| Message ID | 1455571020-18968-2-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
Hi Geert, Thank you for the patch. On Monday 15 February 2016 22:16:50 Geert Uytterhoeven wrote: > The Renesas R-Car System Controller provides power management for the > CPU cores and various coprocessors, following the generic PM domain > bindings in Documentation/devicetree/bindings/power/power_domain.txt. > > This supports R-Car Gen1, Gen2, and Gen3. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > Alternatives I considered: > > - Using a single node per power register block, even if it contains > multiple domains, e.g.: > > pd_ca15_scu: ca15_scu@180 { > reg = <0x180 0x20>; > #address-cells = <1>; > #size-cells = <0>; > #power-domain-cells = <0>; > renesas,interrupt-bits = <12>; > > pd_ca15_cpu: ca15_cpu@40 { > reg = <0x40 0x20>; > #power-domain-cells = <1>; > renesas,pm-domain-indices = <0 1>; > renesas,pm-domain-names = > "ca15_cpu0", "ca15_cpu1"; > renesas,interrupt-bits = <0 1>; > }; > }; > > Notes: > - You cannot just have a property with the number of domains, as > index 0 is not used on R-Car H1. Hence the need for > "renesas,pm-domain-indices" and "renesas,interrupt-bits", > - "#power-domain-cells = <1>" for nodes with multiple domains, > which allows typos in "power-domains = <&pd_ca15_cpu n>", using > an invalid value of "n". > > - Using a linear description in DT: > - Needs parent links for subdomains, > - More complicated to parse (lesson learned from R-Mobile PM > Domain support). > > - Keeping the power register block offset and the bit number as separate > "reg" cells, increasing "#address-cells" from 2 to 3, > > - Merging the interrupt bit (which needs only 5 bits) in the other "reg" > cell, decreasing "#address-cells" from 2 to 1. > > v2: > - Add R-Car H3 (r8a7795) support, > - Use "renesas,<type>-sysc" instead of "renesas,sysc-<type>", > - Add fallback compatibility strings for R-Car Gen2 and Gen3. > --- > .../bindings/power/renesas,sysc-rcar.txt | 87 +++++++++++++++++++ > 1 file changed, 87 insertions(+) create mode 100644 > Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > > diff --git a/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt new file > mode 100644 > index 0000000000000000..92ddc0da7b755215 > --- /dev/null > +++ b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > @@ -0,0 +1,87 @@ > +DT bindings for the Renesas R-Car System Controller > + > +== System Controller Node == > + > +The R-Car System Controller provides power management for the CPU cores and > +various coprocessors. > + > +Required properties: > + - compatible: Must contain one or more of the following: > + - "renesas,r8a7779-sysc" (R-Car H1) > + - "renesas,r8a7790-sysc" (R-Car H2) > + - "renesas,r8a7791-sysc" (R-Car M2-W) > + - "renesas,r8a7792-sysc" (R-Car V2H) > + - "renesas,r8a7793-sysc" (R-Car M2-N) > + - "renesas,r8a7794-sysc" (R-Car E2) > + - "renesas,r8a7795-sysc" (R-Car H3) > + - "renesas,rcar-gen2-sysc" (Generic R-Car Gen2) > + - "renesas,rcar-gen3-sysc" (Generic R-Car Gen3) > + When compatible with the generic version, nodes must list the > SoC-specific > + version corresponding to the platform first, followed by the generic > + version. > + - reg: Address start and address range for the device. This isn't correct. I'll refrain from saying we abuse the reg property, as using the first cell as a power domain number should be fine (the second cell feels a bit more of an abuse to me though, but I won't complain too much), but the bindings document should describe what the reg cells contain. > + - pm-domains: This node contains a hierarchy of PM Domain Nodes. Can't it be an issue that the node happens to have the same name as the standard pm-domains property ? > + Dependencies (e.g. parent SCUs should not be powered off while child > CPUs > + are on) should be reflected using subnodes. > + > + > +== PM Domain Nodes == > + > +Each of the PM domain nodes represents a PM domain, as documented by the > +generic PM domain bindings in > +Documentation/devicetree/bindings/power/power_domain.txt. > + > +Required properties: > + - #power-domain-cells: Must be 0. > + - reg: This property must contain 2 values: > + - The first value is the number of the interrupt bit representing > + the power area in the various Interrupt Registers (e.g. SYSCISR, > + Interrupt Status Register), > + - The second value encodes the power register block offset (which is > + a multiple of 64), and the number of the bit representing