Re: [PATCH] ARM: EDMA: Use platform_get_resource functions for DT

[Mark Rutland]

On Fri, Feb 21, 2014 at 04:24:21AM +0000, Joel Fernandes wrote:
> Currently, EDMA driver uses of_address_to_resource for getting Channel
> controller and x-bar register resources. Use platform_get_resource_by_name
> instead regardless of whether its DT-boot or not, document the new reg-names
> properties.

Doesn't this break existing DTBs?

> 
> Also, while at it get rid of the assumption in the code that "CC" is at reg
> index 0 in the DT and xbar is at offset 1. Instead use reg-names to get the
> memory resource in concern keeping things much cleaner and simpler. This also
> makes it possible to have multiple channel controllers.

While this is nice I think we have to have a fallback to the existing
behaviour if there's no reg-names property present, unless we know for
certain no-one is possibly using an existing DTB.

Cheers,
Mark.

> 
> Signed-off-by: Joel Fernandes <joelf@xxxxxx>
> ---
>  Documentation/devicetree/bindings/dma/ti-edma.txt |    7 ++++++
>  arch/arm/boot/dts/am33xx.dtsi                     |    1 +
>  arch/arm/boot/dts/am4372.dtsi                     |    1 +
>  arch/arm/common/edma.c                            |   28 ++++++++++-----------
>  4 files changed, 22 insertions(+), 15 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/ti-edma.txt b/Documentation/devicetree/bindings/dma/ti-edma.txt
> index 9fbbdb7..176e42b 100644
> --- a/Documentation/devicetree/bindings/dma/ti-edma.txt
> +++ b/Documentation/devicetree/bindings/dma/ti-edma.txt
> @@ -8,6 +8,12 @@ Required properties:
>                Clients should use a single channel number per DMA request.
>  - dma-channels: Specify total DMA channels per CC
>  - reg: Memory map for accessing module
> +- reg-names: Since there can be different memory regions, each reg
> +  entry should correspond to one of the following reg-names (X being 0 to N):
> +	edma_ccX: memory map for Xth Channel Controller
> +	edma_tcX: memory map for Xth Transfer Controller
> +	Additionally there can be a memory map for xbar (in control module):
> +		edma_xbar: memory map for xbar access.
>  - interrupt-parent: Interrupt controller the interrupt is routed through
>  - interrupts: Exactly 3 interrupts need to be specified in the order:
>                1. Transfer completion interrupt.
> @@ -21,6 +27,7 @@ Example:
>  
>  edma: edma@49000000 {
>  	reg = <0x49000000 0x10000>;
> +	reg-names = "edma_cc0";
>  	interrupt-parent = <&intc>;
>  	interrupts = <12 13 14>;
>  	compatible = "ti,edma3";
> diff --git a/arch/arm/boot/dts/am33xx.dtsi b/arch/arm/boot/dts/am33xx.dtsi
> index 2b66e67..55f5723 100644
> --- a/arch/arm/boot/dts/am33xx.dtsi
> +++ b/arch/arm/boot/dts/am33xx.dtsi
> @@ -123,6 +123,7 @@
>  			ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
>  			reg =	<0x49000000 0x10000>,
>  				<0x44e10f90 0x10>;
> +			reg-names = "edma_cc0", "edma_xbar";
>  			interrupts = <12 13 14>;
>  			#dma-cells = <1>;
>  			dma-channels = <64>;
> diff --git a/arch/arm/boot/dts/am4372.dtsi b/arch/arm/boot/dts/am4372.dtsi
> index babdc84..1323a97 100644
> --- a/arch/arm/boot/dts/am4372.dtsi
> +++ b/arch/arm/boot/dts/am4372.dtsi
> @@ -100,6 +100,7 @@
>  			ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
>  			reg =	<0x49000000 0x10000>,
>  				<0x44e10f90 0x10>;
> +			reg-names = "edma_cc0", "edma_xbar";
>  			interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>,
>  					<GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>,
>  					<GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
> index dc95efc..ae0ccae 100644
> --- a/arch/arm/common/edma.c
> +++ b/arch/arm/common/edma.c
> @@ -1458,10 +1458,11 @@ static int edma_xbar_event_map(struct device *dev,
>  			       struct edma_soc_info *pdata, int len)
>  {
>  	int ret, i;
> -	struct resource res;
> +	struct resource *res;
>  	void __iomem *xbar;
>  	const s16 (*xbar_chans)[2];
>  	u32 shift, offset, mux;
> +	struct platform_device *pdev;
>  
>  	xbar_chans = devm_kzalloc(dev,
>  				  len/sizeof(s16) + 2*sizeof(s16),
> @@ -1469,11 +1470,14 @@ static int edma_xbar_event_map(struct device *dev,
>  	if (!xbar_chans)
>  		return -ENOMEM;
>  
> -	ret = of_address_to_resource(node, 1, &res);
> -	if (ret)
> +	pdev = to_platform_device(dev);
> +	res = platform_get_resource_byname(pdev,
> +					   IORESOURCE_MEM,
> +					   "edma_xbar");
> +	if (!res)
>  		return -EIO;
>  
> -	xbar = devm_ioremap(dev, res.start, resource_size(&res));
> +	xbar = devm_ioremap(dev, res->start, resource_size(res));
>  	if (!xbar)
>  		return -ENOMEM;
>  
> @@ -1614,7 +1618,6 @@ static int edma_probe(struct platform_device *pdev)
>  	int			irq[EDMA_MAX_CC] = {0, 0};
>  	int			err_irq[EDMA_MAX_CC] = {0, 0};
>  	struct resource		*r[EDMA_MAX_CC] = {NULL};
> -	struct resource		res[EDMA_MAX_CC];
>  	char			res_name[10];
>  	char			irq_name[10];
>  	struct device_node	*node = pdev->dev.of_node;
> @@ -1653,16 +1656,11 @@ static int edma_probe(struct platform_device *pdev)
>  				return -ENODEV;
>  			break;
>  		}
> -		if (node) {
> -			ret = of_address_to_resource(node, j, &res[j]);
> -			if (!ret)
> -				r[j] = &res[j];
> -		} else {
> -			sprintf(res_name, "edma_cc%d", j);
> -			r[j] = platform_get_resource_byname(pdev,
> -						IORESOURCE_MEM,
> -						res_name);
> -		}
> +
> +		sprintf(res_name, "edma_cc%d", j);
> +		r[j] = platform_get_resource_byname(pdev,
> +					IORESOURCE_MEM,
> +					res_name);
>  		if (!r[j]) {
>  			if (found)
>  				break;
> -- 
> 1.7.9.5
> 
> 
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> 
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