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author | Anson Huang <b20788@freescale.com> | 2016-06-08 17:33:31 +0300 |
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committer | Shawn Guo <shawnguo@kernel.org> | 2016-06-12 14:25:38 +0300 |
commit | ba7f4f557eb67ee21c979c8539dc1886f5d5341c (patch) | |
tree | 48739eaba18d4f0c57bf1dcc8b4aa13d9ec28382 /arch | |
parent | 1a695a905c18548062509178b98bc91e67510864 (diff) | |
download | linux-ba7f4f557eb67ee21c979c8539dc1886f5d5341c.tar.xz |
clk: imx: correct AV PLL rate formula
The audio/video PLL's rate calculation is as below in RM:
Fref * (DIV_SELECT + NUM / DENOM), in origin clk-pllv3's
code, below code is used:
(parent_rate * div) + ((parent_rate / mfd) * mfn
as it does NOT consider the float data using div, so below
formula should be used as a decent method:
(parent_rate * div) + ((parent_rate * mfn) / mfd)
and we also need to consider parent_rate * mfd may overflow
a 32 bit value, 64 bit value should be used.
After updating this formula, the dram PLL's rate is
1066MHz, which is correct, while the old formula gets
1056MHz.
[Aisheng: fix clk_pllv3_av_round_rate too]
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions