Re: [PATCH v1 4/4] mtk-mdp: soc: mediatek: register mdp from mmsys

Enric Balletbo i Serra
2021-04-29T15:47:25Z

Hi Eizan,

Thank you for your patch.

On 23/4/21 7:58, Eizan Miyamoto wrote:
> Rather than hanging the MDP master component driver off of the rdma0
> device, create a "virtual" device by the mmsys driver instead which is
> probed by the mtk_mdp_core driver.
>
> Broadly, four interdependent things are done by this change:
> - A virtual device that is probed by the mtk_mdp_core driver is
> instantiated by the mtk_mmsys driver.
> - Presence of a mediatek,vpu property in a child node to the mmsys
> device node is used to determine what device to use when dispatching
> dma ops from the relevant ioctl.
> - v4l-related setup is moved into from the mtk_mdp_core driver to the
> mtk_mdp_comp driver.
>
> Signed-off-by: Eizan Miyamoto <eizan@chromium.org>
> ---
>
> drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 47 +++++++++-----
> drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 62 ++++++-------------
> drivers/media/platform/mtk-mdp/mtk_mdp_core.h | 2 +
> drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c | 4 +-
> drivers/soc/mediatek/mtk-mmsys.c | 20 +++++-
> 5 files changed, 75 insertions(+), 60 deletions(-)
>
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> index d447bfaadef4..dc5231a1fcfd 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> @@ -106,8 +106,41 @@ static int mtk_mdp_comp_bind(struct device *dev, struct device *master,
> {
> struct mtk_mdp_comp *comp = dev_get_drvdata(dev);
> struct mtk_mdp_dev *mdp = data;
> + struct device_node *vpu_node;
>
> mtk_mdp_register_component(mdp, comp);
> +
> + // If this component has a "mediatek-vpu" property, it is responsible for
> + // notifying the mdp master driver about it so it can be further initialized
> + // later.

Please use c-style comments here.

> + vpu_node = of_parse_phandle(dev->of_node, "mediatek,vpu", 0);

That's a bit confusing to me, please correct me if I am wrong, so, the
mediatek,vpu property is used to tell the code that this component should be the
'vpu master', not to point a vpu node in the DT? I understood correctly?

> + if (vpu_node) {
> + int ret;
> +
> + mdp->vpu_dev = of_find_device_by_node(vpu_node);
> + if (WARN_ON(!mdp->vpu_dev)) {
> + dev_err(dev, "vpu pdev failed\n");
> + of_node_put(vpu_node);
> + }
> +
> + ret = v4l2_device_register(dev, &mdp->v4l2_dev);
> + if (ret) {
> + dev_err(dev, "Failed to register v4l2 device\n");
> + return -EINVAL;
> + }
> +
> + ret = vb2_dma_contig_set_max_seg_size(dev, DMA_BIT_MASK(32));
> + if (ret) {
> + dev_err(dev, "Failed to set vb2 dma mag seg size\n");
> + return -EINVAL;
> + }
> +
> + // presence of the "mediatek,vpu" property in a device node
> + // indicates that it is the primary MDP rdma device and MDP DMA
> + // ops should be handled by its DMA callbacks.

Isn't rdma0 always the primary MDP device? or there are SoCs or configurations
where this is different? At least I think it is for MT8173 and MT8183.

