Re: [PATCH v26 3/7] drm/mediatek: add ovl_adaptor support for MT8195

Guillaume Ranquet
2022-08-19T09:10:40Z

On Fri, 19 Aug 2022 08:14, "" wrote:
>Add ovl_adaptor driver for MT8195.
>Ovl_adaptor is an encapsulated module and designed for simplified
>DRM control flow. This module is composed of 8 RDMAs, 4 MERGEs and
>an ETHDR. Two RDMAs merge into one layer, so this module support 4
>layers.
>
Hi Nancy, sorry I'm late in the review process, but I just applied
your series and I stumbled upon a panic.
(see details inline)

This is due to the fact that my dts is missing the required ovl
components, though, I think the driver
shouldn't cause a panic whenever the dts is not complete.

I'm testing this out with an mt8195-demo board.

>Signed-off-by: Nancy.Lin <nancy.lin@mediatek.com>
>Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
>Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>Tested-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
>---
> drivers/gpu/drm/mediatek/Makefile | 1 +
> drivers/gpu/drm/mediatek/mtk_disp_drv.h | 26 +
> .../gpu/drm/mediatek/mtk_disp_ovl_adaptor.c | 528 ++++++++++++++++++
> drivers/gpu/drm/mediatek/mtk_drm_drv.h | 1 +
> 4 files changed, 556 insertions(+)
> create mode 100644 drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
>
>diff --git a/drivers/gpu/drm/mediatek/Makefile b/drivers/gpu/drm/mediatek/Makefile
>index fb158a1e7f06..3abd27d7c91d 100644
>--- a/drivers/gpu/drm/mediatek/Makefile
>+++ b/drivers/gpu/drm/mediatek/Makefile
>@@ -6,6 +6,7 @@ mediatek-drm-y := mtk_disp_aal.o \
> mtk_disp_gamma.o \
> mtk_disp_merge.o \
> mtk_disp_ovl.o \
>+ mtk_disp_ovl_adaptor.o \
> mtk_disp_rdma.o \
> mtk_drm_crtc.o \
> mtk_drm_ddp_comp.o \
>diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>index 33e61a136bbc..654f8e257984 100644
>--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
>@@ -7,6 +7,8 @@
> #define _MTK_DISP_DRV_H_
>
> #include <linux/soc/mediatek/mtk-cmdq.h>
>+#include <linux/soc/mediatek/mtk-mmsys.h>
>+#include <linux/soc/mediatek/mtk-mutex.h>
> #include "mtk_drm_plane.h"
> #include "mtk_mdp_rdma.h"
>
>@@ -116,6 +118,30 @@ void mtk_rdma_unregister_vblank_cb(struct device *dev);
> void mtk_rdma_enable_vblank(struct device *dev);
> void mtk_rdma_disable_vblank(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);
>+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,
>+ unsigned int next);
>+int mtk_ovl_adaptor_clk_enable(struct device *dev);
>+void mtk_ovl_adaptor_clk_disable(struct device *dev);
>+void mtk_ovl_adaptor_config(struct device *dev, unsigned int w,
>+ unsigned int h, unsigned int vrefresh,
>+ unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
>+void mtk_ovl_adaptor_layer_config(struct device *dev, unsigned int idx,
>+ struct mtk_plane_state *state,
>+ struct cmdq_pkt *cmdq_pkt);
>+void mtk_ovl_adaptor_register_vblank_cb(struct device *dev, void (*vblank_cb)(void *),
>+ void *vblank_cb_data);
>+void mtk_ovl_adaptor_unregister_vblank_cb(struct device *dev);
>+void mtk_ovl_adaptor_enable_vblank(struct device *dev);
>+void mtk_ovl_adaptor_disable_vblank(struct device *dev);
>+void mtk_ovl_adaptor_start(struct device *dev);
>+void mtk_ovl_adaptor_stop(struct device *dev);
>+unsigned int mtk_ovl_adaptor_layer_nr(struct device *dev);
>+struct device *mtk_ovl_adaptor_dma_dev_get(struct device *dev);
>+
> int mtk_mdp_rdma_clk_enable(struct device *dev);
> void mtk_mdp_rdma_clk_disable(struct device *dev);
> void mtk_mdp_rdma_start(struct device *dev, struct cmdq_pkt *cmdq_pkt);
>diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
>new file mode 100644
>index 000000000000..267ee0a1b8fa
>--- /dev/null
>+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
>@@ -0,0 +1,528 @@
>+// SPDX-License-Identifier: GPL-2.0-only
>+/*
>+ * Copyright (c) 2021 MediaTek Inc.
