From 9ca41bccc39f5ebbbb515dfadb2e0f912168c8bd Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Mon, 4 Jun 2012 14:51:32 +0200 Subject: [PATCH] ARM i.MX pllv2: make round_rate accurate in round_rate we made the assumption that we can set arbitrary frequencies and thus returned the input rate. This is not correct, for certain frequencies after setting a frequency with set_rate, recalc_rate will return different values. To fix this, introduce set_rate/recalc_rate functions which work on variables instead of registers directly. This way we can call these in round_rate to get the exact rate which we would get if we call set_rate with this value. Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/clk-pllv2.c | 78 ++++++++++++++++++++++++----------- 1 file changed, 54 insertions(+), 24 deletions(-) diff --git a/arch/arm/mach-imx/clk-pllv2.c b/arch/arm/mach-imx/clk-pllv2.c index 1b0307195a6..0440379e362 100644 --- a/arch/arm/mach-imx/clk-pllv2.c +++ b/arch/arm/mach-imx/clk-pllv2.c @@ -74,24 +74,15 @@ struct clk_pllv2 { void __iomem *base; }; -static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, - unsigned long parent_rate) +static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate, + u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn) { long mfi, mfn, mfd, pdf, ref_clk, mfn_abs; - unsigned long dp_op, dp_mfd, dp_mfn, dp_ctl, dbl; - void __iomem *pllbase; + unsigned long dbl; s64 temp; - struct clk_pllv2 *pll = to_clk_pllv2(hw); - - pllbase = pll->base; - dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN; - dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP); - dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD); - dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN); - pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK; mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET; mfi = (mfi <= 5) ? 5 : mfi; @@ -117,18 +108,30 @@ static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, return temp; } -static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, +static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { + u32 dp_op, dp_mfd, dp_mfn, dp_ctl; + void __iomem *pllbase; struct clk_pllv2 *pll = to_clk_pllv2(hw); + + pllbase = pll->base; + + dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); + dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP); + dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD); + dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN); + + return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn); +} + +static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate, + u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn) +{ u32 reg; - void __iomem *pllbase; long mfi, pdf, mfn, mfd = 999999; s64 temp64; unsigned long quad_parent_rate; - unsigned long dp_ctl; - - pllbase = pll->base; quad_parent_rate = 4 * parent_rate; pdf = mfi = -1; @@ -138,18 +141,41 @@ static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, return -EINVAL; pdf--; - temp64 = rate * (pdf+1) - quad_parent_rate * mfi; - do_div(temp64, quad_parent_rate/1000000); + temp64 = rate * (pdf + 1) - quad_parent_rate * mfi; + do_div(temp64, quad_parent_rate / 1000000); mfn = (long)temp64; + reg = mfi << 4 | pdf; + + *dp_op = reg; + *dp_mfd = mfd; + *dp_mfn = mfn; + + return 0; +} + +static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_pllv2 *pll = to_clk_pllv2(hw); + void __iomem *pllbase; + u32 dp_ctl, dp_op, dp_mfd, dp_mfn; + int ret; + + pllbase = pll->base; + + + ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn); + if (ret) + return ret; + dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); /* use dpdck0_2 */ __raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL); - reg = mfi << 4 | pdf; - __raw_writel(reg, pllbase + MXC_PLL_DP_OP); - __raw_writel(mfd, pllbase + MXC_PLL_DP_MFD); - __raw_writel(mfn, pllbase + MXC_PLL_DP_MFN); + __raw_writel(dp_op, pllbase + MXC_PLL_DP_OP); + __raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD); + __raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN); return 0; } @@ -157,7 +183,11 @@ static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, static long clk_pllv2_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { - return rate; + u32 dp_op, dp_mfd, dp_mfn; + + __clk_pllv2_set_rate(rate, *prate, &dp_op, &dp_mfd, &dp_mfn); + return __clk_pllv2_recalc_rate(*prate, MXC_PLL_DP_CTL_DPDCK0_2_EN, + dp_op, dp_mfd, dp_mfn); } static int clk_pllv2_prepare(struct clk_hw *hw) -- 2.20.1