// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Roccat Lua driver for Linux
 *
 * Copyright (c) 2012 Stefan Achatz <erazor_de@users.sourceforge.net>
 */

/*
 */

/*
 * Roccat Lua is a gamer mouse which cpi, button and light settings can be
 * configured.
 */

#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-lua.h"

static ssize_t lua_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);
        struct lua_device *lua = 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(&lua->lua_lock);
        retval = roccat_common2_receive(usb_dev, command, buf, real_size);
        mutex_unlock(&lua->lua_lock);

        return retval ? retval : real_size;
}

static ssize_t lua_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);
        struct lua_device *lua = 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(&lua->lua_lock);
        retval = roccat_common2_send(usb_dev, command, buf, real_size);
        mutex_unlock(&lua->lua_lock);

        return retval ? retval : real_size;
}

#define LUA_SYSFS_W(thingy, THINGY) \
static ssize_t lua_sysfs_write_ ## thingy(struct file *fp, \
                struct kobject *kobj, const struct bin_attribute *attr, \
                char *buf, loff_t off, size_t count) \
{ \
        return lua_sysfs_write(fp, kobj, buf, off, count, \
                        LUA_SIZE_ ## THINGY, LUA_COMMAND_ ## THINGY); \
}

#define LUA_SYSFS_R(thingy, THINGY) \
static ssize_t lua_sysfs_read_ ## thingy(struct file *fp, \
                struct kobject *kobj, const struct bin_attribute *attr, \
                char *buf, loff_t off, size_t count) \
{ \
        return lua_sysfs_read(fp, kobj, buf, off, count, \
                        LUA_SIZE_ ## THINGY, LUA_COMMAND_ ## THINGY); \
}

#define LUA_BIN_ATTRIBUTE_RW(thingy, THINGY) \
LUA_SYSFS_W(thingy, THINGY) \
LUA_SYSFS_R(thingy, THINGY) \
static const struct bin_attribute lua_ ## thingy ## _attr = { \
        .attr = { .name = #thingy, .mode = 0660 }, \
        .size = LUA_SIZE_ ## THINGY, \
        .read = lua_sysfs_read_ ## thingy, \
        .write = lua_sysfs_write_ ## thingy \
};

LUA_BIN_ATTRIBUTE_RW(control, CONTROL)

static int lua_create_sysfs_attributes(struct usb_interface *intf)
{
        return sysfs_create_bin_file(&intf->dev.kobj, &lua_control_attr);
}

static void lua_remove_sysfs_attributes(struct usb_interface *intf)
{
        sysfs_remove_bin_file(&intf->dev.kobj, &lua_control_attr);
}

static int lua_init_lua_device_struct(struct usb_device *usb_dev,
                struct lua_device *lua)
{
        mutex_init(&lua->lua_lock);

        return 0;
}

static int lua_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 lua_device *lua;
        int retval;

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

        retval = lua_init_lua_device_struct(usb_dev, lua);
        if (retval) {
                hid_err(hdev, "couldn't init struct lua_device\n");
                goto exit;
        }

        retval = lua_create_sysfs_attributes(intf);
        if (retval) {
                hid_err(hdev, "cannot create sysfs files\n");
                goto exit;
        }

        return 0;
exit:
        kfree(lua);
        return retval;
}

static void lua_remove_specials(struct hid_device *hdev)
{
        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
        struct lua_device *lua;

        lua_remove_sysfs_attributes(intf);

        lua = hid_get_drvdata(hdev);
        kfree(lua);
}

static int lua_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 = lua_init_specials(hdev);
        if (retval) {
                hid_err(hdev, "couldn't install mouse\n");
                goto exit_stop;
        }

        return 0;

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

static void lua_remove(struct hid_device *hdev)
{
        lua_remove_specials(hdev);
        hid_hw_stop(hdev);
}

static const struct hid_device_id lua_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_LUA) },
        { }
};

MODULE_DEVICE_TABLE(hid, lua_devices);

static struct hid_driver lua_driver = {
                .name = "lua",
                .id_table = lua_devices,
                .probe = lua_probe,
                .remove = lua_remove
};
module_hid_driver(lua_driver);

MODULE_AUTHOR("Stefan Achatz");
MODULE_DESCRIPTION("USB Roccat Lua driver");
MODULE_LICENSE("GPL v2");