Revert "Staging: android: delete android drivers"

This reverts commit b0a0ccfa.

Turns out I was wrong, we want these in the tree.

Note, I've disabled the drivers from the build at the moment, so other
patches can be applied to fix some build issues due to internal api
changes since the code was removed from the tree.

Cc: Arve Hjønnevåg <arve@android.com>
Cc: Brian Swetland <swetland@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/android/Kconfig

+menu "Android"
+
+config ANDROID
+	bool "Android Drivers"
+	depends on BROKEN
+	default N
+	---help---
+	  Enable support for various drivers needed on the Android platform
+
+if ANDROID
+
+config ANDROID_BINDER_IPC
+	bool "Android Binder IPC Driver"
+	default n
+
+config ANDROID_LOGGER
+	tristate "Android log driver"
+	default n
+
+config ANDROID_RAM_CONSOLE
+	bool "Android RAM buffer console"
+	default n
+
+config ANDROID_RAM_CONSOLE_ENABLE_VERBOSE
+	bool "Enable verbose console messages on Android RAM console"
+	default y
+	depends on ANDROID_RAM_CONSOLE
+
+menuconfig ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+	bool "Android RAM Console Enable error correction"
+	default n
+	depends on ANDROID_RAM_CONSOLE
+	depends on !ANDROID_RAM_CONSOLE_EARLY_INIT
+	select REED_SOLOMON
+	select REED_SOLOMON_ENC8
+	select REED_SOLOMON_DEC8
+
+if ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+
+config ANDROID_RAM_CONSOLE_ERROR_CORRECTION_DATA_SIZE
+	int "Android RAM Console Data data size"
+	default 128
+	help
+	  Must be a power of 2.
+
+config ANDROID_RAM_CONSOLE_ERROR_CORRECTION_ECC_SIZE
+	int "Android RAM Console ECC size"
+	default 16
+
+config ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE
+	int "Android RAM Console Symbol size"
+	default 8
+
+config ANDROID_RAM_CONSOLE_ERROR_CORRECTION_POLYNOMIAL
+	hex "Android RAM Console Polynomial"
+	default 0x19 if (ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE = 4)
+	default 0x29 if (ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE = 5)
+	default 0x61 if (ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE = 6)
+	default 0x89 if (ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE = 7)
+	default 0x11d if (ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE = 8)
+
+endif # ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+
+config ANDROID_RAM_CONSOLE_EARLY_INIT
+	bool "Start Android RAM console early"
+	default n
+	depends on ANDROID_RAM_CONSOLE
+
+config ANDROID_RAM_CONSOLE_EARLY_ADDR
+	hex "Android RAM console virtual address"
+	default 0
+	depends on ANDROID_RAM_CONSOLE_EARLY_INIT
+
+config ANDROID_RAM_CONSOLE_EARLY_SIZE
+	hex "Android RAM console buffer size"
+	default 0
+	depends on ANDROID_RAM_CONSOLE_EARLY_INIT
+
+config ANDROID_TIMED_OUTPUT
+	bool "Timed output class driver"
+	default y
+
+config ANDROID_TIMED_GPIO
+	tristate "Android timed gpio driver"
+	depends on GENERIC_GPIO && ANDROID_TIMED_OUTPUT
+	default n
+
+config ANDROID_LOW_MEMORY_KILLER
+	bool "Android Low Memory Killer"
+	default N
+	---help---
+	  Register processes to be killed when memory is low
+
+endif # if ANDROID
+
+endmenu

drivers/staging/android/Makefile

+obj-$(CONFIG_ANDROID_BINDER_IPC)	+= binder.o
+obj-$(CONFIG_ANDROID_LOGGER)		+= logger.o
+obj-$(CONFIG_ANDROID_RAM_CONSOLE)	+= ram_console.o
+obj-$(CONFIG_ANDROID_TIMED_OUTPUT)	+= timed_output.o
+obj-$(CONFIG_ANDROID_TIMED_GPIO)	+= timed_gpio.o
+obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER)	+= lowmemorykiller.o

drivers/staging/android/TODO

+TODO:
+	- checkpatch.pl cleanups
+	- sparse fixes
+	- rename files to be not so "generic"
+	- make sure things build as modules properly
+	- add proper arch dependancies as needed
+	- audit userspace interfaces to make sure they are sane
+
+Please send patches to Greg Kroah-Hartman <greg@kroah.com> and Cc:
+Brian Swetland <swetland@google.com>

