[alsa-devel] [PATCH 11/17] ASoC: Tegra I2S: Add device tree binding

Thierry Reding thierry.reding at avionic-design.de
Wed Nov 23 08:04:49 CET 2011


* Stephen Warren wrote:
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> ---
>  .../devicetree/bindings/sound/tegra20-i2s.txt      |   16 +++++++++++
>  sound/soc/tegra/tegra_i2s.c                        |   29 ++++++++++++++++---
>  2 files changed, 40 insertions(+), 5 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/sound/tegra20-i2s.txt
> 
> diff --git a/Documentation/devicetree/bindings/sound/tegra20-i2s.txt b/Documentation/devicetree/bindings/sound/tegra20-i2s.txt
> new file mode 100644
> index 0000000..d38abdc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/tegra20-i2s.txt
> @@ -0,0 +1,16 @@
> +NVIDIA Tegra 20 I2S controller
> +
> +Required properties:
> +- compatible : "nvidia,tegra20-i2s"
> +- reg : Should contain I2S registers location and length
> +- interrupts : Should contain I2S interrupt
> +- dma-channel : The Tegra DMA controller's channel ID for this I2S controller
> +
> +Example:
> +
> +i2s at 70002800 {
> +	compatible = "nvidia,tegra20-i2s";
> +	reg = <0x70002800 0x200>;
> +	interrupts = < 45 >;
> +	dma-channel = < 2 >;
> +};
> diff --git a/sound/soc/tegra/tegra_i2s.c b/sound/soc/tegra/tegra_i2s.c
> index 3c0cbd2..b4e19a5 100644
> --- a/sound/soc/tegra/tegra_i2s.c
> +++ b/sound/soc/tegra/tegra_i2s.c
> @@ -36,6 +36,7 @@
>  #include <linux/seq_file.h>
>  #include <linux/slab.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
>  #include <mach/iomap.h>
>  #include <sound/core.h>
>  #include <sound/pcm.h>
> @@ -332,6 +333,7 @@ static __devinit int tegra_i2s_platform_probe(struct platform_device *pdev)
>  	struct tegra_i2s * i2s;
>  	struct resource *mem, *memregion, *dmareq;
>  	int ret;
> +	u32 dma_ch;
>  
>  	i2s = devm_kzalloc(&pdev->dev, sizeof(struct tegra_i2s), GFP_KERNEL);
>  	if (!i2s) {
> @@ -360,9 +362,19 @@ static __devinit int tegra_i2s_platform_probe(struct platform_device *pdev)
>  
>  	dmareq = platform_get_resource(pdev, IORESOURCE_DMA, 0);
>  	if (!dmareq) {
> -		dev_err(&pdev->dev, "No DMA resource\n");
> -		ret = -ENODEV;
> -		goto err_clk_put;
> +		/*
> +		 * FIXME: Perhaps there should be a standard binding for this
> +		 * that ends up creating the IORESOURCE_DMA resource for us.
> +		 */
> +		if (of_property_read_u32(pdev->dev.of_node,
> +					 "nvidia,dma-channels",

The binding documentation says the property is called "nvidia,dma-channel"
but you use "nvidia,dma-channel*s*" here.

> +					 &dma_ch) < 0) {
> +			dev_err(&pdev->dev, "No DMA resource\n");
> +			ret = -ENODEV;
> +			goto err_clk_put;
> +		}
> +	} else {
> +		dma_ch = dmareq->start;
>  	}
>  
>  	memregion = devm_request_mem_region(&pdev->dev, mem->start,
> @@ -383,12 +395,12 @@ static __devinit int tegra_i2s_platform_probe(struct platform_device *pdev)
>  	i2s->capture_dma_data.addr = mem->start + TEGRA_I2S_FIFO2;
>  	i2s->capture_dma_data.wrap = 4;
>  	i2s->capture_dma_data.width = 32;
> -	i2s->capture_dma_data.req_sel = dmareq->start;
> +	i2s->capture_dma_data.req_sel = dma_ch;
>  
>  	i2s->playback_dma_data.addr = mem->start + TEGRA_I2S_FIFO1;
>  	i2s->playback_dma_data.wrap = 4;
>  	i2s->playback_dma_data.width = 32;
> -	i2s->playback_dma_data.req_sel = dmareq->start;
> +	i2s->playback_dma_data.req_sel = dma_ch;
>  
>  	i2s->reg_ctrl = TEGRA_I2S_CTRL_FIFO_FORMAT_PACKED;
>  
> @@ -422,10 +434,16 @@ static int __devexit tegra_i2s_platform_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static const struct of_device_id tegra_i2s_of_match[] __devinitconst = {
> +	{ .compatible = "nvidia,tegra20-i2s", },
> +	{},
> +};
> +
>  static struct platform_driver tegra_i2s_driver = {
>  	.driver = {
>  		.name = DRV_NAME,
>  		.owner = THIS_MODULE,
> +		.of_match_table = tegra_i2s_of_match,
>  	},
>  	.probe = tegra_i2s_platform_probe,
>  	.remove = __devexit_p(tegra_i2s_platform_remove),
> @@ -436,3 +454,4 @@ MODULE_AUTHOR("Stephen Warren <swarren at nvidia.com>");
>  MODULE_DESCRIPTION("Tegra I2S ASoC driver");
>  MODULE_LICENSE("GPL");
>  MODULE_ALIAS("platform:" DRV_NAME);
> +MODULE_DEVICE_TABLE(of, tegra_i2s_of_match);
> -- 
> 1.7.0.4
> 
> --
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> 
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