[PATCH v6 5/9] mtk-mdp: make mdp driver to be loadable by platform_device_register*()

[houlong wei]

On Mon, 2021-08-02 at 20:12 +0800, Eizan Miyamoto wrote:
> Rather than hanging the MDP master component driver off of the rdma0
> device, make it possible too create a "virtual" device by registering
> it with platform_device_register_*() to be probed by the mtk_mdp_core
> driver.
> 
> Broadly, three interdependent things are done by this change:
> - Make it is possible to search for MDP devices in the device tree
>   through the grandparent device's of_node.
> - v4l-related setup is moved into from the mtk_mdp_core driver to the
>   mtk_mdp_comp driver.
> - Presence of a mediatek,vpu property in an MDP component device node
>   is used to determine what device to use when dispatching DMA ops
> from
>   the relevant ioctl, and also do V4L2 initialization in this case.
> 
> Signed-off-by: Eizan Miyamoto <eizan at chromium.org>
> ---

Reviewed-by: Houlong Wei <houlong.wei at mediatek.com>

> Changes in v6:
> - Don't propagate errors from clock_on/off as an afterthought.
> - Split apart modifying mdp driver to be loadable from mmsys from
>   actually loading it from mmsys into two changs to make review
> easier.
> - Update devicetree bindings to reflect no longer needing the
>   mediatek,vpu property in the mdp_rdma0 device node.
> - Some stylistic cleanups.
> 
> Changes in v5:
> - rebase and test on 5.13-next @ e2f74b13dbe6
> 
> Changes in v4:
> - rebase and test on 5.13
> - don't depend on 
> https://patchwork.kernel.org/project/linux-mediatek/list/?series=464873
> 
> Changes in v3:
> - get mdp master from aliases instead of strcmp against of_node->name
> 
> Changes in v2:
> - rebased onto Linux 5.12
> - 100 char line length allowance was utilized in a few places
> - Removal of a redundant dev_err() print at the end of
>   mtk_mdp_comp_init()
> - Instead of printing errors and ignoring them, I've added a patch to
>   correctly propagate them.
> - Use of C style comments.
> - Three additional patches were added to eliminate dependency on the
>   mediatek,vpu property inside the mdp_rdma0 device node.

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