drivers/staging/android/binder.h

+/*
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * Based on, but no longer compatible with, the original
+ * OpenBinder.org binder driver interface, which is:
+ *
+ * Copyright (c) 2005 Palmsource, Inc.
+ *
+ * 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_BINDER_H
+#define _LINUX_BINDER_H
+
+#include <linux/ioctl.h>
+
+#define B_PACK_CHARS(c1, c2, c3, c4) \
+	((((c1)<<24)) | (((c2)<<16)) | (((c3)<<8)) | (c4))
+#define B_TYPE_LARGE 0x85
+
+enum {
+	BINDER_TYPE_BINDER	= B_PACK_CHARS('s', 'b', '*', B_TYPE_LARGE),
+	BINDER_TYPE_WEAK_BINDER	= B_PACK_CHARS('w', 'b', '*', B_TYPE_LARGE),
+	BINDER_TYPE_HANDLE	= B_PACK_CHARS('s', 'h', '*', B_TYPE_LARGE),
+	BINDER_TYPE_WEAK_HANDLE	= B_PACK_CHARS('w', 'h', '*', B_TYPE_LARGE),
+	BINDER_TYPE_FD		= B_PACK_CHARS('f', 'd', '*', B_TYPE_LARGE),
+};
+
+enum {
+	FLAT_BINDER_FLAG_PRIORITY_MASK = 0xff,
+	FLAT_BINDER_FLAG_ACCEPTS_FDS = 0x100,
+};
+
+/*
+ * This is the flattened representation of a Binder object for transfer
+ * between processes.  The 'offsets' supplied as part of a binder transaction
+ * contains offsets into the data where these structures occur.  The Binder
+ * driver takes care of re-writing the structure type and data as it moves
+ * between processes.
+ */
+struct flat_binder_object {
+	/* 8 bytes for large_flat_header. */
+	unsigned long		type;
+	unsigned long		flags;
+
+	/* 8 bytes of data. */
+	union {
+		void		*binder;	/* local object */
+		signed long	handle;		/* remote object */
+	};
+
+	/* extra data associated with local object */
+	void			*cookie;
+};
+
+/*
+ * On 64-bit platforms where user code may run in 32-bits the driver must
+ * translate the buffer (and local binder) addresses apropriately.
+ */
+
+struct binder_write_read {
+	signed long	write_size;	/* bytes to write */
+	signed long	write_consumed;	/* bytes consumed by driver */
+	unsigned long	write_buffer;
+	signed long	read_size;	/* bytes to read */
+	signed long	read_consumed;	/* bytes consumed by driver */
+	unsigned long	read_buffer;
+};
+
+/* Use with BINDER_VERSION, driver fills in fields. */
+struct binder_version {
+	/* driver protocol version -- increment with incompatible change */
+	signed long	protocol_version;
+};
+
+/* This is the current protocol version. */
+#define BINDER_CURRENT_PROTOCOL_VERSION 7
+
+#define BINDER_WRITE_READ   		_IOWR('b', 1, struct binder_write_read)
+#define	BINDER_SET_IDLE_TIMEOUT		_IOW('b', 3, int64_t)
+#define	BINDER_SET_MAX_THREADS		_IOW('b', 5, size_t)
+#define	BINDER_SET_IDLE_PRIORITY	_IOW('b', 6, int)
+#define	BINDER_SET_CONTEXT_MGR		_IOW('b', 7, int)
+#define	BINDER_THREAD_EXIT		_IOW('b', 8, int)
+#define BINDER_VERSION			_IOWR('b', 9, struct binder_version)
+
+/*
+ * NOTE: Two special error codes you should check for when calling
+ * in to the driver are:
+ *
+ * EINTR -- The operation has been interupted.  This should be
+ * handled by retrying the ioctl() until a different error code
+ * is returned.
+ *
+ * ECONNREFUSED -- The driver is no longer accepting operations
+ * from your process.  That is, the process is being destroyed.
+ * You should handle this by exiting from your process.  Note
+ * that once this error code is returned, all further calls to
+ * the driver from any thread will return this same code.
+ */
+
+enum transaction_flags {
+	TF_ONE_WAY	= 0x01,	/* this is a one-way call: async, no return */
+	TF_ROOT_OBJECT	= 0x04,	/* contents are the component's root object */
+	TF_STATUS_CODE	= 0x08,	/* contents are a 32-bit status code */
+	TF_ACCEPT_FDS	= 0x10,	/* allow replies with file descriptors */
+};
+
+struct binder_transaction_data {
+	/* The first two are only used for bcTRANSACTION and brTRANSACTION,
+	 * identifying the target and contents of the transaction.
+	 */
+	union {
+		size_t	handle;	/* target descriptor of command transaction */
+		void	*ptr;	/* target descriptor of return transaction */
+	} target;
+	void		*cookie;	/* target object cookie */
+	unsigned int	code;		/* transaction command */
+
+	/* General information about the transaction. */
+	unsigned int	flags;
+	pid_t		sender_pid;
+	uid_t		sender_euid;
+	size_t		data_size;	/* number of bytes of data */
+	size_t		offsets_size;	/* number of bytes of offsets */
+
+	/* If this transaction is inline, the data immediately
+	 * follows here; otherwise, it ends with a pointer to
+	 * the data buffer.
+	 */
+	union {
+		struct {
+			/* transaction data */
+			const void	*buffer;
+			/* offsets from buffer to flat_binder_object structs */
+			const void	*offsets;
+		} ptr;
+		uint8_t	buf[8];
+	} data;
+};
+
+struct binder_ptr_cookie {
+	void *ptr;
+	void *cookie;
+};
+
+struct binder_pri_desc {
+	int priority;
+	int desc;
+};
+
+struct binder_pri_ptr_cookie {
+	int priority;
+	void *ptr;
+	void *cookie;
+};
+
+enum BinderDriverReturnProtocol {
+	BR_ERROR = _IOR('r', 0, int),
+	/*
+	 * int: error code
+	 */
+
+	BR_OK = _IO('r', 1),
+	/* No parameters! */
+
+	BR_TRANSACTION = _IOR('r', 2, struct binder_transaction_data),
+	BR_REPLY = _IOR('r', 3, struct binder_transaction_data),
+	/*
+	 * binder_transaction_data: the received command.
+	 */
+
+	BR_ACQUIRE_RESULT = _IOR('r', 4, int),
+	/*
+	 * not currently supported
+	 * int: 0 if the last bcATTEMPT_ACQUIRE was not successful.
+	 * Else the remote object has acquired a primary reference.
+	 */
+
+	BR_DEAD_REPLY = _IO('r', 5),
+	/*
+	 * The target of the last transaction (either a bcTRANSACTION or
+	 * a bcATTEMPT_ACQUIRE) is no longer with us.  No parameters.
+	 */
+
+	BR_TRANSACTION_COMPLETE = _IO('r', 6),
+	/*
+	 * No parameters... always refers to the last transaction requested
+	 * (including replies).  Note that this will be sent even for
+	 * asynchronous transactions.
+	 */
+
+	BR_INCREFS = _IOR('r', 7, struct binder_ptr_cookie),
+	BR_ACQUIRE = _IOR('r', 8, struct binder_ptr_cookie),
+	BR_RELEASE = _IOR('r', 9, struct binder_ptr_cookie),
+	BR_DECREFS = _IOR('r', 10, struct binder_ptr_cookie),
+	/*
+	 * void *:	ptr to binder
+	 * void *: cookie for binder
+	 */
+
+	BR_ATTEMPT_ACQUIRE = _IOR('r', 11, struct binder_pri_ptr_cookie),
+	/*
+	 * not currently supported
+	 * int:	priority
+	 * void *: ptr to binder
+	 * void *: cookie for binder
+	 */
+
+	BR_NOOP = _IO('r', 12),
+	/*
+	 * No parameters.  Do nothing and examine the next command.  It exists
+	 * primarily so that we can replace it with a BR_SPAWN_LOOPER command.
+	 */
+
+	BR_SPAWN_LOOPER = _IO('r', 13),
+	/*
+	 * No parameters.  The driver has determined that a process has no
+	 * threads waiting to service incomming transactions.  When a process
+	 * receives this command, it must spawn a new service thread and
+	 * register it via bcENTER_LOOPER.
+	 */
+
+	BR_FINISHED = _IO('r', 14),
+	/*
+	 * not currently supported
+	 * stop threadpool thread
+	 */
+
+	BR_DEAD_BINDER = _IOR('r', 15, void *),
+	/*
+	 * void *: cookie
+	 */
+	BR_CLEAR_DEATH_NOTIFICATION_DONE = _IOR('r', 16, void *),
+	/*
+	 * void *: cookie
+	 */
+
+	BR_FAILED_REPLY = _IO('r', 17),
+	/*
+	 * The the last transaction (either a bcTRANSACTION or
+	 * a bcATTEMPT_ACQUIRE) failed (e.g. out of memory).  No parameters.
+	 */
+};
+
+enum BinderDriverCommandProtocol {
+	BC_TRANSACTION = _IOW('c', 0, struct binder_transaction_data),
+	BC_REPLY = _IOW('c', 1, struct binder_transaction_data),
+	/*
+	 * binder_transaction_data: the sent command.
+	 */
+
+	BC_ACQUIRE_RESULT = _IOW('c', 2, int),
+	/*
+	 * not currently supported
+	 * int:  0 if the last BR_ATTEMPT_ACQUIRE was not successful.
+	 * Else you have acquired a primary reference on the object.
+	 */
+
+	BC_FREE_BUFFER = _IOW('c', 3, int),
+	/*
+	 * void *: ptr to transaction data received on a read
+	 */
+
+	BC_INCREFS = _IOW('c', 4, int),
+	BC_ACQUIRE = _IOW('c', 5, int),
+	BC_RELEASE = _IOW('c', 6, int),
+	BC_DECREFS = _IOW('c', 7, int),
+	/*
+	 * int:	descriptor
+	 */
+
+	BC_INCREFS_DONE = _IOW('c', 8, struct binder_ptr_cookie),
+	BC_ACQUIRE_DONE = _IOW('c', 9, struct binder_ptr_cookie),
+	/*
+	 * void *: ptr to binder
+	 * void *: cookie for binder
+	 */
+
+	BC_ATTEMPT_ACQUIRE = _IOW('c', 10, struct binder_pri_desc),
+	/*
+	 * not currently supported
+	 * int: priority
+	 * int: descriptor
+	 */
+
+	BC_REGISTER_LOOPER = _IO('c', 11),
+	/*
+	 * No parameters.
+	 * Register a spawned looper thread with the device.
+	 */
+
+	BC_ENTER_LOOPER = _IO('c', 12),
+	BC_EXIT_LOOPER = _IO('c', 13),
+	/*
+	 * No parameters.
+	 * These two commands are sent as an application-level thread
+	 * enters and exits the binder loop, respectively.  They are
+	 * used so the binder can have an accurate count of the number
+	 * of looping threads it has available.
+	 */
+
+	BC_REQUEST_DEATH_NOTIFICATION = _IOW('c', 14, struct binder_ptr_cookie),
+	/*
+	 * void *: ptr to binder
+	 * void *: cookie
+	 */
+
+	BC_CLEAR_DEATH_NOTIFICATION = _IOW('c', 15, struct binder_ptr_cookie),
+	/*
+	 * void *: ptr to binder
+	 * void *: cookie
+	 */
+
+	BC_DEAD_BINDER_DONE = _IOW('c', 16, void *),
+	/*
+	 * void *: cookie
+	 */
+};
+
+#endif /* _LINUX_BINDER_H */
+

