drm/komeda: komeda_dev/pipeline/component definition and initialzation

1. Added a brief definition of komeda_dev/pipeline/component, this change
   didn't add the detailed component features and capabilities, which will
   be added in the following changes.
2. Corresponding resources discovery and initialzation functions.

Changes in v4:
- Deleted unnecessary headers

Changes in v3:
- Fixed style problem found by checkpatch.pl --strict.

Changes in v2:
- Unified abbreviation of "pipeline" to "pipe".
Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drivers/gpu/drm/arm/Kconfig

@@ -37,4 +37,6 @@ config DRM_MALI_DISPLAY
 
 	  If compiled as a module it will be called mali-dp.
 
+source "drivers/gpu/drm/arm/display/Kconfig"
+
 endmenu

drivers/gpu/drm/arm/Makefile

@@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_HDLCD)	+= hdlcd.o
 mali-dp-y := malidp_drv.o malidp_hw.o malidp_planes.o malidp_crtc.o
 mali-dp-y += malidp_mw.o
 obj-$(CONFIG_DRM_MALI_DISPLAY)	+= mali-dp.o
+obj-$(CONFIG_DRM_KOMEDA) += display/

drivers/gpu/drm/arm/display/Kbuild

+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DRM_KOMEDA) += komeda/

drivers/gpu/drm/arm/display/Kconfig

+# SPDX-License-Identifier: GPL-2.0
+config DRM_KOMEDA
+	tristate "ARM Komeda display driver"
+	depends on DRM && OF
+	depends on COMMON_CLK
+	select DRM_KMS_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_GEM_CMA_HELPER
+	select VIDEOMODE_HELPERS
+	help
+	  Choose this option if you want to compile the ARM Komeda display
+	  Processor driver. It supports the D71 variants of the hardware.
+
+	  If compiled as a module it will be called komeda.

drivers/gpu/drm/arm/display/include/malidp_product.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#ifndef _MALIDP_PRODUCT_H_
+#define _MALIDP_PRODUCT_H_
+
+/* Product identification */
+#define MALIDP_CORE_ID(__product, __major, __minor, __status) \
+	((((__product) & 0xFFFF) << 16) | (((__major) & 0xF) << 12) | \
+	(((__minor) & 0xF) << 8) | ((__status) & 0xFF))
+
+#define MALIDP_CORE_ID_PRODUCT_ID(__core_id) ((__u32)(__core_id) >> 16)
+#define MALIDP_CORE_ID_MAJOR(__core_id)      (((__u32)(__core_id) >> 12) & 0xF)
+#define MALIDP_CORE_ID_MINOR(__core_id)      (((__u32)(__core_id) >> 8) & 0xF)
+#define MALIDP_CORE_ID_STATUS(__core_id)     (((__u32)(__core_id)) & 0xFF)
+
+/* Mali-display product IDs */
+#define MALIDP_D71_PRODUCT_ID   0x0071
+
+#endif /* _MALIDP_PRODUCT_H_ */

drivers/gpu/drm/arm/display/include/malidp_utils.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#ifndef _MALIDP_UTILS_
+#define _MALIDP_UTILS_
+
+#define has_bit(nr, mask)	(BIT(nr) & (mask))
+#define has_bits(bits, mask)	(((bits) & (mask)) == (bits))
+
+#define dp_for_each_set_bit(bit, mask) \
+	for_each_set_bit((bit), ((unsigned long *)&(mask)), sizeof(mask) * 8)
+
+#endif /* _MALIDP_UTILS_ */

drivers/gpu/drm/arm/display/komeda/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+ccflags-y := \
+	-I$(src)/../include \
+	-I$(src)
+
+komeda-y := \
+	komeda_dev.o \
+	komeda_pipeline.o \
+
+obj-$(CONFIG_DRM_KOMEDA) += komeda.o

