[people/ms/u-boot.git] / arch / arm / include / asm / arch-pxa / bitfield.h

/*
 *	FILE		bitfield.h
 *
 *	Version		1.1
 *	Author		Copyright (c) Marc A. Viredaz, 1998
 *			DEC Western Research Laboratory, Palo Alto, CA
 *	Date		April 1998 (April 1997)
 *	System		Advanced RISC Machine (ARM)
 *	Language	C or ARM Assembly
 *	Purpose		Definition of macros to operate on bit fields.
 */


#ifndef __BITFIELD_H
#define __BITFIELD_H

#ifndef __ASSEMBLY__
#define UData(Data)	((unsigned long) (Data))
#else
#define UData(Data)	(Data)
#endif


/*
 * MACRO: Fld
 *
 * Purpose
 *    The macro "Fld" encodes a bit field, given its size and its shift value
 *    with respect to bit 0.
 *
 * Note
 *    A more intuitive way to encode bit fields would have been to use their
 *    mask. However, extracting size and shift value information from a bit
 *    field's mask is cumbersome and might break the assembler (255-character
 *    line-size limit).
 *
 * Input
 *    Size		Size of the bit field, in number of bits.
 *    Shft		Shift value of the bit field with respect to bit 0.
 *
 * Output
 *    Fld		Encoded bit field.
 */

#define Fld(Size, Shft)	(((Size) << 16) + (Shft))


/*
 * MACROS: FSize, FShft, FMsk, FAlnMsk, F1stBit
 *
 * Purpose
 *    The macros "FSize", "FShft", "FMsk", "FAlnMsk", and "F1stBit" return
 *    the size, shift value, mask, aligned mask, and first bit of a
 *    bit field.
 *
 * Input
 *    Field		Encoded bit field (using the macro "Fld").
 *
 * Output
 *    FSize		Size of the bit field, in number of bits.
 *    FShft		Shift value of the bit field with respect to bit 0.
 *    FMsk		Mask for the bit field.
 *    FAlnMsk		Mask for the bit field, aligned on bit 0.
 *    F1stBit		First bit of the bit field.
 */

#define FSize(Field)	((Field) >> 16)
#define FShft(Field)	((Field) & 0x0000FFFF)
#define FMsk(Field)	(((UData (1) << FSize (Field)) - 1) << FShft (Field))
#define FAlnMsk(Field)	((UData (1) << FSize (Field)) - 1)
#define F1stBit(Field)	(UData (1) << FShft (Field))


/*
 * MACRO: FInsrt
 *
 * Purpose
 *    The macro "FInsrt" inserts a value into a bit field by shifting the
 *    former appropriately.
 *
 * Input
 *    Value		Bit-field value.
 *    Field		Encoded bit field (using the macro "Fld").
 *
 * Output
 *    FInsrt		Bit-field value positioned appropriately.
 */

#define FInsrt(Value, Field) \
			(UData (Value) << FShft (Field))


/*
 * MACRO: FExtr
 *
 * Purpose
 *    The macro "FExtr" extracts the value of a bit field by masking and
 *    shifting it appropriately.
 *
 * Input
 *    Data		Data containing the bit-field to be extracted.
 *    Field		Encoded bit field (using the macro "Fld").
 *
 * Output
 *    FExtr		Bit-field value.
 */

#define FExtr(Data, Field) \
			((UData (Data) >> FShft (Field)) & FAlnMsk (Field))


