How to enable two identical sensors mt9p031 as /dev/video0 and /dev/video1

[evgenymolchanov]

Hello all.

Sorry for my english.

I'm using kernel 3.10.53 from Yocto.

I need to use two identical parallel data sensors from Aptina mt9p031 connected to iMX6Q CSI0 and CSI1.

I have already working both sensors at the same time by writing my own kernel module and capture data from sensors via pread function from user space.

But I want to use sensors with gstreamer, so i need to create /dev/video0 and /dev/video1

I have read this and this but both posts discuss connection one or two different sensors and each module support only one sensor.

Here is part of my dtsi file:

    v4l2_cap_0 {

        compatible = "fsl,imx6q-v4l2-capture";

        ipu_id = <0>;

        csi_id = <0>;

        mclk_source = <0>;

        status = "okay";

    };

    v4l2_cap_1 {

        compatible = "fsl,imx6q-v4l2-capture";

        ipu_id = <1>;

        csi_id = <1>;

        mclk_source = <0>;

        status = "okay";

    };

    v4l2_out {

        compatible = "fsl,mxc_v4l2_output";

        status = "okay";

    };

...

&i2c3 {

    clock-frequency = <100000>;

    pinctrl-names = "default";

    pinctrl-0 = <&pinctrl_i2c3_2>;

    status = "okay";

    camera1: camera1@48 {

        compatible = "aptina,mt9p031";

        reg = <0x48>;

        pinctrl-names = "default";

        pinctrl-0 = <&pinctrl_ipu1_4>;

        clocks = <&clks 200>;

        clock-names = "csi_mclk";

//        vaa = <&reg_2p8v>;  // 2.8v

//        vdd = <&reg_1p5v>;  // 1.5v

//        vdd_io = <&reg_1p5v>;  // 1.5v

//        pwn-gpios = <&gpio? ? ?>;

        reset-gpio = <&gpio1 4 GPIO_ACTIVE_LOW>;

        reset-delay-us = <5000>;

        initially-in-reset;

        oe-gpio = <&gpio5 20 0>;

        interrupt-parent = <&gpio5>;

        interrupts = <26 0>;

        csi_id = <0>;

        mclk = <24000000>;

        mclk_source = <0>;

        port {

            camera1_1: endpoint {

                input-clock-frequency = <24000000>;

                pixel-clock-frequency = <96000000>;

            };

        };

    };

    camera2: camera2@5D {

        compatible = "aptina,mt9p031";

        reg = <0x5D>;

        pinctrl-names = "default";

        pinctrl-0 = <&pinctrl_ipu2_1>;

        clocks = <&clks 200>;

        clock-names = "csi_mclk";

//        vaa = <&reg_2p8v>;  // 2.8v

//        vdd = <&reg_1p5v>;  // 1.5v

//        vdd_io = <&reg_1p5v>;  // 1.5v

//        pwn-gpios = <&gpio? ? ?>;

        reset-gpio = <&gpio2 27 GPIO_ACTIVE_LOW>;

        reset-delay-us = <5000>;

        initially-in-reset;

        oe-gpio = <&gpio3 10 0>;

        interrupt-parent = <&gpio3>;

        interrupts = <1 0>;

        csi_id = <1>;

        mclk = <24000000>;

        mclk_source = <0>;

        port {

            camera2_1: endpoint {

                input-clock-frequency = <24000000>;

                pixel-clock-frequency = <96000000>;

            };

        };

    };

};

sensors connected to i2c3 and they have different i2c addresses.

I have started write module in /drivers/media/platform/mxc/capture/mt9p031.c based on ov5642.c

I've implement only probe function and both sensors probed successfully.

/dev/video0 and /dev/video1 also created.

After this i try from user space get capabilites:

if (ioctl(file_device, VIDIOC_QUERYCAP, &device_params) == -1)

{

  printf ("\"VIDIOC_QUERYCAP\" error %d, %s\n", errno, strerror(errno));

  exit(EXIT_FAILURE);

}

printf("driver : %s\n",device_params.driver);

printf("card : %s\n",device_params.card);

printf("bus_info : %s\n",device_params.bus_info);

printf("version : %d.%d.%d\n",

     ((device_params.version >> 16) & 0xFF),

     ((device_params.version >> 8) & 0xFF),

     (device_params.version & 0xFF));

printf("capabilities: 0x%08x\n", device_params.capabilities);

printf("device capabilities: 0x%08x\n", device_params.device_caps);

and as result I get this:

root@imx6qsabresd:~# ./mt
############## mt9p031 driver in mt9p031_probe:
############## mt9p031 driver in mt9p031_reset:
camera mt9p031 at addr 0x48 is found
############## mt9p031 driver in mt9p031_probe:
############## mt9p031 driver in mt9p031_reset:
camera mt9p031 at addr 0x5d is found
root@imx6qsabresd:~# ./catvd /dev/video1
ERROR: v4l2 capture: slave not found!
/dev/video1 error 11, Resource temporarily unavailable
root@imx6qsabresd:~# ./catvd /dev/video0
driver : mxc_v4l2
card :
bus_info :
version : 0.1.11
capabilities: 0x05000005
device capabilities: 0x00000000

/dev/video0 return caps but /dev/video1 not

I know that the simple way is write two modules with dedicated parameters, but i hope it is possible to use one.

[Yuri]

Hello,

   perhaps the second sensor should be described as

---

  ipu_id = <1>;

  csi_id = <0>;

---

Have a great day,
Yuri

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[evgenymolchanov]

Thank you, Yuri.

Of course I use different ipu for sensors.

My question was incorrect.

Solution is very simple: edit original mt9p031 driver to support more than one instance of driver.