Those are especially useful with hardware device registers.
They behave the same way as their Linux equivalent, with a much
simpler implementation for now.
Example:
#define REG_FIELD_A GENMASK(6, 0)
#define REG_FIELD_B BIT(7)
#define REG_FIELD_C GENMASK(15, 8)
#define REG_FIELD_D GENMASK(31, 16)
Get:
a = FIELD_GET(REG_FIELD_A, reg);
b = FIELD_GET(REG_FIELD_B, reg);
Set:
reg = FIELD_PREP(REG_FIELD_A, 1) |
FIELD_PREP(REG_FIELD_B, 0) |
FIELD_PREP(REG_FIELD_C, c) |
FIELD_PREP(REG_FIELD_D, 0x40);
Modify:
reg &= ~REG_FIELD_C;
reg |= FIELD_PREP(REG_FIELD_C, c);
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
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