[STYLE] Buffer: doxygen comments

Change-Id: I5db3a950b4f8bc9d5444159be5c7e8ba3beacd07
Signed-off-by: Alexander Aksenov <a.aksenov@samsung.com>

9 files changed, 416 insertions, 125 deletions

diff --git a/buffer/buffer_description.h b/buffer/buffer_description.h
index 2be9eaf3..353e33a2 100644
--- a/buffer/buffer_description.h
+++ b/buffer/buffer_description.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/buffer_description.h
+/**
+ * @file buffer/buffer_description.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,19 +18,32 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013         Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * swap_subbuffer structure represents one buffers subbufer
  */
 
-/* SWAP Buffer structure description */
-
 #ifndef __BUFFER_DESCRIPTION_H__
 #define __BUFFER_DESCRIPTION_H__
 
 #include "data_types.h"
 
+/**
+ * @struct swap_subbuffer
+ * @brief This structures are combined in array which represents the SWAP buffer.
+ * @var swap_subbuffer::next_in_queue
+ * Pointer to the next swap_subbufer in queue
+ * @var swap_subbuffer::full_buffer_part
+ * Currently occupied subbuffers size
+ * @var swap_subbuffer::data_buffer
+ * Pointer to subbuffers data itself of type swap_subbuffer_ptr
+ * @var swap_subbuffer::buffer_sync
+ * Subbuffers sync primitive
+ */
 struct swap_subbuffer {
 	/* Pointer to the next subbuffer in queue */
 	struct swap_subbuffer *next_in_queue;
diff --git a/buffer/buffer_queue.c b/buffer/buffer_queue.c
index 2b2f6ec3..1f048ba7 100644
--- a/buffer/buffer_queue.c
+++ b/buffer/buffer_queue.c
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/buffer_queue.c
+/**
+ * buffer/buffer_queue.c
+ * @author Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,14 +18,15 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013	 Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * Implements buffers queues interface
  */
 
-/* SWAP buffer queues implementation */
-
 /* For all memory allocation/deallocation operations, except buffer memory
  * allocation/deallocation should be used 
  *  memory_allocation(size_t memory_size)
@@ -47,8 +50,19 @@
 #include "swap_buffer_errors.h"
 #include "kernel_operations.h"
 
-/* Queue structure. Consist of pointers to the first and the last elements of
- * queue. */
+/**
+ * @struct queue_t
+ * @brief Queue structure. Consist of pointers to the first and the last
+ * elements of queue.
+ * @var queue_t::start_ptr
+ * Pointer to the first subbuffer in queue
+ * @var queue_t::end_ptr
+ * Pointer to the last subbuffer in queue
+ * @var queue_t::subbuffers_count
+ * Subbuffers count in queue
+ * @var queue_t::queue_sync
+ * Queue access sync primitive
+ */
 struct queue_t {
 	struct swap_subbuffer *start_ptr;
 	struct swap_subbuffer *end_ptr;
@@ -56,7 +70,10 @@ struct queue_t {
 	struct sync_t queue_sync;
 };
 
-/* Write queue */
+/**
+ * @var write_queue
+ * @brief Represents write queue.
+ */
 struct queue_t write_queue = {
 	.start_ptr = NULL,
 	.end_ptr = NULL,
@@ -66,7 +83,10 @@ struct queue_t write_queue = {
 	}
 };
 
-/* Read queue */
+/**
+ * @var read_queue
+ * @brief Represents read queue.
+ */
 struct queue_t read_queue = {
 	.start_ptr = NULL,
 	.end_ptr = NULL,
@@ -96,7 +116,14 @@ static struct sync_t buffer_busy_sync = {
 /* Memory pages count in one subbuffer */
 static int pages_order_in_subbuffer = 0;
 
