On Mon, Oct 14, 2024 at 10:51:48AM +0200, AngeloGioacchino Del Regno wrote:
> It is impossible to add each and every possible DDP path combination
> for each and every possible combination of SoC and board: right now,
> this driver hardcodes configuration for 10 SoCs and this is going to
> grow larger and larger, and with new hacks like the introduction of
> mtk_drm_route which is anyway not enough for all final routes as the
> DSI cannot be connected to MERGE if it's not a dual-DSI, or enabling
> DSC preventively doesn't work if the display doesn't support it, or
> others.
>
> Since practically all display IPs in MediaTek SoCs support being
> interconnected with different instances of other, or the same, IPs
> or with different IPs and in different combinations, the final DDP
> pipeline is effectively a board specific configuration.
>
> Implement OF graphs support to the mediatek-drm drivers, allowing to
> stop hardcoding the paths, and preventing this driver to get a huge
> amount of arrays for each board and SoC combination, also paving the
> way to share the same mtk_mmsys_driver_data between multiple SoCs,
> making it more straightforward to add support for new chips.
>
> Note that the OVL_ADAPTOR software component driver needs relatively
> big changes in order to fully support OF Graphs (and more SoCs anyway)
> and such changes will come at a later time.
> As of now, the mtk_disp_ovl_adaptor driver takes the MERGE components
> (for example, on mt8195, merge 1 to 4) dynamically so, even though
> later updates to the ovl-adaptor driver will *not* require bindings
> changes, the merge1-4 will be temporarily omitted in the graph for the
> MT8195 SoC.
>
> This means that an example graph for this SoC looks like:
>
> mdp_rdma (0 ~ 7) -> padding (0 ~ 7) -> ethdr -> merge5
>
> and the resulting path in this driver will be `ovl_adaptor -> merge5`
>
> Later updates to the ovl adaptor will expand it to support more SoCs
> and, in turn, to also fully support graphs.
>
> Reviewed-by: Alexandre Mergnat <amerg...@baylibre.com>
> Tested-by: Alexandre Mergnat <amerg...@baylibre.com>
> Acked-by: Sui Jingfeng <sui.jingf...@linux.dev>
> Tested-by: Michael Walle <mwa...@kernel.org> # on kontron-sbc-i1200
> Reviewed-by: CK Hu <ck...@mediatek.com>
> Signed-off-by: AngeloGioacchino Del Regno
> <angelogioacchino.delre...@collabora.com>
> ---
> drivers/gpu/drm/mediatek/mtk_disp_drv.h | 1 +
> .../gpu/drm/mediatek/mtk_disp_ovl_adaptor.c | 43 ++-
> drivers/gpu/drm/mediatek/mtk_dpi.c | 21 +-
> drivers/gpu/drm/mediatek/mtk_drm_drv.c | 253 +++++++++++++++++-
> drivers/gpu/drm/mediatek/mtk_drm_drv.h | 2 +-
> drivers/gpu/drm/mediatek/mtk_dsi.c | 14 +-
> 6 files changed, 312 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index 082ac18fe04a..94843974851f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> @@ -108,6 +108,7 @@ size_t mtk_ovl_get_num_formats(struct device *dev);
>
> void mtk_ovl_adaptor_add_comp(struct device *dev, struct mtk_mutex *mutex);
> void mtk_ovl_adaptor_remove_comp(struct device *dev, struct mtk_mutex
> *mutex);
> +bool mtk_ovl_adaptor_is_comp_present(struct device_node *node);
> void mtk_ovl_adaptor_connect(struct device *dev, struct device *mmsys_dev,
> unsigned int next);
> void mtk_ovl_adaptor_disconnect(struct device *dev, struct device *mmsys_dev,
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> index c6768210b08b..4e064d3c97cc 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> @@ -490,6 +490,41 @@ static int compare_of(struct device *dev, void *data)
> return dev->of_node == data;
> }
>
> +static int ovl_adaptor_of_get_ddp_comp_type(struct device_node *node,
> + enum mtk_ovl_adaptor_comp_type
> *ctype)
> +{
> + const struct of_device_id *of_id =
> of_match_node(mtk_ovl_adaptor_comp_dt_ids, node);
> +
> + if (!of_id)
> + return -EINVAL;
> +
> + *ctype = (enum mtk_ovl_adaptor_comp_type)((uintptr_t)of_id->data);
> +
> + return 0;
> +}
> +
> +bool mtk_ovl_adaptor_is_comp_present(struct device_node *node)
> +{
> + enum mtk_ovl_adaptor_comp_type type;
> + int ret;
> +
> + ret = ovl_adaptor_of_get_ddp_comp_type(node, &type);
> + if (ret)
> + return false;
> +
> + if (type >= OVL_ADAPTOR_TYPE_NUM)
> + return false;
> +
> + /*
> + * In the context of mediatek-drm, ETHDR, MDP_RDMA and Padding are
> + * used exclusively by OVL Adaptor: if this component is not one of
> + * those, it's likely not an OVL Adaptor path.
