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


> Signed-off-by: Jianqun <jay.xu@rock-chips.com>
> ---
> 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?


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,



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