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From:   Faiz Abbas <faiz.abbas@arm.com>
To:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Cc:     liviu.dudau@arm.com, airlied@gmail.com, daniel@ffwll.ch,
        faiz.abbas@arm.com
Subject: [PATCH] drm/arm/komeda: Remove component framework and add a simple encoder
Date:   Wed, 21 Jun 2023 14:11:16 +0530
Message-Id: <20230621084116.26882-1-faiz.abbas@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The Komeda driver always expects the remote connector node to initialize
an encoder. It uses the component aggregator framework which consists
of component->bind() calls used to initialize the remote encoder and attach
it to the crtc. This is different from other drm implementations which expect
the display driver to supply a crtc and connect an encoder to it.

Remove all component framework calls from the komeda driver and declare and
attach an encoder inside komeda_crtc_add().

The remote connector driver has to implement the DRM bridge APIs which
can be used to glue the encoder to the remote connector.

Signed-off-by: Faiz Abbas <faiz.abbas@arm.com>
---
 .../gpu/drm/arm/display/komeda/komeda_crtc.c  | 22 +++++++-
 .../gpu/drm/arm/display/komeda/komeda_drv.c   | 56 ++-----------------
 .../gpu/drm/arm/display/komeda/komeda_kms.c   |  4 --
 .../gpu/drm/arm/display/komeda/komeda_kms.h   |  3 +
 4 files changed, 30 insertions(+), 55 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index cea3fd5772b57..144736a69b0ee 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -12,6 +12,8 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_print.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_simple_kms_helper.h>
+#include <drm/drm_bridge.h>
 
 #include "komeda_dev.h"
 #include "komeda_kms.h"
@@ -612,9 +614,11 @@ static int komeda_crtc_add(struct komeda_kms_dev *kms,
 			   struct komeda_crtc *kcrtc)
 {
 	struct drm_crtc *crtc = &kcrtc->base;
+	struct drm_device *base = &kms->base;
+	struct drm_bridge *bridge;
 	int err;
 
-	err = drm_crtc_init_with_planes(&kms->base, crtc,
+	err = drm_crtc_init_with_planes(base, crtc,
 					get_crtc_primary(kms, kcrtc), NULL,
 					&komeda_crtc_funcs, NULL);
 	if (err)
@@ -626,6 +630,22 @@ static int komeda_crtc_add(struct komeda_kms_dev *kms,
 
 	drm_crtc_enable_color_mgmt(crtc, 0, true, KOMEDA_COLOR_LUT_SIZE);
 
+	/* Construct an encoder for each pipeline and attach it to the remote
+	 * bridge
+	 */
+	kcrtc->encoder.possible_crtcs = drm_crtc_mask(crtc);
+	err = drm_simple_encoder_init(base, &kcrtc->encoder,
+				      DRM_MODE_ENCODER_TMDS);
+	if (err)
+		return err;
+
+	bridge = devm_drm_of_get_bridge(base->dev, kcrtc->master->of_node,
+					KOMEDA_OF_PORT_OUTPUT, 0);
+	if (IS_ERR(bridge))
+		return PTR_ERR(bridge);
+
+	err = drm_bridge_attach(&kcrtc->encoder, bridge, NULL, 0);
+
 	return err;
 }
 
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
index 28f76e07dd958..70b1b693c6eff 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
@@ -28,13 +28,11 @@ struct komeda_dev *dev_to_mdev(struct device *dev)
 	return mdrv ? mdrv->mdev : NULL;
 }
 
-static void komeda_unbind(struct device *dev)
+static int komeda_platform_remove(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct komeda_drv *mdrv = dev_get_drvdata(dev);
 
-	if (!mdrv)
-		return;
-
 	komeda_kms_detach(mdrv->kms);
 
 	if (pm_runtime_enabled(dev))
@@ -46,10 +44,13 @@ static void komeda_unbind(struct device *dev)
 
 	dev_set_drvdata(dev, NULL);
 	devm_kfree(dev, mdrv);
+
+	return 0;
 }
 
-static int komeda_bind(struct device *dev)
+static int komeda_platform_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct komeda_drv *mdrv;
 	int err;
 
@@ -89,52 +90,7 @@ static int komeda_bind(struct device *dev)
 free_mdrv:
 	devm_kfree(dev, mdrv);
 	return err;
-}
-
-static const struct component_master_ops komeda_master_ops = {
-	.bind	= komeda_bind,
-	.unbind	= komeda_unbind,
-};
 
-static void komeda_add_slave(struct device *master,
-			     struct component_match **match,
-			     struct device_node *np,
-			     u32 port, u32 endpoint)
-{
-	struct device_node *remote;
-
-	remote = of_graph_get_remote_node(np, port, endpoint);
-	if (remote) {
-		drm_of_component_match_add(master, match, component_compare_of, remote);
-		of_node_put(remote);
-	}
-}
-
-static int komeda_platform_probe(struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	struct component_match *match = NULL;
-	struct device_node *child;
-
-	if (!dev->of_node)
-		return -ENODEV;
-
-	for_each_available_child_of_node(dev->of_node, child) {
-		if (of_node_cmp(child->name, "pipeline") != 0)
-			continue;
-
-		/* add connector */
-		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT, 0);
-		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT, 1);
-	}
-
-	return component_master_add_with_match(dev, &komeda_master_ops, match);
-}
-
-static int komeda_platform_remove(struct platform_device *pdev)
-{
-	component_master_del(&pdev->dev, &komeda_master_ops);
-	return 0;
 }
 
 static const struct of_device_id komeda_of_match[] = {
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 62dc64550793e..91cbcb6974021 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -305,10 +305,6 @@ struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev)
 	if (err)
 		goto cleanup_mode_config;
 
-	err = component_bind_all(mdev->dev, kms);
-	if (err)
-		goto cleanup_mode_config;
-
 	drm_mode_config_reset(drm);
 
 	err = devm_request_irq(drm->dev, mdev->irq,
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 3a872c2920912..6ef6553263570 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -84,6 +84,9 @@ struct komeda_crtc {
 
 	/** @disable_done: this flip_done is for tracing the disable */
 	struct completion *disable_done;
+
+	/** @encoder: encoder at the end of the pipeline */
+	struct drm_encoder encoder;
 };
 
 /**
-- 
2.25.1