> + */
> + return type == OVL_ADAPTOR_TYPE_ETHDR ||
> + type == OVL_ADAPTOR_TYPE_MDP_RDMA ||
> + type == OVL_ADAPTOR_TYPE_PADDING;
> +}
> +
> static int ovl_adaptor_comp_init(struct device *dev, struct component_match
> **match)
> {
> struct mtk_disp_ovl_adaptor *priv = dev_get_drvdata(dev);
> @@ -499,12 +534,11 @@ static int ovl_adaptor_comp_init(struct device *dev,
> struct component_match **ma
> parent = dev->parent->parent->of_node->parent;
>
> for_each_child_of_node_scoped(parent, node) {
> - const struct of_device_id *of_id;
> enum mtk_ovl_adaptor_comp_type type;
> - int id;
> + int id, ret;
>
> - of_id = of_match_node(mtk_ovl_adaptor_comp_dt_ids, node);
> - if (!of_id)
> + ret = ovl_adaptor_of_get_ddp_comp_type(node, &type);
> + if (ret)
> continue;
>
> if (!of_device_is_available(node)) {
> @@ -513,7 +547,6 @@ static int ovl_adaptor_comp_init(struct device *dev,
> struct component_match **ma
> continue;
> }
>
> - type = (enum mtk_ovl_adaptor_comp_type)(uintptr_t)of_id->data;
> id = ovl_adaptor_comp_get_id(dev, node, type);
> if (id < 0) {
> dev_warn(dev, "Skipping unknown component %pOF\n",
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index e4da5cc75e60..ad37b0ecafb9 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -755,6 +755,20 @@ static int mtk_dpi_bridge_attach(struct drm_bridge
> *bridge,
> enum drm_bridge_attach_flags flags)
> {
> struct mtk_dpi *dpi = bridge_to_dpi(bridge);
> + int ret;
> +
> + dpi->next_bridge = devm_drm_of_get_bridge(dpi->dev, dpi->dev->of_node,
> 1, -1);
> + if (IS_ERR(dpi->next_bridge)) {
> + ret = PTR_ERR(dpi->next_bridge);
> + if (ret == -EPROBE_DEFER)
> + return ret;
> +
> + /* Old devicetree has only one endpoint */
> + dpi->next_bridge = devm_drm_of_get_bridge(dpi->dev,
> dpi->dev->of_node, 0, 0);
> + if (IS_ERR(dpi->next_bridge))
> + return dev_err_probe(dpi->dev,
> PTR_ERR(dpi->next_bridge),
> + "Failed to get bridge\n");
> + }
>
> return drm_bridge_attach(bridge->encoder, dpi->next_bridge,
> &dpi->bridge, flags);
> @@ -1162,13 +1176,6 @@ static int mtk_dpi_probe(struct platform_device *pdev)
> if (dpi->irq < 0)
> return dpi->irq;
>
> - dpi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
> - if (IS_ERR(dpi->next_bridge))
> - return dev_err_probe(dev, PTR_ERR(dpi->next_bridge),
> - "Failed to get bridge\n");
> -
> - dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);
> -
> platform_set_drvdata(pdev, dpi);
>
> dpi->bridge.funcs = &mtk_dpi_bridge_funcs;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index a4594f8873d5..85be035a209a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -27,6 +27,7 @@
>
> #include "mtk_crtc.h"
> #include "mtk_ddp_comp.h"
> +#include "mtk_disp_drv.h"
> #include "mtk_drm_drv.h"
> #include "mtk_gem.h"
>
> @@ -820,12 +821,235 @@ static const struct of_device_id mtk_ddp_comp_dt_ids[]
> = {
> { }
> };
>
> +static int mtk_drm_of_get_ddp_comp_type(struct device_node *node, enum
> mtk_ddp_comp_type *ctype)
> +{
> + const struct of_device_id *of_id = of_match_node(mtk_ddp_comp_dt_ids,
> node);
> +
> + if (!of_id)
> + return -EINVAL;
> +
> + *ctype = (enum mtk_ddp_comp_type)((uintptr_t)of_id->data);
> +
> + return 0;
> +}
> +
