| .. SPDX-License-Identifier: GPL-2.0 |
| |
| .. include:: <isonum.txt> |
| |
| OMAP 3 Image Signal Processor (ISP) driver |
| ========================================== |
| |
| Copyright |copy| 2010 Nokia Corporation |
| |
| Copyright |copy| 2009 Texas Instruments, Inc. |
| |
| Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>, |
| Sakari Ailus <sakari.ailus@iki.fi>, David Cohen <dacohen@gmail.com> |
| |
| |
| Introduction |
| ------------ |
| |
| This file documents the Texas Instruments OMAP 3 Image Signal Processor (ISP) |
| driver located under drivers/media/platform/ti/omap3isp. The original driver was |
| written by Texas Instruments but since that it has been rewritten (twice) at |
| Nokia. |
| |
| The driver has been successfully used on the following versions of OMAP 3: |
| |
| - 3430 |
| - 3530 |
| - 3630 |
| |
| The driver implements V4L2, Media controller and v4l2_subdev interfaces. |
| Sensor, lens and flash drivers using the v4l2_subdev interface in the kernel |
| are supported. |
| |
| |
| Split to subdevs |
| ---------------- |
| |
| The OMAP 3 ISP is split into V4L2 subdevs, each of the blocks inside the ISP |
| having one subdev to represent it. Each of the subdevs provide a V4L2 subdev |
| interface to userspace. |
| |
| - OMAP3 ISP CCP2 |
| - OMAP3 ISP CSI2a |
| - OMAP3 ISP CCDC |
| - OMAP3 ISP preview |
| - OMAP3 ISP resizer |
| - OMAP3 ISP AEWB |
| - OMAP3 ISP AF |
| - OMAP3 ISP histogram |
| |
| Each possible link in the ISP is modelled by a link in the Media controller |
| interface. For an example program see [#]_. |
| |
| |
| Controlling the OMAP 3 ISP |
| -------------------------- |
| |
| In general, the settings given to the OMAP 3 ISP take effect at the beginning |
| of the following frame. This is done when the module becomes idle during the |
| vertical blanking period on the sensor. In memory-to-memory operation the pipe |
| is run one frame at a time. Applying the settings is done between the frames. |
| |
| All the blocks in the ISP, excluding the CSI-2 and possibly the CCP2 receiver, |
| insist on receiving complete frames. Sensors must thus never send the ISP |
| partial frames. |
| |
| Autoidle does have issues with some ISP blocks on the 3430, at least. |
| Autoidle is only enabled on 3630 when the omap3isp module parameter autoidle |
| is non-zero. |
| |
| Technical reference manuals (TRMs) and other documentation |
| ---------------------------------------------------------- |
| |
| OMAP 3430 TRM: |
| <URL:http://focus.ti.com/pdfs/wtbu/OMAP34xx_ES3.1.x_PUBLIC_TRM_vZM.zip> |
| Referenced 2011-03-05. |
| |
| OMAP 35xx TRM: |
| <URL:http://www.ti.com/litv/pdf/spruf98o> Referenced 2011-03-05. |
| |
| OMAP 3630 TRM: |
| <URL:http://focus.ti.com/pdfs/wtbu/OMAP36xx_ES1.x_PUBLIC_TRM_vQ.zip> |
| Referenced 2011-03-05. |
| |
| DM 3730 TRM: |
| <URL:http://www.ti.com/litv/pdf/sprugn4h> Referenced 2011-03-06. |
| |
| |
| References |
| ---------- |
| |
| .. [#] http://git.ideasonboard.org/?p=media-ctl.git;a=summary |
