Re: [linux-sunxi] [PATCH v4 4/5] ARM: sunxi: h3/h5: switch apb0-related clocks to r_ccu

[icenowy]

å 2017-07-20 10:03ïicenowy@xxxxxxx åéï
> å 2017-07-20 06:59ïOndÅej Jirman åéï
> > Hi,
> >
> > Icenowy Zheng pÃÅe v Ãt 04. 04. 2017 v 17:50 +0800:
> > > From: Icenowy Zheng <icenowy@xxxxxxxx>
> > >
> > > Now we have driver for the PRCM CCU, switch to use it instead of
> > > old-style clock nodes for apb0-related clocks in sunxi-h3-h5.dtsi .
> > >
> > > The mux 3 of R_CCU is still the internal oscillator, which is said to 
> > > be
> > > 16MHz plus minus 30%, and get a measured value of 15MHz~16MHz on my 
> > > two
> > > H3 boards and one H5 board.
> >
> > There's issue with the new r_ccu that breaks r_i2c. (no devices can be
> > found on the bus). Reverting this patch fixes the issue with the I2C
> > controller. (everything else being the same)
> >
> > Here's the code I'm using: 
> > https://github.com/megous/linux/commits/oran
> > ge-pi-4.12
> >
> > The last commit is the revert.
> >
> > The issue manifests itself by non-working DVFS, because kernel lacks
> > access to SY8106A regulator, because r_i2c doesn't work with sunxi-ng
> > clock driver (sun8i-r).
> >
> > Relevant difference in registers between working/non-working state is
> > just this (diff -u):
> >
> >  0x01f02400 = 0x00000000
> >  0x01f02404 = 0x00000000
> > -0x01f02408 = 0x00000091
> > +0x01f02408 = 0x00000095 DATA register inisde the I2C controller
> >  0x01f0240c = 0x00000044
> >  0x01f02410 = 0x000000f8
> > -0x01f02414 = 0x00000059
> > +0x01f02414 = 0x00000000 CLOCK setup register inside the I2C 
> > controller
> >  0x01f02418 = 0x00000000
> >  0x01f0241c = 0x00000000
> >  0x01f02420 = 0x0000003a
> >
> > It looks like the new sunxi-ng clock driver causes the I2C driver to
> > not correctly configure the CLOCK register. I don't know why and I'm
> > not sure how to deal with this. Any ideas what can I do next?
> >
> > thank you and regards,
> >   o.
>
> It seems to be a very very very weird problem -- the CPUS_CFG register
> seems to be not accessible in non-secure mode on H3, and if the r_ccu
> driver reads it a value of 0x0 is read out (which means that the parent
> of ar100 is osc32k), but the real initial value of the register is
> 0x00010000 (which means the parent is osc24M).
>
> So the bus clock of r_i2c is wrongly claimed as 32kHz, not 24MHz, then
> the r_i2c fails to work.
>
> This clock problem doesn't exist for A64.

H5 doesn't have this issue either.

> > > Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx>
> > > ---
> > > Changes in v4:
> > > - Temporarily dropped the CCU headers.
> > > Changes in v3:
> > > - Change osc32000 to iosc.
> > >
> > >  arch/arm/boot/dts/sunxi-h3-h5.dtsi | 45 
> > > ++++++++++++--------------------------
> > >  1 file changed, 14 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/arch/arm/boot/dts/sunxi-h3-h5.dtsi 
> > > b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> > > index 6640ebfa6419..1aeeacb3a884 100644
> > > --- a/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> > > +++ b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> > > @@ -68,31 +68,12 @@
> > >  			clock-output-names = "osc32k";
> > >  		};
> > >
> > > -		apb0: apb0_clk {
> > > -			compatible = "fixed-factor-clock";
> > > +		iosc: internal-osc-clk {
> > >  			#clock-cells = <0>;
> > > -			clock-div = <1>;
> > > -			clock-mult = <1>;
> > > -			clocks = <&osc24M>;
> > > -			clock-output-names = "apb0";
> > > -		};
> > > -
> > > -		apb0_gates: clk@01f01428 {
> > > -			compatible = "allwinner,sun8i-h3-apb0-gates-clk",
> > > -				     "allwinner,sun4i-a10-gates-clk";
> > > -			reg = <0x01f01428 0x4>;
> > > -			#clock-cells = <1>;
> > > -			clocks = <&apb0>;
> > > -			clock-indices = <0>, <1>;
> > > -			clock-output-names = "apb0_pio", "apb0_ir";
> > > -		};
> > > -
> > > -		ir_clk: ir_clk@01f01454 {
> > > -			compatible = "allwinner,sun4i-a10-mod0-clk";
> > > -			reg = <0x01f01454 0x4>;
> > > -			#clock-cells = <0>;
> > > -			clocks = <&osc32k>, <&osc24M>;
> > > -			clock-output-names = "ir";
> > > +			compatible = "fixed-clock";
> > > +			clock-frequency = <16000000>;
> > > +			clock-accuracy = <300000000>;
> > > +			clock-output-names = "iosc";
> > >  		};
> > >  	};
> > >
> > > @@ -576,9 +557,12 @@
> > >  				     <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>;
> > >  		};
> > >
> > > -		apb0_reset: reset@01f014b0 {
> > > -			reg = <0x01f014b0 0x4>;
> > > -			compatible = "allwinner,sun6i-a31-clock-reset";
> > > +		r_ccu: clock@1f01400 {
> > > +			compatible = "allwinner,sun50i-a64-r-ccu";
> > > +			reg = <0x01f01400 0x100>;
> > > +			clocks = <&osc24M>, <&osc32k>, <&iosc>;
> > > +			clock-names = "hosc", "losc", "iosc";
> > > +			#clock-cells = <1>;
> > >  			#reset-cells = <1>;
> > >  		};
> > >
> > > @@ -589,9 +573,9 @@
> > >
> > >  		ir: ir@01f02000 {
> > >  			compatible = "allwinner,sun5i-a13-ir";
> > > -			clocks = <&apb0_gates 1>, <&ir_clk>;
> > > +			clocks = <&r_ccu 4>, <&r_ccu 11>;
> > >  			clock-names = "apb", "ir";
> > > -			resets = <&apb0_reset 1>;
> > > +			resets = <&r_ccu 0>;
> > >  			interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
> > >  			reg = <0x01f02000 0x40>;
> > >  			status = "disabled";
> > > @@ -601,9 +585,8 @@
> > >  			compatible = "allwinner,sun8i-h3-r-pinctrl";
> > >  			reg = <0x01f02c00 0x400>;
> > >  			interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
> > > -			clocks = <&apb0_gates 0>, <&osc24M>, <&osc32k>;
> > > +			clocks = <&r_ccu 3>, <&osc24M>, <&osc32k>;
> > >  			clock-names = "apb", "hosc", "losc";
> > > -			resets = <&apb0_reset 0>;
> > >  			gpio-controller;
> > >  			#gpio-cells = <3>;
> > >  			interrupt-controller;
> > > --
> > > 2.12.2
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