drivers/gpu/drm/arm/display/komeda/komeda_dev.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include "komeda_dev.h"
+
+struct komeda_dev *komeda_dev_create(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	const struct komeda_product_data *product;
+	struct komeda_dev *mdev;
+	struct resource *io_res;
+	int err = 0;
+
+	product = of_device_get_match_data(dev);
+	if (!product)
+		return ERR_PTR(-ENODEV);
+
+	io_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!io_res) {
+		DRM_ERROR("No registers defined.\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	mdev = devm_kzalloc(dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return ERR_PTR(-ENOMEM);
+
+	mdev->dev = dev;
+	mdev->reg_base = devm_ioremap_resource(dev, io_res);
+	if (IS_ERR(mdev->reg_base)) {
+		DRM_ERROR("Map register space failed.\n");
+		err = PTR_ERR(mdev->reg_base);
+		mdev->reg_base = NULL;
+		goto err_cleanup;
+	}
+
+	mdev->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(mdev->pclk)) {
+		DRM_ERROR("Get APB clk failed.\n");
+		err = PTR_ERR(mdev->pclk);
+		mdev->pclk = NULL;
+		goto err_cleanup;
+	}
+
+	/* Enable APB clock to access the registers */
+	clk_prepare_enable(mdev->pclk);
+
+	mdev->funcs = product->identify(mdev->reg_base, &mdev->chip);
+	if (!komeda_product_match(mdev, product->product_id)) {
+		DRM_ERROR("DT configured %x mismatch with real HW %x.\n",
+			  product->product_id,
+			  MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id));
+		err = -ENODEV;
+		goto err_cleanup;
+	}
+
+	DRM_INFO("Found ARM Mali-D%x version r%dp%d\n",
+		 MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id),
+		 MALIDP_CORE_ID_MAJOR(mdev->chip.core_id),
+		 MALIDP_CORE_ID_MINOR(mdev->chip.core_id));
+
+	err = mdev->funcs->enum_resources(mdev);
+	if (err) {
+		DRM_ERROR("enumerate display resource failed.\n");
+		goto err_cleanup;
+	}
+
+	return mdev;
+
+err_cleanup:
+	komeda_dev_destroy(mdev);
+	return ERR_PTR(err);
+}
+
+void komeda_dev_destroy(struct komeda_dev *mdev)
+{
+	struct device *dev = mdev->dev;
+	struct komeda_dev_funcs *funcs = mdev->funcs;
+	int i;
+
+	for (i = 0; i < mdev->n_pipelines; i++) {
+		komeda_pipeline_destroy(mdev, mdev->pipelines[i]);
+		mdev->pipelines[i] = NULL;
+	}
+
+	mdev->n_pipelines = 0;
+
+	if (funcs && funcs->cleanup)
+		funcs->cleanup(mdev);
+
+	if (mdev->reg_base) {
+		devm_iounmap(dev, mdev->reg_base);
+		mdev->reg_base = NULL;
+	}
+
+	if (mdev->mclk) {
+		devm_clk_put(dev, mdev->mclk);
+		mdev->mclk = NULL;
+	}
+
+	if (mdev->pclk) {
+		clk_disable_unprepare(mdev->pclk);
+		devm_clk_put(dev, mdev->pclk);
+		mdev->pclk = NULL;
+	}
+
+	devm_kfree(dev, mdev);
+}

