drm/komeda: Add DT parsing

Parse DT and initialize corresponding dev/pipeline attributes.

Changes in v4:
- Rebase.

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>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

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

@@ -9,6 +9,76 @@
 #include <linux/of_graph.h>
 #include "komeda_dev.h"
 
+static int komeda_parse_pipe_dt(struct komeda_dev *mdev, struct device_node *np)
+{
+	struct komeda_pipeline *pipe;
+	struct clk *clk;
+	u32 pipe_id;
+	int ret = 0;
+
+	ret = of_property_read_u32(np, "reg", &pipe_id);
+	if (ret != 0 || pipe_id >= mdev->n_pipelines)
+		return -EINVAL;
+
+	pipe = mdev->pipelines[pipe_id];
+
+	clk = of_clk_get_by_name(np, "aclk");
+	if (IS_ERR(clk)) {
+		DRM_ERROR("get aclk for pipeline %d failed!\n", pipe_id);
+		return PTR_ERR(clk);
+	}
+	pipe->aclk = clk;
+
+	clk = of_clk_get_by_name(np, "pxclk");
+	if (IS_ERR(clk)) {
+		DRM_ERROR("get pxclk for pipeline %d failed!\n", pipe_id);
+		return PTR_ERR(clk);
+	}
+	pipe->pxlclk = clk;
+
+	/* enum ports */
+	pipe->of_output_dev =
+		of_graph_get_remote_node(np, KOMEDA_OF_PORT_OUTPUT, 0);
+	pipe->of_output_port =
+		of_graph_get_port_by_id(np, KOMEDA_OF_PORT_OUTPUT);
+
+	pipe->of_node = np;
+
+	return 0;
+}
+
+static int komeda_parse_dt(struct device *dev, struct komeda_dev *mdev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct device_node *child, *np = dev->of_node;
+	struct clk *clk;
+	int ret;
+
+	clk = devm_clk_get(dev, "mclk");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	mdev->mclk = clk;
+	mdev->irq  = platform_get_irq(pdev, 0);
+	if (mdev->irq < 0) {
+		DRM_ERROR("could not get IRQ number.\n");
+		return mdev->irq;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		if (of_node_cmp(child->name, "pipeline") == 0) {
+			ret = komeda_parse_pipe_dt(mdev, child);
+			if (ret) {
+				DRM_ERROR("parse pipeline dt error!\n");
+				of_node_put(child);
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
 struct komeda_dev *komeda_dev_create(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -71,6 +141,12 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
 		goto err_cleanup;
 	}
 
+	err = komeda_parse_dt(dev, mdev);
+	if (err) {
+		DRM_ERROR("parse device tree failed.\n");
+		goto err_cleanup;
+	}
+
 	return mdev;
 
 err_cleanup:

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

@@ -72,6 +72,9 @@ struct komeda_dev {
 	/** @mck: HW main engine clk */
 	struct clk *mclk;
 
+	/** @irq: irq number */
+	u32 irq;
+
 	int n_pipelines;
 	struct komeda_pipeline *pipelines[KOMEDA_MAX_PIPELINES];
 

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

@@ -53,6 +53,10 @@ void komeda_pipeline_destroy(struct komeda_dev *mdev,
 	clk_put(pipe->pxlclk);
 	clk_put(pipe->aclk);
 
+	of_node_put(pipe->of_output_dev);
+	of_node_put(pipe->of_output_port);
+	of_node_put(pipe->of_node);
+
 	devm_kfree(mdev->dev, pipe);
 }
 

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

@@ -288,6 +288,13 @@ struct komeda_pipeline {
 	struct komeda_improc *improc;
 	struct komeda_timing_ctrlr *ctrlr;
 	struct komeda_pipeline_funcs *funcs; /* private pipeline functions */
+
+	/** @of_node: pipeline dt node */
+	struct device_node *of_node;
+	/** @of_output_port: pipeline output port */
+	struct device_node *of_output_port;
+	/** @of_output_dev: output connector device node */
+	struct device_node *of_output_dev;
 };
 
 /**