[yocto] adding a udev entry for a camera
Gary Thomas
gary at mlbassoc.com
Thu Oct 31 09:34:55 PDT 2013
On 2013-10-31 10:20, Khem Raj wrote:
> On Thu, Oct 31, 2013 at 8:55 AM, Gary Thomas <gary at mlbassoc.com> wrote:
>> On 2013-10-31 09:45, Edward Vidal wrote:
>>>
>>> Hello all,
>>> less /etc/udev/rules.d/10-c920.rules
>>> WARNING: terminal is not fully functional
>>> SUBSYSTEM=="video4linux", BUS=="usb", ATTRS{idvendor}=="0x046d",
>>> ATTRS{idProduct
>>> }=="0x082d", NAME="video0", MODE:="0660"
>>> It appears the key BUS is not correct based on the tests below.
>>> My mknod is /bin/mknod.
>>> find / -name sysfs
>>> /usr/include/sysfs
>>> /usr/src/kernel/fs/sysfs
>>
>>
>> Note: chasing this udev behaviour is a waste of time if the kernel doesn't
>> recognize
>> and support your device.
>
> Look at the first post. Its recognised and displayed ok with lsusb.
That doesn't mean it has a driver which hooks it into the video subsystem
(which is what will evoke the creation of /dev/video*)
>
>>
>> Have you even looked to see if this camera is supported in your kernel? I
>> could
>> not find a driver for it when I looked, even in the latest mainline kernel.
>>
>> What kernel are you trying to use?
>>
>>>
>>> udevadm test --action=add /usr/include/sysfs or udevadm test --action=add
>>> /usr/src/kernel/fs/sysfs unable to open device
>>> '/sys/usr/src/kernel/fs/sysfs'
>>> run_command: calling: test
>>> adm_test: version 182
>>> This program is for debugging only, it does not run any program,
>>> specified by a RUN key. It may show incorrect results, because
>>> some values may be different, or not available at a simulation run.
>>>
>>> builtin_kmod_init: load module index
>>> add_matching_files: unable to open '/var/run/udev/rules.d': No such file
>>> or directory
>>> parse_file: reading '/etc/udev/rules.d/10-c920.rules' as rules file
>>> add_rule: unknown key 'BUS' in /etc/udev/rules.d/10-c920.rules:1
>>> add_rule: invalid rule '/etc/udev/rules.d/10-c920.rules:1'
>>>
>>> lots of output
>>>
>>> udev_rules_new: rules use 18408 bytes tokens (1534 * 12 bytes), 12756
>>> bytes buffer
>>> udev_rules_new: temporary index used 12800 bytes (640 * 20 bytes)
>>> unable to open device '/sys/usr/include/sysfs'
>>> builtin_kmod_exit: unload module index
>>>
>>> Do I add RUN+="/bin/mknod /dev/video0 c 81 0" see below new version of
>>> 1--c920.rules
>>> cat 10-c920.rules
>>> SUBSYSTEM=="video4linux", BUS=="usb", ATTRS{idvendor}=="0x046d",
>>> ATTRS{idProduct}=="0x082d", NAME="video0", MODE:="0660", RUN+="/bin/mknod
>>> /dev/video0 c 81 0"
>>> udevadm test --action=add /usr/src/kernel/fs/sysfs
>>> run_command: calling: test
>>> adm_test: version 182
>>> This program is for debugging only, it does not run any program,
>>> specified by a RUN key. It may show incorrect results, because
>>> some values may be different, or not available at a simulation run.
>>>
>>> builtin_kmod_init: load module index
>>> add_matching_files: unable to open '/var/run/udev/rules.d': No such file
>>> or directory
>>> parse_file: reading '/etc/udev/rules.d/10-c920.rules' as rules file
>>> add_rule: unknown key 'BUS' in /etc/udev/rules.d/10-c920.rules:1
>>> add_rule: invalid rule '/etc/udev/rules.d/10-c920.rules:1'
>>>
>>> Where do you find information for working with rules other than just some
>>> examples?
