Re: [PATCH] clk: rockchip: rk3288: i2s_frac adds flag to set parent's rate

From: Jianqun
Date: Sun Oct 12 2014 - 20:33:20 EST



å 10/12/2014 02:54 AM, Heiko StÃbner åé:
> Hi Jianqun,
>
> Am Dienstag, 30. September 2014, 11:12:04 schrieb Jianqun:
>> The relation of i2s nodes as follows:
>> i2s_src 0 0 594000000 0
>> i2s_frac 0 0 11289600 0
>> i2s_pre 0 0 11289600 0
>> sclk_i2s0 0 0 11289600 0
>> i2s0_clkout 0 0 11289600 0
>> hclk_i2s0 1 1 99000000 0
>>
>> sclk_i2s0 is the master clock, when to set rate of sclk_i2s0, should
>> allow to set its parent's rate, by add flag CLK_SET_RATE_PARENT for
>> "i2s_frac", "i2s_pre", "i2s0_clkout" and "sclk_i2s0".
>>
>> Tested on rk3288 board using max98090, with command "aplay <music.wav>"
>>
>> Change-Id: I12faad082566532b65a7de8c0a6845e1c17870e6
> Please no "Change-Id"s in upstream patches.
ok
>
>
>> Signed-off-by: Jianqun <jay.xu@xxxxxxxxxxxxxx>
>> ---
>> drivers/clk/rockchip/clk-rk3288.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/clk/rockchip/clk-rk3288.c
>> b/drivers/clk/rockchip/clk-rk3288.c index c770de0..baf19b4 100644
>> --- a/drivers/clk/rockchip/clk-rk3288.c
>> +++ b/drivers/clk/rockchip/clk-rk3288.c
>> @@ -301,15 +301,15 @@ static struct rockchip_clk_branch
>> rk3288_clk_branches[] __initdata = { COMPOSITE(0, "i2s_src",
>> mux_pll_src_cpll_gpll_p, 0,
>> RK3288_CLKSEL_CON(4), 15, 1, MFLAGS, 0, 7, DFLAGS,
>> RK3288_CLKGATE_CON(4), 1, GFLAGS),
>> - COMPOSITE_FRAC(0, "i2s_frac", "i2s_src", 0,
>> + COMPOSITE_FRAC(0, "i2s_frac", "i2s_src", CLK_SET_RATE_PARENT,
>> RK3288_CLKSEL_CON(8), 0,
>> RK3288_CLKGATE_CON(4), 2, GFLAGS),
>> - MUX(0, "i2s_pre", mux_i2s_pre_p, 0,
>> + MUX(0, "i2s_pre", mux_i2s_pre_p, CLK_SET_RATE_PARENT,
>> RK3288_CLKSEL_CON(4), 8, 2, MFLAGS),
>> - COMPOSITE_NODIV(0, "i2s0_clkout", mux_i2s_clkout_p, 0,
>> + COMPOSITE_NODIV(0, "i2s0_clkout", mux_i2s_clkout_p, CLK_SET_RATE_PARENT,
> are you sure it is correct that i2s0_clkout should also be able to set the
> core i2s clock?
>
> I.e. as it is now, the i2s controller could set one frequency through
> sclk_i2s0 and whatever uses i2s0_clkout would be able to set it to something
> completely different, which may call for trouble.
>
> So in my mind, it might be better to limit i2s0_clkout to select between its
> two parent without being able influence the core i2s clock?
ok, you are right, here is the new clock tree with your suggestion, when play music
i2s_src 1 1 594000000 0
i2s_frac 1 1 11289600 0
i2s_pre 1 1 11289600 0
sclk_i2s0 1 1 11289600 0
i2s0_clkout 0 0 11289600 0
hclk_i2s0 1 1 148500000 0

I'll make an patch v2 soon
>
> Heiko
>
>
>> RK3288_CLKSEL_CON(4), 12, 1, MFLAGS,
>> RK3288_CLKGATE_CON(4), 0, GFLAGS),
>> - GATE(SCLK_I2S0, "sclk_i2s0", "i2s_pre", 0,
>> + GATE(SCLK_I2S0, "sclk_i2s0", "i2s_pre", CLK_SET_RATE_PARENT,
>> RK3288_CLKGATE_CON(4), 3, GFLAGS),
>>
>> MUX(0, "spdif_src", mux_pll_src_cpll_gpll_p, 0,
>
>
>

--
Jianqun Xu

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