>+ */
>+
>+#include <drm/drm_fourcc.h>
>+#include <drm/drm_of.h>
>+#include <linux/clk.h>
>+#include <linux/component.h>
>+#include <linux/of_device.h>
>+#include <linux/of_address.h>
>+#include <linux/platform_device.h>
>+#include <linux/pm_runtime.h>
>+#include <linux/reset.h>
>+#include <linux/soc/mediatek/mtk-cmdq.h>
>+#include <linux/soc/mediatek/mtk-mmsys.h>
>+#include <linux/soc/mediatek/mtk-mutex.h>
>+
>+#include "mtk_disp_drv.h"
>+#include "mtk_drm_crtc.h"
>+#include "mtk_drm_ddp_comp.h"
>+#include "mtk_drm_drv.h"
>+#include "mtk_ethdr.h"
>+
>+#define MTK_OVL_ADAPTOR_RDMA_MAX_WIDTH 1920
>+#define MTK_OVL_ADAPTOR_LAYER_NUM 4
>+
>+enum mtk_ovl_adaptor_comp_type {
>+ OVL_ADAPTOR_TYPE_RDMA = 0,
>+ OVL_ADAPTOR_TYPE_MERGE,
>+ OVL_ADAPTOR_TYPE_ETHDR,
>+ OVL_ADAPTOR_TYPE_NUM,
>+};
>+
>+enum mtk_ovl_adaptor_comp_id {
>+ OVL_ADAPTOR_MDP_RDMA0,
>+ OVL_ADAPTOR_MDP_RDMA1,
>+ OVL_ADAPTOR_MDP_RDMA2,
>+ OVL_ADAPTOR_MDP_RDMA3,
>+ OVL_ADAPTOR_MDP_RDMA4,
>+ OVL_ADAPTOR_MDP_RDMA5,
>+ OVL_ADAPTOR_MDP_RDMA6,
>+ OVL_ADAPTOR_MDP_RDMA7,
>+ OVL_ADAPTOR_MERGE0,
>+ OVL_ADAPTOR_MERGE1,
>+ OVL_ADAPTOR_MERGE2,
>+ OVL_ADAPTOR_MERGE3,
>+ OVL_ADAPTOR_ETHDR0,
>+ OVL_ADAPTOR_ID_MAX
>+};
>+
>+struct ovl_adaptor_comp_match {
>+ enum mtk_ovl_adaptor_comp_type type;
>+ int alias_id;
>+};
>+
>+struct mtk_disp_ovl_adaptor {
>+ struct device *ovl_adaptor_comp[OVL_ADAPTOR_ID_MAX];
>+ struct device *mmsys_dev;
>+ bool children_bound;
>+};
>+
>+static const char * const private_comp_stem[OVL_ADAPTOR_TYPE_NUM] = {
>+ [OVL_ADAPTOR_TYPE_RDMA] = "vdo1-rdma",
>+ [OVL_ADAPTOR_TYPE_MERGE] = "merge",
>+ [OVL_ADAPTOR_TYPE_ETHDR] = "ethdr",
>+};
>+
>+static const struct ovl_adaptor_comp_match comp_matches[OVL_ADAPTOR_ID_MAX] = {
>+ [OVL_ADAPTOR_MDP_RDMA0] = { OVL_ADAPTOR_TYPE_RDMA, 0 },
>+ [OVL_ADAPTOR_MDP_RDMA1] = { OVL_ADAPTOR_TYPE_RDMA, 1 },
>+ [OVL_ADAPTOR_MDP_RDMA2] = { OVL_ADAPTOR_TYPE_RDMA, 2 },
>+ [OVL_ADAPTOR_MDP_RDMA3] = { OVL_ADAPTOR_TYPE_RDMA, 3 },
>+ [OVL_ADAPTOR_MDP_RDMA4] = { OVL_ADAPTOR_TYPE_RDMA, 4 },
>+ [OVL_ADAPTOR_MDP_RDMA5] = { OVL_ADAPTOR_TYPE_RDMA, 5 },
>+ [OVL_ADAPTOR_MDP_RDMA6] = { OVL_ADAPTOR_TYPE_RDMA, 6 },
>+ [OVL_ADAPTOR_MDP_RDMA7] = { OVL_ADAPTOR_TYPE_RDMA, 7 },
>+ [OVL_ADAPTOR_MERGE0] = { OVL_ADAPTOR_TYPE_MERGE, 1 },
>+ [OVL_ADAPTOR_MERGE1] = { OVL_ADAPTOR_TYPE_MERGE, 2 },
>+ [OVL_ADAPTOR_MERGE2] = { OVL_ADAPTOR_TYPE_MERGE, 3 },
>+ [OVL_ADAPTOR_MERGE3] = { OVL_ADAPTOR_TYPE_MERGE, 4 },
>+ [OVL_ADAPTOR_ETHDR0] = { OVL_ADAPTOR_TYPE_ETHDR, 0 },
>+};
>+
>+void mtk_ovl_adaptor_layer_config(struct device *dev, unsigned int idx,
>+ struct mtk_plane_state *state,
>+ struct cmdq_pkt *cmdq_pkt)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+ struct mtk_plane_pending_state *pending = &state->pending;
>+ struct mtk_mdp_rdma_cfg rdma_config = {0};
>+ struct device *rdma_l;
>+ struct device *rdma_r;
>+ struct device *merge;
>+ struct device *ethdr;
>+ const struct drm_format_info *fmt_info = drm_format_info(pending->format);
>+ bool use_dual_pipe = false;
>+ unsigned int align_width;
>+ unsigned int l_w = 0;
>+ unsigned int r_w = 0;
>+
>+ dev_dbg(dev, "%s+ idx:%d, enable:%d, fmt:0x%x\n", __func__, idx,
