Re: [PATCH v6, 00/15] Using component framework to support multi hardware decode

["yunfei.dong@mediatek.com" <yunfei.dong@mediatek.com>]

Hi Ezequiel,

On Fri, 2021-09-03 at 11:08 +0800, yunfei.dong@mediatek.com wrote:
> Hi Ezequiel,
> 
> Thanks for your suggestion.
> On Thu, 2021-09-02 at 13:30 -0300, Ezequiel Garcia wrote:
> > On Wed, 1 Sept 2021 at 05:32, Yunfei Dong <yunfei.dong@mediatek.com
> > >
> > wrote:
> > > 
> > > This series adds support for multi hardware decode into mtk-
> > > vcodec, 
> > > by first
> > > adding component framework to manage each hardware information:
> > > interrupt,
> > > clock, register bases and power. Secondly add core thread to deal
> > > with core
> > > hardware message, at the same time, add msg queue for different
> > > hardware
> > > share messages. Lastly, the architecture of different specs are
> > > not
> > > the same,
> > > using specs type to separate them.
> > > 
> > > This series has been tested with both MT8183 and MT8173. Decoding
> > > was working
> > > for both chips.
> > > 
> > > Patches 1~3 rewrite get register bases and power on/off
> > > interface.
> > > 
> > > Patch 4 add component framework to support multi hardware.
> > > 
> > > Patch 5 separate video encoder and decoder document
> > > 
> > > Patches 6-15 add interfaces to support core hardware.
> > > ----
> > > This patch dependents on : "media: mtk-vcodec: support for MT8183
> > > decoder"[1] and
> > > "Mediatek MT8192 clock support"[2].
> > > 
> > > 1: Multi hardware decode is based on stateless decoder, MT8183 is
> > > the first time
> > > to add stateless decoder. Otherwise it will cause conflict. This
> > > patch will be
> > > accepted in 5.15[1].
> > > 
> > > 2: The definition of decoder clocks are in mt8192-clk.h, this
> > > patch
> > > already in clk tree[2].
> > > 
> > > [1]
> > > 
https://patchwork.linuxtv.org/project/linux-media/list/?series=5826
> > > [2]
> > > 
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/commit/?h=clk-next&id=f35f1a23e0e12e3173e9e9dedbc150d139027189
> > > ----
> > > Changes compared with v5:
> > > -Add decoder hardware block diagram for patch 13/15
> > > 
> > 
> > 
> > The discussion on v5 was still on-going, so sending this v6
> > is not helpful. The context for v5's discussion is now harder to
> > find.
> > 
> > Please avoid sending a new version without properly
> > discussing all the feedback, and without reaching consensus.
> > This is very important, please keep it in mind.
> > 
> 
> Thanks for your remind, I will keep this patch until get the
> solution.
> 
> > Specifically, the feedback on v5 was NAK, with the request to avoid
> > using any async framework, and instead try to find a simpler
> > solution.
> > 
> > For instance, you can model things with a bus-like pattern,
> > which ties all the devices together, under a parent node.
> > This pattern is common in the kernel, the parent
> > node can use of_platform_populate or similar
> > (git grep of_platform_populate, you will see plenty of examples).
> > 
> > You will still have to do some work to have the proper
> > regs resources, but this is doable. Each child is a device,
> > so it can have its own resources (clocks, interrupts, iommus).
> > 
> > You don't need any async framework.
> > 
> 
Thanks for your suggestion very much, and there are several actions
need to check.

1: The iommu register like this:
ret = bus_set_iommu(&platform_bus_type,
&mtk_iommu_ops); 
It expect the consumer is a standard platform device.
otherwise it
could not enter to the iommu of_xlate.)

So if putting the iommus property in the child node, all the child
device need to registered as platform device.

2: For the interrupt in each child node, but the logical processing in
parent part. Child and parent need to send message for each other. In
order to control clk/power/irq for multi instance, need send message to
child to separate different hardware; child also need send message to
parent when get interrupt.

3: About Chen-Yu's mail, do you have any advice?

Do you have any suggestion about these two scenarios?
I'm very happy to get your reply.

Thanks
Yunfei Dong

> >     vcodec_dec: vcodec_dec@16000000 {
> >         compatible = "mediatek,mt8192-vcodec-dec";
> >         reg = <something>;
> >         mediatek,scp = <&scp>;
> >         iommus = <&iommu0 M4U_PORT_L4_VDEC_MC_EXT>;
> >         dma-ranges = <0x1 0x0 0x0 0x40000000 0x0 0xfff00000>;
> > 
> >         vcodec_lat@0x10000 {
> >             compatible = "mediatek,mtk-vcodec-lat";
> >             reg = <0x10000 0x800>;      /* VDEC_MISC */
> >             interrupts = <GIC_SPI 426 IRQ_TYPE_LEVEL_HIGH 0>;
> >             // etc
> >         };
> > 
> >         vcodec_core@0x25000 {
> >            compatible = "mediatek,mtk-vcodec-core";
> >            reg = <0x25000 0x1000>;      /* VDEC_CORE_MISC */
> >            interrupts = <GIC_SPI 425 IRQ_TYPE_LEVEL_HIGH 0>;
> >            // etc
> >         };
> >     };
> > 
> > Thanks,
> > Ezequiel