-
+/**
+ * @brief Allocates memory for swap_subbuffer structures and subbuffers.
+ * Total allocated memory = subbuffer_size * subbuffers_count.
+ *
+ * @param subbuffer_size Size of each subbuffer.
+ * @param subbuffers_count Count of subbuffers.
+ * @return 0 on success, negative error code otherwise.
+ */
 int buffer_queue_allocation(size_t subbuffer_size,
 			    unsigned int subbuffers_count)
 {
@@ -220,6 +247,11 @@ buffer_allocation_error_ret:
 	return result;
 }
 
+/**
+ * @brief Resets all subbuffers for writing.
+ *
+ * @return 0 on success, negative error code otherwise.
+ */
 int buffer_queue_reset(void)
 {
 	struct swap_subbuffer *buffer = read_queue.start_ptr;
@@ -261,6 +293,11 @@ int buffer_queue_reset(void)
 	return E_SB_SUCCESS;
 }
 
+/**
+ * @brief Free all allocated subbuffers.
+ *
+ * @return Void.
+ */
 void buffer_queue_free(void)
 {
 	struct swap_subbuffer *tmp = NULL;
@@ -322,7 +359,11 @@ static void next_queue_element(struct queue_t *queue)
 	--queue->subbuffers_count;
 }
 
-/* Get first subbuffer from read list */
+/**
+ * @brief Get first subbuffer from read list.
+ *
+ * @return Pointer to swap_subbuffer
+ */
 struct swap_subbuffer *get_from_read_list(void)
 {
 	struct swap_subbuffer *result = NULL;
@@ -346,7 +387,12 @@ get_from_read_list_unlock:
 	return result;
 }
 
-/* Add subbuffer to read list */
+/**
+ * @brief Add subbuffer to read list.
+ *
+ * @param subbuffer Pointer to the subbuffer to add.
+ * @return Void.
+ */
 void add_to_read_list(struct swap_subbuffer *subbuffer)
 {
 	/* Lock read sync primitive */
@@ -369,7 +415,12 @@ void add_to_read_list(struct swap_subbuffer *subbuffer)
 	sync_unlock(&read_queue.queue_sync);
 }
 
-/* Call add to read list and callback function from driver module */
+/**
+ * @brief Call add to read list and callback function from driver module.
+ *
+ * @param subbuffer Pointer to the subbuffer to add.
+ * @return swap_buffer_callback result.
+ */
 int add_to_read_list_with_callback(struct swap_subbuffer *subbuffer)
 {
 	int result = 0;
@@ -381,14 +432,25 @@ int add_to_read_list_with_callback(struct swap_subbuffer *subbuffer)
 	return result;
 }
 
-/* Returns subbuffers to read count */
+/**
+ * @brief Returns subbuffers to read count.
+ *
+ * @return Count of subbuffers in read_queue.
+ */
 unsigned int get_readable_buf_cnt(void)
 {
 	return read_queue.subbuffers_count;
 }
 
 
-/* Get first writable subbuffer from write list */
+/**
+ * @brief Get first writable subbuffer from write list.
+ *
+ * @param size Minimum amount of free space in subbuffer.
+ * @param[out] ptr_to_write Pointer to the variable where pointer to the beginning
+ * of memory for writing should be stored.
+ * @return Found swap_subbuffer.
+ */
 struct swap_subbuffer *get_from_write_list(size_t size, void **ptr_to_write)
 {
 	struct swap_subbuffer *result = NULL;
@@ -461,7 +523,12 @@ struct swap_subbuffer *get_from_write_list(size_t size, void **ptr_to_write)
 	return result;
 }
 
-/* Add subbuffer to write list */
+/**
+ * @brief Add subbuffer to write list.
+ *
+ * @param subbuffer Pointer to the swap_subbuffer that should be stored.
+ * @return Void.
+ */
 void add_to_write_list(struct swap_subbuffer *subbuffer)
 {
 	sync_lock(&write_queue.queue_sync);
@@ -484,14 +551,23 @@ void add_to_write_list(struct swap_subbuffer *subbuffer)
 	sync_unlock(&write_queue.queue_sync);
 }
 
