");