drm/komeda: Unify mclk/pclk/pipeline->aclk to one MCLK

Current komeda driver uses three dedicated clks for a specific purpose:
- mclk: main engine clock
- pclk: APB clock
- pipeline->aclk: AXI clock.

But per spec the komeda HW only has three input clks:
- ACLK: used for AXI masters, APB slave and most pipeline processing
- PXCLK for pipeline 0: output pixel clock for pipeline 0
- PXCLK for pipeline 1: output pixel clock for pipeline 1

So one ACLK is enough, no need to split it to three mclk/pclk/axiclk.
drop pclk/pipeline->axiclk. but only keep one mclk in komeda driver.

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

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

@@ -123,9 +123,6 @@ komeda_crtc_prepare(struct komeda_crtc *kcrtc)
 			DRM_ERROR("failed to enable mclk.\n");
 	}
 
-	err = clk_prepare_enable(master->aclk);
-	if (err)
-		DRM_ERROR("failed to enable axi clk for pipe%d.\n", master->id);
 	err = clk_set_rate(master->pxlclk, pxlclk_rate);
 	if (err)
 		DRM_ERROR("failed to set pxlclk for pipe%d\n", master->id);
@@ -166,7 +163,6 @@ komeda_crtc_unprepare(struct komeda_crtc *kcrtc)
 	mdev->dpmode = new_mode;
 
 	clk_disable_unprepare(master->pxlclk);
-	clk_disable_unprepare(master->aclk);
 	if (new_mode == KOMEDA_MODE_INACTIVE)
 		clk_disable_unprepare(mdev->mclk);
 
@@ -362,13 +358,6 @@ komeda_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *m)
 		return MODE_CLOCK_HIGH;
 	}
 
-	if (clk_round_rate(master->aclk, mode_clk) < pxlclk) {
-		DRM_DEBUG_ATOMIC("aclk can't satisfy the requirement of %s-clk: %ld.\n",
-				 m->name, pxlclk);
-
-		return MODE_CLOCK_HIGH;
-	}
-
 	return MODE_OK;
 }
 

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

@@ -116,13 +116,6 @@ static int komeda_parse_pipe_dt(struct komeda_dev *mdev, struct device_node *np)
 
 	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);
@@ -145,14 +138,8 @@ 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");
@@ -206,16 +193,15 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
 		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;
+	mdev->mclk = devm_clk_get(dev, "mclk");
+	if (IS_ERR(mdev->mclk)) {
+		DRM_ERROR("Get engine clk failed.\n");
+		err = PTR_ERR(mdev->mclk);
+		mdev->mclk = NULL;
 		goto err_cleanup;
 	}
 
-	/* Enable APB clock to access the registers */
-	clk_prepare_enable(mdev->pclk);
+	clk_prepare_enable(mdev->mclk);
 
 	mdev->funcs = product->identify(mdev->reg_base, &mdev->chip);
 	if (!komeda_product_match(mdev, product->product_id)) {
@@ -315,15 +301,10 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
 	}
 
 	if (mdev->mclk) {
+		clk_disable_unprepare(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

@@ -160,8 +160,6 @@ struct komeda_dev {
 	struct komeda_chip_info chip;
 	/** @fmt_tbl: initialized by &komeda_dev_funcs->init_format_table */
 	struct komeda_format_caps_table fmt_tbl;
-	/** @pclk: APB clock for register access */
-	struct clk *pclk;
 	/** @mclk: HW main engine clk */
 	struct clk *mclk;
 

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

@@ -53,7 +53,6 @@ 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);

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

@@ -343,8 +343,6 @@ struct komeda_pipeline {
 	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 */