Revert "staging: Remove the Android logger driver"

	  It is, in theory, a good memory allocator for low-memory devices,

	  because it can discard shared memory units when under memory pressure.

config ANDROID_LOGGER

	tristate "Android log driver"

	default n

	---help---

	  This adds support for system-wide logging using four log buffers.

	  These are:

	      1: main

	      2: events

	      3: radio

	      4: system

	  Log reading and writing is performed via normal Linux reads and

	  optimized writes. This optimization avoids logging having too

	  much overhead in the system.

config ANDROID_TIMED_OUTPUT

	bool "Timed output class driver"

	default y

/* include/linux/logger.h

 *

 * Copyright (C) 2007-2008 Google, Inc.

 * Author: Robert Love <rlove@android.com>

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */

#ifndef _LINUX_LOGGER_H

#define _LINUX_LOGGER_H

#include <linux/types.h>

#include <linux/ioctl.h>

/**

 * struct user_logger_entry_compat - defines a single entry that is given to a logger

 * @len:	The length of the payload

 * @__pad:	Two bytes of padding that appear to be required

 * @pid:	The generating process' process ID

 * @tid:	The generating process' thread ID

 * @sec:	The number of seconds that have elapsed since the Epoch

 * @nsec:	The number of nanoseconds that have elapsed since @sec

 * @msg:	The message that is to be logged

 *

 * The userspace structure for version 1 of the logger_entry ABI.

 * This structure is returned to userspace unless the caller requests

 * an upgrade to a newer ABI version.

 */

struct user_logger_entry_compat {

	__u16		len;

	__u16		__pad;

	__s32		pid;

	__s32		tid;

	__s32		sec;

	__s32		nsec;

	char		msg[0];

};

/**

 * struct logger_entry - defines a single entry that is given to a logger

 * @len:	The length of the payload

 * @hdr_size:	sizeof(struct logger_entry_v2)

 * @pid:	The generating process' process ID

 * @tid:	The generating process' thread ID

 * @sec:	The number of seconds that have elapsed since the Epoch

 * @nsec:	The number of nanoseconds that have elapsed since @sec

 * @euid:	Effective UID of logger

 * @msg:	The message that is to be logged

 *

 * The structure for version 2 of the logger_entry ABI.

 * This structure is returned to userspace if ioctl(LOGGER_SET_VERSION)

 * is called with version >= 2

 */

struct logger_entry {

	__u16		len;

	__u16		hdr_size;

	__s32		pid;

	__s32		tid;

	__s32		sec;

	__s32		nsec;

	kuid_t		euid;

	char		msg[0];

};

#define LOGGER_LOG_RADIO	"log_radio"	/* radio-related messages */

#define LOGGER_LOG_EVENTS	"log_events"	/* system/hardware events */

#define LOGGER_LOG_SYSTEM	"log_system"	/* system/framework messages */

#define LOGGER_LOG_MAIN		"log_main"	/* everything else */

#define LOGGER_ENTRY_MAX_PAYLOAD	4076

#define __LOGGERIO	0xAE

#define LOGGER_GET_LOG_BUF_SIZE		_IO(__LOGGERIO, 1) /* size of log */

#define LOGGER_GET_LOG_LEN		_IO(__LOGGERIO, 2) /* used log len */

#define LOGGER_GET_NEXT_ENTRY_LEN	_IO(__LOGGERIO, 3) /* next entry len */

#define LOGGER_FLUSH_LOG		_IO(__LOGGERIO, 4) /* flush log */

#define LOGGER_GET_VERSION		_IO(__LOGGERIO, 5) /* abi version */

#define LOGGER_SET_VERSION		_IO(__LOGGERIO, 6) /* abi version */

#endif /* _LINUX_LOGGER_H */