drivers/gpu/drm/arm/display/komeda/komeda_dev.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#ifndef _KOMEDA_DEV_H_
+#define _KOMEDA_DEV_H_
+
+#include <linux/device.h>
+#include <linux/clk.h>
+#include "komeda_pipeline.h"
+#include "malidp_product.h"
+
+/* malidp device id */
+enum {
+	MALI_D71 = 0,
+};
+
+/* pipeline DT ports */
+enum {
+	KOMEDA_OF_PORT_OUTPUT		= 0,
+	KOMEDA_OF_PORT_COPROC		= 1,
+};
+
+struct komeda_chip_info {
+	u32 arch_id;
+	u32 core_id;
+	u32 core_info;
+	u32 bus_width;
+};
+
+struct komeda_product_data {
+	u32 product_id;
+	struct komeda_dev_funcs *(*identify)(u32 __iomem *reg,
+					     struct komeda_chip_info *info);
+};
+
+struct komeda_dev;
+
+/**
+ * struct komeda_dev_funcs
+ *
+ * Supplied by chip level and returned by the chip entry function xxx_identify,
+ */
+struct komeda_dev_funcs {
+	/**
+	 * @enum_resources:
+	 *
+	 * for CHIP to report or add pipeline and component resources to CORE
+	 */
+	int (*enum_resources)(struct komeda_dev *mdev);
+	/** @cleanup: call to chip to cleanup komeda_dev->chip data */
+	void (*cleanup)(struct komeda_dev *mdev);
+};
+
+/**
+ * struct komeda_dev
+ *
+ * Pipeline and component are used to describe how to handle the pixel data.
+ * komeda_device is for describing the whole view of the device, and the
+ * control-abilites of device.
+ */
+struct komeda_dev {
+	struct device *dev;
+	u32 __iomem   *reg_base;
+
+	struct komeda_chip_info chip;
+
+	/** @pclk: APB clock for register access */
+	struct clk *pclk;
+	/** @mck: HW main engine clk */
+	struct clk *mclk;
+
+	int n_pipelines;
+	struct komeda_pipeline *pipelines[KOMEDA_MAX_PIPELINES];
+
+	/** @funcs: chip funcs to access to HW */
+	struct komeda_dev_funcs *funcs;
+	/**
+	 * @chip_data:
+	 *
+	 * chip data will be added by &komeda_dev_funcs.enum_resources() and
+	 * destroyed by &komeda_dev_funcs.cleanup()
+	 */
+	void *chip_data;
+};
+
+static inline bool
+komeda_product_match(struct komeda_dev *mdev, u32 target)
+{
+	return MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id) == target;
+}
+
+struct komeda_dev *komeda_dev_create(struct device *dev);
+void komeda_dev_destroy(struct komeda_dev *mdev);
+
+#endif /*_KOMEDA_DEV_H_*/

drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#include "komeda_dev.h"
+#include "komeda_pipeline.h"
+
+/** komeda_pipeline_add - Add a pipeline to &komeda_dev */
+struct komeda_pipeline *
+komeda_pipeline_add(struct komeda_dev *mdev, size_t size,
+		    struct komeda_pipeline_funcs *funcs)
+{
+	struct komeda_pipeline *pipe;
+
+	if (mdev->n_pipelines + 1 > KOMEDA_MAX_PIPELINES) {
+		DRM_ERROR("Exceed max support %d pipelines.\n",
+			  KOMEDA_MAX_PIPELINES);
+		return NULL;
+	}
+
+	if (size < sizeof(*pipe)) {
+		DRM_ERROR("Request pipeline size too small.\n");
+		return NULL;
+	}
+
+	pipe = devm_kzalloc(mdev->dev, size, GFP_KERNEL);
+	if (!pipe)
+		return NULL;
+
+	pipe->mdev = mdev;
+	pipe->id   = mdev->n_pipelines;
+	pipe->funcs = funcs;
+
+	mdev->pipelines[mdev->n_pipelines] = pipe;
+	mdev->n_pipelines++;
+
+	return pipe;
+}
+
+void komeda_pipeline_destroy(struct komeda_dev *mdev,
+			     struct komeda_pipeline *pipe)
+{
+	struct komeda_component *c;
+	int i;
+
+	dp_for_each_set_bit(i, pipe->avail_comps) {
+		c = komeda_pipeline_get_component(pipe, i);
+		komeda_component_destroy(mdev, c);
+	}
+
+	clk_put(pipe->pxlclk);
+	clk_put(pipe->aclk);
+
+	devm_kfree(mdev->dev, pipe);
+}
+
+struct komeda_component **
+komeda_pipeline_get_component_pos(struct komeda_pipeline *pipe, int id)
+{
+	struct komeda_dev *mdev = pipe->mdev;
+	struct komeda_pipeline *temp = NULL;
+	struct komeda_component **pos = NULL;
+
+	switch (id) {
+	case KOMEDA_COMPONENT_LAYER0:
+	case KOMEDA_COMPONENT_LAYER1:
+	case KOMEDA_COMPONENT_LAYER2:
+	case KOMEDA_COMPONENT_LAYER3:
+		pos = to_cpos(pipe->layers[id - KOMEDA_COMPONENT_LAYER0]);
+		break;
+	case KOMEDA_COMPONENT_WB_LAYER:
+		pos = to_cpos(pipe->wb_layer);
+		break;
+	case KOMEDA_COMPONENT_COMPIZ0:
+	case KOMEDA_COMPONENT_COMPIZ1:
+		temp = mdev->pipelines[id - KOMEDA_COMPONENT_COMPIZ0];
+		if (!temp) {
+			DRM_ERROR("compiz-%d doesn't exist.\n", id);
+			return NULL;
+		}
+		pos = to_cpos(temp->compiz);
+		break;
+	case KOMEDA_COMPONENT_SCALER0:
+	case KOMEDA_COMPONENT_SCALER1:
+		pos = to_cpos(pipe->scalers[id - KOMEDA_COMPONENT_SCALER0]);
+		break;
+	case KOMEDA_COMPONENT_IPS0:
+	case KOMEDA_COMPONENT_IPS1:
+		temp = mdev->pipelines[id - KOMEDA_COMPONENT_IPS0];
+		if (!temp) {
+			DRM_ERROR("ips-%d doesn't exist.\n", id);
+			return NULL;
+		}
+		pos = to_cpos(temp->improc);
+		break;
+	case KOMEDA_COMPONENT_TIMING_CTRLR:
+		pos = to_cpos(pipe->ctrlr);
+		break;
+	default:
+		pos = NULL;
+		DRM_ERROR("Unknown pipeline resource ID: %d.\n", id);
+		break;
+	}
+
+	return pos;
+}
+
+struct komeda_component *
+komeda_pipeline_get_component(struct komeda_pipeline *pipe, int id)
+{
+	struct komeda_component **pos = NULL;
+	struct komeda_component *c = NULL;
+
+	pos = komeda_pipeline_get_component_pos(pipe, id);
+	if (pos)
+		c = *pos;
+
+	return c;
+}
+
+/** komeda_component_add - Add a component to &komeda_pipeline */
+struct komeda_component *
+komeda_component_add(struct komeda_pipeline *pipe,
+		     size_t comp_sz, u32 id, u32 hw_id,
+		     struct komeda_component_funcs *funcs,
+		     u8 max_active_inputs, u32 supported_inputs,
+		     u8 max_active_outputs, u32 __iomem *reg,
+		     const char *name_fmt, ...)
+{
+	struct komeda_component **pos;
+	struct komeda_component *c;
+	int idx, *num = NULL;
+
+	if (max_active_inputs > KOMEDA_COMPONENT_N_INPUTS) {
+		WARN(1, "please large KOMEDA_COMPONENT_N_INPUTS to %d.\n",
+		     max_active_inputs);
+		return NULL;
+	}
+
+	pos = komeda_pipeline_get_component_pos(pipe, id);
+	if (!pos || (*pos))
+		return NULL;
+
+	if (has_bit(id, KOMEDA_PIPELINE_LAYERS)) {
+		idx = id - KOMEDA_COMPONENT_LAYER0;
+		num = &pipe->n_layers;
+		if (idx != pipe->n_layers) {
+			DRM_ERROR("please add Layer by id sequence.\n");
+			return NULL;
+		}
+	} else if (has_bit(id,  KOMEDA_PIPELINE_SCALERS)) {
+		idx = id - KOMEDA_COMPONENT_SCALER0;
+		num = &pipe->n_scalers;
+		if (idx != pipe->n_scalers) {
+			DRM_ERROR("please add Scaler by id sequence.\n");
+			return NULL;
+		}
+	}
+
+	c = devm_kzalloc(pipe->mdev->dev, comp_sz, GFP_KERNEL);
+	if (!c)
+		return NULL;
+
+	c->id = id;
+	c->hw_id = hw_id;
+	c->reg = reg;
+	c->pipeline = pipe;
+	c->max_active_inputs = max_active_inputs;
+	c->max_active_outputs = max_active_outputs;
+	c->supported_inputs = supported_inputs;
+	c->funcs = funcs;
+
+	if (name_fmt) {
+		va_list args;
+
+		va_start(args, name_fmt);
+		vsnprintf(c->name, sizeof(c->name), name_fmt, args);
+		va_end(args);
+	}
+
+	if (num)
+		*num = *num + 1;
+
+	pipe->avail_comps |= BIT(c->id);
+	*pos = c;
+
+	return c;
+}
+
+void komeda_component_destroy(struct komeda_dev *mdev,
+			      struct komeda_component *c)
+{
+	devm_kfree(mdev->dev, c);
+}

drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#ifndef _KOMEDA_PIPELINE_H_
+#define _KOMEDA_PIPELINE_H_
+
+#include <linux/types.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include "malidp_utils.h"
+
+#define KOMEDA_MAX_PIPELINES		2
+#define KOMEDA_PIPELINE_MAX_LAYERS	4
+#define KOMEDA_PIPELINE_MAX_SCALERS	2
+#define KOMEDA_COMPONENT_N_INPUTS	5
+
+/* pipeline component IDs */
+enum {
+	KOMEDA_COMPONENT_LAYER0		= 0,
+	KOMEDA_COMPONENT_LAYER1		= 1,
+	KOMEDA_COMPONENT_LAYER2		= 2,
+	KOMEDA_COMPONENT_LAYER3		= 3,
+	KOMEDA_COMPONENT_WB_LAYER	= 7, /* write back layer */
+	KOMEDA_COMPONENT_SCALER0	= 8,
+	KOMEDA_COMPONENT_SCALER1	= 9,
+	KOMEDA_COMPONENT_SPLITTER	= 12,
+	KOMEDA_COMPONENT_MERGER		= 14,
+	KOMEDA_COMPONENT_COMPIZ0	= 16, /* compositor */
+	KOMEDA_COMPONENT_COMPIZ1	= 17,
+	KOMEDA_COMPONENT_IPS0		= 20, /* post image processor */
+	KOMEDA_COMPONENT_IPS1		= 21,
+	KOMEDA_COMPONENT_TIMING_CTRLR	= 22, /* timing controller */
+};
+
+#define KOMEDA_PIPELINE_LAYERS		(BIT(KOMEDA_COMPONENT_LAYER0) |\
+					 BIT(KOMEDA_COMPONENT_LAYER1) |\
+					 BIT(KOMEDA_COMPONENT_LAYER2) |\
+					 BIT(KOMEDA_COMPONENT_LAYER3))
+
+#define KOMEDA_PIPELINE_SCALERS		(BIT(KOMEDA_COMPONENT_SCALER0) |\
+					 BIT(KOMEDA_COMPONENT_SCALER1))
+
+#define KOMEDA_PIPELINE_COMPIZS		(BIT(KOMEDA_COMPONENT_COMPIZ0) |\
+					 BIT(KOMEDA_COMPONENT_COMPIZ1))
+
+#define KOMEDA_PIPELINE_IMPROCS		(BIT(KOMEDA_COMPONENT_IPS0) |\
+					 BIT(KOMEDA_COMPONENT_IPS1))
+struct komeda_component;
+struct komeda_component_state;
+
+/** komeda_component_funcs - component control functions */
+struct komeda_component_funcs {
+	/** @validate: optional,
+	 * component may has special requirements or limitations, this function
+	 * supply HW the ability to do the further HW specific check.
+	 */
+	int (*validate)(struct komeda_component *c,
+			struct komeda_component_state *state);
+	/** @update: update is a active update */
+	void (*update)(struct komeda_component *c,
+		       struct komeda_component_state *state);
+	/** @disable: disable component */
+	void (*disable)(struct komeda_component *c);
+	/** @dump_register: Optional, dump registers to seq_file */
+	void (*dump_register)(struct komeda_component *c, struct seq_file *seq);
+};
+
+/**
+ * struct komeda_component
+ *
+ * struct komeda_component describe the data flow capabilities for how to link a
+ * component into the display pipeline.
+ * all specified components are subclass of this structure.
+ */
+struct komeda_component {
+	/** @obj: treat component as private obj */
+	struct drm_private_obj obj;
+	/** @pipeline: the komeda pipeline this component belongs to */
+	struct komeda_pipeline *pipeline;
+	/** @name: component name */
+	char name[32];
+	/**
+	 * @reg:
+	 * component register base,
+	 * which is initialized by chip and used by chip only
+	 */
+	u32 __iomem *reg;
+	/** @id: component id */
+	u32 id;
+	/** @hw_ic: component hw id,
+	 *  which is initialized by chip and used by chip only
+	 */
+	u32 hw_id;
+
+	/**
+	 * @max_active_inputs:
+	 * @max_active_outpus:
+	 *
+	 * maximum number of inputs/outputs that can be active in the same time
+	 * Note:
+	 * the number isn't the bit number of @supported_inputs or
+	 * @supported_outputs, but may be less than it, since component may not
+	 * support enabling all @supported_inputs/outputs at the same time.
+	 */
+	u8 max_active_inputs;
+	u8 max_active_outputs;
+	/**
+	 * @supported_inputs:
+	 * @supported_outputs:
+	 *
+	 * bitmask of BIT(component->id) for the supported inputs/outputs
