Re: [PATCH v8 3/3] drm/mediatek: Implement OF graphs support for display paths

From: AngeloGioacchino Del Regno
Date: Tue Sep 10 2024 - 04:38:45 EST


Il 08/08/24 05:48, CK Hu (胡俊光) ha scritto:
Hi, Angelo:

On Tue, 2024-06-18 at 12:17 +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.

Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
Tested-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---

[snip]

+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_err(dev, "Adding OVL Adaptor for %pOF\n", next);

This looks not an error.


Thanks for catching that, I used that line for debugging and forgot to change it
back to dev_dbg(). Will fix.

+ 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;
@@ -824,7 +1048,31 @@ 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;
+
+ private->data = kmemdup(mtk_drm_data, sizeof(*mtk_drm_data), GFP_KERNEL);

This is redundant. You would assign private->data below.


Right. Will remove.

+ if (!private->data)
+ return -ENOMEM;
+
+ /* 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),
@@ -846,12 +1094,11 @@ 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)) {
@@ -860,8 +1107,6 @@ 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;
@@ -890,22 +1135,24 @@ static int mtk_drm_probe(struct platform_device *pdev)
* blocks have separate component platform drivers and initialize their own
* DDP component structure. The others are initialized here.
*/
- if (comp_type == MTK_DISP_AAL ||
- comp_type == MTK_DISP_CCORR ||
- comp_type == MTK_DISP_COLOR ||
- comp_type == MTK_DISP_GAMMA ||
- comp_type == MTK_DISP_MERGE ||
- comp_type == MTK_DISP_OVL ||
- comp_type == MTK_DISP_OVL_2L ||
- comp_type == MTK_DISP_OVL_ADAPTOR ||
- comp_type == MTK_DISP_RDMA ||
- comp_type == MTK_DP_INTF ||
- comp_type == MTK_DPI ||
- comp_type == MTK_DSI) {
- dev_info(dev, "Adding component match for %pOF\n",
- node);
- drm_of_component_match_add(dev, &match, component_compare_of,
- node);
+ switch (comp_type) {
+ default:
+ break;
+ case MTK_DISP_AAL:
+ case MTK_DISP_CCORR:
+ case MTK_DISP_COLOR:
+ case MTK_DISP_GAMMA:
+ case MTK_DISP_MERGE:
+ case MTK_DISP_OVL:
+ case MTK_DISP_OVL_2L:
+ case MTK_DISP_OVL_ADAPTOR:
+ case MTK_DISP_RDMA:
+ case MTK_DP_INTF:
+ case MTK_DPI:
+ case MTK_DSI:
+ dev_info(dev, "Adding component match for %pOF\n", node);
+ drm_of_component_match_add(dev, &match, component_compare_of, node);
+ break;

This modification seems not related to OF graphs support. If you need this, separate this to another patch.


Will do for v9.

Thanks,
Angelo

}
ret = mtk_ddp_comp_init(node, &private->ddp_comp[comp_id], comp_id);
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
index 78d698ede1bf..7e54d86e25a3 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
@@ -59,7 +59,7 @@ 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 c255559cc56e..880ea37937da 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -904,9 +904,17 @@ 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);
+ if (IS_ERR(dsi->next_bridge))
+ return PTR_ERR(dsi->next_bridge);
+ }
drm_bridge_add(&dsi->bridge);