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

houlong wei
2021-06-08T15:40:58Z

On Fri, 2021-05-14 at 18:14 +0800, Enric Balletbo i Serra wrote:
> Hi Eizan,
>
>
> On 3/5/21 8:42, Eizan Miyamoto wrote:
> > On Fri, Apr 30, 2021 at 1:46 AM Enric Balletbo i Serra
> > <enric.balletbo@collabora.com> wrote:
> >>
> >> 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.
> >
> > Thank you for the reminder, I'll update these in the next version of
> > this patch series.
> >
> >>
> >>> + 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?
> >
> > Is what you mean by 'vpu master' is that it is the device whose driver
> > implements the wdt reset function? In that case, the mtk_mdp_core
> > driver is still the 'vpu master' because mtk_mdp_reset_handler
> > (contained in mtk_mdp_core) is passed to vpu_wdt_reg_handler(). The
> > presence of the property in any MDP component device node can do the
> > job of passing the vpu device (obtained from the node being pointed
> > to) back mtk_mdp_core's mtk_mdp_master_bind() function.
> >
> > *However*, I'm using the presence of that property to indicate another
> > thing: this is the device that the mdp filesystem device node in /dev
> > should be registered against for v4l2. We will need to save this
> > device for later (in mdp->rdma_dev) to be used to find the DMA
> > callbacks when a call to mtk_mdp_m2m_queue_init is made from the file
> > open() callback (mtk_mdp_m2m_open) attached to the filesystem device
> > node.
> >
> > Before this change, the mtk_mdp_core driver was serving triple duty as
> > the driver for the device that provided DMA op callbacks, the vpu
> > master, and the MDP component master. Now it is the vpu master and the
> > MDP component master, but not the driver for the device that provides
> > DMA op callbacks.
> >
> >>
> >>
> >>> + 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.
> >
> > I suppose you're right, though now it seems to be called mdp_rdma0 in
> > the device tree?
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/mediatek/mt8173.dtsi?id=9ccce092fc64d19504fa54de4fd659e279cc92e7#n1004
> >
> > Maybe somebody from MediaTek can confirm this?
>
> That's the case on all the devices that are upstream, so maybe we can just
> assume that for now if nobody from MediaTek confirms. I am in the opinion that
> we should avoid use the mediatek,vpu property if is possible.
>

Hi Enric,
You are right! Currently, for the upstream MDP driver, the mdp_rdma
device node always stands for the primary MDP device. In some projects,
there may be more than one mdp_rdma device nodes, so there may be more
than one MDP device.
In original code, the 'vpu_dev' is retrieved from the return value of
vpu_get_plat_device(). Maybe we don't have to implement the duplicated
code to parse it again.But the 'vpu_dev' is necessary for
vpu_wdt_reg_handler(), vpu_ipi_register() and vpi_ipi_send().

Regards,
Houlong

> >
> >>
> >>> + 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[] = {
> >>>