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