RADEON_PPLL_REF_DIV_MASK
p1pll->reference_div = tmp & RADEON_PPLL_REF_DIV_MASK;
pll_ref_div & RADEON_PPLL_REF_DIV_MASK,
if ((pll_ref_div == (RREG32_PLL(RADEON_PPLL_REF_DIV) & RADEON_PPLL_REF_DIV_MASK)) &&
~RADEON_PPLL_REF_DIV_MASK);