drivers/staging/android/logger.c

+/*
+ * drivers/misc/logger.c
+ *
+ * A Logging Subsystem
+ *
+ * Copyright (C) 2007-2008 Google, Inc.
+ *
+ * Robert Love <rlove@google.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.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+#include <linux/time.h>
+#include "logger.h"
+
+#include <asm/ioctls.h>
+
+/*
+ * struct logger_log - represents a specific log, such as 'main' or 'radio'
+ *
+ * This structure lives from module insertion until module removal, so it does
+ * not need additional reference counting. The structure is protected by the
+ * mutex 'mutex'.
+ */
+struct logger_log {
+	unsigned char 		*buffer;/* the ring buffer itself */
+	struct miscdevice	misc;	/* misc device representing the log */
+	wait_queue_head_t	wq;	/* wait queue for readers */
+	struct list_head	readers; /* this log's readers */
+	struct mutex		mutex;	/* mutex protecting buffer */
+	size_t			w_off;	/* current write head offset */
+	size_t			head;	/* new readers start here */
+	size_t			size;	/* size of the log */
+};
+
+/*
+ * struct logger_reader - a logging device open for reading
+ *
+ * This object lives from open to release, so we don't need additional
+ * reference counting. The structure is protected by log->mutex.
+ */
+struct logger_reader {
+	struct logger_log	*log;	/* associated log */
+	struct list_head	list;	/* entry in logger_log's list */
+	size_t			r_off;	/* current read head offset */
+};
+
+/* logger_offset - returns index 'n' into the log via (optimized) modulus */
+#define logger_offset(n)	((n) & (log->size - 1))
+
+/*
+ * file_get_log - Given a file structure, return the associated log
+ *
+ * This isn't aesthetic. We have several goals:
+ *
+ * 	1) Need to quickly obtain the associated log during an I/O operation
+ * 	2) Readers need to maintain state (logger_reader)
+ * 	3) Writers need to be very fast (open() should be a near no-op)
+ *
+ * In the reader case, we can trivially go file->logger_reader->logger_log.
+ * For a writer, we don't want to maintain a logger_reader, so we just go
+ * file->logger_log. Thus what file->private_data points at depends on whether
+ * or not the file was opened for reading. This function hides that dirtiness.
+ */
+static inline struct logger_log *file_get_log(struct file *file)
+{
+	if (file->f_mode & FMODE_READ) {
+		struct logger_reader *reader = file->private_data;
+		return reader->log;
+	} else
+		return file->private_data;
+}
+
+/*
+ * get_entry_len - Grabs the length of the payload of the next entry starting
+ * from 'off'.
+ *
+ * Caller needs to hold log->mutex.
+ */
+static __u32 get_entry_len(struct logger_log *log, size_t off)
+{
+	__u16 val;
+
+	switch (log->size - off) {
+	case 1:
+		memcpy(&val, log->buffer + off, 1);
+		memcpy(((char *) &val) + 1, log->buffer, 1);
+		break;
+	default:
+		memcpy(&val, log->buffer + off, 2);
+	}
+
+	return sizeof(struct logger_entry) + val;
+}
+
+/*
+ * do_read_log_to_user - reads exactly 'count' bytes from 'log' into the
+ * user-space buffer 'buf'. Returns 'count' on success.
+ *
+ * Caller must hold log->mutex.
+ */
+static ssize_t do_read_log_to_user(struct logger_log *log,
+				   struct logger_reader *reader,
+				   char __user *buf,
+				   size_t count)
+{
+	size_t len;
+
+	/*
+	 * We read from the log in two disjoint operations. First, we read from
+	 * the current read head offset up to 'count' bytes or to the end of
+	 * the log, whichever comes first.
+	 */
+	len = min(count, log->size - reader->r_off);
+	if (copy_to_user(buf, log->buffer + reader->r_off, len))
+		return -EFAULT;
+
+	/*
+	 * Second, we read any remaining bytes, starting back at the head of
+	 * the log.
+	 */
+	if (count != len)
+		if (copy_to_user(buf + len, log->buffer, count - len))
+			return -EFAULT;
+
+	reader->r_off = logger_offset(reader->r_off + count);
+
+	return count;
+}
+
+/*
+ * logger_read - our log's read() method
+ *
+ * Behavior:
+ *
+ * 	- O_NONBLOCK works
+ * 	- If there are no log entries to read, blocks until log is written to
+ * 	- Atomically reads exactly one log entry
+ *
+ * Optimal read size is LOGGER_ENTRY_MAX_LEN. Will set errno to EINVAL if read
+ * buffer is insufficient to hold next entry.
+ */
+static ssize_t logger_read(struct file *file, char __user *buf,
+			   size_t count, loff_t *pos)
+{
+	struct logger_reader *reader = file->private_data;
+	struct logger_log *log = reader->log;
+	ssize_t ret;
+	DEFINE_WAIT(wait);
+
+start:
+	while (1) {
+		prepare_to_wait(&log->wq, &wait, TASK_INTERRUPTIBLE);
+
+		mutex_lock(&log->mutex);
+		ret = (log->w_off == reader->r_off);
+		mutex_unlock(&log->mutex);
+		if (!ret)
+			break;
+
+		if (file->f_flags & O_NONBLOCK) {
+			ret = -EAGAIN;
+			break;
+		}
+
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
+		schedule();
+	}
+
+	finish_wait(&log->wq, &wait);
+	if (ret)
+		return ret;
+
+	mutex_lock(&log->mutex);
+
+	/* is there still something to read or did we race? */
+	if (unlikely(log->w_off == reader->r_off)) {
+		mutex_unlock(&log->mutex);
+		goto start;
+	}
+
+	/* get the size of the next entry */
+	ret = get_entry_len(log, reader->r_off);
+	if (count < ret) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* get exactly one entry from the log */
+	ret = do_read_log_to_user(log, reader, buf, ret);
+
+out:
+	mutex_unlock(&log->mutex);
+
+	return ret;
+}
+
+/*
+ * get_next_entry - return the offset of the first valid entry at least 'len'
+ * bytes after 'off'.
+ *
+ * Caller must hold log->mutex.
+ */
+static size_t get_next_entry(struct logger_log *log, size_t off, size_t len)
+{
+	size_t count = 0;
+
+	do {
+		size_t nr = get_entry_len(log, off);
+		off = logger_offset(off + nr);
+		count += nr;
+	} while (count < len);
+
+	return off;
+}
+
+/*
+ * clock_interval - is a < c < b in mod-space? Put another way, does the line
+ * from a to b cross c?
+ */
+static inline int clock_interval(size_t a, size_t b, size_t c)
+{
+	if (b < a) {
+		if (a < c || b >= c)
+			return 1;
+	} else {
+		if (a < c && b >= c)
+			return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * fix_up_readers - walk the list of all readers and "fix up" any who were
+ * lapped by the writer; also do the same for the default "start head".
+ * We do this by "pulling forward" the readers and start head to the first
+ * entry after the new write head.
+ *
+ * The caller needs to hold log->mutex.
+ */
+static void fix_up_readers(struct logger_log *log, size_t len)
+{
+	size_t old = log->w_off;
+	size_t new = logger_offset(old + len);
+	struct logger_reader *reader;
+
+	if (clock_interval(old, new, log->head))
+		log->head = get_next_entry(log, log->head, len);
+
+	list_for_each_entry(reader, &log->readers, list)
+		if (clock_interval(old, new, reader->r_off))
+			reader->r_off = get_next_entry(log, reader->r_off, len);
+}
+
+/*
+ * do_write_log - writes 'len' bytes from 'buf' to 'log'
+ *
+ * The caller needs to hold log->mutex.
+ */
+static void do_write_log(struct logger_log *log, const void *buf, size_t count)
+{
+	size_t len;
+
+	len = min(count, log->size - log->w_off);
+	memcpy(log->buffer + log->w_off, buf, len);
+
+	if (count != len)
+		memcpy(log->buffer, buf + len, count - len);
+
+	log->w_off = logger_offset(log->w_off + count);
+
+}
+
+/*
+ * do_write_log_user - writes 'len' bytes from the user-space buffer 'buf' to
+ * the log 'log'
+ *
+ * The caller needs to hold log->mutex.
+ *
+ * Returns 'count' on success, negative error code on failure.
+ */
