drivers/net/wireless/ralink/rt2x00/rt2x00reg.h

Source file repositories/reference/linux-study-clean/drivers/net/wireless/ralink/rt2x00/rt2x00reg.h

File Facts

System
Linux kernel
Corpus path
drivers/net/wireless/ralink/rt2x00/rt2x00reg.h
Extension
.h
Size
5659 bytes
Lines
267
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct rt2x00_field8 {
	u8 bit_offset;
	u8 bit_mask;
};

struct rt2x00_field16 {
	u16 bit_offset;
	u16 bit_mask;
};

struct rt2x00_field32 {
	u32 bit_offset;
	u32 bit_mask;
};

/*
 * Power of two check, this will check
 * if the mask that has been given contains and contiguous set of bits.
 * Note that we cannot use the is_power_of_2() function since this
 * check must be done at compile-time.
 */
#define is_power_of_two(x)	( !((x) & ((x)-1)) )
#define low_bit_mask(x)		( ((x)-1) & ~(x) )
#define is_valid_mask(x)	is_power_of_two(1LU + (x) + low_bit_mask(x))

/*
 * Macros to find first set bit in a variable.
 * These macros behave the same as the __ffs() functions but
 * the most important difference that this is done during
 * compile-time rather then run-time.
 */
#define compile_ffs2(__x) \
	__builtin_choose_expr(((__x) & 0x1), 0, 1)

#define compile_ffs4(__x) \
	__builtin_choose_expr(((__x) & 0x3), \
			      (compile_ffs2((__x))), \
			      (compile_ffs2((__x) >> 2) + 2))

#define compile_ffs8(__x) \
	__builtin_choose_expr(((__x) & 0xf), \
			      (compile_ffs4((__x))), \
			      (compile_ffs4((__x) >> 4) + 4))

#define compile_ffs16(__x) \
	__builtin_choose_expr(((__x) & 0xff), \
			      (compile_ffs8((__x))), \
			      (compile_ffs8((__x) >> 8) + 8))

#define compile_ffs32(__x) \
	__builtin_choose_expr(((__x) & 0xffff), \
			      (compile_ffs16((__x))), \
			      (compile_ffs16((__x) >> 16) + 16))

/*
 * This macro will check the requirements for the FIELD{8,16,32} macros
 * The mask should be a constant non-zero contiguous set of bits which
 * does not exceed the given typelimit.
 */
#define FIELD_CHECK(__mask, __type)			\
	BUILD_BUG_ON(!(__mask) ||			\
		     !is_valid_mask(__mask) ||		\
		     (__mask) != (__type)(__mask))	\

#define FIELD8(__mask)				\
({						\
	FIELD_CHECK(__mask, u8);		\
	(struct rt2x00_field8) {		\
		compile_ffs8(__mask), (__mask)	\
	};					\
})

#define FIELD16(__mask)				\
({						\
	FIELD_CHECK(__mask, u16);		\
	(struct rt2x00_field16) {		\
		compile_ffs16(__mask), (__mask)	\
	};					\
})

#define FIELD32(__mask)				\
({						\
	FIELD_CHECK(__mask, u32);		\
	(struct rt2x00_field32) {		\
		compile_ffs32(__mask), (__mask)	\
	};					\
})

#define SET_FIELD(__reg, __type, __field, __value)\
({						\

Annotation

Implementation Notes