On Thu, Apr 22, 2021 at 02:16:53PM -0300, Ezequiel Garcia wrote: > (Adding Kever) > > Hi Benjamin, > > Thanks a lot for working on this, it looks amazing. Together with the great > work > that Rockchip is doing, it seems RK3566/RK3568 will have decent support very > soon. > > One comment here: > > On Thu, 2021-04-22 at 16:15 +0200, Benjamin Gaignard wrote: > > Convert Rockchip IOMMU to DT schema > > > > Signed-off-by: Benjamin Gaignard <benjamin.gaign...@collabora.com> > > --- > > version 2: > > - Change maintainer > > - Change reg maxItems > > - Change interrupt maxItems > > > > .../bindings/iommu/rockchip,iommu.txt | 38 --------- > > .../bindings/iommu/rockchip,iommu.yaml | 79 +++++++++++++++++++ > > 2 files changed, 79 insertions(+), 38 deletions(-) > > delete mode 100644 > > Documentation/devicetree/bindings/iommu/rockchip,iommu.txt > > create mode 100644 > > Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml > > > > diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt > > b/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt > > deleted file mode 100644 > > index 6ecefea1c6f9..000000000000 > > --- a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt > > +++ /dev/null > > @@ -1,38 +0,0 @@ > > -Rockchip IOMMU > > -============== > > - > > -A Rockchip DRM iommu translates io virtual addresses to physical addresses > > for > > -its master device. Each slave device is bound to a single master device, > > and > > -shares its clocks, power domain and irq. > > - > > -Required properties: > > -- compatible : Should be "rockchip,iommu" > > -- reg : Address space for the configuration registers > > -- interrupts : Interrupt specifier for the IOMMU instance > > -- interrupt-names : Interrupt name for the IOMMU instance > > -- #iommu-cells : Should be <0>. This indicates the iommu is a > > - "single-master" device, and needs no additional > > information > > - to associate with its master device. See: > > - Documentation/devicetree/bindings/iommu/iommu.txt > > -- clocks : A list of clocks required for the IOMMU to be > > accessible by > > - the host CPU. > > -- clock-names : Should contain the following: > > - "iface" - Main peripheral bus clock (PCLK/HCL) (required) > > - "aclk" - AXI bus clock (required) > > - > > -Optional properties: > > -- rockchip,disable-mmu-reset : Don't use the mmu reset operation. > > - Some mmu instances may produce unexpected > > results > > - when the reset operation is used. > > - > > -Example: > > - > > - vopl_mmu: iommu@ff940300 { > > - compatible = "rockchip,iommu"; > > - reg = <0xff940300 0x100>; > > - interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>; > > - interrupt-names = "vopl_mmu"; > > - clocks = <&cru ACLK_VOP1>, <&cru HCLK_VOP1>; > > - clock-names = "aclk", "iface"; > > - #iommu-cells = <0>; > > - }; > > diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml > > b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml > > new file mode 100644 > > index 000000000000..0db208cf724a > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml > > @@ -0,0 +1,79 @@ > > +# SPDX-License-Identifier: GPL-2.0-only > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/iommu/rockchip,iommu.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Rockchip IOMMU > > + > > +maintainers: > > + - Heiko Stuebner <he...@sntech.de> > > + > > +description: |+ > > + A Rockchip DRM iommu translates io virtual addresses to physical > > addresses for > > + its master device. Each slave device is bound to a single master device > > and > > + shares its clocks, power domain and irq. > > + > > + For information on assigning IOMMU controller to its peripheral devices, > > + see generic IOMMU bindings. > > + > > +properties: > > + compatible: > > + const: rockchip,iommu > > + > > + reg: > > + minItems: 1 > > + maxItems: 2 > > + > > + interrupts: > > + minItems: 1 > > + maxItems: 2 > > + > > + interrupt-names: > > + minItems: 1 > > + maxItems: 2 > > + > > AFAICS, the driver supports handling multiple MMUs, and there's one reg and > interrupt cell for each MMU. IOW, there's no requirement that maxItems is 2. > > Is there any way we can describe that? Or maybe just allow a bigger maximum?
With #iommu-cells == 0, how would one distinguish which IOMMU is associated with a device? IOW, is more that 1 really usable? If you need more just pick a maxItems value that's either the most seen or 'should be enough'TM. If the entries are just multiple instances of the same thing, please note that here. Rob _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu