Commit 9ca41bcc authored by Sascha Hauer's avatar Sascha Hauer
Browse files

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: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent 6cc90d6d

arch/arm/mach-imx/clk-pllv2.c

+54 −24
Original line number Diff line number Diff line
@@ -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;
@@ -142,14 +145,37 @@ static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, 
	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)

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