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

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

Hi, Laurent

On 3/18/2014 9:36 PM, Laurent Pinchart wrote:
> Hi Josh,
>
> Thank you for the patch.

Thanks for your review.

>
> On Tuesday 18 March 2014 19:19:54 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
>> ---
>>   .../devicetree/bindings/media/atmel-isi.txt        |   51 +++++++++++++++++
>>   drivers/media/platform/soc_camera/atmel-isi.c      |   33 ++++++++++++-
>>   2 files changed, 82 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..07f00eb
>> --- /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_mck" is optinal, it is the master clock output to
>> sensor.
> The mck clock should be handled by the sensor driver instead. I know we have a
> legacy mode in the atmel-isi driver to manage that clock internally, but let's
> not propagate that to DT.

I agree with you.

I put the isi_mck as optional here because current the sensor driver 
code only managed the v4l2 clock not the common clock.
There should add additional code to manager mck clock.
So if you want to ISI work for now, you should put the isi_mck in 
atmel-isi DT node.

But for sure I can remove the isi_mck in atmel-isi DT document. In the 
future it will be add in sensor's DT document.

> I would also drop the "isi_" prefix from the isi_clk
> name.

hmm,  I think "isi_clk" indicates it is a ISI peripheral clock. And 
which is consistent with other peripheral clock name in sama5.

>
> You should also describe the port node. You can just mention the related
> bindings document, and state that the ISI has a single port.

OK. will add in the v2.

>
>> +Optional properties:
>> +- atmel,isi-disable-preview: a boolean property to disable the preview
>> channel;
> That doesn't really sound like a hardware property to me. Isn't it full mode
> related to software configuration instead, which should be performed at
> runtime by userspace ?

yes, this configuration can be disable/enable by driver according to 
user select format.
I will remove it in v2. Thanks.

Best Regards,
Josh Wu

>
>> +
>> +Example:
>> +	isi: isi@f0034000 {
>> +		compatible = "atmel,at91sam9g45-isi";
>> +		reg = <0xf0034000 0x4000>;
>> +		interrupts = <37 IRQ_TYPE_LEVEL_HIGH 5>;
>> +
>> +		clocks = <&isi_clk>, <&pck1>;
>> +		clock-names = "isi_clk", "isi_mck";
>> +
>> +		pinctrl-names = "default";
>> +		pinctrl-0 = <&pinctrl_isi &pinctrl_pck1_as_isi_mck>;
>> +
>> +		port {
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +
>> +			isi_0: endpoint {
>> +				remote-endpoint = <&ov2640_0>;
>> +			};
>> +		};
>> +	};
>> +
>> +	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 93bf1cb..1822129
>> 100644
>> --- a/drivers/media/platform/soc_camera/atmel-isi.c
>> +++ b/drivers/media/platform/soc_camera/atmel-isi.c
>> @@ -19,6 +19,7 @@
>>   #include <linux/interrupt.h>
>>   #include <linux/kernel.h>
>>   #include <linux/module.h>
>> +#include <linux/of.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/slab.h>
>>
>> @@ -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 {
>> @@ -878,6 +880,22 @@ 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 *node = pdev->dev.of_node;
>> +
>> +	isi->pdata.full_mode = !of_property_read_bool(node,
>> +			"atmel,isi-disable-preview");
>> +
>> +	/* Default settings for ISI */
>> +	isi->pdata.mck_hz = ISI_DEFAULT_MCLK_FREQ;
>> +	isi->pdata.frate = ISI_CFG1_FRATE_CAPTURE_ALL;
>> +	isi->pdata.data_width_flags = ISI_DATAWIDTH_8 | ISI_DATAWIDTH_10;
>> +
>> +	return 0;
>> +}
>> +
>>   static int atmel_isi_probe(struct platform_device *pdev)
>>   {
>>   	unsigned int irq;
>> @@ -889,7 +907,7 @@ 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;
>> @@ -905,7 +923,11 @@ static int atmel_isi_probe(struct platform_device
>> *pdev) if (IS_ERR(isi->pclk))
>>   		return PTR_ERR(isi->pclk);
>>
>> -	memcpy(&isi->pdata, pdata, sizeof(struct isi_platform_data));
>> +	if (pdata)
>> +		memcpy(&isi->pdata, pdata, sizeof(struct isi_platform_data));
>> +	else	/* dt probe */
>> +		atmel_isi_probe_dt(isi, pdev);
>> +
>>   	isi->active = NULL;
>>   	spin_lock_init(&isi->lock);
>>   	INIT_LIST_HEAD(&isi->video_buffer_list);
>> @@ -1007,11 +1029,18 @@ 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,
>>   	},
>>   };