>>>
>>> Thanks
>>>
>>>
>>> On Thu, Oct 31, 2013 at 8:41 AM, Khem Raj <raj.khem at gmail.com
>>> <mailto:raj.khem at gmail.com>> wrote:
>>>
>>>
>>> On Wed, Oct 30, 2013 at 6:12 PM, Edward Vidal
>>> <vidal.develone at gmail.com <mailto:vidal.develone at gmail.com>> wrote:
>>> > Hello,
>>> > This is when I connect the camera
>>> > udevadm monitor test
>>> > monitor will print the received events for:
>>> > UDEV - the event which udev sends out after rule processing
>>> > KERNEL - the kernel uevent
>>> >
>>> > KERNEL[803.263336] add
>>> > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>>> (usb)
>>> > KERNEL[803.267456] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>> > (usb)
>>> > KERNEL[803.269287] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>> > (usb)
>>> > KERNEL[803.269958] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>> > (usb)
>>> > KERNEL[803.270721] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>> > (usb)
>>> > KERNEL[803.276214] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>> > (usb_device)**********
>>> > UDEV [803.277191] add
>>> > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>>> (usb)
>>> > UDEV [803.306091] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>> > (usb_device)
>>> > UDEV [803.318603] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>> > (usb)
>>> > UDEV [803.324249] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>> > (usb)
>>> > UDEV [803.329712] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>> > (usb)
>>> > UDEV [803.333160] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>> > (usb)
>>> >
>>> > still no /dev/video0
>>> > ls -la /dev/v*
>>> > crw-rw---- 1 root tty 7, 0 Jan 1 2000 /dev/vcs
>>> > crw-rw---- 1 root tty 7, 1 Jan 1 2000 /dev/vcs1
>>> > crw-rw---- 1 root tty 7, 2 Jan 1 2000 /dev/vcs2
>>> > crw-rw---- 1 root tty 7, 3 Oct 29 13:51 /dev/vcs3
>>> > crw-rw---- 1 root tty 7, 128 Jan 1 2000 /dev/vcsa
>>> > crw-rw---- 1 root tty 7, 129 Jan 1 2000 /dev/vcsa1
>>> > crw-rw---- 1 root tty 7, 130 Jan 1 2000 /dev/vcsa2
>>> > crw-rw---- 1 root tty 7, 131 Oct 29 13:51 /dev/vcsa3
>>> > root at beagleboard:~# lsusb
>>> > Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
>>> > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>>> > Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>>> > Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
>>> > Bus 001 Device 004: ID 0409:0059 NEC Corp. HighSpeed Hub
>>> > Bus 001 Device 005: ID 413c:2005 Dell Computer Corp. RT7D50 Keyboard
>>> > Bus 001 Device 006: ID 046d:c001 Logitech, Inc. N48/M-BB48
>>> [FirstMouse Plus]
>>> > Bus 001 Device 015: ID 046d:082d Logitech, Inc.
>>> >
>>> ***********************************************************************************
>>> >
>>> >
>>> > udevadm monitor --udev
>>> > monitor will print the received events for:
>>> > UDEV - the event which udev sends out after rule processing
>>> > camera removed*****************************************************
>>> > UDEV [1325.916811] remove
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>> > (usb)
>>> > UDEV [1325.918489] remove
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>> > (usb)
>>> > UDEV [1325.919282] remove
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>> > (usb)
>>> > UDEV [1325.923005] remove
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>> > (usb)
>>> > UDEV [1325.928437] remove
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>> > (usb_device)
>>> > UDEV [1325.932709] remove
>>> > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>>> (usb)
>>> > camera added
>>> >
>>> ***************************************************************************
>>> > UDEV [1329.344727] add
>>> > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>>> (usb)
>>> > UDEV [1329.376313] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.16
>>> > (usb_device)
>>> > UDEV [1329.389008] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>> > (usb)
>>> > UDEV [1329.396241] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>> > (usb)
>>> > UDEV [1329.401795] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>> > (usb)
>>> > UDEV [1329.406739] add
>>> >
>>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>> > (usb)
>>> >
>>> > This is what I get in /var/log/messages
>>> > Oct 29 14:17:28 beagleboarduser.info <http://user.info> kernel: usb
>>> 1-2.3.4: USB disconnect,
>>> > device number 16
>>> > Oct 29 14:17:31 beagleboarduser.info <http://user.info> kernel: usb
>>> 1-2.3.4: new high-speed
>>>
>>> > USB device number 17 using ehci-omap
>>> > Is there anything else that I can test / provide
>>>
>>> OK another thing to try is
>>>
>>> udevadm test --action=add /sys/....
>>>
>>> where /sys/... is path to your device in sysfs
>>>
>>> this should give enough reason to what udev is doing when its getting
>>> an add
>>> event for this device.
>>>
>>> Secondly in your udev rule refer mknod with absolute path like
>>> /sbin/mknod or /bin/mknod where ever it is
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> yocto mailing list
>>> yocto at yoctoproject.org
>>> https://lists.yoctoproject.org/listinfo/yocto
>>>
>>
>> --
>> ------------------------------------------------------------
>> Gary Thomas | Consulting for the
>> MLB Associates | Embedded world
>> ------------------------------------------------------------
>> _______________________________________________
>> yocto mailing list
>> yocto at yoctoproject.org
>> https://lists.yoctoproject.org/listinfo/yocto
--
------------------------------------------------------------
Gary Thomas | Consulting for the
MLB Associates | Embedded world
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