ISC Image Sensor Controller (Camera)

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

Tested on Linux Kernel 5.15

Hardware used

Omnivision OV5640 camera

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