// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Debug support for HID Nintendo Wii / Wii U peripherals
 * Copyright (c) 2011-2013 David Herrmann <dh.herrmann@gmail.com>
 */

/*
 */

#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include "hid-wiimote.h"

struct wiimote_debug {
        struct wiimote_data *wdata;
        struct dentry *eeprom;
        struct dentry *drm;
};

static ssize_t wiidebug_eeprom_read(struct file *f, char __user *u, size_t s,
                                                                loff_t *off)
{
        struct wiimote_debug *dbg = f->private_data;
        struct wiimote_data *wdata = dbg->wdata;
        unsigned long flags;
        ssize_t ret;
        char buf[16];
        __u16 size = 0;

        if (s == 0)
                return -EINVAL;
        if (*off > 0xffffff)
                return 0;
        if (s > 16)
                s = 16;

        ret = wiimote_cmd_acquire(wdata);
        if (ret)
                return ret;

        spin_lock_irqsave(&wdata->state.lock, flags);
        wdata->state.cmd_read_size = s;
        wdata->state.cmd_read_buf = buf;
        wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, *off & 0xffff);
        wiiproto_req_reeprom(wdata, *off, s);
        spin_unlock_irqrestore(&wdata->state.lock, flags);

        ret = wiimote_cmd_wait(wdata);
        if (!ret)
                size = wdata->state.cmd_read_size;

        spin_lock_irqsave(&wdata->state.lock, flags);
        wdata->state.cmd_read_buf = NULL;
        spin_unlock_irqrestore(&wdata->state.lock, flags);

        wiimote_cmd_release(wdata);

        if (ret)
                return ret;
        else if (size == 0)
                return -EIO;

        if (copy_to_user(u, buf, size))
                return -EFAULT;

        *off += size;
        ret = size;

        return ret;
}

static const struct file_operations wiidebug_eeprom_fops = {
        .owner = THIS_MODULE,
        .open = simple_open,
        .read = wiidebug_eeprom_read,
        .llseek = generic_file_llseek,
};

static const char *wiidebug_drmmap[] = {
        [WIIPROTO_REQ_NULL] = "NULL",
        [WIIPROTO_REQ_DRM_K] = "K",
        [WIIPROTO_REQ_DRM_KA] = "KA",
        [WIIPROTO_REQ_DRM_KE] = "KE",
        [WIIPROTO_REQ_DRM_KAI] = "KAI",
        [WIIPROTO_REQ_DRM_KEE] = "KEE",
        [WIIPROTO_REQ_DRM_KAE] = "KAE",
        [WIIPROTO_REQ_DRM_KIE] = "KIE",
        [WIIPROTO_REQ_DRM_KAIE] = "KAIE",
        [WIIPROTO_REQ_DRM_E] = "E",
        [WIIPROTO_REQ_DRM_SKAI1] = "SKAI1",
        [WIIPROTO_REQ_DRM_SKAI2] = "SKAI2",
        [WIIPROTO_REQ_MAX] = NULL
};

static int wiidebug_drm_show(struct seq_file *f, void *p)
{
        struct wiimote_debug *dbg = f->private;
        const char *str = NULL;
        unsigned long flags;
        __u8 drm;

        spin_lock_irqsave(&dbg->wdata->state.lock, flags);
        drm = dbg->wdata->state.drm;
        spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);

        if (drm < WIIPROTO_REQ_MAX)
                str = wiidebug_drmmap[drm];
        if (!str)
                str = "unknown";

        seq_printf(f, "%s\n", str);

        return 0;
}

static int wiidebug_drm_open(struct inode *i, struct file *f)
{
        return single_open(f, wiidebug_drm_show, i->i_private);
}

static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
                                                        size_t s, loff_t *off)
{
        struct seq_file *sf = f->private_data;
        struct wiimote_debug *dbg = sf->private;
        unsigned long flags;
        char buf[16];
        ssize_t len;
        int i;

        if (s == 0)
                return -EINVAL;

        len = min((size_t) 15, s);
        if (copy_from_user(buf, u, len))
                return -EFAULT;

        buf[len] = 0;

        for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
                if (!wiidebug_drmmap[i])
                        continue;
                if (!strcasecmp(buf, wiidebug_drmmap[i]))
                        break;
        }

        if (i == WIIPROTO_REQ_MAX)
                i = simple_strtoul(buf, NULL, 16);

        spin_lock_irqsave(&dbg->wdata->state.lock, flags);
        dbg->wdata->state.flags &= ~WIIPROTO_FLAG_DRM_LOCKED;
        wiiproto_req_drm(dbg->wdata, (__u8) i);
        if (i != WIIPROTO_REQ_NULL)
                dbg->wdata->state.flags |= WIIPROTO_FLAG_DRM_LOCKED;
        spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);

        return len;
}

static const struct file_operations wiidebug_drm_fops = {
        .owner = THIS_MODULE,
        .open = wiidebug_drm_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .write = wiidebug_drm_write,
        .release = single_release,
};

int wiidebug_init(struct wiimote_data *wdata)
{
        struct wiimote_debug *dbg;
        unsigned long flags;

        dbg = kzalloc_obj(*dbg);
        if (!dbg)
                return -ENOMEM;

        dbg->wdata = wdata;

        dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
                dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);

        dbg->drm = debugfs_create_file("drm", S_IRUSR,
                        dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);

        spin_lock_irqsave(&wdata->state.lock, flags);
        wdata->debug = dbg;
        spin_unlock_irqrestore(&wdata->state.lock, flags);

        return 0;

}

void wiidebug_deinit(struct wiimote_data *wdata)
{
        struct wiimote_debug *dbg = wdata->debug;
        unsigned long flags;

        if (!dbg)
                return;

        spin_lock_irqsave(&wdata->state.lock, flags);
        wdata->debug = NULL;
        spin_unlock_irqrestore(&wdata->state.lock, flags);

        debugfs_remove(dbg->drm);
        debugfs_remove(dbg->eeprom);
        kfree(dbg);
}