-/* Returns subbuffers to write count */
+/**
+ * @brief Returns subbuffers to write count.
+ *
+ * @return Count of subbuffers in write queue.
+ */
 unsigned int get_writable_buf_cnt(void)
 {
 	return write_queue.subbuffers_count;
 }
 
 
-/* Add subbuffer to busy list when it is read from out of the buffer */
+/**
+ * @brief Add subbuffer to busy list when it is read from out of the buffer.
+ *
+ * @param subbuffer Pointer to the swap_subbuffer that should be added.
+ * @return Void.
+ */
 void add_to_busy_list(struct swap_subbuffer *subbuffer)
 {
 	/* Lock busy sync primitive */
@@ -505,7 +581,12 @@ void add_to_busy_list(struct swap_subbuffer *subbuffer)
 	sync_unlock(&buffer_busy_sync);
 }
 
-/* Remove subbuffer from busy list when it is released */
+/**
+ * @brief Remove subbuffer from busy list when it is released.
+ *
+ * @param subbuffer Pointer to the swap_subbuffer that should be removed.
+ * @return 0 on success, negative error code otherwise.
+ */
 int remove_from_busy_list(struct swap_subbuffer *subbuffer)
 {
 	int result = -E_SB_NO_SUBBUFFER_IN_BUSY; // For sanitization
@@ -531,7 +612,11 @@ int remove_from_busy_list(struct swap_subbuffer *subbuffer)
 	return result;
 }
 
-/* Set all subbuffers in write list to read list */
+/**
+ * @brief Set all subbuffers in write list to read list.
+ *
+ * @return Void.
+ */
 void buffer_queue_flush(void)
 {
 	struct swap_subbuffer *buffer = write_queue.start_ptr;
@@ -558,7 +643,11 @@ void buffer_queue_flush(void)
 	sync_unlock(&write_queue.queue_sync);
 }
 
-/* Get subbuffers count in busy list */
+/**
+ * @brief Get subbuffers count in busy list.
+ *
+ * @return Count of swap_subbuffers in busy  list.
+ */
 int get_busy_buffers_count(void)
 {
 	int result;
@@ -570,7 +659,11 @@ int get_busy_buffers_count(void)
 	return result;
 }
 
-/* Get memory pages count in subbuffer */
+/**
+ * @brief Get memory pages count in subbuffer.
+ *
+ * @return Pages count in subbuffer.
+ */
 int get_pages_count_in_subbuffer(void)
 {
 /* Return 1 if pages order 0, or 2 of power pages_order_in_subbuffer otherwise */
diff --git a/buffer/buffer_queue.h b/buffer/buffer_queue.h
index a0833b5d..9f627fbb 100644
--- a/buffer/buffer_queue.h
+++ b/buffer/buffer_queue.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/buffer_queue.h
+/**
+ * @file buffer/buffer_queue.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,10 +18,13 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013         Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * Represents buffers queues interface
  */
 
 /* SWAP Buffer queues interface */
diff --git a/buffer/data_types.h b/buffer/data_types.h
index 6da8b4c7..47ef1d87 100644
--- a/buffer/data_types.h
+++ b/buffer/data_types.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/data_types.h
+/**
+ * @file buffer/data_types.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,10 +18,13 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013	 Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * Declares data types for SWAP buffer.
  */
 
 #ifndef __DATA_TYPES_H__
@@ -31,13 +36,22 @@
 
 struct page;
 
-/* Using spinlocks as sync primitives */
+/**
+ * @struct sync_t
+ * @brief Using spinlocks as sync primitives.
+ * @var sync_t::spinlock
+ * Spinlock.
+ * @var sync_t::flags
+ * Flags for spinlock.
+ */
 struct sync_t {
 	spinlock_t spinlock;
 	unsigned long flags;
 };
 
-/* swap_subbuffer_ptr points to the first memory page of the subbuffer */
+/**
+ * @brief swap_subbuffer_ptr points to the first memory page of the subbuffer.
+ */
 typedef struct page *swap_subbuffer_ptr;
 