>+ pending->enable, pending->format);
>+ dev_dbg(dev, "addr 0x%pad, fb w:%d, {%d,%d,%d,%d}\n",
>+ &pending->addr, (pending->pitch / fmt_info->cpp[0]),
>+ pending->x, pending->y, pending->width, pending->height);
>+
>+ rdma_l = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_MDP_RDMA0 + 2 * idx];
>+ rdma_r = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_MDP_RDMA0 + 2 * idx + 1];
>+ merge = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_MERGE0 + idx];
>+ ethdr = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0];
>+
>+ if (!pending->enable) {
>+ mtk_merge_stop_cmdq(merge, cmdq_pkt);
>+ mtk_mdp_rdma_stop(rdma_l, cmdq_pkt);
>+ mtk_mdp_rdma_stop(rdma_r, cmdq_pkt);
>+ mtk_ethdr_layer_config(ethdr, idx, state, cmdq_pkt);
>+ return;
>+ }
>+
>+ /* ETHDR is in 1T2P domain, width needs to be 2 pixels align */
>+ align_width = ALIGN_DOWN(pending->width, 2);
>+
>+ if (align_width > MTK_OVL_ADAPTOR_RDMA_MAX_WIDTH)
>+ use_dual_pipe = true;
>+
>+ if (use_dual_pipe) {
>+ l_w = (align_width / 2) + ((pending->width / 2) % 2);
>+ r_w = align_width - l_w;
>+ } else {
>+ l_w = align_width;
>+ }
>+ mtk_merge_advance_config(merge, l_w, r_w, pending->height, 0, 0, cmdq_pkt);
>+ mtk_mmsys_merge_async_config(ovl_adaptor->mmsys_dev, idx, align_width / 2,
>+ pending->height, cmdq_pkt);
>+
>+ rdma_config.width = l_w;
>+ rdma_config.height = pending->height;
>+ rdma_config.addr0 = pending->addr;
>+ rdma_config.pitch = pending->pitch;
>+ rdma_config.fmt = pending->format;
>+ rdma_config.color_encoding = pending->color_encoding;
>+ mtk_mdp_rdma_config(rdma_l, &rdma_config, cmdq_pkt);
>+
>+ if (use_dual_pipe) {
>+ rdma_config.x_left = l_w;
>+ rdma_config.width = r_w;
>+ mtk_mdp_rdma_config(rdma_r, &rdma_config, cmdq_pkt);
>+ }
>+
>+ mtk_merge_start_cmdq(merge, cmdq_pkt);
>+
>+ mtk_mdp_rdma_start(rdma_l, cmdq_pkt);
>+ if (use_dual_pipe)
>+ mtk_mdp_rdma_start(rdma_r, cmdq_pkt);
>+ else
>+ mtk_mdp_rdma_stop(rdma_r, cmdq_pkt);
>+
>+ mtk_ethdr_layer_config(ethdr, idx, state, cmdq_pkt);
>+}
>+
>+void mtk_ovl_adaptor_config(struct device *dev, unsigned int w,
>+ unsigned int h, unsigned int vrefresh,
>+ unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_config(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0], w, h,
>+ vrefresh, bpc, cmdq_pkt);
>+}
>+
>+void mtk_ovl_adaptor_start(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_start(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
>+}
>+
>+void mtk_ovl_adaptor_stop(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_stop(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
>+}
>+
>+int mtk_ovl_adaptor_clk_enable(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+ struct device *comp;
>+ int ret;
>+ int i;
>+
>+ for (i = 0; i < OVL_ADAPTOR_MERGE0; i++) {
>+ comp = ovl_adaptor->ovl_adaptor_comp[i];
>+ ret = pm_runtime_get_sync(comp);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to enable power domain %d, err %d\n", i, ret);
>+ goto pwr_err;
>+ }
>+ }
>+
>+ for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
>+ comp = ovl_adaptor->ovl_adaptor_comp[i];
>+
>+ if (i < OVL_ADAPTOR_MERGE0)
>+ ret = mtk_mdp_rdma_clk_enable(comp);
>+ else if (i < OVL_ADAPTOR_ETHDR0)
>+ ret = mtk_merge_clk_enable(comp);
>+ else
>+ ret = mtk_ethdr_clk_enable(comp);
>+ if (ret) {
>+ dev_err(dev, "Failed to enable clock %d, err %d\n", i, ret);
>+ goto clk_err;
>+ }
>+ }
>+
>+ return ret;
>+
>+clk_err:
>+ while (--i >= 0) {
>+ comp = ovl_adaptor->ovl_adaptor_comp[i];
>+ if (i < OVL_ADAPTOR_MERGE0)
>+ mtk_mdp_rdma_clk_disable(comp);
>+ else if (i < OVL_ADAPTOR_ETHDR0)
>+ mtk_merge_clk_disable(comp);
>+ else
>+ mtk_ethdr_clk_disable(comp);
>+ }
>+ i = OVL_ADAPTOR_MERGE0;
>+
>+pwr_err:
>+ while (--i >= 0)
>+ pm_runtime_put(ovl_adaptor->ovl_adaptor_comp[i]);
>+
>+ return ret;
>+}
>+
>+void mtk_ovl_adaptor_clk_disable(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+ struct device *comp;
>+ int i;
>+
>+ for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
>+ comp = ovl_adaptor->ovl_adaptor_comp[i];
>+
>+ if (i < OVL_ADAPTOR_MERGE0) {
>+ mtk_mdp_rdma_clk_disable(comp);
>+ pm_runtime_put(comp);
>+ } else if (i < OVL_ADAPTOR_ETHDR0) {
>+ mtk_merge_clk_disable(comp);
>+ } else {
>+ mtk_ethdr_clk_disable(comp);
>+ }
>+ }
>+}
>+
>+unsigned int mtk_ovl_adaptor_layer_nr(struct device *dev)
>+{
>+ return MTK_OVL_ADAPTOR_LAYER_NUM;
>+}
>+
>+struct device *mtk_ovl_adaptor_dma_dev_get(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ return ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_MDP_RDMA0];
>+}
>+
>+void mtk_ovl_adaptor_register_vblank_cb(struct device *dev, void (*vblank_cb)(void *),
>+ void *vblank_cb_data)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_register_vblank_cb(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0],
>+ vblank_cb, vblank_cb_data);
>+}
>+
>+void mtk_ovl_adaptor_unregister_vblank_cb(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_unregister_vblank_cb(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
>+}
>+
>+void mtk_ovl_adaptor_enable_vblank(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_enable_vblank(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
>+}
>+
>+void mtk_ovl_adaptor_disable_vblank(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
>+
>+ mtk_ethdr_disable_vblank(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
>+}
>+
>+void mtk_ovl_adaptor_add_comp(struct device *dev, struct mtk_mutex *mutex)
>+{
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA0);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA1);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA2);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA3);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA4);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA5);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA6);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MDP_RDMA7);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MERGE1);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MERGE2);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MERGE3);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_MERGE4);
>+ mtk_mutex_add_comp(mutex, DDP_COMPONENT_ETHDR_MIXER);
>+}
>+
>+void mtk_ovl_adaptor_remove_comp(struct device *dev, struct mtk_mutex *mutex)