the > + power area in the various Power Control Registers (e.g. PWROFFSR, > + Power Shutoff Status Register). This value is created by ORing > + these two numbers. > + The parent's node must contain the following two properties: > + - #address-cells: Must be 2, > + - #size-cells: Must be 0. > + > + > +Example: > + > + sysc: system-controller@e6180000 { > + compatible = "renesas,r8a7791-sysc", "renesas,rcar-gen2-sysc"; > + reg = <0 0xe6180000 0 0x0200>; > + > + pm-domains { > + #address-cells = <2>; > + #size-cells = <0>; > + > + pd_ca15_scu: scu@12 { > + reg = <12 0x180>; > + #address-cells = <2>; > + #size-cells = <0>; > + #power-domain-cells = <0>; > + > + pd_ca15_cpu0: cpu@0 { > + reg = <0 0x40>; > + #power-domain-cells = <0>; > + }; > + > + pd_ca15_cpu1: cpu@1 { > + reg = <1 0x41>; > + #power-domain-cells = <0>; > + }; > + }; > + > + pd_sh: sh@16 { > + reg = <16 0x80>; > + #power-domain-cells = <0>; > + }; > + > + pd_sgx: sgx@20 { > + reg = <20 0xc0>; > + #power-domain-cells = <0>; > + }; > + }; > + };
On Tuesday 16 February 2016 01:08:18 Laurent Pinchart wrote: > On Monday 15 February 2016 22:16:50 Geert Uytterhoeven wrote: > > The Renesas R-Car System Controller provides power management for the > > CPU cores and various coprocessors, following the generic PM domain > > bindings in Documentation/devicetree/bindings/power/power_domain.txt. > > > > This supports R-Car Gen1, Gen2, and Gen3. > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > --- [snip] > > > > .../bindings/power/renesas,sysc-rcar.txt | 87 +++++++++++++++++ > > 1 file changed, 87 insertions(+) create mode 100644 > > > > Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > > > > diff --git a/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > > b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt new file > > mode 100644 > > index 0000000000000000..92ddc0da7b755215 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > > @@ -0,0 +1,87 @@ [snip] > > + - pm-domains: This node contains a hierarchy of PM Domain Nodes. > > Can't it be an issue that the node happens to have the same name as the > standard pm-domains property ? Scratch this, it's power-domains, not pm-domains, mybad. > > + Dependencies (e.g. parent SCUs should not be powered off while child > > CPUs > > + are on) should be reflected using subnodes.
Hi Laurent, On Tue, Feb 16, 2016 at 12:08 AM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt >> @@ -0,0 +1,87 @@ >> +DT bindings for the Renesas R-Car System Controller >> + >> +== System Controller Node == >> + >> +The R-Car System Controller provides power management for the CPU cores and >> +various coprocessors. >> + >> +Required properties: >> + - compatible: Must contain one or more of the following: >> + - "renesas,r8a7779-sysc" (R-Car H1) >> + - "renesas,r8a7790-sysc" (R-Car H2) >> + - "renesas,r8a7791-sysc" (R-Car M2-W) >> + - "renesas,r8a7792-sysc" (R-Car V2H) >> + - "renesas,r8a7793-sysc" (R-Car M2-N) >> + - "renesas,r8a7794-sysc" (R-Car E2) >> + - "renesas,r8a7795-sysc" (R-Car H3) >> + - "renesas,rcar-gen2-sysc" (Generic R-Car Gen2) >> + - "renesas,rcar-gen3-sysc" (Generic R-Car Gen3) >> + When compatible with the generic version, nodes must list the >> SoC-specific >> + version corresponding to the platform first, followed by the generic >> + version. >> + - reg: Address start and address range for the device. You're quoting the description of the "reg" property for the SYSC device node... > This isn't correct. I'll refrain from saying we abuse the reg property, as > using the first cell as a power domain number should be fine (the second cell > feels a bit more of an abuse to me though, but I won't complain too much), but > the bindings document should describe what the reg cells contain. ... while the two cell format is for the PM domain nodes, not for the SYSC device node. Please check the other "reg" description. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Feb 15, 2016 at 10:16:50PM +0100, Geert Uytterhoeven wrote: > The Renesas R-Car System Controller provides power management for the > CPU cores and various coprocessors, following the generic PM domain > bindings in Documentation/devicetree/bindings/power/power_domain.txt. > > This supports R-Car Gen1, Gen2, and Gen3. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > Alternatives I considered: > > - Using a single node per power register block, even if it contains > multiple domains, e.g.: > > pd_ca15_scu: ca15_scu@180 { > reg = <0x180 0x20>; > #address-cells = <1>; > #size-cells = <0>; > #power-domain-cells = <0>; > renesas,interrupt-bits = <12>; > > pd_ca15_cpu: ca15_cpu@40 { > reg = <0x40 0x20>; > #power-domain-cells = <1>; > renesas,pm-domain-indices = <0 1>; > renesas,pm-domain-names = > "ca15_cpu0", "ca15_cpu1"; > renesas,interrupt-bits = <0 1>; > }; > }; > > Notes: > - You cannot just have a property with the number of domains, as > index 0 is not used on R-Car H1. Hence the need for > "renesas,pm-domain-indices" and "renesas,interrupt-bits", > - "#power-domain-cells = <1>" for nodes with multiple domains, > which allows typos in "power-domains = <&pd_ca15_cpu n>", using > an invalid value of "n". > > - Using a linear description in DT: > - Needs parent links for subdomains, > - More complicated to parse (lesson learned from R-Mobile PM > Domain support). > > - Keeping the power register block offset and the bit number as separate > "reg" cells, increasing "#address-cells" from 2 to 3, > > - Merging the interrupt bit (which needs only 5 bits) in the other "reg" > cell, decreasing "#address-cells" from 2 to 1. I think I'd move to not encoding mulitple things into reg. This seems like a bit of abuse of reg. Otherwise, I don't have much to comment on. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Rob, On Thu, Feb 18, 2016 at 3:38 PM, Rob Herring <robh@kernel.org> wrote: > On Mon, Feb 15, 2016 at 10:16:50PM +0100, Geert Uytterhoeven wrote: >> The Renesas R-Car System Controller provides power management for the >> CPU cores and various coprocessors, following the generic PM domain >> bindings in Documentation/devicetree/bindings/power/power_domain.txt. >> >> This supports R-Car Gen1, Gen2, and Gen3. >> >> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> >> --- >> Alternatives I considered: >> >> - Using a single node per power register block, even if it contains >> multiple domains, e.g.: >> >> pd_ca15_scu: ca15_scu@180 { >> reg = <0x180 0x20>; >> #address-cells = <1>; >> #size-cells = <0>; >> #power-domain-cells = <0>; >> renesas,interrupt-bits = <12>; >> >> pd_ca15_cpu: ca15_cpu@40 { >> reg = <0x40 0x20>; >> #power-domain-cells = <1>; >> renesas,pm-domain-indices = <0 1>; >> renesas,pm-domain-names = >> "ca15_cpu0", "ca15_cpu1"; >> renesas,interrupt-bits = <0 1>; >> }; >> }; >> >> Notes: >> - You cannot just have a property with the number of domains, as >> index 0 is not used on R-Car H1. Hence the need for >> "renesas,pm-domain-indices" and "renesas,interrupt-bits", >> - "#power-domain-cells = <1>" for nodes with multiple domains, >> which allows typos in "power-domains = <&pd_ca15_cpu n>", using >> an invalid value of "n". >> >> - Using a linear description in DT: >> - Needs parent links for subdomains, >> - More complicated to parse (lesson learned from R-Mobile PM >> Domain support). >> >> - Keeping the power register block offset and the bit number as separate >> "reg" cells, increasing "#address-cells" from 2 to 3, >> >> - Merging the interrupt bit (which needs only 5 bits) in the other "reg" >> cell, decreasing "#address-cells" from 2 to 1. > > I think I'd move to not encoding mulitple things into reg. This seems > like a bit of abuse of reg. Otherwise, I don't have much to comment on. Thanks! (quoting the encoding of the reg properties) > +== PM Domain Nodes == > + > +Each of the PM domain nodes represents a PM domain, as documented by the > +generic PM domain bindings in > +Documentation/devicetree/bindings/power/power_domain.txt. > + > +Required properties: > + - #power-domain-cells: Must be 0. > + - reg: This property must contain 2 values: > + - The first value is the number of the interrupt bit representing > + the power area in the various Interrupt Registers (e.g. SYSCISR, > + Interrupt Status Register), > + - The second value encodes the power register block offset (which is > + a multiple of 64), and the number of the bit representing the > + power area in the various Power Control Registers (e.g. PWROFFSR, > + Power Shutoff Status Register). This value is created by ORing > + these two numbers. Not encoding multiple things into reg means adding more properties to provide that information, iff we want to describe the PM Domain Nodes in DT. I considered the reg property a two-dimensional address space. Taking the lessons from CCF and the new CPG/MSSR bindings into account (which was BTW designed after the SYSC DT bindings), perhaps the PM Domain hierarchy should be moved from DT to C, in the driver, too? That would mean we have in DT: 1) "#power-domain-cells = <1>" 2) defines for the various domains, e.g. "#define R8A7791_PD_CA15_SCU 12" 3) e.g. "power-domains = <&sysc R8A7791_PD_CA15_SCU>" 4) and we can get rid of the fallback compatibility strings again. Thoughts? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Geert, On Thursday 18 February 2016 18:18:56 Geert Uytterhoeven wrote: > On Thu, Feb 18, 2016 at 3:38 PM, Rob Herring <robh@kernel.org> wrote: > > On Mon, Feb 15, 2016 at 10:16:50PM +0100, Geert Uytterhoeven wrote: > >> The Renesas R-Car System Controller provides power management for the > >> CPU cores and various coprocessors, following the generic PM domain > >> bindings in Documentation/devicetree/bindings/power/power_domain.txt. > >> > >> This supports R-Car Gen1, Gen2, and Gen3. > >> > >> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > >> --- > >> > >> Alternatives I considered: > >> - Using a single node per power register block, even if it contains > >> multiple domains, e.g.: > >> pd_ca15_scu: ca15_scu@180 { > >> reg = <0x180 0x20>; > >> #address-cells = <1>; > >> #size-cells = <0>; > >> #power-domain-cells = <0>; > >> renesas,interrupt-bits = <12>; > >> > >> pd_ca15_cpu: ca15_cpu@40 { > >> reg = <0x40 0x20>; > >> #power-domain-cells = <1>; > >> renesas,pm-domain-indices = <0 1>; > >> renesas,pm-domain-names = > >> "ca15_cpu0", "ca15_cpu1"; > >> renesas,interrupt-bits = <0 1>; > >> }; > >> }; > >> > >> Notes: > >> - You cannot just have a property with the number of domains, as > >> index 0 is not used on R-Car H1. Hence the need for > >> "renesas,pm-domain-indices" and "renesas,interrupt-bits", > >> - "#power-domain-cells = <1>" for nodes with multiple domains, > >> which allows typos in "power-domains = <&pd_ca15_cpu n>", using > >> an invalid value of "n". > >> > >> - Using a linear description in DT: > >> - Needs parent links for subdomains, > >> - More complicated to parse (lesson learned from R-Mobile PM > >> Domain support). > >> > >> - Keeping the power register block offset and the bit number as > >> separate > >> "reg" cells, increasing "#address-cells" from 2 to 3, > >> > >> - Merging the interrupt bit (which needs only 5 bits) in the other > >> "reg" > >> cell, decreasing "#address-cells" from 2 to 1. > > > > I think I'd move to not encoding mulitple things into reg. This seems > > like a bit of abuse of reg. Otherwise, I don't have much to comment on. > > Thanks! > > (quoting the encoding of the reg properties) > > > +== PM Domain Nodes == > > + > > +Each of the PM domain nodes represents a PM domain, as documented by the > > +generic PM domain bindings in > > +Documentation/devicetree/bindings/power/power_domain.txt. > > + > > +Required properties: > > + - #power-domain-cells: Must be 0. > > + - reg: This property must contain 2 values: > > + - The first value is the number of the interrupt bit > > representing > > + the power area in the various Interrupt Registers (e.g. > > SYSCISR, > > + Interrupt Status Register), > > + - The second value encodes the power register block offset > > (which is > > + a multiple of 64), and the number of the bit representing the > > + power area in the various Power Control Registers (e.g. > > PWROFFSR, > > + Power Shutoff Status Register). This value is created by > > ORing > > + these two numbers. > > Not encoding multiple things into reg means adding more properties to > provide that information, iff we want to describe the PM Domain Nodes in > DT. I considered the reg property a two-dimensional address space. > > Taking the lessons from CCF and the new CPG/MSSR bindings into account > (which was BTW designed after the SYSC DT bindings), perhaps the PM Domain > hierarchy should be moved from DT to C, in the driver, too? > > That would mean we have in DT: > 1) "#power-domain-cells = <1>" > 2) defines for the various domains, e.g. "#define R8A7791_PD_CA15_SCU > 12" > 3) e.g. "power-domains = <&sysc R8A7791_PD_CA15_SCU>" > 4) and we can get rid of the fallback compatibility strings again. > > Thoughts? That simplifies DT and will give more flexibility to handle all the weird details in C code, so I like it. Additionally the amount of per-SoC data related to power domains is pretty limited, so we shouldn't have a size issue, even for multi-platform kernels. The removal of DT parsing code might even make the kernel smaller. The only driver I'm concerned about when it comes to per-SoC data size is the PFC driver.
On Thu, Feb 18, 2016 at 06:18:56PM +0100, Geert Uytterhoeven wrote: > Hi Rob, > > On Thu, Feb 18, 2016 at 3:38 PM, Rob Herring <robh@kernel.org> wrote: > > On Mon, Feb 15, 2016 at 10:16:50PM +0100, Geert Uytterhoeven wrote: > >> The Renesas R-Car System Controller provides power management for the > >> CPU cores and various coprocessors, following the generic PM domain > >> bindings in Documentation/devicetree/bindings/power/power_domain.txt. > >> > >> This supports R-Car Gen1, Gen2, and Gen3. > >> > >> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > >> --- > >> - Keeping the power register block offset and the bit number as separate > >> "reg" cells, increasing "#address-cells" from 2 to 3, > >> > >> - Merging the interrupt bit (which needs only 5 bits) in the other "reg" > >> cell, decreasing "#address-cells" from 2 to 1. > > > > I think I'd move to not encoding mulitple things into reg. This seems > > like a bit of abuse of reg. Otherwise, I don't have much to comment on. > > Thanks! > > (quoting the encoding of the reg properties) > > +== PM Domain Nodes == > > + > > +Each of the PM domain nodes represents a PM domain, as documented by the > > +generic PM domain bindings in > > +Documentation/devicetree/bindings/power/power_domain.txt. > > + > > +Required properties: > > + - #power-domain-cells: Must be 0. > > + - reg: This property must contain 2 values: > > + - The first value is the number of the interrupt bit representing > > + the power area in the various Interrupt Registers (e.g. SYSCISR, > > + Interrupt Status Register), > > + - The second value encodes the power register block offset (which is > > + a multiple of 64), and the number of the bit representing the > > + power area in the various Power Control Registers (e.g. PWROFFSR, > > + Power Shutoff Status Register). This value is created by ORing > > + these two numbers. > > Not encoding multiple things into reg means adding more properties to provide > that information, iff we want to describe the PM Domain Nodes in DT. > I considered the reg property a two-dimensional address space. > > Taking the lessons from CCF and the new CPG/MSSR bindings into account > (which was BTW designed after the SYSC DT bindings), perhaps the PM Domain > hierarchy should be moved from DT to C, in the driver, too? > > That would mean we have in DT: > 1) "#power-domain-cells = <1>" > 2) defines for the various domains, e.g. "#define R8A7791_PD_CA15_SCU 12" > 3) e.g. "power-domains = <&sysc R8A7791_PD_CA15_SCU>" > 4) and we can get rid of the fallback compatibility strings again. > > Thoughts? Seems fine to me. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt new file mode 100644 index 0000000000000000..92ddc0da7b755215 --- /dev/null +++ b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt @@ -0,0 +1,87 @@ +DT bindings for the Renesas R-Car System Controller + +== System Controller Node == + +The R-Car System Controller provides power management for the CPU cores and +various coprocessors. + +Required properties: + - compatible: Must contain one or more of the following: + - "renesas,r8a7779-sysc" (R-Car H1) + - "renesas,r8a7790-sysc" (R-Car H2) + - "renesas,r8a7791-sysc" (R-Car M2-W) + - "renesas,r8a7792-sysc" (R-Car V2H) + - "renesas,r8a7793-sysc" (R-Car M2-N) + - "renesas,r8a7794-sysc" (R-Car E2) + - "renesas,r8a7795-sysc" (R-Car H3) + - "renesas,rcar-gen2-sysc" (Generic R-Car Gen2) + - "renesas,rcar-gen3-sysc" (Generic R-Car Gen3) + When compatible with the generic version, nodes must list the SoC-specific + version corresponding to the platform