On Mon, 2021-08-02 at 20:12 +0800, Eizan Miyamoto wrote: > Broadly, this patch (1) adds a driver for various MTK MDP components > to > go alongside the main MTK MDP driver, and (2) hooks them all together > using the component framework. > > (1) Up until now, the MTK MDP driver controls 8 devices in the device > tree on its own. When running tests for the hardware video decoder, > we > found that the iommus and LARBs were not being properly configured. > To > configure them, a driver for each be added to mtk_mdp_comp so that > mtk_iommu_add_device() can (eventually) be called from > dma_configure() > inside really_probe(). > > (2) The integration into the component framework allows us to defer > the > registration with the v4l2 subsystem until all the MDP-related > devices > have been probed, so that the relevant device node does not become > available until initialization of all the components is complete. > > Some notes about how the component framework has been integrated: > > - The driver for the rdma0 component serves double duty as the > "master" > (aggregate) driver as well as a component driver. This is a non- > ideal > compromise until a better solution is developed. This device is > differentiated from the rest by checking for a "mediatek,vpu" > property > in the device node. > > - The list of mdp components remains hard-coded as > mtk_mdp_comp_dt_ids[] > in mtk_mdp_core.c, and as mtk_mdp_comp_driver_dt_match[] in > mtk_mdp_comp.c. This unfortunate duplication of information is > addressed in a following patch in this series. > > - The component driver calls component_add() for each device that is > probed. > > - In mtk_mdp_probe (the "master" device), we scan the device tree for > any matching nodes against mtk_mdp_comp_dt_ids, and add component > matches for them. The match criteria is a matching device node > pointer. > > - When the set of components devices that have been probed > corresponds > with the list that is generated by the "master", the callback to > mtk_mdp_master_bind() is made, which then calls the component bind > functions. > > - Inside mtk_mdp_master_bind(), once all the component bind functions > have been called, we can then register our device to the v4l2 > subsystem. > > - The call to pm_runtime_enable() in the master device is called > after > all the components have been registered by their bind() functions > called by mtk_mtp_master_bind(). As a result, the list of > components > will not change while power management callbacks mtk_mdp_suspend()/ > resume() are accessing the list of components. > > Signed-off-by: Eizan Miyamoto <eizan@xxxxxxxxxxxx> > --- > Reviewed-by: Houlong Wei <houlong.wei@xxxxxxxxxxxx> > (no changes since v1) > [...]