 #endif /* __DATA_TYPES_H__ */
diff --git a/buffer/kernel_operations.h b/buffer/kernel_operations.h
index feb544b1..62aefb21 100644
--- a/buffer/kernel_operations.h
+++ b/buffer/kernel_operations.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/kernel_operations.h
+/**
+ * @file buffer/kernel_operations.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,14 +18,15 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013	 Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * Kernel functions wrap.
  */
 
-/* Kernel functions wrap */
-
 #ifndef __KERNEL_OPERATIONS_H__
 #define __KERNEL_OPERATIONS_H__
 
@@ -40,60 +43,96 @@
 
 
 /* MESSAGES */
+/** Prints debug message.*/
 #define print_debug(msg, args...) \
 	printk(KERN_DEBUG "SWAP_BUFFER DEBUG : " msg, ##args)
+/** Prints info message.*/
 #define print_msg(msg, args...)   \
 	printk(KERN_INFO "SWAP_BUFFER : " msg, ##args)
+/** Prints warning message.*/
 #define print_warn(msg, args...)  \
 	printk(KERN_WARNING "SWAP_BUFFER WARNING : " msg, ##args)
+/** Prints error message.*/
 #define print_err(msg, args...)   \
 	printk(KERN_ERR "SWAP_BUFFER ERROR : " msg, ##args)
+/** Prints critical error message.*/
 #define print_crit(msg, args...)  \
 	printk(KERN_CRIT "SWAP_BUFFER CRITICAL : " msg, ##args)
 
 
-
-
-/* LOCKS */
-
-/* Spinlocks initialization */
+/**
+ * @brief struct sync_t initialization.
+ *
+ * @param buffer_sync Target sync primitive.
+ * @return Void.
+ */
 static inline void sync_init(struct sync_t *buffer_sync)
 {
 	spin_lock_init(&buffer_sync->spinlock);
 }
 
-/* Lock spinlock with save flags */
+/**
+ * @brief Lock sync_t with saving flags.
+ *
+ * @param buffer_sync Target sync primitive.
+ * @return Void.
+ */
 static inline void sync_lock(struct sync_t *buffer_sync)
 {
 	spin_lock_irqsave(&buffer_sync->spinlock, buffer_sync->flags);
 }
 
-/* Unlock spinlock with restore flags */
+/**
+ * @brief Unlock sync_t with restoring flags.
+ *
+ * @param buffer_sync Target sync primitive.
+ * @return Void.
+ */
 static inline void sync_unlock(struct sync_t *buffer_sync)
 {
 	spin_unlock_irqrestore(&buffer_sync->spinlock, buffer_sync->flags);
 }
 
-/* Lock spinlock */
+/**
+ * @brief Lock sync_t without saving flags.
+ *
+ * @param buffer_sync Target sync primitive.
+ * @return Void.
+ */
 static inline void sync_lock_no_flags(struct sync_t *buffer_sync)
 {
 	spin_lock(&buffer_sync->spinlock);
 }
 
-/* Unlock spinlock */
+/**
+ * @brief Unlock sync_t without restoring flags.
+ *
+ * @param buffer_sync Target sync primitive.
+ * @return Void.
+ */
 static inline void sync_unlock_no_flags(struct sync_t *buffer_sync)
 {
 	spin_unlock(&buffer_sync->spinlock);
 }
 
-/* Disable preemption and irqs */
+/**
+ * @brief Disable preemption and irqs.
+ *
+ * @param flags Variable to save flags to.
+ * @return Void.
+ */
 static inline void swap_irq_disable(unsigned long *flags)
 {
 	preempt_disable();
 	local_irq_save(*flags);
 }
 
