From: Stephen Warren swarren@nvidia.com
This programming sequence is correct per Jimmy Zhang, and makes sense too!
Signed-off-by: Stephen Warren swarren@nvidia.com --- v2: New patch, split out from the later Tegra124 changes. --- arch/arm/cpu/arm720t/tegra-common/cpu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/arm/cpu/arm720t/tegra-common/cpu.c b/arch/arm/cpu/arm720t/tegra-common/cpu.c index 03f67b163cc5..322ce10d6fe3 100644 --- a/arch/arm/cpu/arm720t/tegra-common/cpu.c +++ b/arch/arm/cpu/arm720t/tegra-common/cpu.c @@ -144,18 +144,23 @@ int pllx_set_rate(struct clk_pll_simple *pll , u32 divn, u32 divm, reg |= (1 << PLL_DCCON_SHIFT); writel(reg, &pll->pll_misc);
- /* Enable PLLX */ - reg = readl(&pll->pll_base); - reg |= PLL_ENABLE_MASK; - /* Disable BYPASS */ + reg = readl(&pll->pll_base); reg &= ~PLL_BYPASS_MASK; writel(reg, &pll->pll_base); + debug("pllx_set_rate: base = 0x%08X\n", reg);
/* Set lock_enable to PLLX_MISC */ reg = readl(&pll->pll_misc); reg |= PLL_LOCK_ENABLE_MASK; writel(reg, &pll->pll_misc); + debug("pllx_set_rate: misc = 0x%08X\n", reg); + + /* Enable PLLX last, once it's all configured */ + reg = readl(&pll->pll_base); + reg |= PLL_ENABLE_MASK; + writel(reg, &pll->pll_base); + debug("pllx_set_rate: base final = 0x%08X\n", reg);
return 0; }