tree efbdc234058f9534633c840c00db8129f77b02d4
parent d341267955cf6e99101cc25312432e0b65cc11b8
author Axel Lin <axel.lin@ingics.com> 1372401906 +0800
committer Sonic Zhang <sonic.zhang@analog.com> 1375260963 +0800

blackfin: gpio: Use proper mask for comparing function

The function return from P_FUNCT2MUX(per) takes 2 bits, however
for BF537_FAMILY with offset != 1 the function is 1 bit.

Also has small refactor for better readability.
In portmux_setup(), it looks odd having "muxreg &= ~(3 << 1);"
while in current code we do muxreg |= (function << offset);.

Signed-off-by: Axel Lin <axel.lin@ingics.com>