-/* Enable preemption and irqs */
+/**
+ * @brief Enable preemption and irqs.
+ *
+ * @param flags Variable to restore flags from.
+ * @return Void.
+ */
 static inline void swap_irq_enable(unsigned long *flags)
 {
 	local_irq_restore(*flags);
@@ -104,26 +143,36 @@ static inline void swap_irq_enable(unsigned long *flags)
 
 
 /* We alloc memory for swap_subbuffer structures with common kmalloc */
+/** Allocates memory for subbuffer structures.*/
 #define memory_allocation(memory_size)  kmalloc(memory_size, GFP_KERNEL)
+/** Free subbuffer structures memory.*/
 #define memory_free(ptr)                kfree(ptr)
 
-/* For subbuffers themselves, we allocate memory with alloc_pages, so, we have
+/** For subbuffers themselves, we allocate memory with alloc_pages, so, we have
  * to evaluate required pages order */
 #define buffer_allocation(memory_size)                        \
 	alloc_pages(GFP_KERNEL, (pages_order_in_subbuffer >= 0) ? \
 		pages_order_in_subbuffer :                            \
 		get_order_for_alloc_pages(memory_size))
 
+/** Free buffer's memory.*/
 #define buffer_free(ptr, subbuf_size)                         \
 	__free_pages(ptr, (pages_order_in_subbuffer >= 0) ?       \
 		 pages_order_in_subbuffer :                           \
 		 get_order_for_alloc_pages(subbuf_size))
 
+/** Returns buffer address.*/
 #define buffer_address(buffer_ptr)  page_address(buffer_ptr)
+/** Sets page order in subbuffer.*/
 #define set_pages_order_in_subbuffer(memory_size) \
 	pages_order_in_subbuffer = get_order_for_alloc_pages(memory_size)
 
-/* Functions for pages allocation */
+/**
+ * @brief Functions for pages allocation.
+ *
+ * @param number Target number.
+ * @return Power of two.
+ */
 static inline unsigned int nearest_power_of_two(unsigned int number)
 {
 	unsigned int result = 0;
@@ -141,6 +190,12 @@ static inline unsigned int nearest_power_of_two(unsigned int number)
 	return result;
 }
 
+/**
+ * @brief Order for alloc pages.
+ *
+ * @param memory_size Wishful memory size.
+ * @return Pages order.
+ */
 static inline unsigned int get_order_for_alloc_pages(size_t memory_size)
 {
 	/* First evaluate remainder of the division memory_size by PAGE_SIZE.
diff --git a/buffer/swap_buffer_errors.h b/buffer/swap_buffer_errors.h
index 81bdb5f7..f1532143 100644
--- a/buffer/swap_buffer_errors.h
+++ b/buffer/swap_buffer_errors.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/swap_buffer_errors.h
+/**
+ * @file buffer/swap_buffer_errors.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,38 +18,81 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013	 Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * SWAP Buffer error codes enumeration.
  */
 
-/* SWAP Buffer error codes enumeration */
-
 #ifndef __SWAP_BUFFER_ERRORS_H__
 #define __SWAP_BUFFER_ERRORS_H__
 
