# ISC Image Sensor Controller (Camera) 

<abstract>
This page describes how to configure and use of the ISC port on Roadrunner SOM.
</abstract>

Tested on Linux Kernel 5.15

## Hardware used

Omnivision OV5640 camera

<img src="./waveshare.jpg" width="360px">


## Wirings

| Signal    | SAMA5D2 pin | Camera pin 
|-----------|-------------|------------
| ISC_D4    | PB30	      | D2		
| ISC_D5    | PB31	      | D3
| ISC_D6    | PC0	      | D4
| ISC_D7    | PC1	      | D5
| ISC_D8    | PC2	      | D6
| ISC_D9    | PC3 	      | D7
| ISC_D10   | PB24	      | D8
| ISC_D11   | PB25	      | D9
| ISC_VSYNC | PC5	      | VSYNC  OUT Active High Frame Valid; indicates active frame
| ISC_HSYNC | PC6         | HREF   OUT Active High: Line/Data Valid; indicates active pixels
| ISC_MCK   | PC7         | XCLK   INP Master Clock into Sensor
| ISC_PCK   | PC4         | PCLK   OUT Pixel Clock output from sensor
| TWCK1     | PD5	      | SIOC   I2C Clock
| TWD1      | PD4	      | SIOD   I2C Data 
| PB11   	| PB11	      | RST	   INP Sensor reset signal, active low
| PB12      | PB12        | PWON   INP Power down input, active high
| 3V		|		      | 3.3V
| GND		|		      | GND


## Linux driver

	Device Drivers  --->
		<*> Multimedia support  ---> 
			Media drivers  --->
				[*] V4L platform devices  --->
					<*>   ATMEL Image Sensor Controller (ISC) support
					<*>   ATMEL eXtended Image Sensor Controller (XISC) support
					<*>   ATMEL Image Sensor Interface (ISI) support
			Media ancillary drivers  --->
				<*> OmniVision OV5640 sensor support  

## Device tree and defconfig

definitions inside apb section:

	//********************
	// Camera ISC Port
	//********************

	/* Omnivision OV5640 (5Mpixel) */

	i2c1: i2c@fc028000 {
		#address-cells = <1>;
		#size-cells = <0>;
		pinctrl-names = "default","gpio";
		//pinctrl-names = "default";
		pinctrl-0 = <&pinctrl_i2c1_default>;
		pinctrl-1 = <&pinctrl_i2c1_gpio>;
		i2c-analog-filter;
		i2c-digital-filter;
		i2c-digital-filter-width-ns = <35>;
		sda-gpios = <&pioA PIN_PD4 GPIO_ACTIVE_HIGH>;
		scl-gpios = <&pioA PIN_PD5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
		status = "okay";

		ov5640: camera@3c {
			compatible = "ovti,ov5640";
			reg = <0x3c>;
			pinctrl-names = "default";
			pinctrl-0 = <&pinctrl_sensor_power &pinctrl_sensor_reset>;
			reset-gpios = <&pioA PIN_PB11 GPIO_ACTIVE_LOW>;
			powerdown-gpios = <&pioA PIN_PB12 GPIO_ACTIVE_HIGH>;
			clocks = <&isc>;
			clock-names = "xclk";
			assigned-clocks = <&isc>;
			assigned-clock-rates = <25000000>;
			status = "okay";

			port {
				ov5640_0: endpoint {
					remote-endpoint = <&isc_0>;
					bus-width = <8>;
					data-shift = <2>;
					hsync-active = <1>;
					vsync-active = <1>;
					pclk-sample = <1>;
				};
			};
		};

	};


	isc: isc@f0008000 {
		pinctrl-names = "default";
		pinctrl-0 = <&pinctrl_isc_base &pinctrl_isc_data_8bit>;
		status = "okay";

		port {
			isc_0: endpoint@0 {
				remote-endpoint = <&ov5640_0>;
				bus-width = <8>;
				data-shift = <2>;
				hsync-active = <0>;
				vsync-active = <0>;
				pclk-sample = <1>;
			};
		};
	}; 


definitions inside pinctrl@fc038000 section:

	pinctrl_isc_base: isc_base {
		pinmux = <PIN_PC4__ISC_PCK>,
			 <PIN_PC5__ISC_VSYNC>,
			 <PIN_PC6__ISC_HSYNC>,
			 <PIN_PC7__ISC_MCK>;
		bias-disable;
	};

	pinctrl_isc_data_8bit: isc_data_8bit {
		pinmux = <PIN_PB25__ISC_D11>,
			 <PIN_PB24__ISC_D10>,
			 <PIN_PC3__ISC_D9>,
			 <PIN_PC2__ISC_D8>,
			 <PIN_PC1__ISC_D7>,
			 <PIN_PC0__ISC_D6>,
			 <PIN_PB31__ISC_D5>,
			 <PIN_PB30__ISC_D4>;
		bias-disable;
	};

	pinctrl_sensor_power: sensor_power {
		pinmux = <PIN_PB12__GPIO>;
		bias-pull-up;
	};

	pinctrl_sensor_reset: sensor_reset {
		pinmux = <PIN_PB11__GPIO>;
		bias-pull-up;
	};

## Use the camera from user space

### Test the v4l2 API compliance of the ISC driver

	sudo v4l2-compliance

### Display all information available

	sudo v4l2-ctl --all

### Use the Microchip script to capture 

Configure the media controller pipeline

	sudo media-ctl -d /dev/media0 --set-v4l2 '4:0[fmt:SRGGB8_1X8/1920x1080@1/30 field:none colorspace:srgb]'
	sudo media-ctl -d /dev/media0 --set-v4l2 '"atmel_isc_scaler":0[fmt:SRGGB8_1X8/1920x1080 field:none colorspace:srgb]'
	sudo v4l2-ctl -d /dev/video0 -v pixelformat=RGBP,height=1080,width=1920

Capture an image:

	sudo fswebcam -d /dev/video0 -i 0 -p BAYER -r 1920x1080 /var/www/html/out.jpg

## Links

* [Linux4Sam: UsingISC (Image Sensor Controller)](https://www.linux4sam.org/bin/view/Linux4SAM/UsingISC)
* [GitHub - Video Capture AT91](https://github.com/linux4sam/video-capture-at91)
* [Datasheet Omnivision OV5640](./OV5640.pdf)
* [5MP: OV5640](https://www.arducam.com/products/camera-breakout-board/5mp-ov5640/)
* [ov5640.dtso](https://github.com/linux4sam/dt-overlay-at91/blob/master/sama5d2_xplained/sama5d2_xplained_ov5640.dtso)

@include='adv_roadrunner'