On Sun 27 Sep 2009 04:56, Cai, Cliff pondered:
> >-----Original Message-----
> >From: Robin Getz [mailto:[email protected]]
[snip] - thanks for the feedback.
> >> +/* PLL settings coefficients, add more here... */ static
> >const struct
> >> +_pll_settings pll_settings[] = {
> >> + /* 96k */
> >> + /* {12288000, 96000, 0, 0, 0x0, 0x8, 0x0}, */
> >> + /* 88.2k */
> >> + /* {12288000, 88200, 20, 7, 0x0, 0x7, 0x1}, */
> >> + /* 48k */
> >> + {12288000, 48000, 0, 0, 0x0, 0x4, 0x0},
> >> + /* 44.1k */
> >> + {12288000, 44100, 40, 27, 0x0, 0x3, 0x1},
> >> + {11289600, 44100, 0, 0, 0x0, 0x4, 0x0},
> >> + /* 22.050k */
> >> + {12288000, 22050, 40, 27, 0x1, 0x3, 0x1},
> >> + {11289600, 22050, 0, 0, 0x0, 0x2, 0x0},
> >> + /* 8k */
> >> + /* {12288000, 8000, 3, 2, 0x3, 0x2, 0x1}, */
> >> +
> >> +};
> >
> >Don't these need to be calculated - as they depend on the
> >crystal input?
> >
>
> The rates commented can't be got through PLL
> Currently,and Yao Wei said he will check it with me once he is free.
I wasn't concerned about the commented out versions - my comment was that the
pll_settings[] are used to directly write into the codec (in
adau1371_hw_params() ).
struct _pll_settings {
u32 mclk;
u32 rate;
u16 n; /* N and M registers are inverted on REVB */
u16 m;
u8 input_div:2;
u8 integer:4;
u8 type:1;
The value for 48k:
{12288000, 48000, 0, 0, 0x0, 0x4, 0x0}
mclk changes depending on what CLKIN (clk) is - doesn't it?
It appears that in:
../blackfin/bf5xx-adau1371.c:bf5xx_adau1371_hw_params it does:
/* Change input crystal source here */
unsigned int clk = 12288000;
snd_soc_dai_set_sysclk(codec_dai, 0, clk, 0);
which is:
dai->ops->set_sysclk(codec_dai, 0, clk, 0);
which is (based on the fops)
adau1371_set_dai_sysclk(codec_dai, 0, clk, 0);
which sets adau1371->sysclk
which is used in adau1371_hw_params():
get_coeff(adau1371->sysclk, params_rate(params));
so, rather than calculate things based on the sysclk at run time, it is doing
a lookup on static/pre-calculated values....???
doesn't n and m need to be determined at run time?
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