Hi Michael, On Monday 16 August 2010 17:38:43 Michael Jones wrote: > Hi Laurent, > > I'm working on a sensor driver with a parallel interface to the ISP. In my > OMAP35x TRM (spruf98h.pdf), I only find 2 occurrences of "CCP2", with no > discussion or description, whereas in the ISP sources on omap3camera/devel > I see that it is a building block of the ISP. From the sources, I'm > guessing that it is involved in interfacing a serial sensor data stream to > the CCDC, and would be uninvolved in parallel data from a sensor. That's correct. CCP2 stands for Compact Camera Port 2 and is an interface standard for serial cameras used in mobile phones (and possibly elsewhere). A quick search on Google turns up this link http://www.sunex.com/SIMA/SMIA_CCP2_specification_1.0.pdf. If I'm not mistaken, CCP2 is a superset of the CSI-1 interface standard defined by the MIPI alliance. > Is the CCP2 indeed documented somewhere for the OMAP35x? Or is this > perhaps only available in the OMAP34x? The physical CCP2 interface is only available in the OMAP34xx and OMAP36xx processors. The OMAP35xx family has a parallel receiver only. However, the CCP2 module can also read back raw data from memory. Even though the physical CCP2 interface is not present on the OMAP34xx/36xx families (at least according to the TRM, I don't think anymore has built an OMAP35xx board to verify this), the CCP2 module itself is available and can be used in memory input mode. > In omap34xxcam_video_init(), the media_entity links are activated. In this > if/else there, > > if (vdev->vdev_sensor->entity.links[0].sink->entity == > &isp->isp_csi2a.subdev.entity) {...} else {...} > > the assumption is made that a sensor is either connected > A. (sensor->)CSI2A->CCDC or > B. sensor->CCP2->CCDC That's correct. > but if I'm correct that the CCP2 is related to serial data, there is an > option (C) missing for parallel data: sensor->CCDC. In fact, this is the > link that is created in omap34xxcam_probe() if 'case > ISP_INTERFACE_PARALLEL'. Is this correct, that I would need to add an > 'else if' to get parallel data working? You shouldn't use the video nodes /dev/video0 and /dev/video1. They're legacy and will soon be removed. You should instead use the new video nodes /dev/video[2-8] along with the media controller API. They should support parallel sensors properly. -- Regards, Laurent Pinchart -- 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
