Searched hist:de2a3eaea552f2d562fae46bd495eb83298a1b3c (Results 1 – 1 of 1) sorted by relevance
| /openbmc/linux/drivers/nvmem/ |
| H A D | sunxi_sid.c | diff de2a3eaea552f2d562fae46bd495eb83298a1b3c Sat Apr 13 05:32:50 CDT 2019 Chen-Yu Tsai <wens@csie.org> nvmem: sunxi_sid: Optimize register read-out method
SID cells are 32-bit aligned, and a multiple of 32 bits in length. The
only outlier is the thermal sensor calibration data, which is 16 bits
per sensor. However a whole 64 bits is allocated for this purpose, so
we could consider it conforming to the rule above.
Also, the register read-out method assumes native endian, unlike the
direct MMIO method, which assumes big endian. Thus no endian conversion
is involved.
Under these assumptions, the register read-out method can be slightly
optimized. Instead of reading one word then discarding 3 bytes, read
the whole word directly into the buffer. However, for reads under 4
bytes or trailing bytes, we still use a scratch buffer to extract the
requested bytes.
We could go one step further if .word_size was 4, but changing that
would affect the sysfs interface's behavior.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|