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

[Josh Wu <josh.wu@atmel.com>]

Hi, Guennadi

On 7/27/2014 3:57 AM, Guennadi Liakhovetski wrote:
> 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@atmel.com>
>> Cc: devicetree@vger.kernel.org
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@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@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@f0018000 {
>> +		ov2640: camera@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?

yes. That's what I want to supported. Thanks.
>
>> +	default:
>> +		dev_err(&pdev->dev, "Not supported bus width: %d\n",
> Wouldn't "Unsupported" be better?
OK.

>
>> +				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 for review. I will fix above by your suggestion in next version.

Best Regards,
Josh Wu

> Thanks
> Guennadi
>
>>   	},
>>   };
>>   
>> -- 
>> 1.9.1
>>