> + mdp->rdma_dev = dev;
> + }
> +
> pm_runtime_enable(dev);
>
> return 0;
> @@ -164,23 +197,9 @@ int mtk_mdp_comp_init(struct mtk_mdp_comp *comp, struct device *dev)
> static int mtk_mdp_comp_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct device_node *vpu_node;
> int status;
> struct mtk_mdp_comp *comp;
>
> - vpu_node = of_parse_phandle(dev->of_node, "mediatek,vpu", 0);
> - if (vpu_node) {
> - of_node_put(vpu_node);
> - /*
> - * The device tree node with a mediatek,vpu property is deemed
> - * the MDP "master" device, we don't want to add a component
> - * for it in this function because the initialization for the
> - * master is done elsewhere.
> - */
> - dev_info(dev, "vpu node found, not probing\n");
> - return -ENODEV;
> - }
> -
> comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
> if (!comp)
> return -ENOMEM;
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> index 5e71496e2517..4d7aa4e26be6 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> @@ -121,6 +121,17 @@ static int mtk_mdp_master_bind(struct device *dev)
> goto err_component_bind_all;
> }
>
> + if (mdp->vpu_dev) {
> + int ret = vpu_wdt_reg_handler(mdp->vpu_dev, mtk_mdp_reset_handler, mdp,
> + VPU_RST_MDP);
> + if (ret) {
> + dev_err(dev, "Failed to register reset handler\n");
> + goto err_wdt_reg;
> + }
> + } else {
> + dev_err(dev, "no vpu_dev found\n");
> + }
> +
> status = mtk_mdp_register_m2m_device(mdp);
> if (status) {
> dev_err(dev, "Failed to register m2m device: %d\n", status);
> @@ -133,6 +144,8 @@ static int mtk_mdp_master_bind(struct device *dev)
> return 0;
>
> err_mtk_mdp_register_m2m_device:
> +
> +err_wdt_reg:
> component_unbind_all(dev, mdp);
>
> err_component_bind_all:
> @@ -191,8 +204,13 @@ static int mtk_mdp_probe(struct platform_device *pdev)
> of_node_put(node);
> parent = dev->of_node;
> dev_warn(dev, "device tree is out of date\n");
> - } else {
> + } else if (dev->of_node) {
> parent = dev->of_node->parent;
> + } else if (dev->parent) {
> + // maybe we were created from a call to platform_device_register_data()
> + parent = dev->parent->parent->of_node;
> + } else {
> + return -ENODEV;
> }
>
> /* Iterate over sibling MDP function blocks */
> @@ -225,16 +243,6 @@ static int mtk_mdp_probe(struct platform_device *pdev)
> }
> }
>
> - /*
> - * Create a component for myself so that clocks can be toggled in
> - * clock_on().
> - */
> - ret = mtk_mdp_comp_init(&mdp->comp_self, dev);
> - if (ret) {
> - dev_err(dev, "Failed to initialize component\n");
> - goto err_comp;
> - }
> -
> mdp->job_wq = create_singlethread_workqueue(MTK_MDP_MODULE_NAME);
> if (!mdp->job_wq) {
> dev_err(&pdev->dev, "unable to alloc job workqueue\n");
> @@ -250,29 +258,8 @@ static int mtk_mdp_probe(struct platform_device *pdev)
> }
> INIT_WORK(&mdp->wdt_work, mtk_mdp_wdt_worker);
>
> - ret = v4l2_device_register(dev, &mdp->v4l2_dev);
> - if (ret) {
> - dev_err(&pdev->dev, "Failed to register v4l2 device\n");
> - ret = -EINVAL;
> - goto err_dev_register;
> - }
> -
> - mdp->vpu_dev = vpu_get_plat_device(pdev);
> - ret = vpu_wdt_reg_handler(mdp->vpu_dev, mtk_mdp_reset_handler, mdp,
> - VPU_RST_MDP);
> - if (ret) {
> - dev_err(&pdev->dev, "Failed to register reset handler\n");
> - goto err_wdt_reg;
> - }
> -
> platform_set_drvdata(pdev, mdp);
>
> - ret = vb2_dma_contig_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
> - if (ret) {
> - dev_err(&pdev->dev, "Failed to set vb2 dma mag seg size\n");
> - goto err_set_max_seg_size;
> - }
> -
> ret = component_master_add_with_match(dev, &mtk_mdp_com_ops, match);