> +static int mtk_drm_of_get_ddp_ep_cid(struct device_node *node,
> + int output_port, enum mtk_crtc_path
> crtc_path,
> + struct device_node **next, unsigned int
> *cid)
> +{
> + struct device_node *ep_dev_node, *ep_out;
> + enum mtk_ddp_comp_type comp_type;
> + int ret;
> +
> + ep_out = of_graph_get_endpoint_by_regs(node, output_port, crtc_path);
> + if (!ep_out)
> + return -ENOENT;
> +
> + ep_dev_node = of_graph_get_remote_port_parent(ep_out);
> + of_node_put(ep_out);
> + if (!ep_dev_node)
> + return -EINVAL;
> +
> + /*
> + * Pass the next node pointer regardless of failures in the later code
> + * so that if this function is called in a loop it will walk through all
> + * of the subsequent endpoints anyway.
> + */
> + *next = ep_dev_node;
> +
> + if (!of_device_is_available(ep_dev_node))
> + return -ENODEV;
> +
> + ret = mtk_drm_of_get_ddp_comp_type(ep_dev_node, &comp_type);
> + if (ret) {
> + if (mtk_ovl_adaptor_is_comp_present(ep_dev_node)) {
> + *cid = (unsigned int)DDP_COMPONENT_DRM_OVL_ADAPTOR;
> + return 0;
> + }
> + return ret;
> + }
> +
> + ret = mtk_ddp_comp_get_id(ep_dev_node, comp_type);
> + if (ret < 0)
> + return ret;
> +
> + /* All ok! Pass the Component ID to the caller. */
> + *cid = (unsigned int)ret;
> +
> + return 0;
> +}
> +
> +/**
> + * mtk_drm_of_ddp_path_build_one - Build a Display HW Pipeline for a CRTC
> Path
> + * @dev: The mediatek-drm device
> + * @cpath: CRTC Path relative to a VDO or MMSYS
> + * @out_path: Pointer to an array that will contain the new pipeline
> + * @out_path_len: Number of entries in the pipeline array
> + *
> + * MediaTek SoCs can use different DDP hardware pipelines (or paths)
> depending
> + * on the board-specific desired display configuration; this function walks
> + * through all of the output endpoints starting from a VDO or MMSYS hardware
> + * instance and builds the right pipeline as specified in device trees.
> + *
> + * Return:
> + * * %0 - Display HW Pipeline successfully built and validated
> + * * %-ENOENT - Display pipeline was not specified in device tree
> + * * %-EINVAL - Display pipeline built but validation failed
> + * * %-ENOMEM - Failure to allocate pipeline array to pass to the caller
> + */
> +static int mtk_drm_of_ddp_path_build_one(struct device *dev, enum
> mtk_crtc_path cpath,
> + const unsigned int **out_path,
> + unsigned int *out_path_len)
> +{
> + struct device_node *next, *prev, *vdo = dev->parent->of_node;
> + unsigned int temp_path[DDP_COMPONENT_DRM_ID_MAX] = { 0 };
> + unsigned int *final_ddp_path;
> + unsigned short int idx = 0;
> + bool ovl_adaptor_comp_added = false;
> + int ret;
> +
> + /* Get the first entry for the temp_path array */
> + ret = mtk_drm_of_get_ddp_ep_cid(vdo, 0, cpath, &next, &temp_path[idx]);
> + if (ret) {
> + if (next && temp_path[idx] == DDP_COMPONENT_DRM_OVL_ADAPTOR) {
> + dev_dbg(dev, "Adding OVL Adaptor for %pOF\n", next);
> + ovl_adaptor_comp_added = true;
> + } else {
> + if (next)
> + dev_err(dev, "Invalid component %pOF\n", next);
> + else
> + dev_err(dev, "Cannot find first endpoint for
> path %d\n", cpath);
> +
> + return ret;
> + }
> + }
> + idx++;
> +
> + /*
> + * Walk through port outputs until we reach the last valid mediatek-drm
> component.