+/**
+ * @enum _swap_buffer_errors
+ * @brief SWAP buffer errors enumeration.
+ */
 enum _swap_buffer_errors {
-	E_SB_SUCCESS = 0,               /* Success */
-	E_SB_UNRELEASED_BUFFERS = 1,    /* There are some unreleased buffers. Mainly
-					   returned by swap_buffer_uninit */
-	E_SB_NO_WRITABLE_BUFFERS = 2,   /* No buffers for writing */
-	E_SB_WRONG_DATA_SIZE = 3,       /* Wrong data size: size == 0 or
-					   size > subbuffer size */
-	E_SB_IS_STOPPED = 4,            /* Trying to write data after SWAP buffer
-					   has been stopped. */
-	E_SB_OVERLAP = 5,               /* Memory areas of data to be written and
-					   subbuffer itself are overlap */
-	E_SB_NO_READABLE_BUFFERS = 6,   /* No buffers for reading */
-	E_SB_NO_CALLBACK = 7,           /* Callback function ptr == NULL */
-	E_SB_NO_MEM_QUEUE_BUSY = 8,     /* Memory for queue_busy wasn't allocated */
-	E_SB_NO_MEM_BUFFER_STRUCT = 9,  /* Memory for one of struct swap_buffer
-					   wasn't allocated */
-	E_SB_NO_MEM_DATA_BUFFER = 10,   /* Memort for data buffer itself wasn't
-					   allocated */
-	E_SB_NO_SUBBUFFER_IN_BUSY = 11, /* No such subbuffer in busy_list */
-	E_SB_NOT_ALLOC = 12,            /* Subbuffers aren't allocated */
-	E_SB_WRONG_THRESHOLD = 13       /* Thresholds > 100, top < lower */
+	/**
+	 * @brief Success.
+	 */
+	E_SB_SUCCESS = 0,
+	/**
+	 * @brief There are some unreleased buffers.
+	 * Mainly returned by swap_buffer_uninit.
+	 */
+	E_SB_UNRELEASED_BUFFERS = 1,
+	/**
+	 * @brief No buffers for writing.
+	 */
+	E_SB_NO_WRITABLE_BUFFERS = 2,
+	/**
+	 * @brief Wrong data size: size == 0 or size > subbuffer size.
+	 */
+	E_SB_WRONG_DATA_SIZE = 3,
+	/**
+	 * @brief Trying to write data after SWAP buffer has been stopped.
+	 */
+	E_SB_IS_STOPPED = 4,
+	/**
+	 * @brief Memory areas of data to be written and subbuffer itself
+	 * are overlap.
+	 */
+	E_SB_OVERLAP = 5,
+	/**
+	 * @brief No buffers for reading.
+	 */
+	E_SB_NO_READABLE_BUFFERS = 6,
+	/**
+	 * @brief Callback function ptr == NULL.
+	 */
+	E_SB_NO_CALLBACK = 7,
+	/**
+	 * @brief Memory for queue_busy wasn't allocated.
+	 */
+	E_SB_NO_MEM_QUEUE_BUSY = 8,
+	/**
+	 * @brief Memory for one of struct swap_buffer wasn't allocated.
+	 */
+	E_SB_NO_MEM_BUFFER_STRUCT = 9,
+	/**
+	 * @brief Memort for data buffer itself wasn't allocated.
+	 */
+	E_SB_NO_MEM_DATA_BUFFER = 10,
+	/**
+	 * @brief No such subbuffer in busy_list.
+	 */
+	E_SB_NO_SUBBUFFER_IN_BUSY = 11,
+	/**
+	 * @brief Subbuffers aren't allocated.
+	 */
+	E_SB_NOT_ALLOC = 12,
+	/**
+	 * @brief Thresholds > 100, top < lower.
+	 */
+	E_SB_WRONG_THRESHOLD = 13
 };
 
 #endif /* __SWAP_BUFFER_ERRORS_H__ */
diff --git a/buffer/swap_buffer_module.c b/buffer/swap_buffer_module.c
index 211601a8..603ed58b 100644
--- a/buffer/swap_buffer_module.c
+++ b/buffer/swap_buffer_module.c
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/swap_buffer_module.c
+/**
+ * buffer/swap_buffer_module.c
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,37 +18,37 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013	 Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * SWAP Buffer interface implementation.
  */
 
-/* SWAP Buffer interface implementation */
-
 #include "swap_buffer_module.h"
 #include "buffer_queue.h"
 #include "buffer_description.h"
 #include "swap_buffer_errors.h"
 #include "kernel_operations.h"
 