first, followed by the generic + version. + - reg: Address start and address range for the device. + - pm-domains: This node contains a hierarchy of PM Domain Nodes. + Dependencies (e.g. parent SCUs should not be powered off while child CPUs + are on) should be reflected using subnodes. + + +== PM Domain Nodes == + +Each of the PM domain nodes represents a PM domain, as documented by the +generic PM domain bindings in +Documentation/devicetree/bindings/power/power_domain.txt. + +Required properties: + - #power-domain-cells: Must be 0. + - reg: This property must contain 2 values: + - The first value is the number of the interrupt bit representing + the power area in the various Interrupt Registers (e.g. SYSCISR, + Interrupt Status Register), + - The second value encodes the power register block offset (which is + a multiple of 64), and the number of the bit representing the + power area in the various Power Control Registers (e.g. PWROFFSR, + Power Shutoff Status Register). This value is created by ORing + these two numbers. + The parent's node must contain the following two properties: + - #address-cells: Must be 2, + - #size-cells: Must be 0. + + +Example: + + sysc: system-controller@e6180000 { + compatible = "renesas,r8a7791-sysc", "renesas,rcar-gen2-sysc"; + reg = <0 0xe6180000 0 0x0200>; + + pm-domains { + #address-cells = <2>; + #size-cells = <0>; + + pd_ca15_scu: scu@12 { + reg = <12 0x180>; + #address-cells = <2>; + #size-cells = <0>; + #power-domain-cells = <0>; + + pd_ca15_cpu0: cpu@0 { + reg = <0 0x40>; + #power-domain-cells = <0>; + }; + + pd_ca15_cpu1: cpu@1 { + reg = <1 0x41>; + #power-domain-cells = <0>; + }; + }; + + pd_sh: sh@16 { + reg = <16 0x80>; + #power-domain-cells = <0>; + }; + + pd_sgx: sgx@20 { + reg = <20 0xc0>; + #power-domain-cells = <0>; + }; + }; + };
The Renesas R-Car System Controller provides power management for the CPU cores and various coprocessors, following the generic PM domain bindings in Documentation/devicetree/bindings/power/power_domain.txt. This supports R-Car Gen1, Gen2, and Gen3. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Alternatives I considered: - Using a single node per power register block, even if it contains multiple domains, e.g.: pd_ca15_scu: ca15_scu@180 { reg = <0x180 0x20>; #address-cells = <1>; #size-cells = <0>; #power-domain-cells = <0>; renesas,interrupt-bits = <12>; pd_ca15_cpu: ca15_cpu@40 { reg = <0x40 0x20>; #power-domain-cells = <1>; renesas,pm-domain-indices = <0 1>; renesas,pm-domain-names = "ca15_cpu0", "ca15_cpu1"; renesas,interrupt-bits = <0 1>; }; }; Notes: - You cannot just have a property with the number of domains, as index 0 is not used on R-Car H1. Hence the need for "renesas,pm-domain-indices" and "renesas,interrupt-bits", - "#power-domain-cells = <1>" for nodes with multiple domains, which allows typos in "power-domains = <&pd_ca15_cpu n>", using an invalid value of "n". - Using a linear description in DT: - Needs parent links for subdomains, - More complicated to parse (lesson learned from R-Mobile PM Domain support). - Keeping the power register block offset and the bit number as separate "reg" cells, increasing "#address-cells" from 2 to 3, - Merging the interrupt bit (which needs only 5 bits) in the other "reg" cell, decreasing "#address-cells" from 2 to 1. v2: - Add R-Car H3 (r8a7795) support, - Use "renesas,<type>-sysc" instead of "renesas,sysc-<type>", - Add fallback compatibility strings for R-Car Gen2 and Gen3. --- .../bindings/power/renesas,sysc-rcar.txt | 87 ++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt