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

[Vinod Koul <vinod.koul@intel.com>]

Pls do CC DT folks and Rob for bindings update

On Wed, Feb 14, 2018 at 05:27:33PM +0100, Gregory CLEMENT wrote:
> On the CP110 components whic are present on the Armada 7K/8K SoC we need

/s/whic/which

> to explicitly enable the registers clock. However it is not needed for

/s/registers/register

> the AP8xx componenet, that's why this clock is optional.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  .../devicetree/bindings/dma/mv-xor-v2.txt          |  6 +++++-
>  drivers/dma/mv_xor_v2.c                            | 23 +++++++++++++++++-----
>  2 files changed, 23 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/mv-xor-v2.txt b/Documentation/devicetree/bindings/dma/mv-xor-v2.txt
> index 217a90eaabe7..9c38bbe7e6d7 100644
> --- a/Documentation/devicetree/bindings/dma/mv-xor-v2.txt
> +++ b/Documentation/devicetree/bindings/dma/mv-xor-v2.txt
> @@ -11,7 +11,11 @@ Required properties:
>    interrupts.
>  
>  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?

> +	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
>