[PATCH] dmaengine: mv_xor_v2: Fix clock resource by adding a register clock

[Gregory CLEMENT]

Hi Vinod,
 
 On jeu., mars 01 2018, Vinod Koul <vinod.koul at intel.com> wrote:


>> >>  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
>> >> +   name must be "core" for the first clock and "reg" for the second
>> >> +   one
>> >> +
>> >>  
>> >>  Example:
>> >>  
>> >> diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
>> >> index f652a0e0f5a2..93b3d80ce701 100644
>> >> --- a/drivers/dma/mv_xor_v2.c
>> >> +++ b/drivers/dma/mv_xor_v2.c
>> >> @@ -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;
>> >> @@ -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?
>> 
>> 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


>
>> 
>> About the typo, do you need a new version or do you plan to fix them
>> while applying the patch?
>> 
>> Thanks,
>> 
>> Gregory
>> 
>> 
>> >
>> >> +	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;
>> >>  }
>> >>  
>> >> -- 
>> >> 2.15.1
>> >> 
>> >
>> > -- 
>> > ~Vinod
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe dmaengine" in
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>> 
>> -- 
>> Gregory Clement, Bootlin (formerly Free Electrons)
>> Embedded Linux and Kernel engineering
>> http://bootlin.com
>> --
>> To unsubscribe from this list: send the line "unsubscribe dmaengine" in
>> the body of a message to majordomo at vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> -- 
> ~Vinod

-- 
Gregory Clement, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com