+	 * describes the possibilities of how a component is linked into a
+	 * pipeline.
+	 */
+	u32 supported_inputs;
+	u32 supported_outputs;
+
+	/**
+	 * @funcs: chip functions to access HW
+	 */
+	struct komeda_component_funcs *funcs;
+};
+
+/**
+ * struct komeda_component_output
+ *
+ * a component has multiple outputs, if want to know where the data
+ * comes from, only know the component is not enough, we still need to know
+ * its output port
+ */
+struct komeda_component_output {
+	/** @component: indicate which component the data comes from */
+	struct komeda_component *component;
+	/** @output_port:
+	 * the output port of the &komeda_component_output.component
+	 */
+	u8 output_port;
+};
+
+/**
+ * struct komeda_component_state
+ *
+ * component_state is the data flow configuration of the component, and it's
+ * the superclass of all specific component_state like @komeda_layer_state,
+ * @komeda_scaler_state
+ */
+struct komeda_component_state {
+	/** @obj: tracking component_state by drm_atomic_state */
+	struct drm_private_state obj;
+	struct komeda_component *component;
+	/**
+	 * @binding_user:
+	 * currently bound user, the user can be crtc/plane/wb_conn, which is
+	 * valid decided by @component and @inputs
+	 *
+	 * -  Layer: its user always is plane.
+	 * -  compiz/improc/timing_ctrlr: the user is crtc.
+	 * -  wb_layer: wb_conn;
+	 * -  scaler: plane when input is layer, wb_conn if input is compiz.
+	 */
+	union {
+		struct drm_crtc *crtc;
+		struct drm_plane *plane;
+		struct drm_connector *wb_conn;
+		void *binding_user;
+	};
+	/**
+	 * @active_inputs:
+	 *
+	 * active_inputs is bitmask of @inputs index
+	 *
+	 * -  active_inputs = changed_active_inputs + unchanged_active_inputs
+	 * -  affected_inputs = old->active_inputs + new->active_inputs;
+	 * -  disabling_inputs = affected_inputs ^ active_inputs;
+	 * -  changed_inputs = disabling_inputs + changed_active_inputs;
+	 *
+	 * NOTE:
+	 * changed_inputs doesn't include all active_input but only
+	 * @changed_active_inputs, and this bitmask can be used in chip
+	 * level for dirty update.
+	 */
+	u16 active_inputs;
+	u16 changed_active_inputs;
+	u16 affected_inputs;
+	/**
+	 * @inputs:
+	 *
+	 * the specific inputs[i] only valid on BIT(i) has been set in
+	 * @active_inputs, if not the inputs[i] is undefined.
+	 */
+	struct komeda_component_output inputs[KOMEDA_COMPONENT_N_INPUTS];
+};
+
+static inline u16 component_disabling_inputs(struct komeda_component_state *st)
+{
+	return st->affected_inputs ^ st->active_inputs;
+}
+
+static inline u16 component_changed_inputs(struct komeda_component_state *st)
+{
+	return component_disabling_inputs(st) | st->changed_active_inputs;
+}
+
+#define to_comp(__c)	(((__c) == NULL) ? NULL : &((__c)->base))
+#define to_cpos(__c)	((struct komeda_component **)&(__c))
+
+/* these structures are going to be filled in in uture patches */
+struct komeda_layer {
+	struct komeda_component base;
+	/* layer specific features and caps */
+};
+
+struct komeda_layer_state {
+	struct komeda_component_state base;
+	/* layer specific configuration state */
+};
+
+struct komeda_compiz {
+	struct komeda_component base;
+	/* compiz specific features and caps */
+};
+
+struct komeda_compiz_state {
+	struct komeda_component_state base;
+	/* compiz specific configuration state */
+};
+
+struct komeda_scaler {
+	struct komeda_component base;
+	/* scaler features and caps */
+};
+
+struct komeda_scaler_state {
+	struct komeda_component_state base;
