RE: [PATCH v4 1/5] dt-bindings: aspeed-lpc: Remove LPC partitioning

[ChiaWei Wang <chiawei_wang@aspeedtech.com>]

Hi Rob,

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Tuesday, January 12, 2021 4:39 AM
> To: ChiaWei Wang <chiawei_wang@aspeedtech.com>
> cyrilbur@gmail.com; rlippert@google.com
> Subject: Re: [PATCH v4 1/5] dt-bindings: aspeed-lpc: Remove LPC partitioning
> 
> On Tue, Dec 29, 2020 at 02:31:53PM +0800, Chia-Wei, Wang wrote:
> > The LPC controller has no concept of the BMC and the Host partitions.
> > This patch fixes the documentation by removing the description on LPC
> > partitions. The register offsets illustrated in the DTS node examples
> > are also fixed to adapt to the LPC DTS change.
> >
> > Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
> > ---
> >  .../devicetree/bindings/mfd/aspeed-lpc.txt    | 99 ++++---------------
> >  1 file changed, 21 insertions(+), 78 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> > b/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> > index d0a38ba8b9ce..90eb0ecc95d1 100644
> > --- a/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> > +++ b/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> > @@ -9,13 +9,7 @@ primary use case of the Aspeed LPC controller is as a
> > slave on the bus  conditions it can also take the role of bus master.
> >
> >  The LPC controller is represented as a multi-function device to
> > account for the -mix of functionality it provides. The principle split
> > is between the register -layout at the start of the I/O space which
> > is, to quote the Aspeed datasheet, -"basically compatible with the
> > [LPC registers from the] popular BMC controller -H8S/2168[1]", and
> > everything else, where everything else is an eclectic -collection of
> > functions with a esoteric register layout. "Everything else", -here
> > labeled the "host" portion of the controller, includes, but is not
> > limited
> > -to:
> > +mix of functionality, which includes, but is not limited to:
> >
> >  * An IPMI Block Transfer[2] Controller
> >
> > @@ -44,80 +38,29 @@ Required properties  ===================
> >
> >  - compatible:	One of:
> > -		"aspeed,ast2400-lpc", "simple-mfd"
> > -		"aspeed,ast2500-lpc", "simple-mfd"
> > -		"aspeed,ast2600-lpc", "simple-mfd"
> > +		"aspeed,ast2400-lpc-v2", "simple-mfd", "syscon"
> > +		"aspeed,ast2500-lpc-v2", "simple-mfd", "syscon"
> > +		"aspeed,ast2600-lpc-v2", "simple-mfd", "syscon"
> >
> >  - reg:		contains the physical address and length values of the Aspeed
> >                  LPC memory region.
> >
> >  - #address-cells: <1>
> >  - #size-cells:	<1>
> > -- ranges: 	Maps 0 to the physical address and length of the LPC memory
> > -                region
> > -
> > -Required LPC Child nodes
> > -========================
> > -
> > -BMC Node
> > ---------
> > -
> > -- compatible:	One of:
> > -		"aspeed,ast2400-lpc-bmc"
> > -		"aspeed,ast2500-lpc-bmc"
> > -		"aspeed,ast2600-lpc-bmc"
> > -
> > -- reg:		contains the physical address and length values of the
> > -                H8S/2168-compatible LPC controller memory region
> > -
> > -Host Node
> > ----------
> > -
> > -- compatible:   One of:
> > -		"aspeed,ast2400-lpc-host", "simple-mfd", "syscon"
> > -		"aspeed,ast2500-lpc-host", "simple-mfd", "syscon"
> > -		"aspeed,ast2600-lpc-host", "simple-mfd", "syscon"
> > -
> > -- reg:		contains the address and length values of the host-related
> > -                register space for the Aspeed LPC controller
> > -
> > -- #address-cells: <1>
> > -- #size-cells:	<1>
> > -- ranges: 	Maps 0 to the address and length of the host-related LPC
> memory
> > +- ranges:	Maps 0 to the physical address and length of the LPC memory
> >                  region
> >
> >  Example:
> >
> >  lpc: lpc@1e789000 {
> > -	compatible = "aspeed,ast2500-lpc", "simple-mfd";
> > +	compatible = "aspeed,ast2500-lpc-v2", "simple-mfd", "syscon";
> >  	reg = <0x1e789000 0x1000>;
> >
> >  	#address-cells = <1>;
> >  	#size-cells = <1>;
> >  	ranges = <0x0 0x1e789000 0x1000>;
> 
> No child nodes? Then you don't need 'ranges', '#size-cells', nor '#address-cells'.
> 
There are child nodes in LPC, should I list all of them or just few for the example?

Chiawei

> > -
> > -	lpc_bmc: lpc-bmc@0 {
> > -		compatible = "aspeed,ast2500-lpc-bmc";
> > -		reg = <0x0 0x80>;
> > -	};
> > -
> > -	lpc_host: lpc-host@80 {
> > -		compatible = "aspeed,ast2500-lpc-host", "simple-mfd", "syscon";
> > -		reg = <0x80 0x1e0>;
> > -		reg-io-width = <4>;
> > -
> > -		#address-cells = <1>;
> > -		#size-cells = <1>;
> > -		ranges = <0x0 0x80 0x1e0>;
> > -	};
> >  };
> >
> > -BMC Node Children
> > -==================
> > -
> > -
> > -Host Node Children
> > -==================
> >
> >  LPC Host Interface Controller
> >  -------------------
> > @@ -149,14 +92,12 @@ Optional properties:
> >
> >  Example:
> >
> > -lpc-host@80 {
> > -	lpc_ctrl: lpc-ctrl@0 {
> > -		compatible = "aspeed,ast2500-lpc-ctrl";
> > -		reg = <0x0 0x80>;
> > -		clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
> > -		memory-region = <&flash_memory>;
> > -		flash = <&spi>;
> > -	};
> > +lpc_ctrl: lpc-ctrl@80 {
> > +	compatible = "aspeed,ast2500-lpc-ctrl";
> > +	reg = <0x80 0x80>;
> > +	clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
> > +	memory-region = <&flash_memory>;
> > +	flash = <&spi>;
> >  };
> >
> >  LPC Host Controller
> > @@ -179,9 +120,9 @@ Required properties:
> >
> >  Example:
> >
> > -lhc: lhc@20 {
> > +lhc: lhc@a0 {
> >  	compatible = "aspeed,ast2500-lhc";
> > -	reg = <0x20 0x24 0x48 0x8>;
> > +	reg = <0xa0 0x24 0xc8 0x8>;
> >  };
> >
> >  LPC reset control
> > @@ -192,16 +133,18 @@ state of the LPC bus. Some systems may chose to
> modify this configuration.
> >
> >  Required properties:
> >
> > - - compatible:		"aspeed,ast2600-lpc-reset" or
> > -			"aspeed,ast2500-lpc-reset"
> > -			"aspeed,ast2400-lpc-reset"
> > + - compatible:		One of:
> > +			"aspeed,ast2600-lpc-reset";
> > +			"aspeed,ast2500-lpc-reset";
> > +			"aspeed,ast2400-lpc-reset";
> > +
> >   - reg:			offset and length of the IP in the LHC memory region
> >   - #reset-controller	indicates the number of reset cells expected
> >
> >  Example:
> >
> > -lpc_reset: reset-controller@18 {
> > +lpc_reset: reset-controller@98 {
> >          compatible = "aspeed,ast2500-lpc-reset";
> > -        reg = <0x18 0x4>;
> > +        reg = <0x98 0x4>;
> >          #reset-cells = <1>;
> >  };
> > --
> > 2.17.1
> >