>+{
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA0);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA1);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA2);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA3);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA4);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA5);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA6);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MDP_RDMA7);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MERGE1);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MERGE2);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MERGE3);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_MERGE4);
>+ mtk_mutex_remove_comp(mutex, DDP_COMPONENT_ETHDR_MIXER);
>+}
>+
>+void mtk_ovl_adaptor_connect(struct device *dev, struct device *mmsys_dev, unsigned int next)
>+{
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MDP_RDMA0, DDP_COMPONENT_MERGE1);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MDP_RDMA1, DDP_COMPONENT_MERGE1);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MDP_RDMA2, DDP_COMPONENT_MERGE2);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MERGE1, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MERGE2, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MERGE3, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_MERGE4, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_connect(mmsys_dev, DDP_COMPONENT_ETHDR_MIXER, next);
>+}
>+
>+void mtk_ovl_adaptor_disconnect(struct device *dev, struct device *mmsys_dev, unsigned int next)
>+{
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MDP_RDMA0, DDP_COMPONENT_MERGE1);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MDP_RDMA1, DDP_COMPONENT_MERGE1);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MDP_RDMA2, DDP_COMPONENT_MERGE2);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MERGE1, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MERGE2, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MERGE3, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_MERGE4, DDP_COMPONENT_ETHDR_MIXER);
>+ mtk_mmsys_ddp_disconnect(mmsys_dev, DDP_COMPONENT_ETHDR_MIXER, next);
>+}
>+
>+static int ovl_adaptor_comp_get_id(struct device *dev, struct device_node *node,
>+ enum mtk_ovl_adaptor_comp_type type)
>+{
>+ int alias_id = of_alias_get_id(node, private_comp_stem[type]);
>+ int i;
>+
>+ for (i = 0; i < ARRAY_SIZE(comp_matches); i++)
>+ if (comp_matches[i].type == type &&
>+ comp_matches[i].alias_id == alias_id)
>+ return i;
>+
>+ dev_warn(dev, "Failed to get id. type: %d, alias: %d\n", type, alias_id);
>+ return -EINVAL;
>+}
>+
>+static const struct of_device_id mtk_ovl_adaptor_comp_dt_ids[] = {
>+ {
>+ .compatible = "mediatek,mt8195-vdo1-rdma",
>+ .data = (void *)OVL_ADAPTOR_TYPE_RDMA,
>+ }, {
>+ .compatible = "mediatek,mt8195-disp-merge",
>+ .data = (void *)OVL_ADAPTOR_TYPE_MERGE,
>+ }, {
>+ .compatible = "mediatek,mt8195-disp-ethdr",
>+ .data = (void *)OVL_ADAPTOR_TYPE_ETHDR,
>+ },
>+ {},
>+};
>+
>+static int compare_of(struct device *dev, void *data)
