[PATCH v3 3/3] media: atmel-isi: add primary DT support

[Guennadi Liakhovetski]

Hi Josh,

Thanks for a prompt update! A couple of minor questions:

On Fri, 25 Jul 2014, Josh Wu wrote:

> This patch add the DT support for Atmel ISI driver.
> It use the same v4l2 DT interface that defined in video-interfaces.txt.
> 
> Signed-off-by: Josh Wu <josh.wu at atmel.com>
> Cc: devicetree at vger.kernel.org
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> v2 -> v3:
>   add bus-width property support.
>   add error handling when calling atmel_isi_probe_dt().
> 
> v1 -> v2:
>   refine the binding document.
>   add port node description.
>   removed the optional property.
> 
>  .../devicetree/bindings/media/atmel-isi.txt        | 51 +++++++++++++++++
>  drivers/media/platform/soc_camera/atmel-isi.c      | 64 +++++++++++++++++++++-
>  2 files changed, 113 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/media/atmel-isi.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/atmel-isi.txt b/Documentation/devicetree/bindings/media/atmel-isi.txt
> new file mode 100644
> index 0000000..17e71b7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/atmel-isi.txt
> @@ -0,0 +1,51 @@
> +Atmel Image Sensor Interface (ISI) SoC Camera Subsystem
> +----------------------------------------------
> +
> +Required properties:
> +- compatible: must be "atmel,at91sam9g45-isi"
> +- reg: physical base address and length of the registers set for the device;
> +- interrupts: should contain IRQ line for the ISI;
> +- clocks: list of clock specifiers, corresponding to entries in
> +          the clock-names property;
> +- clock-names: must contain "isi_clk", which is the isi peripherial clock.
> +
> +ISI supports a single port node with parallel bus. It should contain one
> +'port' child node with child 'endpoint' node. Please refer to the bindings
> +defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
> +
> +Example:
> +	isi: isi at f0034000 {
> +		compatible = "atmel,at91sam9g45-isi";
> +		reg = <0xf0034000 0x4000>;
> +		interrupts = <37 IRQ_TYPE_LEVEL_HIGH 5>;
> +
> +		clocks = <&isi_clk>;
> +		clock-names = "isi_clk";
> +
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_isi>;
> +
> +		port {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			isi_0: endpoint {
> +				remote-endpoint = <&ov2640_0>;
> +				bus-width = <8>;
> +			};
> +		};
> +	};
> +
> +	i2c1: i2c at f0018000 {
> +		ov2640: camera at 0x30 {
> +			compatible = "omnivision,ov2640";
> +			reg = <0x30>;
> +
> +			port {
> +				ov2640_0: endpoint {
> +					remote-endpoint = <&isi_0>;
> +					bus-width = <8>;
> +				};
> +			};
> +		};
> +	};
> diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
> index 74af560..ca4e43e 100644
> --- a/drivers/media/platform/soc_camera/atmel-isi.c
> +++ b/drivers/media/platform/soc_camera/atmel-isi.c
> @@ -25,6 +25,7 @@
>  #include <media/atmel-isi.h>
>  #include <media/soc_camera.h>
>  #include <media/soc_mediabus.h>
> +#include <media/v4l2-of.h>
>  #include <media/videobuf2-dma-contig.h>
>  
>  #define MAX_BUFFER_NUM			32
> @@ -33,6 +34,7 @@
>  #define VID_LIMIT_BYTES			(16 * 1024 * 1024)
>  #define MIN_FRAME_RATE			15
>  #define FRAME_INTERVAL_MILLI_SEC	(1000 / MIN_FRAME_RATE)
> +#define ISI_DEFAULT_MCLK_FREQ		25000000
>  
>  /* Frame buffer descriptor */
>  struct fbd {
> @@ -883,6 +885,50 @@ static int atmel_isi_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int atmel_isi_probe_dt(struct atmel_isi *isi,
> +			struct platform_device *pdev)
> +{
> +	struct device_node *np= pdev->dev.of_node;
> +	struct v4l2_of_endpoint ep;
> +	int err;
> +
> +	/* Default settings for ISI */
> +	isi->pdata.full_mode = 1;
> +	isi->pdata.mck_hz = ISI_DEFAULT_MCLK_FREQ;
> +	isi->pdata.frate = ISI_CFG1_FRATE_CAPTURE_ALL;
> +
> +	np = of_graph_get_next_endpoint(np, NULL);
> +	if (!np) {
> +		dev_err(&pdev->dev, "Could not find the endpoint\n");
> +		return -EINVAL;
> +	}
> +
> +	err = v4l2_of_parse_endpoint(np, &ep);
> +	if (err) {
> +		dev_err(&pdev->dev, "Could not parse the endpoint\n");
> +		goto err_probe_dt;
> +	}
> +
> +	switch (ep.bus.parallel.bus_width) {
> +	case 8:
> +		isi->pdata.data_width_flags = ISI_DATAWIDTH_8;
> +		break;
> +	case 10:
> +		isi->pdata.data_width_flags = ISI_DATAWIDTH_10;
> +		break;

Wouldn't it be natural, if bus_width=10 is specified in DT to enable both 
ISI_DATAWIDTH_8 and ISI_DATAWIDTH_10?

> +	default:
> +		dev_err(&pdev->dev, "Not supported bus width: %d\n",

Wouldn't "Unsupported" be better?

> +				ep.bus.parallel.bus_width);
> +		err = -EINVAL;
> +		goto err_probe_dt;
> +	}
> +
> +err_probe_dt:
> +	of_node_put(np);
> +
> +	return err;
> +}
> +
>  static int atmel_isi_probe(struct platform_device *pdev)
>  {
>  	unsigned int irq;
> @@ -894,7 +940,7 @@ static int atmel_isi_probe(struct platform_device *pdev)
>  	struct isi_platform_data *pdata;
>  
>  	pdata = dev->platform_data;
> -	if (!pdata || !pdata->data_width_flags) {
> +	if ((!pdata || !pdata->data_width_flags) && !pdev->dev.of_node) {
>  		dev_err(&pdev->dev,
>  			"No config available for Atmel ISI\n");
>  		return -EINVAL;
> @@ -910,7 +956,14 @@ static int atmel_isi_probe(struct platform_device *pdev)
>  	if (IS_ERR(isi->pclk))
>  		return PTR_ERR(isi->pclk);
>  
> -	memcpy(&isi->pdata, pdata, sizeof(isi->pdata));
> +	if (pdata) {
> +		memcpy(&isi->pdata, pdata, sizeof(isi->pdata));
> +	} else {
> +		ret = atmel_isi_probe_dt(isi, pdev);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	isi->active = NULL;
>  	spin_lock_init(&isi->lock);
>  	INIT_LIST_HEAD(&isi->video_buffer_list);
> @@ -1012,11 +1065,18 @@ err_alloc_ctx:
>  	return ret;
>  }
>  
> +static const struct of_device_id atmel_isi_of_match[] = {
> +	{ .compatible = "atmel,at91sam9g45-isi" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, atmel_isi_of_match);
> +
>  static struct platform_driver atmel_isi_driver = {
>  	.remove		= atmel_isi_remove,
>  	.driver		= {
>  		.name = "atmel_isi",
>  		.owner = THIS_MODULE,
> +		.of_match_table = atmel_isi_of_match,

I think you're supposed to use of_match_ptr() here for your driver to be 
usable both with and without DT?

Thanks
Guennadi

>  	},
>  };
>  
> -- 
> 1.9.1
>