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>
This commit is contained in:
Axel Lin 2013-06-28 14:45:06 +08:00 committed by Sonic Zhang
parent 2ced773a1a
commit 9868b14263

View File

@ -247,7 +247,7 @@ static struct {
static void portmux_setup(unsigned short per)
{
u16 y, offset, muxreg;
u16 y, offset, muxreg, mask;
u16 function = P_FUNCT2MUX(per);
for (y = 0; y < ARRAY_SIZE(port_mux_lut); y++) {
@ -258,12 +258,13 @@ static void portmux_setup(unsigned short per)
offset = port_mux_lut[y].offset;
muxreg = bfin_read_PORT_MUX();
if (offset != 1)
muxreg &= ~(1 << offset);
if (offset == 1)
mask = 3;
else
muxreg &= ~(3 << 1);
mask = 1;
muxreg |= (function << offset);
muxreg &= ~(mask << offset);
muxreg |= ((function & mask) << offset);
bfin_write_PORT_MUX(muxreg);
}
}