+static ssize_t do_write_log_from_user(struct logger_log *log,
+				      const void __user *buf, size_t count)
+{
+	size_t len;
+
+	len = min(count, log->size - log->w_off);
+	if (len && copy_from_user(log->buffer + log->w_off, buf, len))
+		return -EFAULT;
+
+	if (count != len)
+		if (copy_from_user(log->buffer, buf + len, count - len))
+			return -EFAULT;
+
+	log->w_off = logger_offset(log->w_off + count);
+
+	return count;
+}
+
+/*
+ * logger_aio_write - our write method, implementing support for write(),
+ * writev(), and aio_write(). Writes are our fast path, and we try to optimize
+ * them above all else.
+ */
+ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
+			 unsigned long nr_segs, loff_t ppos)
+{
+	struct logger_log *log = file_get_log(iocb->ki_filp);
+	size_t orig = log->w_off;
+	struct logger_entry header;
+	struct timespec now;
+	ssize_t ret = 0;
+
+	now = current_kernel_time();
+
+	header.pid = current->tgid;
+	header.tid = current->pid;
+	header.sec = now.tv_sec;
+	header.nsec = now.tv_nsec;
+	header.len = min_t(size_t, iocb->ki_left, LOGGER_ENTRY_MAX_PAYLOAD);
+
+	/* null writes succeed, return zero */
+	if (unlikely(!header.len))
+		return 0;
+
+	mutex_lock(&log->mutex);
+
+	/*
+	 * Fix up any readers, pulling them forward to the first readable
+	 * entry after (what will be) the new write offset. We do this now
+	 * because if we partially fail, we can end up with clobbered log
+	 * entries that encroach on readable buffer.
+	 */
+	fix_up_readers(log, sizeof(struct logger_entry) + header.len);
+
+	do_write_log(log, &header, sizeof(struct logger_entry));
+
+	while (nr_segs-- > 0) {
+		size_t len;
+		ssize_t nr;
+
+		/* figure out how much of this vector we can keep */
+		len = min_t(size_t, iov->iov_len, header.len - ret);
+
+		/* write out this segment's payload */
+		nr = do_write_log_from_user(log, iov->iov_base, len);
+		if (unlikely(nr < 0)) {
+			log->w_off = orig;
+			mutex_unlock(&log->mutex);
+			return nr;
+		}
+
+		iov++;
+		ret += nr;
+	}
+
+	mutex_unlock(&log->mutex);
+
+	/* wake up any blocked readers */
+	wake_up_interruptible(&log->wq);
+
+	return ret;
+}
+
+static struct logger_log *get_log_from_minor(int);
+
+/*
+ * logger_open - the log's open() file operation
+ *
+ * Note how near a no-op this is in the write-only case. Keep it that way!
+ */
+static int logger_open(struct inode *inode, struct file *file)
+{
+	struct logger_log *log;
+	int ret;
+
+	ret = nonseekable_open(inode, file);
+	if (ret)
+		return ret;
+
+	log = get_log_from_minor(MINOR(inode->i_rdev));
+	if (!log)
+		return -ENODEV;
+
+	if (file->f_mode & FMODE_READ) {
+		struct logger_reader *reader;
+
+		reader = kmalloc(sizeof(struct logger_reader), GFP_KERNEL);
+		if (!reader)
+			return -ENOMEM;
+
+		reader->log = log;
+		INIT_LIST_HEAD(&reader->list);
+
+		mutex_lock(&log->mutex);
+		reader->r_off = log->head;
+		list_add_tail(&reader->list, &log->readers);
+		mutex_unlock(&log->mutex);
+
+		file->private_data = reader;
+	} else
+		file->private_data = log;
+
+	return 0;
+}
+
+/*
+ * logger_release - the log's release file operation
+ *
+ * Note this is a total no-op in the write-only case. Keep it that way!
+ */
+static int logger_release(struct inode *ignored, struct file *file)
+{
+	if (file->f_mode & FMODE_READ) {
+		struct logger_reader *reader = file->private_data;
+		list_del(&reader->list);
+		kfree(reader);
+	}
+
+	return 0;
+}
+
+/*
+ * logger_poll - the log's poll file operation, for poll/select/epoll
+ *
+ * Note we always return POLLOUT, because you can always write() to the log.
+ * Note also that, strictly speaking, a return value of POLLIN does not
+ * guarantee that the log is readable without blocking, as there is a small
