On 06/07/2011 12:35 AM, Hans de Goede wrote: > Hi, > > On 06/07/2011 07:24 AM, John McMaster wrote: >> On 06/06/2011 12:43 AM, Hans de Goede wrote: >>> Hi, >>> >>> On 06/06/2011 07:40 AM, John McMaster wrote: >>>> On 06/03/2011 06:22 AM, Hans de Goede wrote: >>>>> Hi, >>>>> >>>>> On 06/03/2011 02:15 PM, Mauro Carvalho Chehab wrote: >>>>>> Em 03-06-2011 02:40, John McMaster escreveu: >>>>>>> I'd like to write a driver for an Anchor Chips (seems to be >>>>>>> bought by >>>>>>> Cypress) USB camera Linux driver sold as an AmScope MD1800. It >>>>>>> seems >>>>>>> like this implies I need to write a V4L2 driver. The camera >>>>>>> does not >>>>>>> seem its currently supported (checked on Fedora 13 / 2.6.34.8) >>>>>>> and I >>>>>>> did >>>>>>> not find any information on it in mailing list archives. Does >>>>>>> anyone >>>>>>> know or can help me identify if a similar camera might already be >>>>>>> supported? >>>>>> >>>>>> I've no idea. Better to wait for a couple days for developers to >>>>>> manifest >>>>>> about that, if they're already working on it. >>>>>> >>>>>>> lsusb gives the following output: >>>>>>> >>>>>>> Bus 001 Device 111: ID 0547:4d88 Anchor Chips, Inc. >>>>>>> >>>>>>> I've started reading the "Video for Linux Two API Specification" >>>>>>> which >>>>>>> seems like a good starting point and will move onto using source >>>>>>> code as >>>>>>> appropriate. Any help would be appreciated. Thanks! >>>>>> >>>>>> You'll find other useful information at linuxtv.org wiki page. The >>>>>> better >>>>>> is to write it as a sub-driver for gspca. The gspca core have >>>>>> already >>>>>> all >>>>>> that it is needed for cameras. So, you'll need to focus only at the >>>>>> device-specific >>>>>> stuff. >>>>> >>>>> I can second that you should definitely use gspca for usb webcam(ish) >>>>> device >>>>> drivers. As for how to go about this, first of all grep through the >>>>> windows drivers >>>>> for strings which may hint on the actual bridge chip used, chances >>>>> are >>>>> good >>>>> there is an already supported bridge inside the camera. >>>>> >>>>> If not then make usb dumps, and start reverse engineering ... >>>>> >>>>> Usually it is enough to replay the windows init sequence to get the >>>>> device >>>>> to stream over either an bulk or iso endpoint, and then it is time to >>>>> figure out what that stream contains (jpeg, raw bayer, some custom >>>>> format ???) >>>>> >>>>> Regards, >>>>> >>>>> Hans >>>> Thanks for the response. I replayed some packets (using libusb) >>>> and am >>>> able to get something resembling the desired image through its bulk >>>> endpoint. So now I just need to figure out how to decode it better, >>>> options, etc. I'll post back to the list once I get something >>>> moderately stable running and have taken a swing at the kernel driver. >>>> >>> >>> Hmm, bulk you say and cypress and 8mp usb2.0 have you tried looking >>> at the gspca-ovfx2 driver? Likely you've an ovfx2 cam with an as of >>> yet unknown usb-id. Chances are just adding the id is enough, although >>> your sensor may be unknown. >>> >>> Regards, >>> >>> Hans >> If it helps, I should have also mentioned that with a small amount of >> digging I found that the camera unit is put together by ScopeTek. My >> reference WIP implementation is at >> https://github.com/JohnDMcMaster/uvscopetek which I'm comparing to >> 2.6.39.1 drivers. >> >> Anyway, looking at reg_w() I see that it likes to make 0x00, 0x02, or >> 0x0A requests where as mine makes 0x01, 0x0A, and mostly 0x0B requests. >> I do see that it tends to want a byte back though like mine (0x0A except >> at end). My code has a few 3 byte returns (byte 0 varies, byte 1 fixed >> at 0x00, byte 2 fixed at 0x08 like others), so I'm not sure if its a >> good match for reg read. Following that I tried to grep around some >> more for a number of the more interesting numbers (eg: 90D8 as opposed >> to 0001) in the $SRC/drivers/media/video dir and could only find >> scattered matches. I do realize that a lot of the more esoteric numbers >> could be specific settings and not registers, commands, etc. Or maybe >> tofx2 is related and I'm not understanding the bridge concept? > > I think you may have been looking at the wrong driver, if your trace > shows > mostly 0x0a, 0x0b and 0x02 requests then chances are high it is indeed > an ovfx2, the ovfx2 driver is part of drivers/media/video/gspca/ov519.c > because it shares a bunch of functions (mostly sensor detect stuff) with > the ov511/ov518/ov519 driver. > > And it makes 0x0a request for ovfx2 (bridge) register writes, 0x0b > requests for ovfx2 (bridge) register reads and 