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dmaengine: mv_xor_v2: Fix clock resource by adding a register clock

DISCUSSION Gregory CLEMENT 1 participant 1 message Mar 1, 2018 dmaengine

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Hi Vinod,

Quoted 32 lines · Vinod Koul
Quoted 32 lines
Quoted 31 lines
Quoted 23 lines

Optional properties:
-- clocks: Optional reference to the clock used by the XOR engine.

+- clocks: Optional reference to the clocks used by the XOR engine.
+- clock-names: mandatory if there is a second clock, in this case the
(quoted diff) +3 -0
+   name must be "core" for the first clock and "reg" for the second
+   one
+
 
 Example:
drivers/dma/mv_xor_v2.c +1 -0
index f652a0e0f5a2..93b3d80ce701 100644
@@ -163,6 +163,7 @@ struct mv_xor_v2_device {
 	void __iomem *dma_base;
 	void __iomem *glob_base;
 	struct clk *clk;
+	struct clk *reg_clk;
 	struct tasklet_struct irq_tasklet;
 	struct list_head free_sw_desc;
 	struct dma_device dmadev;

drivers/dma/mv_xor_v2.c static int mv_xor_v2_probe(struct platform_device *pdev) · line 753

Quoted 6 lines
drivers/dma/mv_xor_v2.c +1 -2
@@ -749,13 +750,24 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER)
+	xor_dev->reg_clk = devm_clk_get(&pdev->dev, "reg");

is this an exiting property?

Quoted 5 lines
Quoted 2 lines

It is the name of the new optional clock described in the first part of this patch.

okay I am missing something then, you are reading "reg" but property added is "clock-names", where are you reading this?

"reg" is actually the _name_ of the clock given by the clock-names property.

With devm_clk_get the second parameter is a pointer to the name of the clock name. When it is NULL then, the first clock is used, else in the common clock framework looks for the clock associated with the name given.

With this patch both clock have now a name, but in order to be backward compatible, I don't use the name for the first clock. It allows to still use this clock with a device tree using the old binding.

Gregory

Quoted 66 lines
Quoted 63 lines

About the typo, do you need a new version or do you plan to fix them while applying the patch?

Thanks,

Gregory

Quoted 44 lines
Quoted 37 lines
drivers/dma/mv_xor_v2.c +16 -3
+	if (!IS_ERR(xor_dev->reg_clk)) {
+		ret = clk_prepare_enable(xor_dev->reg_clk);
+		if (ret)
+			return ret;
+	} else if (PTR_ERR(xor_dev->reg_clk) == -EPROBE_DEFER) {
 		return -EPROBE_DEFER;
+	}
+
+	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
+		ret = EPROBE_DEFER;
+		goto disable_reg_clk;
+	}
 	if (!IS_ERR(xor_dev->clk)) {
 		ret = clk_prepare_enable(xor_dev->clk);
 		if (ret)
-			return ret;
+			goto disable_reg_clk;
 	}
 
 	ret = platform_msi_domain_alloc_irqs(&pdev->dev, 1,
@@ -866,8 +878,9 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 free_msi_irqs:
 	platform_msi_domain_free_irqs(&pdev->dev);
 disable_clk:
-	if (!IS_ERR(xor_dev->clk))
-		clk_disable_unprepare(xor_dev->clk);
+	clk_disable_unprepare(xor_dev->clk);
+disable_reg_clk:
+	clk_disable_unprepare(xor_dev->reg_clk);
 	return ret;
 }
 
Signature · 1 line
2.15.1
Signature · 5 lines
~Vinod
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Signature · 7 lines
Gregory Clement, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com
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~Vinod