#endif /* __BITFIELD_H */
Commit	Line	Data
1cb8e980	1	/*
53677ef1	2	* FILE bitfield.h
1cb8e980	3	*
53677ef1 WD	4	* Version 1.1
	5	* Author Copyright (c) Marc A. Viredaz, 1998
	6	* DEC Western Research Laboratory, Palo Alto, CA
	7	* Date April 1998 (April 1997)
	8	* System Advanced RISC Machine (ARM)
1cb8e980	9	* Language C or ARM Assembly
53677ef1	10	* Purpose Definition of macros to operate on bit fields.
1cb8e980 WD	11	*/
	12
	13
1cb8e980 WD	14	#ifndef __BITFIELD_H
	15	#define __BITFIELD_H
	16
	17	#ifndef __ASSEMBLY__
	18	#define UData(Data) ((unsigned long) (Data))
	19	#else
	20	#define UData(Data) (Data)
	21	#endif
	22
	23
	24	/*
	25	* MACRO: Fld
	26	*
	27	* Purpose
	28	* The macro "Fld" encodes a bit field, given its size and its shift value
	29	* with respect to bit 0.
	30	*
	31	* Note
	32	* A more intuitive way to encode bit fields would have been to use their
	33	* mask. However, extracting size and shift value information from a bit
	34	* field's mask is cumbersome and might break the assembler (255-character
	35	* line-size limit).
	36	*
	37	* Input
53677ef1 WD	38	* Size Size of the bit field, in number of bits.
53677ef1 WD	39	* Shft Shift value of the bit field with respect to bit 0.
1cb8e980 WD	40	*
1cb8e980 WD	41	* Output
53677ef1	42	* Fld Encoded bit field.
1cb8e980 WD	43	*/
	44
	45	#define Fld(Size, Shft) (((Size) << 16) + (Shft))
	46
	47
	48	/*
	49	* MACROS: FSize, FShft, FMsk, FAlnMsk, F1stBit
	50	*
	51	* Purpose
	52	* The macros "FSize", "FShft", "FMsk", "FAlnMsk", and "F1stBit" return
	53	* the size, shift value, mask, aligned mask, and first bit of a
	54	* bit field.
	55	*
	56	* Input
53677ef1	57	* Field Encoded bit field (using the macro "Fld").
1cb8e980 WD	58	*
1cb8e980 WD	59	* Output
53677ef1 WD	60	* FSize Size of the bit field, in number of bits.
	61	* FShft Shift value of the bit field with respect to bit 0.
	62	* FMsk Mask for the bit field.
	63	* FAlnMsk Mask for the bit field, aligned on bit 0.
	64	* F1stBit First bit of the bit field.
1cb8e980 WD	65	*/
	66
	67	#define FSize(Field) ((Field) >> 16)
	68	#define FShft(Field) ((Field) & 0x0000FFFF)
	69	#define FMsk(Field) (((UData (1) << FSize (Field)) - 1) << FShft (Field))
	70	#define FAlnMsk(Field) ((UData (1) << FSize (Field)) - 1)
	71	#define F1stBit(Field) (UData (1) << FShft (Field))
	72
	73
	74	/*
	75	* MACRO: FInsrt
	76	*
	77	* Purpose
	78	* The macro "FInsrt" inserts a value into a bit field by shifting the
	79	* former appropriately.
	80	*
	81	* Input
53677ef1 WD	82	* Value Bit-field value.
53677ef1 WD	83	* Field Encoded bit field (using the macro "Fld").
1cb8e980 WD	84	*
1cb8e980 WD	85	* Output
53677ef1	86	* FInsrt Bit-field value positioned appropriately.
1cb8e980 WD	87	*/
	88
	89	#define FInsrt(Value, Field) \
8bde7f77	90	(UData (Value) << FShft (Field))
1cb8e980 WD	91
	92
	93	/*
	94	* MACRO: FExtr
	95	*
	96	* Purpose
	97	* The macro "FExtr" extracts the value of a bit field by masking and
	98	* shifting it appropriately.
	99	*
	100	* Input
53677ef1 WD	101	* Data Data containing the bit-field to be extracted.
53677ef1 WD	102	* Field Encoded bit field (using the macro "Fld").
1cb8e980 WD	103	*
1cb8e980 WD	104	* Output
53677ef1	105	* FExtr Bit-field value.
1cb8e980 WD	106	*/
	107
	108	#define FExtr(Data, Field) \
8bde7f77	109	((UData (Data) >> FShft (Field)) & FAlnMsk (Field))
1cb8e980 WD	110
	111
	112	#endif /* __BITFIELD_H */