On Mon, 2021-08-16 at 11:00 +0800, houlong wei wrote:
> On Mon, 2021-08-02 at 20:12 +0800, Eizan Miyamoto wrote:
> > ... Instead of depending on the presence of a mediatek,vpu property
> > in
> > the device node.
> >
> > That property was originally added to link to the vpu node so that
> > the
> > mtk_mdp_core driver could pass the right device to
> > vpu_wdt_reg_handler(). However in a previous patch in this series,
> > the driver has been modified to search the device tree for that
> > node
> > instead.
> >
> > That property was also used to indicate the primary MDP device, so
> > that
> > it can be passed to the V4L2 subsystem as well as register it to be
> > used when setting up queues in the open() callback for the
> > filesystem
> > device node that is created. In this case, assuming that the
> > primary
> > MDP device is the one with a specific alias seems useable because
> > the
> > alternative is to add a property to the device tree which doesn't
> > actually represent any facet of hardware (i.e., this being the
> > primary
> > MDP device is a software decision). In other words, this solution
> > is
> > equally as arbitrary, but at least it doesn't add a property to a
> > device node where said property is unrelated to the hardware
> > present.
> >
> > Signed-off-by: Eizan Miyamoto <eizan@xxxxxxxxxxxx>
> > ---
> >
> > (no changes since v1)
> >
> > drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 56 +++++++++++++--
> > ----
> > drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 36 ++++++++----
> > 2 files changed, 64 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> > b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> > index 85ef274841a3..9527649de98e 100644
> > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
> > @@ -151,29 +151,50 @@ void mtk_mdp_comp_clock_off(struct
> > mtk_mdp_comp
> > *comp)
> > mtk_smi_larb_put(comp->larb_dev);
> > }
> >
> > -static int mtk_mdp_comp_bind(struct device *dev, struct device
> > *master, void *data)
> > +/*
> > + * The MDP master device node is identified by the device tree
> > alias
> > + * "mdp-rdma0".
> > + */
> > +static bool is_mdp_master(struct device *dev)
> > +{
> > + struct device_node *aliases, *mdp_rdma0_node;
> > + const char *mdp_rdma0_path;
> > +
> > + if (!dev->of_node)
> > + return false;
> > +
> > + aliases = of_find_node_by_path("/aliases");
> > + if (!aliases) {
> > + dev_err(dev, "no aliases found for mdp-rdma0");
> > + return false;
> > + }
> > +
> > + mdp_rdma0_path = of_get_property(aliases, "mdp-rdma0", NULL);
> > + if (!mdp_rdma0_path) {
> > + dev_err(dev, "get mdp-rdma0 property of /aliases
> > failed");
> > + return false;
> > + }
> > +
> > + mdp_rdma0_node = of_find_node_by_path(mdp_rdma0_path);
> > + if (!mdp_rdma0_node) {
> > + dev_err(dev, "path resolution failed for %s",
> > mdp_rdma0_path);
> > + return false;
> > + }
> > +
>
> Hi Eizan,
>
> "mdp-rdma0" may be not the only one master device node. In fact,
> there
> are 2 "mdp-rdma" in mt8173. You can see "mdp_rdma1" via below link.
>
>
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/arch/arm64/boot/dts/mediatek/mt8173.dtsi?h=v5.13.11#n1016
> If we add "mediatek,mt8173-mdp" to "mdp_rdma1" like below, we will
> have
> one more V4L2 video devie node.
>
> mdp_rdma1: rdma@14002000 {
> compatible = "mediatek,mt8173-mdp-rdma",
> "mediatek,mt8173-mdp";
> ...
> }
>
> We should consider the case that there are more than one "MDP_RDMA"
> components.
>
> Regards,
> Houlong
>
> > + return dev->of_node == mdp_rdma0_node;
> > +}
> > +
> > +static int mtk_mdp_comp_bind(struct device *dev, struct device
> > *master,
> > + void *data)
> > {
> > 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.
> > - */
> > - vpu_node = of_parse_phandle(dev->of_node, "mediatek,vpu", 0);
> > - if (vpu_node) {
> > + if (is_mdp_master(dev)) {
> > 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");
> > @@ -187,9 +208,8 @@ static int mtk_mdp_comp_bind(struct device
> > *dev,
> > struct device *master, void *da
> > }
> >
> > /*
> > - * 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.
> > + * MDP DMA ops will be handled by the DMA callbacks
> > associated with this
> > + * device;
> > */
> > mdp->rdma_dev = dev;
> > }
> > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > index 50eafcc9993d..6a775463399c 100644
> > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > @@ -150,8 +150,9 @@ static void release_of(struct device *dev, void
> > *data)
> >
> > static int mtk_mdp_master_bind(struct device *dev)
> > {
> > - int status;
> > struct mtk_mdp_dev *mdp = dev_get_drvdata(dev);
> > + struct device_node *vpu_node;
> > + int status;
> >
> > status = component_bind_all(dev, mdp);
> > if (status) {
> > @@ -159,15 +160,30 @@ 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");
> > + if (mdp->rdma_dev == NULL) {
> > + dev_err(dev, "Primary MDP device not found");
> > + status = -ENODEV;
> > + goto err_component_bind_all;
> > + }
> > +
> > + vpu_node = of_find_node_by_name(NULL, "vpu");
> > + if (!vpu_node) {
> > + dev_err(dev, "unable to find vpu node");
> > + status = -ENODEV;
> > + goto err_wdt_reg;
> > + }
Hi Eizan,
Is your removing "mediatek,vpu" necessary for this series "Refactor MTK
MDP driver into core/components" ?
In some MediaTek projects (not upstream yet), the device-tree node name
"vpu" may be changed to something like "vpu0", "vpu1" or other name,
which depends on the implementation of "mtk-vpu" driver. We can specify
the different phandle to "mediatek,vpu" in .dtsi file. If we use
of_find_node_by_name() to get the vpu_node, we have to modify the name
string in different project.
If the answer of my previous questions is "No", I prefer to slow down
the modification of removing "mediatek,vpu".
Sorry for late reply.
Regards,
Houlong
> > +
> > + mdp->vpu_dev = of_find_device_by_node(vpu_node);
> > + if (!mdp->vpu_dev) {
> > + dev_err(dev, "unable to find vpu device");
> > + status = -ENODEV;
> > + goto err_wdt_reg;
> > + }
> > +
> > + status = vpu_wdt_reg_handler(mdp->vpu_dev,
> > mtk_mdp_reset_handler, mdp, VPU_RST_MDP);
> > + if (status) {
> > + dev_err(dev, "Failed to register reset handler\n");
> > + goto err_wdt_reg;
> > }
> >
> > status = mtk_mdp_register_m2m_device(mdp);
> > --
> > 2.32.0.554.ge1b32706d8-goog
> >
>
>