-/* Bitwise mask for buffer status */
+/**
+ * @enum _swap_buffer_status_mask
+ * @brief Bitwise mask for buffer status.
+ */
 enum _swap_buffer_status_mask {
-	BUFFER_FREE = 0,
-	BUFFER_ALLOC = 1,
-	BUFFER_PAUSE = 2,
-	BUFFER_WORK = 4
+	BUFFER_FREE = 0,                /**< 000 - memory free. */
+	BUFFER_ALLOC = 1,               /**< 001 - memory allocated. */
+	BUFFER_PAUSE = 2,               /**< 010 - buffer overflow. */
+	BUFFER_WORK = 4                 /**< @brief 100 - buffer work. */
 };
 
-/* Buffer status masks:
- *   0 - memory free
- *   1 - memory allocated
- *  10 - buffer overflow
- * 100 - buffer work
- * */
 static unsigned char swap_buffer_status = BUFFER_FREE;
 
-/* Callback type */
+/**
+ * @brief Subbuffer callback type.
+ */
 typedef int(*subbuffer_callback_type)(void);
 
 /* Callback that is called when full subbuffer appears */
@@ -81,6 +83,14 @@ static inline unsigned int percent_to_count(unsigned char percent,
 	return (percent * cnt) / 100;
 }
 
+/**
+ * @brief Initializes SWAP buffer and allocates memory.
+ *
+ * @param buf_init Pointer to the buffer_init_t structure which contains
+ * information about subbuffers count, subbuffers size and subbuffer-full-
+ * callback.
+ * @return 0 on success, negative error code otherwise.
+ */
 int swap_buffer_init(struct buffer_init_t *buf_init)
 {
 	int result = -1;
@@ -131,7 +141,11 @@ swap_buffer_init_work:
 }
 EXPORT_SYMBOL_GPL(swap_buffer_init);
 
-
+/**
+ * @brief Uninitializes SWAP buffer, releases allocated memory.
+ *
+ * @return 0 on success, negative error code otherwise.
+ */
 int swap_buffer_uninit(void)
 {
 	/* Check whether buffer is allocated */
@@ -164,7 +178,13 @@ int swap_buffer_uninit(void)
 }
 EXPORT_SYMBOL_GPL(swap_buffer_uninit);
 
-
+/**
+ * @brief Writes data to SWAP buffer.
+ *
+ * @param data Pointer to a data for writing.
+ * @param size Size of a data for writing.
+ * @return Size of written data on success, negative error code otherwise.
+ */
 ssize_t swap_buffer_write(void *data, size_t size)
 {
 	int result = E_SB_SUCCESS;
@@ -219,7 +239,12 @@ buf_write_sem_post:
 }
 EXPORT_SYMBOL_GPL(swap_buffer_write);
 
-
+/**
+ * @brief Gets pointer to subbuffer for reading.
+ *
+ * @param[out] subbuffer Pointer to a variable which points on target subbuffer.
+ * @return 0 on success, negative error code otherwise.
+ */
 int swap_buffer_get(struct swap_subbuffer **subbuffer)
 {
 	int result = 0;
@@ -246,7 +271,12 @@ int swap_buffer_get(struct swap_subbuffer **subbuffer)
 }
 EXPORT_SYMBOL_GPL(swap_buffer_get);
 
-
+/**
+ * @brief Releases subbuffer after reading.
+ *
+ * @param subbuffer Subbuffer that should be released.
+ * @return 0 on success, negative error code otherwise.
+ */
 int swap_buffer_release(struct swap_subbuffer **subbuffer)
 {
 	int result;
@@ -270,7 +300,11 @@ int swap_buffer_release(struct swap_subbuffer **subbuffer)
 }
 EXPORT_SYMBOL_GPL(swap_buffer_release);
 
-
+/**
+ * @brief Sets all subbuffers for reading.
+ *
+ * @return Count of subbeffers for reading.
+ */
 unsigned int swap_buffer_flush(void)
 {
 	unsigned int result;
@@ -285,7 +319,13 @@ unsigned int swap_buffer_flush(void)
 }
 EXPORT_SYMBOL_GPL(swap_buffer_flush);
 
