diff options
Diffstat (limited to 'src/include/superio/hwm5_conf.h')
| -rw-r--r-- | src/include/superio/hwm5_conf.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/include/superio/hwm5_conf.h b/src/include/superio/hwm5_conf.h index 2cf13c60e6..f26a0171f5 100644 --- a/src/include/superio/hwm5_conf.h +++ b/src/include/superio/hwm5_conf.h @@ -45,4 +45,32 @@ static inline void pnp_write_hwm5_index(u16 base, u8 reg, u8 value) pnp_write_index(base + 5, reg, value); } +/* + * void pnp_unset_and_set_hwm5_index(u16 base, u8 reg, u8 unset, u8 set) + * Description: + * This routine unsets and sets bits from indexed I/O registers. The + * reg byte is written to the index register at I/O address = base + 5. + * The value byte to update is data register at I/O address = base + 6. + * + * Unlike and-then-or style operations, no bitwise negation is necessary + * to specify the bits to unset. Because the bitwise negation implicitly + * promotes operands to int before operating, one may have to explicitly + * downcast the result if the data width is smaller than that of an int. + * Since warnings are errors in coreboot, explicit casting is necessary. + * + * Performing said negation inside this routine alleviates this problem, + * while allowing the compiler to warn if the input parameters overflow. + * Casting outside this function would silence valid compiler warnings. + * + * Parameters: + * @param[in] u16 base = The address of the base index register. + * @param[in] u8 reg = The offset within the indexed space. + * @param[in] u8 unset = Bitmask with ones to the bits to unset from the data register. + * @param[in] u8 set = Bitmask with ones to the bits to set from the data register. + */ +static inline void pnp_unset_and_set_hwm5_index(u16 base, u8 reg, u8 unset, u8 set) +{ + pnp_unset_and_set_index(base + 5, reg, unset, set); +} + #endif /* DEVICE_PNP_HWM5_CONF_H */ |