> if (ret) {
> dev_err(dev, "Component master add failed\n");
> @@ -284,22 +271,12 @@ static int mtk_mdp_probe(struct platform_device *pdev)
> return 0;
>
> err_component_master_add:
> - vb2_dma_contig_clear_max_seg_size(&pdev->dev);
> -
> -err_set_max_seg_size:
> -
> -err_wdt_reg:
> - v4l2_device_unregister(&mdp->v4l2_dev);
> -
> -err_dev_register:
> destroy_workqueue(mdp->wdt_wq);
>
> err_alloc_wdt_wq:
> destroy_workqueue(mdp->job_wq);
>
> err_alloc_job_wq:
> -
> -err_comp:
> dev_dbg(dev, "err %d\n", ret);
> return ret;
> }
> @@ -371,7 +348,6 @@ static struct platform_driver mtk_mdp_driver = {
> .driver = {
> .name = MTK_MDP_MODULE_NAME,
> .pm = &mtk_mdp_pm_ops,
> - .of_match_table = mtk_mdp_of_ids,
> }
> };
>
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.h b/drivers/media/platform/mtk-mdp/mtk_mdp_core.h
> index 230f531400ca..78c3c77cd226 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.h
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.h
> @@ -133,6 +133,7 @@ struct mtk_mdp_variant {
> * struct mtk_mdp_dev - abstraction for image processor entity
> * @lock: the mutex protecting this data structure
> * @vpulock: the mutex protecting the communication with VPU
> + * @rdma_dev: device pointer to rdma device for MDP
> * @pdev: pointer to the image processor platform device
> * @variant: the IP variant information
> * @id: image processor device index (0..MTK_MDP_MAX_DEVS)
> @@ -151,6 +152,7 @@ struct mtk_mdp_variant {
> struct mtk_mdp_dev {
> struct mutex lock;
> struct mutex vpulock;
> + struct device *rdma_dev;
> struct platform_device *pdev;
> struct mtk_mdp_variant *variant;
> u16 id;
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> index d351e5a44768..c80ad8299c5e 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> @@ -932,7 +932,7 @@ static int mtk_mdp_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
> src_vq->mem_ops = &vb2_dma_contig_memops;
> src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> - src_vq->dev = &ctx->mdp_dev->pdev->dev;
> + src_vq->dev = ctx->mdp_dev->rdma_dev;
> src_vq->lock = &ctx->mdp_dev->lock;
>
> ret = vb2_queue_init(src_vq);
> @@ -947,7 +947,7 @@ static int mtk_mdp_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
> dst_vq->mem_ops = &vb2_dma_contig_memops;
> dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> - dst_vq->dev = &ctx->mdp_dev->pdev->dev;
> + dst_vq->dev = ctx->mdp_dev->rdma_dev;
> dst_vq->lock = &ctx->mdp_dev->lock;
>
> return vb2_queue_init(dst_vq);
> diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
> index 18f93979e14a..6f9cf7725529 100644
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
> @@ -305,6 +305,7 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct platform_device *clks;
> struct platform_device *drm;
> + struct platform_device *mdp;
> void __iomem *config_regs;
> int ret;
>
> @@ -328,10 +329,27 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
> PLATFORM_DEVID_AUTO, NULL, 0);
> if (IS_ERR(drm)) {
> platform_device_unregister(clks);
> - return PTR_ERR(drm);
> + ret = PTR_ERR(drm);
> + goto err_drm;
> + }
> +
> + mdp = platform_device_register_data(&pdev->dev, "mtk-mdp",
> + PLATFORM_DEVID_AUTO, NULL, 0);
> + if (IS_ERR(mdp)) {
> + ret = PTR_ERR(mdp);
> + dev_err(dev, "Failed to register mdp: %d\n", ret);
> + goto err_mdp;
> }
>
> return 0;
> +
> +err_mdp:
> + platform_device_unregister(drm);
> +
> +err_drm:
> + platform_device_unregister(clks);
> +
> + return ret;
> }
>
> static const struct of_device_id of_match_mtk_mmsys[] = {