/*
   * Debug support for HID Nintendo Wii / Wii U peripherals
   * Copyright (c) 2011-2013 David Herrmann <dh.herrmann@gmail.com>
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   */
  
  #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
  ", 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;
  	int ret = -ENOMEM;
  
  	dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
  	if (!dbg)
  		return -ENOMEM;
  
  	dbg->wdata = wdata;
  
  	dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
  		dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
  	if (!dbg->eeprom)
  		goto err;
  
  	dbg->drm = debugfs_create_file("drm", S_IRUSR,
  			dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
  	if (!dbg->drm)
  		goto err_drm;
  
  	spin_lock_irqsave(&wdata->state.lock, flags);
  	wdata->debug = dbg;
  	spin_unlock_irqrestore(&wdata->state.lock, flags);
  
  	return 0;
  
  err_drm:
  	debugfs_remove(dbg->eeprom);
  err:
  	kfree(dbg);
  	return ret;
  }
  
  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);
  }