webcamd and cameras with Micron (MT9M0x1 and MT9T0x1) chips

[maillist at diode.be]

Quoting Hans Petter Selasky <hselasky at c2i.net>:

> Hi,
>
>> For both Micron cameras, #webcamd -B just gives `Cannot find USB device'.
>
> This usually happens when the webcamd is not listed.
>
>>
>> dmesg output for the Mightex camera (MT9M001 chip):
>> ugen3.2: <Mightex> at usbus3
>>
>> and usbconfig -d ugen3.2 dump_device_desc gives:
>> ugen3.2: <USB-MT9M001-2 Mightex> at usbus3, cfg=0 md=HOST spd=HIGH
>> (480Mbps) pwr=ON
>>
>>     bLength = 0x0012
>>     bDescriptorType = 0x0001
>>     bcdUSB = 0x0200
>>     bDeviceClass = 0x0000
>>     bDeviceSubClass = 0x0000
>>     bDeviceProtocol = 0x0000
>>     bMaxPacketSize0 = 0x0040
>>     idVendor = 0x04b4
>>     idProduct = 0x0228
>>     bcdDevice = 0x0000
>>     iManufacturer = 0x0001  <Mightex>
>>     iProduct = 0x0002  <USB-MT9M001-2>
>>     iSerialNumber = 0x0000  <no string>
>>     bNumConfigurations = 0x0001
>>
>>
>> For the MT9T031 camera (likely prototype), dmesg gives:
>> ugen3.2: <Micron> at usbus3
>>
>> and usbconfig -d ugen3.2 dump_device_desc:
>> ugen3.2: <Demo2A Micron> at usbus3, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON
>>
>>     bLength = 0x0012
>>     bDescriptorType = 0x0001
>>     bcdUSB = 0x0200
>>     bDeviceClass = 0x0000
>>     bDeviceSubClass = 0x0000
>>     bDeviceProtocol = 0x0000
>>     bMaxPacketSize0 = 0x0040
>>     idVendor = 0x0634
>>     idProduct = 0x1007
>>     bcdDevice = 0x0021
>>     iManufacturer = 0x0001  <Micron>
>>     iProduct = 0x0002  <Demo2A>
>>     iSerialNumber = 0x0000  <no string>
>>     bNumConfigurations = 0x0001
>>
>>
>>
>>
>> Now, I have no coding skills, but thought it would be good to have a
>> look into the driver code. I hoped I would find Vendor and Product
>> id's that differed from how the camera identified, this explaining the
>> refusal to associate. But while some other v4l drivers appear to
>> contain things like {USB_DEVICE(0xXXXX, 0xXXXX), .driver_info=XXXXX},
>> such code is absent from the mt9xxxx.c files. Instead, there is a
>> function data = reg_read(client, MT9M001_CHIP_VERSION) that does some
>> sort of identification. But this is on the i2c level, reading the chip
>> version number. I thought that for doing this, the system would
>> already need to know what Micron chip it is dealing with.
>>
>> Any thoughts would be appreciated.
>
> Hi,
>
> I did a little bit of grepping, and I think you need to patch the following
> file to get your webcam working:
>
> v4l-dvb/linux/drivers/media/video/gspca/sn9c20x.c
>
> You can use this entry as an example:
>
> {USB_DEVICE(0x0c45, 0x6240), SN9C20X(MT9M001, 0x5d, 0)},
>
> The iProduct dump indicates this is the right place to hack for the MT9M001
> one :-)
>
> --HPS
>

I added
{USB_DEVICE(0x04b4, 0x0228), SN9C20X(MT9M001, 0x5d, 0)},
to the list, with 0x5d as i2c address as the other two MT9M001 entries  
have it too. After re-making ulinux and using the new webcamd from  
that directory, I get

Attached ugen3.2[0] to cuse init 0
Cannot find USB device

Interestingly, the other (MT9T031) camera, for which nothing changed,  
only states `Cannot find USB device' without returning `Attached  
[...]'. The Logitech cam, which used to work, states `Attached [...]'  
and then `Creating /dev/video0'.

But for this Logitech cam, pwcview now complains `Failed to access  
webcam: Device not configured'. Note that I used the webcamd from  
ports before, so I must have messed something up. I updated to the  
latest svn version. I will update my ports too, as this doesn't appear  
to have anything to do with the change to the code I made.

On the other hand, webcamd still returns `Cannot find USB device' for  
the MT9M001 camera. Maybe simply adding the corresponding USB_DEVICE()  
entry was not what you meant?

Regards,

Tiemen