+ * chance that the writer can lap the reader in the interim between poll()
+ * returning and the read() request.
+ */
+static unsigned int logger_poll(struct file *file, poll_table *wait)
+{
+	struct logger_reader *reader;
+	struct logger_log *log;
+	unsigned int ret = POLLOUT | POLLWRNORM;
+
+	if (!(file->f_mode & FMODE_READ))
+		return ret;
+
+	reader = file->private_data;
+	log = reader->log;
+
+	poll_wait(file, &log->wq, wait);
+
+	mutex_lock(&log->mutex);
+	if (log->w_off != reader->r_off)
+		ret |= POLLIN | POLLRDNORM;
+	mutex_unlock(&log->mutex);
+
+	return ret;
+}
+
+static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct logger_log *log = file_get_log(file);
+	struct logger_reader *reader;
+	long ret = -ENOTTY;
+
+	mutex_lock(&log->mutex);
+
+	switch (cmd) {
+	case LOGGER_GET_LOG_BUF_SIZE:
+		ret = log->size;
+		break;
+	case LOGGER_GET_LOG_LEN:
+		if (!(file->f_mode & FMODE_READ)) {
+			ret = -EBADF;
+			break;
+		}
+		reader = file->private_data;
+		if (log->w_off >= reader->r_off)
+			ret = log->w_off - reader->r_off;
+		else
+			ret = (log->size - reader->r_off) + log->w_off;
+		break;
+	case LOGGER_GET_NEXT_ENTRY_LEN:
+		if (!(file->f_mode & FMODE_READ)) {
+			ret = -EBADF;
+			break;
+		}
+		reader = file->private_data;
+		if (log->w_off != reader->r_off)
+			ret = get_entry_len(log, reader->r_off);
+		else
+			ret = 0;
+		break;
+	case LOGGER_FLUSH_LOG:
+		if (!(file->f_mode & FMODE_WRITE)) {
+			ret = -EBADF;
+			break;
+		}
+		list_for_each_entry(reader, &log->readers, list)
+			reader->r_off = log->w_off;
+		log->head = log->w_off;
+		ret = 0;
+		break;
+	}
+
+	mutex_unlock(&log->mutex);
+
+	return ret;
+}
+
+static const struct file_operations logger_fops = {
+	.owner = THIS_MODULE,
+	.read = logger_read,
+	.aio_write = logger_aio_write,
+	.poll = logger_poll,
+	.unlocked_ioctl = logger_ioctl,
+	.compat_ioctl = logger_ioctl,
+	.open = logger_open,
+	.release = logger_release,
+};
+
+/*
+ * Defines a log structure with name 'NAME' and a size of 'SIZE' bytes, which
+ * must be a power of two, greater than LOGGER_ENTRY_MAX_LEN, and less than
+ * LONG_MAX minus LOGGER_ENTRY_MAX_LEN.
+ */
+#define DEFINE_LOGGER_DEVICE(VAR, NAME, SIZE) \
+static unsigned char _buf_ ## VAR[SIZE]; \
+static struct logger_log VAR = { \
+	.buffer = _buf_ ## VAR, \
+	.misc = { \
+		.minor = MISC_DYNAMIC_MINOR, \
+		.name = NAME, \
+		.fops = &logger_fops, \
+		.parent = NULL, \
+	}, \
+	.wq = __WAIT_QUEUE_HEAD_INITIALIZER(VAR .wq), \
+	.readers = LIST_HEAD_INIT(VAR .readers), \
+	.mutex = __MUTEX_INITIALIZER(VAR .mutex), \
+	.w_off = 0, \
+	.head = 0, \
+	.size = SIZE, \
+};
+
+DEFINE_LOGGER_DEVICE(log_main, LOGGER_LOG_MAIN, 64*1024)
+DEFINE_LOGGER_DEVICE(log_events, LOGGER_LOG_EVENTS, 256*1024)
+DEFINE_LOGGER_DEVICE(log_radio, LOGGER_LOG_RADIO, 64*1024)
+
+static struct logger_log *get_log_from_minor(int minor)
+{
+	if (log_main.misc.minor == minor)
+		return &log_main;
+	if (log_events.misc.minor == minor)
+		return &log_events;
+	if (log_radio.misc.minor == minor)
+		return &log_radio;
+	return NULL;
+}
+
+static int __init init_log(struct logger_log *log)
+{
+	int ret;
+
+	ret = misc_register(&log->misc);
+	if (unlikely(ret)) {
+		printk(KERN_ERR "logger: failed to register misc "
+		       "device for log '%s'!\n", log->misc.name);
+		return ret;
+	}
+
+	printk(KERN_INFO "logger: created %luK log '%s'\n",
+	       (unsigned long) log->size >> 10, log->misc.name);
+
+	return 0;
+}
+
+static int __init logger_init(void)
+{
+	int ret;
+
+	ret = init_log(&log_main);
+	if (unlikely(ret))
+		goto out;
+
+	ret = init_log(&log_events);
+	if (unlikely(ret))
+		goto out;
+
+	ret = init_log(&log_radio);
+	if (unlikely(ret))
+		goto out;
+
+out:
+	return ret;
+}
+device_initcall(logger_init);