>+{
>+ return dev->of_node == data;
>+}
>+
>+static int ovl_adaptor_comp_init(struct device *dev, struct component_match **match)
>+{
>+ struct mtk_disp_ovl_adaptor *priv = dev_get_drvdata(dev);
>+ struct device_node *node, *parent;
>+ struct platform_device *comp_pdev;
>+
>+ parent = dev->parent->parent->of_node->parent;
>+
>+ for_each_child_of_node(parent, node) {
>+ const struct of_device_id *of_id;
>+ enum mtk_ovl_adaptor_comp_type type;
>+ int id;
>+
>+ of_id = of_match_node(mtk_ovl_adaptor_comp_dt_ids, node);
>+ if (!of_id)
>+ continue;
>+
>+ if (!of_device_is_available(node)) {
>+ dev_dbg(dev, "Skipping disabled component %pOF\n",
>+ node);
>+ continue;
>+ }
>+
>+ type = (enum mtk_ovl_adaptor_comp_type)of_id->data;
>+ id = ovl_adaptor_comp_get_id(dev, node, type);
>+ if (id < 0) {
>+ dev_warn(dev, "Skipping unknown component %pOF\n",
>+ node);
>+ continue;
>+ }
>+
>+ comp_pdev = of_find_device_by_node(node);
>+ if (!comp_pdev)
>+ return -EPROBE_DEFER;
>+
>+ priv->ovl_adaptor_comp[id] = &comp_pdev->dev;
>+
>+ drm_of_component_match_add(dev, match, compare_of, node);
>+ dev_dbg(dev, "Adding component match for %pOF\n", node);
>+ }
>+
>+ return 0;
>+}
>+
>+static int mtk_disp_ovl_adaptor_comp_bind(struct device *dev, struct device *master,
>+ void *data)
>+{
>+ struct mtk_disp_ovl_adaptor *priv = dev_get_drvdata(dev);
>+
>+ if (!priv->children_bound)
>+ return -EPROBE_DEFER;
>+
>+ return 0;
>+}
>+
>+static void mtk_disp_ovl_adaptor_comp_unbind(struct device *dev, struct device *master,
>+ void *data)
>+{
>+}
>+
>+static const struct component_ops mtk_disp_ovl_adaptor_comp_ops = {
>+ .bind = mtk_disp_ovl_adaptor_comp_bind,
>+ .unbind = mtk_disp_ovl_adaptor_comp_unbind,
>+};
>+
>+static int mtk_disp_ovl_adaptor_master_bind(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *priv = dev_get_drvdata(dev);
>+ int ret;
>+
>+ ret = component_bind_all(dev, priv->mmsys_dev);
>+ if (ret)
>+ return dev_err_probe(dev, ret, "component_bind_all failed!\n");
>+
>+ priv->children_bound = true;
>+ return 0;
>+}
>+
>+static void mtk_disp_ovl_adaptor_master_unbind(struct device *dev)
>+{
>+ struct mtk_disp_ovl_adaptor *priv = dev_get_drvdata(dev);
>+
>+ priv->children_bound = false;
>+}
>+
>+static const struct component_master_ops mtk_disp_ovl_adaptor_master_ops = {
>+ .bind = mtk_disp_ovl_adaptor_master_bind,
>+ .unbind = mtk_disp_ovl_adaptor_master_unbind,
>+};
>+
>+static int mtk_disp_ovl_adaptor_probe(struct platform_device *pdev)
>+{
>+ struct mtk_disp_ovl_adaptor *priv;
>+ struct device *dev = &pdev->dev;
>+ struct component_match *match = NULL;
>+ int ret;
>+
>+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>+ if (!priv)
>+ return -ENOMEM;
>+
>+ platform_set_drvdata(pdev, priv);
>+
>+ ret = ovl_adaptor_comp_init(dev, &match);
>+ if (ret < 0)
>+ return ret;
>+
>+ priv->mmsys_dev = pdev->dev.platform_data;
>+
>+ component_master_add_with_match(dev, &mtk_disp_ovl_adaptor_master_ops, match);

Here the code assumes match is not NULL and that
ovl_adaptor_comp_init() allocated it
with a call to drm_of_component_match_add() which never happens in
case of a buggy dts.
