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- /*
- * Copyright 2013 Broadcom Corporation.
- *
- * SPDX-License-Identifier: GPL-2.0+
- */
- /*
- * Bitfield operations
- *
- * These are generic bitfield operations which allow manipulation of variable
- * width bitfields within a word. One use of this would be to use data tables
- * to determine how to reprogram fields within R/W hardware registers.
- *
- * Example:
- *
- * old_reg_val
- * +--------+----+---+--+-----+----------+
- * | | | | | old | |
- * +--------+----+---+--+-----+----------+
- *
- * new_reg_val
- * +--------+----+---+--+-----+----------+
- * | | | | | new | |
- * +--------+----+---+--+-----+----------+
- *
- * mask = bitfield_mask(10, 5);
- * old = bitfield_extract(old_reg_val, 10, 5);
- * new_reg_val = bitfield_replace(old_reg_val, 10, 5, new);
- *
- * The numbers 10 and 5 could for example come from data
- * tables which describe all bitfields in all registers.
- */
- #include <linux/types.h>
- /* Produces a mask of set bits covering a range of a uint value */
- static inline uint bitfield_mask(uint shift, uint width)
- {
- return ((1 << width) - 1) << shift;
- }
- /* Extract the value of a bitfield found within a given register value */
- static inline uint bitfield_extract(uint reg_val, uint shift, uint width)
- {
- return (reg_val & bitfield_mask(shift, width)) >> shift;
- }
- /*
- * Replace the value of a bitfield found within a given register value
- * Returns the newly modified uint value with the replaced field.
- */
- static inline uint bitfield_replace(uint reg_val, uint shift, uint width,
- uint bitfield_val)
- {
- uint mask = bitfield_mask(shift, width);
- return (reg_val & ~mask) | (bitfield_val << shift);
- }
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