-
+/**
+ * @brief Executes subbuffer-full-callback.
+ *
+ * @param buffer Pointer to the full subbuffer.
+ * @return -E_SB_NO_CALLBACK if no callback is registered or callbacks ret
+ * value otherwise.
+ */
 int swap_buffer_callback(void *buffer)
 {
 	int result;
diff --git a/buffer/swap_buffer_module.h b/buffer/swap_buffer_module.h
index cc70b02d..1c047ada 100644
--- a/buffer/swap_buffer_module.h
+++ b/buffer/swap_buffer_module.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/swap_buffer_module.h
+/**
+ * @file buffer/swap_buffer_module.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,14 +18,15 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
+ * @section COPYRIGHT
+ *
  * Copyright (C) Samsung Electronics, 2013
  *
- * 2013         Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * @section DESCRIPTION
  *
+ * SWAP Buffer interface declaration.
  */
 
-/* SWAP Buffer interface description */
-
 #ifndef __SWAP_BUFFER_MODULE_H__
 #define __SWAP_BUFFER_MODULE_H__
 
@@ -31,18 +34,37 @@
 
 struct swap_subbuffer;
 
+/**
+ * @struct buffer_init_t
+ * @brief Buffer init structure. Contains information necessary for SWAP buffer
+ * initialization.
+ * @var buffer_init_t::subbuffer_size
+ * Subbuffer size.
+ * @var buffer_init_t::nr_subbuffers
+ * Subbuffers count.
+ * @var buffer_init_t::subbuffer_full_cb
+ * Callback. Called when one of subbuffers is full.
+ * @var buffer_init_t::lower_threshold
+ * Lower threshold in percent. When buffers fall below this limit
+ * low_mem_cb is called and swap_buffer is suspended.
+ * @var buffer_init_t::low_mem_cb
+ * Callback that is called when count of free subbuffers falls below
+ * lower_threshold.
+ * @var buffer_init_t::top_threshold
+ * Top threshold in percent. When buffers exceed this limit
+ * enough_mem_cb is called.
+ * @var buffer_init_t::enough_mem_cb
+ * Callback that is called when count of free subbuffers exceeds top_threshold.
+ */
+
 struct buffer_init_t {
 	size_t subbuffer_size;
 	unsigned int nr_subbuffers;
 	int (*subbuffer_full_cb)(void);
 
-	/* Lower threshold in percent. When buffers fall below this limit
-	 * low_mem_cb is called and swap_buffer is suspended. */
 	unsigned char lower_threshold;
 	int (*low_mem_cb)(void);
 
-	/* Top threshold in percent. When buffers exceed this limit
-	 * enough_mem_cb is called */
 	unsigned char top_threshold;
 	int (*enough_mem_cb)(void);
 };
diff --git a/buffer/swap_buffer_to_buffer_queue.h b/buffer/swap_buffer_to_buffer_queue.h
index fec222fa..4d1da3ac 100644
--- a/buffer/swap_buffer_to_buffer_queue.h
+++ b/buffer/swap_buffer_to_buffer_queue.h
@@ -1,6 +1,8 @@
-/*
- *  SWAP Buffer Module
- *  modules/buffer/swap_buffer_to_buffer_queue.h
+/**
+ * @file buffer/swap_buffer_to_buffer_queue.h
+ * @author Alexander Aksenov <a.aksenov@samsung.com>
+ *
+ * @section LICENSE
  *
  * 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
@@ -16,14 +18,14 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
- * Copyright (C) Samsung Electronics, 2013
+ * @section COPYRIGHT
  *
- * 2013         Alexander Aksenov <a.aksenov@samsung.com>: SWAP Buffer implement
+ * Copyright (C) Samsung Electronics, 2013
  *
+ * @section DESCRIPTION
+ * SWAP Buffer interface for buffer queue.
  */
 
-/* SWAP Buffer interface for buffer queue */
-
 #ifndef __SWAP_BUFFER_TO_BUFFER_QUEUE_H__
 #define __SWAP_BUFFER_TO_BUFFER_QUEUE_H__