Re: [PATCH 1/3] ARM: imx: clk-vf610: fix SAI clock tree

[Shawn Guo <shawnguo@kernel.org>]

On Sat, Oct 17, 2015 at 09:05:20PM -0700, Stefan Agner wrote:
> The Synchronous Audio Interface (SAI) instances are clocked by
> independent clocks: The bus clock and the audio clock (as shown in
> Figure 51-1 in the Vybrid Reference Manual). The clock gates in
> CCGR0/CCGR1 for SAI0 through SAI3 are bus clock gates, as access
> tests to the registers with/without gating those clocks have shown.
> The audio clock is gated by the SAIx_EN gates in CCM_CSCDR1,
> followed by a clock divider (SAIx_DIV). Currently, the parent of
> the bus clock gates has been assigned to SAIx_DIV, which is not
> involved in the bus clock path for the SAI instances (see chapter
> 9.10.12, SAI clocking in the Vybrid Reference Manual).
> 
> Fix this by define the parent clock of VF610_CLK_SAIx to be the bus
> clock.
> 
> If the driver needs the audio clock (when used in master mode), a
> fixed device tree is required which assign the audio clock properly
> to VF610_CLK_SAIx_DIV.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
> Hi all,
> 
> Patch 1 and 2 are actual fixes and should be applied toghether. If
> the clock tree changes are applied only, master mode won't work
> anymore. With only the device tree changes applied, it probably
> will still work but the VF610_CLK_SAIx_DIV will be enabled twice.

Though I'm not happy about that the new kernel will break old DTBs which
is actually buggy, I do not see other way around to get it fixed.  So I
have no objections.

> 
> Since Patch 3 also uses the fixed clock layout, it should be
> applied after the clock tree fix too...
> 
> Not sure through which tree these changes should go?

Mike, Stephen,

Can I have your ACK on patch #1 so that I can send it together with 
#2 for v4.4-rc inclusion?

Shawn

> 
> --
> Stefan
> 
>  drivers/clk/imx/clk-vf610.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-vf610.c b/drivers/clk/imx/clk-vf610.c
> index bff45ea..42a7a23 100644
> --- a/drivers/clk/imx/clk-vf610.c
> +++ b/drivers/clk/imx/clk-vf610.c
> @@ -335,22 +335,22 @@ static void __init vf610_clocks_init(struct device_node *ccm_node)
>  	clk[VF610_CLK_SAI0_SEL] = imx_clk_mux("sai0_sel", CCM_CSCMR1, 0, 2, sai_sels, 4);
>  	clk[VF610_CLK_SAI0_EN] = imx_clk_gate("sai0_en", "sai0_sel", CCM_CSCDR1, 16);
>  	clk[VF610_CLK_SAI0_DIV] = imx_clk_divider("sai0_div", "sai0_en", CCM_CSCDR1, 0, 4);
> -	clk[VF610_CLK_SAI0] = imx_clk_gate2("sai0", "sai0_div", CCM_CCGR0, CCM_CCGRx_CGn(15));
> +	clk[VF610_CLK_SAI0] = imx_clk_gate2("sai0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(15));
>  
>  	clk[VF610_CLK_SAI1_SEL] = imx_clk_mux("sai1_sel", CCM_CSCMR1, 2, 2, sai_sels, 4);
>  	clk[VF610_CLK_SAI1_EN] = imx_clk_gate("sai1_en", "sai1_sel", CCM_CSCDR1, 17);
>  	clk[VF610_CLK_SAI1_DIV] = imx_clk_divider("sai1_div", "sai1_en", CCM_CSCDR1, 4, 4);
> -	clk[VF610_CLK_SAI1] = imx_clk_gate2("sai1", "sai1_div", CCM_CCGR1, CCM_CCGRx_CGn(0));
> +	clk[VF610_CLK_SAI1] = imx_clk_gate2("sai1", "ipg_bus", CCM_CCGR1, CCM_CCGRx_CGn(0));
>  
>  	clk[VF610_CLK_SAI2_SEL] = imx_clk_mux("sai2_sel", CCM_CSCMR1, 4, 2, sai_sels, 4);
>  	clk[VF610_CLK_SAI2_EN] = imx_clk_gate("sai2_en", "sai2_sel", CCM_CSCDR1, 18);
>  	clk[VF610_CLK_SAI2_DIV] = imx_clk_divider("sai2_div", "sai2_en", CCM_CSCDR1, 8, 4);
> -	clk[VF610_CLK_SAI2] = imx_clk_gate2("sai2", "sai2_div", CCM_CCGR1, CCM_CCGRx_CGn(1));
> +	clk[VF610_CLK_SAI2] = imx_clk_gate2("sai2", "ipg_bus", CCM_CCGR1, CCM_CCGRx_CGn(1));
>  
>  	clk[VF610_CLK_SAI3_SEL] = imx_clk_mux("sai3_sel", CCM_CSCMR1, 6, 2, sai_sels, 4);
>  	clk[VF610_CLK_SAI3_EN] = imx_clk_gate("sai3_en", "sai3_sel", CCM_CSCDR1, 19);
>  	clk[VF610_CLK_SAI3_DIV] = imx_clk_divider("sai3_div", "sai3_en", CCM_CSCDR1, 12, 4);
> -	clk[VF610_CLK_SAI3] = imx_clk_gate2("sai3", "sai3_div", CCM_CCGR1, CCM_CCGRx_CGn(2));
> +	clk[VF610_CLK_SAI3] = imx_clk_gate2("sai3", "ipg_bus", CCM_CCGR1, CCM_CCGRx_CGn(2));
>  
>  	clk[VF610_CLK_NFC_SEL] = imx_clk_mux("nfc_sel", CCM_CSCMR1, 12, 2, nfc_sels, 4);
>  	clk[VF610_CLK_NFC_EN] = imx_clk_gate("nfc_en", "nfc_sel", CCM_CSCDR2, 9);
> -- 
> 2.6.1
>