+};
+
+struct komeda_improc {
+	struct komeda_component base;
+};
+
+struct komeda_improc_state {
+	struct komeda_component_state base;
+};
+
+/* display timing controller */
+struct komeda_timing_ctrlr {
+	struct komeda_component base;
+};
+
+struct komeda_timing_ctrlr_state {
+	struct komeda_component_state base;
+};
+
+/** struct komeda_pipeline_funcs */
+struct komeda_pipeline_funcs {
+	/* dump_register: Optional, dump registers to seq_file */
+	void (*dump_register)(struct komeda_pipeline *pipe,
+			      struct seq_file *sf);
+};
+
+/**
+ * struct komeda_pipeline
+ *
+ * Represent a complete display pipeline and hold all functional components.
+ */
+struct komeda_pipeline {
+	/** @obj: link pipeline as private obj of drm_atomic_state */
+	struct drm_private_obj obj;
+	/** @mdev: the parent komeda_dev */
+	struct komeda_dev *mdev;
+	/** @pxlclk: pixel clock */
+	struct clk *pxlclk;
+	/** @aclk: AXI clock */
+	struct clk *aclk;
+	/** @id: pipeline id */
+	int id;
+	/** @avail_comps: available components mask of pipeline */
+	u32 avail_comps;
+	int n_layers;
+	struct komeda_layer *layers[KOMEDA_PIPELINE_MAX_LAYERS];
+	int n_scalers;
+	struct komeda_scaler *scalers[KOMEDA_PIPELINE_MAX_SCALERS];
+	struct komeda_compiz *compiz;
+	struct komeda_layer  *wb_layer;
+	struct komeda_improc *improc;
+	struct komeda_timing_ctrlr *ctrlr;
+	struct komeda_pipeline_funcs *funcs; /* private pipeline functions */
+};
+
+/**
+ * struct komeda_pipeline_state
+ *
+ * NOTE:
+ * Unlike the pipeline, pipeline_state doesn’t gather any component_state
+ * into it. It because all component will be managed by drm_atomic_state.
+ */
+struct komeda_pipeline_state {
+	/** @obj: tracking pipeline_state by drm_atomic_state */
+	struct drm_private_state obj;
+	struct komeda_pipeline *pipe;
+	/** @crtc: currently bound crtc */
+	struct drm_crtc *crtc;
+	/**
+	 * @active_comps:
+	 *
+	 * bitmask - BIT(component->id) of active components
+	 */
+	u32 active_comps;
+};
+
+#define to_layer(c)	container_of(c, struct komeda_layer, base)
+#define to_compiz(c)	container_of(c, struct komeda_compiz, base)
+#define to_scaler(c)	container_of(c, struct komeda_scaler, base)
+#define to_improc(c)	container_of(c, struct komeda_improc, base)
+#define to_ctrlr(c)	container_of(c, struct komeda_timing_ctrlr, base)
+
+#define to_layer_st(c)	container_of(c, struct komeda_layer_state, base)
+#define to_compiz_st(c)	container_of(c, struct komeda_compiz_state, base)
+#define to_scaler_st(c) container_of(c, struct komeda_scaler_state, base)
+#define to_improc_st(c)	container_of(c, struct komeda_improc_state, base)
+#define to_ctrlr_st(c)	container_of(c, struct komeda_timing_ctrlr_state, base)
+
+/* pipeline APIs */
+struct komeda_pipeline *
+komeda_pipeline_add(struct komeda_dev *mdev, size_t size,
+		    struct komeda_pipeline_funcs *funcs);
+void komeda_pipeline_destroy(struct komeda_dev *mdev,
+			     struct komeda_pipeline *pipe);
+
+struct komeda_component *
+komeda_pipeline_get_component(struct komeda_pipeline *pipe, int id);
+
+/* component APIs */
+struct komeda_component *
+komeda_component_add(struct komeda_pipeline *pipe,
+		     size_t comp_sz, u32 id, u32 hw_id,
+		     struct komeda_component_funcs *funcs,
+		     u8 max_active_inputs, u32 supported_inputs,
+		     u8 max_active_outputs, u32 __iomem *reg,
+		     const char *name_fmt, ...);
+
+void komeda_component_destroy(struct komeda_dev *mdev,
+			      struct komeda_component *c);
+
+#endif /* _KOMEDA_PIPELINE_H_*/