> + * To be valid, this must end with an "invalid" component that is a
> display node.
> + */
> + do {
> + prev = next;
> + ret = mtk_drm_of_get_ddp_ep_cid(next, 1, cpath, &next,
> &temp_path[idx]);
> + of_node_put(prev);
> + if (ret) {
> + of_node_put(next);
> + break;
> + }
> +
> + /*
> + * If this is an OVL adaptor exclusive component and one of
> those
> + * was already added, don't add another instance of the generic
> + * DDP_COMPONENT_OVL_ADAPTOR, as this is used only to decide
> whether
> + * to probe that component master driver of which only one
> instance
> + * is needed and possible.
> + */
> + if (temp_path[idx] == DDP_COMPONENT_DRM_OVL_ADAPTOR) {
> + if (!ovl_adaptor_comp_added)
> + ovl_adaptor_comp_added = true;
> + else
> + idx--;
> + }
> + } while (++idx < DDP_COMPONENT_DRM_ID_MAX);
> +
> + /*
> + * The device component might not be enabled: in that case, don't
> + * check the last entry and just report that the device is missing.
> + */
> + if (ret == -ENODEV)
> + return ret;
> +
> + /* If the last entry is not a final display output, the configuration
> is wrong */
> + switch (temp_path[idx - 1]) {
> + case DDP_COMPONENT_DP_INTF0:
> + case DDP_COMPONENT_DP_INTF1:
> + case DDP_COMPONENT_DPI0:
> + case DDP_COMPONENT_DPI1:
> + case DDP_COMPONENT_DSI0:
> + case DDP_COMPONENT_DSI1:
> + case DDP_COMPONENT_DSI2:
> + case DDP_COMPONENT_DSI3:
> + break;
> + default:
> + dev_err(dev, "Invalid display hw pipeline. Last component: %d
> (ret=%d)\n",
> + temp_path[idx - 1], ret);
> + return -EINVAL;
> + }
> +
> + final_ddp_path = devm_kmemdup(dev, temp_path, idx *
> sizeof(temp_path[0]), GFP_KERNEL);
> + if (!final_ddp_path)
> + return -ENOMEM;
> +
> + dev_dbg(dev, "Display HW Pipeline built with %d components.\n", idx);
> +
> + /* Pipeline built! */
> + *out_path = final_ddp_path;
> + *out_path_len = idx;
> +
> + return 0;
> +}
> +
> +static int mtk_drm_of_ddp_path_build(struct device *dev, struct device_node
> *node,
> + struct mtk_mmsys_driver_data *data)
> +{
> + struct device_node *ep_node;
> + struct of_endpoint of_ep;
> + bool output_present[MAX_CRTC] = { false };
> + int ret;
> +
> + for_each_endpoint_of_node(node, ep_node) {
> + ret = of_graph_parse_endpoint(ep_node, &of_ep);
> + if (ret) {
> + dev_err_probe(dev, ret, "Cannot parse endpoint\n");
> + break;
> + }
> +
> + if (of_ep.id >= MAX_CRTC) {
> + ret = dev_err_probe(dev, -EINVAL,
> + "Invalid endpoint%u number\n",
> of_ep.port);
> + break;
> + }
> +
> + output_present[of_ep.id] = true;
> + }
> +
> + if (ret) {
> + of_node_put(ep_node);
> + return ret;
> + }
> +
> + if (output_present[CRTC_MAIN]) {
> + ret = mtk_drm_of_ddp_path_build_one(dev, CRTC_MAIN,
> + &data->main_path,
> &data->main_len);
> + if (ret && ret != -ENODEV)
> + return ret;
> + }
> +
> + if (output_present[CRTC_EXT]) {
> + ret = mtk_drm_of_ddp_path_build_one(dev, CRTC_EXT,
> + &data->ext_path,
> &data->ext_len);
> + if (ret && ret != -ENODEV)
> + return ret;
> + }
> +
> + if (output_present[CRTC_THIRD]) {
> + ret = mtk_drm_of_ddp_path_build_one(dev, CRTC_THIRD,
> + &data->third_path,
> &data->third_len);
> + if (ret && ret != -ENODEV)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int mtk_drm_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *phandle = dev->parent->of_node;
> const struct of_device_id *of_id;
> struct mtk_drm_private *private;
> + struct mtk_mmsys_driver_data *mtk_drm_data;
