From 063578dc5f407f67d149133818efabe457daafda Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 5 Sep 2017 11:32:40 +0200 Subject: [PATCH] clk: axi-clkgen: Correctly handle nocount bit in recalc_rate() If the nocount bit is set the divider is bypassed and the settings for the divider count should be ignored and a divider value of 1 should be assumed. Handle this correctly in the driver recalc_rate() callback. While the driver sets up the part so that the read back dividers values yield the correct result the power-on reset settings of the part might not reflect this and hence calling e.g. clk_get_rate() without prior calls to clk_set_rate() will yield the wrong result. Signed-off-by: Lars-Peter Clausen Signed-off-by: Stephen Boyd --- drivers/clk/clk-axi-clkgen.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c index 5e918e7..95a6e98 100644 --- a/drivers/clk/clk-axi-clkgen.c +++ b/drivers/clk/clk-axi-clkgen.c @@ -40,6 +40,10 @@ #define MMCM_REG_FILTER1 0x4e #define MMCM_REG_FILTER2 0x4f +#define MMCM_CLKOUT_NOCOUNT BIT(6) + +#define MMCM_CLK_DIV_NOCOUNT BIT(12) + struct axi_clkgen { void __iomem *base; struct clk_hw clk_hw; @@ -315,12 +319,27 @@ static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw, unsigned int reg; unsigned long long tmp; - axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); - dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_2, ®); + if (reg & MMCM_CLKOUT_NOCOUNT) { + dout = 1; + } else { + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); + dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); + } + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, ®); - d = (reg & 0x3f) + ((reg >> 6) & 0x3f); - axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); - m = (reg & 0x3f) + ((reg >> 6) & 0x3f); + if (reg & MMCM_CLK_DIV_NOCOUNT) + d = 1; + else + d = (reg & 0x3f) + ((reg >> 6) & 0x3f); + + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB2, ®); + if (reg & MMCM_CLKOUT_NOCOUNT) { + m = 1; + } else { + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); + m = (reg & 0x3f) + ((reg >> 6) & 0x3f); + } if (d == 0 || dout == 0) return 0; -- 2.7.4