drivers/staging/android/logger.h

+/* 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 logger_entry {
+	__u16		len;	/* length of the payload */
+	__u16		__pad;	/* no matter what, we get 2 bytes of padding */
+	__s32		pid;	/* generating process's pid */
+	__s32		tid;	/* generating process's tid */
+	__s32		sec;	/* seconds since Epoch */
+	__s32		nsec;	/* nanoseconds */
+	char		msg[0];	/* the entry's payload */
+};
+
+#define LOGGER_LOG_RADIO	"log_radio"	/* radio-related messages */
+#define LOGGER_LOG_EVENTS	"log_events"	/* system/hardware events */
+#define LOGGER_LOG_MAIN		"log_main"	/* everything else */
+
+#define LOGGER_ENTRY_MAX_LEN		(4*1024)
+#define LOGGER_ENTRY_MAX_PAYLOAD	\
+	(LOGGER_ENTRY_MAX_LEN - sizeof(struct logger_entry))
+
+#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 */
+
+#endif /* _LINUX_LOGGER_H */

drivers/staging/android/timed_gpio.h

+/* include/linux/timed_gpio.h
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * 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_TIMED_GPIO_H
+#define _LINUX_TIMED_GPIO_H
+
+#define TIMED_GPIO_NAME "timed-gpio"
+
+struct timed_gpio {
+	const char *name;
+	unsigned 	gpio;
+	int		max_timeout;
+	u8 		active_low;
+};
+
+struct timed_gpio_platform_data {
+	int 		num_gpios;
+	struct timed_gpio *gpios;
+};
+
+#endif

drivers/staging/android/timed_output.h

+/* include/linux/timed_output.h
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * 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_TIMED_OUTPUT_H
+#define _LINUX_TIMED_OUTPUT_H
+
+struct timed_output_dev {
+	const char	*name;
+
+	/* enable the output and set the timer */
+	void	(*enable)(struct timed_output_dev *sdev, int timeout);
+
+	/* returns the current number of milliseconds remaining on the timer */
+	int		(*get_time)(struct timed_output_dev *sdev);
+
+	/* private data */
+	struct device	*dev;
+	int		index;
+	int		state;
+};
+
+extern int timed_output_dev_register(struct timed_output_dev *dev);
+extern void timed_output_dev_unregister(struct timed_output_dev *dev);
+
+#endif