IMHO, ovl_adaptor_comp_init() should return an error in case no
components have been found.

[ 0.936986] mediatek-disp-ovl-adaptor
mediatek-disp-ovl-adaptor.2.auto: Failed to get id. type: 1, alias:
-19
[ 0.938238] mediatek-disp-ovl-adaptor
mediatek-disp-ovl-adaptor.2.auto: Skipping unknown component
/soc/merge@1c014000
[ 0.939596] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
[ 0.940701] Mem abort info:
[ 0.941064] ESR = 0x0000000096000004
[ 0.941538] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.942208] SET = 0, FnV = 0
[ 0.942595] EA = 0, S1PTW = 0
[ 0.942993] FSC = 0x04: level 0 translation fault
[ 0.943607] Data abort info:
[ 0.943972] ISV = 0, ISS = 0x00000004
[ 0.944455] CM = 0, WnR = 0
[ 0.944835] [0000000000000000] user address but active_mm is swapper
[ 0.945636] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 0.946340] CPU: 6 PID: 1 Comm: swapper/0 Not tainted
6.0.0-rc1-next-20220818-mtk #17
[ 0.947327] swapper/0[1] cmdline: b
[ 0.947327]
[ 0.947976] Hardware name: MediaTek MT8195 demo board (DT)
[ 0.948666] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 0.949545] pc : component_master_add_with_match+0x24/0x100
[ 0.950257] lr : mtk_disp_ovl_adaptor_probe+0x1d0/0x280
[ 0.950925] sp : ffff80000a62b720
[ 0.951344] x29: ffff80000a62b720 x28: 0000000000000000 x27: ffff0000048dac10
[ 0.952248] x26: ffff00007fbbdda0 x25: 0000000000000001 x24: 0000000000000000
[ 0.953149] x23: ffff0000048dac00 x22: ffff8000097e29d0 x21: ffff0000048dac10
[ 0.954050] x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff
[ 0.954951] x17: 70696b53203a6f74 x16: 75612e322e726f74 x15: 0720072007200720
[ 0.955852] x14: 0720072007200720 x13: ffff80000a3787e0 x12: 00000000000002af
[ 0.956752] x11: 00000000000000e5 x10: ffff84000bfe5dc8 x9 : 0000000000000002
[ 0.957653] x8 : 0101010101010101 x7 : 7f7f7f7f7f7f7f7f x6 : 01fefefefefefeff
[ 0.958553] x5 : 0000000000000014 x4 : 0000000000000000 x3 : ffff0000048db000
[ 0.959453] x2 : 0000000000000000 x1 : ffff8000097e29d0 x0 : ffff0000048dac10
[ 0.960354] Call trace:
[ 0.960664] component_master_add_with_match+0x24/0x100
[ 0.961326] mtk_disp_ovl_adaptor_probe+0x1d0/0x280
[ 0.961945] platform_probe+0x6c/0xe0
[ 0.962411] really_probe+0xbc/0x2d4
[ 0.962864] __driver_probe_device+0x78/0xe0
[ 0.963404] driver_probe_device+0x40/0x12c
[ 0.963933] __device_attach_driver+0xec/0x154
[ 0.964496] bus_for_each_drv+0x78/0xd0
[ 0.964982] __device_attach+0xa8/0x1c0
[ 0.965467] device_initial_probe+0x18/0x2c
[ 0.965997] bus_probe_device+0x9c/0xa4