> struct device_node *node;
> struct component_match *match = NULL;
> struct platform_device *ovl_adaptor;
> @@ -846,7 +1070,27 @@ static int mtk_drm_probe(struct platform_device *pdev)
> if (!of_id)
> return -ENODEV;
>
> - private->data = of_id->data;
> + mtk_drm_data = (struct mtk_mmsys_driver_data *)of_id->data;
> + if (!mtk_drm_data)
> + return -EINVAL;
> +
> + /* Try to build the display pipeline from devicetree graphs */
> + if (of_graph_is_present(phandle)) {
> + dev_dbg(dev, "Building display pipeline for MMSYS %u\n",
> + mtk_drm_data->mmsys_id);
> + private->data = devm_kmemdup(dev, mtk_drm_data,
> + sizeof(*mtk_drm_data), GFP_KERNEL);
> + if (!private->data)
> + return -ENOMEM;
> +
> + ret = mtk_drm_of_ddp_path_build(dev, phandle, private->data);
> + if (ret)
> + return ret;
> + } else {
> + /* No devicetree graphs support: go with hardcoded paths if
> present */
> + dev_dbg(dev, "Using hardcoded paths for MMSYS %u\n",
> mtk_drm_data->mmsys_id);
> + private->data = mtk_drm_data;
> + };
>
> private->all_drm_private = devm_kmalloc_array(dev,
> private->data->mmsys_dev_num,
>
> sizeof(*private->all_drm_private),
> @@ -868,12 +1112,11 @@ static int mtk_drm_probe(struct platform_device *pdev)
>
> /* Iterate over sibling DISP function blocks */
> for_each_child_of_node(phandle->parent, node) {
> - const struct of_device_id *of_id;
> enum mtk_ddp_comp_type comp_type;
> int comp_id;
>
> - of_id = of_match_node(mtk_ddp_comp_dt_ids, node);
> - if (!of_id)
> + ret = mtk_drm_of_get_ddp_comp_type(node, &comp_type);
> + if (ret)
> continue;
>
> if (!of_device_is_available(node)) {
> @@ -882,8 +1125,6 @@ static int mtk_drm_probe(struct platform_device *pdev)
> continue;
> }
>
> - comp_type = (enum mtk_ddp_comp_type)(uintptr_t)of_id->data;
> -
> if (comp_type == MTK_DISP_MUTEX) {
> int id;
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index ce897984de51..675cdc90a440 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -63,7 +63,7 @@ struct mtk_drm_private {
> struct device *mmsys_dev;
> struct device_node *comp_node[DDP_COMPONENT_DRM_ID_MAX];
> struct mtk_ddp_comp ddp_comp[DDP_COMPONENT_DRM_ID_MAX];
> - const struct mtk_mmsys_driver_data *data;
> + struct mtk_mmsys_driver_data *data;
> struct drm_atomic_state *suspend_state;
> unsigned int mbox_index;
> struct mtk_drm_private **all_drm_private;
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index eeec641cab60..33ceeb8d6925 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -988,9 +988,17 @@ static int mtk_dsi_host_attach(struct mipi_dsi_host
> *host,
> dsi->lanes = device->lanes;
> dsi->format = device->format;
> dsi->mode_flags = device->mode_flags;
> - dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
> - if (IS_ERR(dsi->next_bridge))
> - return PTR_ERR(dsi->next_bridge);
> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
> + if (IS_ERR(dsi->next_bridge)) {
> + ret = PTR_ERR(dsi->next_bridge);
> + if (ret == -EPROBE_DEFER)
> + return ret;
> +
> + /* Old devicetree has only one endpoint */
> + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0,
> 0);
Here's the problem with your binding change.
next_bridge was port 0, and now it is port 1. Yes, you have a fallback
for an old DT, but what happens with a new DT passed to a kernel without
the change here?
Plus now we've got to carry this fallback code path when it's completely
avoidable.
Rob