0x02 requests for i2c > writes. > > If things indeed seem a better match with the ovfx2 support in ov519.c, > one quick way to find out if it is an ovfx2 is to just add the usb-id of > your camera to ov519.c as an ovfx2 camera, and load the driver, first > thing the driver does is try to detect the sensor type through the i2c > bus between the bridge and the sensor, if that works (even if it > detects an unknown sensor, but the sensor id found seems sensible) it > it likely is an ovfx2. > > You could also try grapping for strings like fx2 and cypress in the > windows > driver. Also try looking at the .inf file from the windows driver, if > that > contains different (maybe commented out) usb-ids of potentially > compatible > cams. > > Regards, > > Hans > > >> >> John >> Hi, Time to resurrect a dead thread ;) Got busy with work but I'm still determined to get this working. A lot of things sound close but maybe not quite right? I will not doubt your fx2 was a good guess. I also dug a little more and found some addition Windows driver files I didn't notice before and tried to grep for FX. I did previously try to match up some of the other VID/PIDs before and no luck there. I finally decided to open it up and its a Cypress CY7C68013A, an "EZ-USB-FX2LP". This is what happens when I patch it to my VID / PID with some debugging turned on: gspca: main v2.9.0 registered usbcore: registered new interface driver ov519 registered usb 2-1: new high speed USB device using ehci_hcd and address 5 usb 2-1: config 1 interface 0 altsetting 0 bulk endpoint 0x82 has invalid maxpacket 1024 usb 2-1: New USB device found, idVendor=0547, idProduct=4d88 usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 2-1: Product: DCM800 usb 2-1: Manufacturer: ScopeTek gspca: probing 0547:4d88 Write reg 0x0060 -> [0x00] Write reg 0x0001 -> [0x02] Write reg 0x001d -> [0x0f] Write reg 0x0082 -> [0xe9] Write reg 0x00c7 -> [0xea] Write reg 0x0010 -> [0xeb] Write reg 0x00f6 -> [0xec] Write reg 0x0042 -> [0x00] i2c 0x80 -> [0x12] failed Write reg 0x00c0 -> [0x00] i2c 0x80 -> [0x12] failed Write reg 0x00a0 -> [0x00] i2c 0x80 -> [0x12] failed Write reg 0x0060 -> [0x00] i2c 0x80 -> [0x12] failed Can't determine sensor slave IDs OV519 Config failed ov519: probe of 2-1:1.0 failed with error -16 Maybe a key piece of data I gleaned that might help identify it. To set the resolution it sends: request = 0x0B, request type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value = width, index = 0x034C, ret = {0x08} and request = 0x0B, request type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value = height index = 0x034E, ret = {0x08} This seems to point that a 0x0B request would be some sort of write, wValue is a register value, and wIndex is the register. However in the OV519 this type of request seems to be a read: static int reg_r(struct sd *sd, __u16 index) ... case BRIDGE_OVFX2: req = 0x0b; ... On the off chance that the numbers were just switched around I tried the following quick switches as a long shot: reg_w() Does bulk setup Orig: 0x0A Switched to 0x0B reg_r() Orig: 0x0B Switched to 0x0A i2c_w() => ovfx2_i2c_w() Orig: 0x02 Switched to 0x01 i2c_r() => ovfx2_i2c_r() Orig: 0x03 Switched to 0x02 on loose grounds But not too surprisingly it didn't do very well and stopped right after "Write reg 0x0060 -> [0x00] failed". Additionally, I haven't been able to figure out how to find SOF/EOF and none of the algorithms presented in ov519.c seem to be applicable to the data streams I'm seeing. The biggest hint I have is that there seems to be a darkened pixel row the second from the top and left in case that's familiar. In any case, I got a bit more serious and learned the basic V4L API as well as GSPCA enough to write a proof of concept driver for it (I used dead reckoning on frame size to find SOF/EOF but it of course gets messed up if a packet drops which sometimes happens during init). I figure even if there is an existing driver it was a good experience for me and it should help fitting it in. I also read the datasheet enough to figure out how to rip the firmware off although I don't know if it would be of any use. From what I can tell from the datasheet though even if its the same chip it could be configured in a number of different ways and there is no guarantee the requests would line up. Of course, I'm not going to deny that they are the same requests and I'm still misinterpreting it since you did predict the chip before me ;) Thanks for the help and hopefully with a little more prodding we'll be able to straighten this out. John -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