[ 0.966482] device_add+0x384/0x870
[ 0.966927] platform_device_add+0x118/0x23c
[ 0.967470] platform_device_register_full+0x104/0x18c
[ 0.968120] mtk_drm_probe+0x31c/0x440
[ 0.968596] platform_probe+0x6c/0xe0
[ 0.969061] really_probe+0xbc/0x2d4
[ 0.969515] __driver_probe_device+0x78/0xe0
[ 0.970055] driver_probe_device+0x40/0x12c
[ 0.970584] __driver_attach+0x120/0x1d0
[ 0.971080] bus_for_each_dev+0x70/0xcc
[ 0.971569] driver_attach+0x28/0x34
[ 0.972022] bus_add_driver+0x148/0x200
[ 0.972507] driver_register+0x7c/0x13c
[ 0.972993] __platform_register_drivers+0x54/0xdc
[ 0.973600] mtk_drm_init+0x24/0x30
[ 0.974044] do_one_initcall+0x6c/0x148
[ 0.974530] kernel_init_freeable+0x208/0x288
[ 0.975080] kernel_init+0x28/0x130
[ 0.975526] ret_from_fork+0x10/0x20
[ 0.975984] Code: aa0203f4 a9025bf5 aa0003f5 aa0103f6 (a9400440)
[ 0.976753] ---[ end trace 0000000000000000 ]---
[ 0.977347] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b
[ 0.978311] SMP: stopping secondary CPUs
[ 0.978811] Kernel Offset: disabled
[ 0.979252] CPU features: 0x2000,0001c029,19801c82
[ 0.979856] Memory Limit: none
[ 0.980243] ---[ end Kernel panic - not syncing: Attempted to kill
init! exitcode=0x0000000b ]---

Thx,
Guillaume.
>+ pm_runtime_enable(dev);
>+
>+ ret = component_add(dev, &mtk_disp_ovl_adaptor_comp_ops);
>+ if (ret != 0) {
>+ pm_runtime_disable(dev);
>+ dev_err(dev, "Failed to add component: %d\n", ret);
>+ }
>+
>+ return ret;
>+}
>+
>+static int mtk_disp_ovl_adaptor_remove(struct platform_device *pdev)
>+{
>+ component_master_del(&pdev->dev, &mtk_disp_ovl_adaptor_master_ops);
>+ pm_runtime_disable(&pdev->dev);
>+ return 0;
>+}
>+
>+struct platform_driver mtk_disp_ovl_adaptor_driver = {
>+ .probe = mtk_disp_ovl_adaptor_probe,
>+ .remove = mtk_disp_ovl_adaptor_remove,
>+ .driver = {
>+ .name = "mediatek-disp-ovl-adaptor",
>+ .owner = THIS_MODULE,
>+ },
>+};
>diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>index 3b393e4b364a..51bee36579ef 100644
>--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>@@ -57,6 +57,7 @@ extern struct platform_driver mtk_disp_ccorr_driver;
> extern struct platform_driver mtk_disp_color_driver;
> extern struct platform_driver mtk_disp_gamma_driver;
> extern struct platform_driver mtk_disp_merge_driver;
>+extern struct platform_driver mtk_disp_ovl_adaptor_driver;
> extern struct platform_driver mtk_disp_ovl_driver;
> extern struct platform_driver mtk_disp_rdma_driver;
> extern struct platform_driver mtk_dpi_driver;
>--
>2.18.0
>
>