> Subject: Re: [PATCH v2 2/2] ARM: dts: Append clock bindings for sai2 on VF610 > platform > > Hi Shawn, > > Thanks for the comments, but... > > On Wed, Apr 02, 2014 at 09:03:04PM +0800, Shawn Guo wrote: > > On Wed, Apr 02, 2014 at 06:10:20PM +0800, Nicolin Chen wrote: > > > Since we added fours clock to the DT binding, we should update the current > > > SAI dts/dtsi so as not to break their functions. > > > > > > Signed-off-by: Nicolin Chen <Guangyu.Chen@xxxxxxxxxxxxx> > > > --- > > > arch/arm/boot/dts/vf610.dtsi | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/arm/boot/dts/vf610.dtsi b/arch/arm/boot/dts/vf610.dtsi > > > index d31ce1b..9fd0007 100644 > > > --- a/arch/arm/boot/dts/vf610.dtsi > > > +++ b/arch/arm/boot/dts/vf610.dtsi > > > @@ -139,8 +139,10 @@ > > > compatible = "fsl,vf610-sai"; > > > reg = <0x40031000 0x1000>; > > > interrupts = <0 86 0x04>; > > > - clocks = <&clks VF610_CLK_SAI2>; > > > - clock-names = "sai"; > > > + clocks = <&clks VF610_CLK_SAI2>, > > > + <&clks VF610_CLK_SAI2>, > > > + <&clks 0>, <&clks 0>; > > > > So it seems that SAI on vf610 does work with only one clock. So the > > driver change will break old DTB for vf610? If that's case, we will > > have to need a new compatible for cases where 4 clocks are needed. > > According to Vybrid's RM Chapter 9.11.12 SAI clocking, the SoC actually > connects SAI with two clocks: SAI_CLK and Platform Bus Clock. So the DT > binding here still needs to be corrected even if ignoring driver change. > > Besides, I've checked both SAI on imx and vf610 and found that they are > seemly identical, especially for the clock part -- "The transmitter and > receiver can independently select between the bus clock and up to three > audio master clocks to generate the bit clock." And the driver that was > designed for vf610 already contains the code to switch the clock between > Bus Clock and Three MCLKs. What I want to say is, even if SAI on vf610 > does work with only one clock, it still doesn't have the full function > on vf610 -- driving clock from Platform Bus Clock unless we make this > improvement to the DT binding. > > So I think it's fair to complete the code here for both platforms, even > though we might take the risk of merging conflict. And I understand > your point to avoid function break on those platform both of us aren't > convenient to test. But I've already involved Xiubo in the list. And > we can wait for his test result. > This has been test on my Vybird-TWR board and it's fine. Thanks, Brs Xiubo > Hope you can understand the circumstance, > Nicolin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
