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diff --git a/Documentation/video4linux/omap3isp.txt b/Documentation/video4linux/omap3isp.txt deleted file mode 100644 index b9a9f83b1587..000000000000 --- a/Documentation/video4linux/omap3isp.txt +++ /dev/null @@ -1,279 +0,0 @@ -OMAP 3 Image Signal Processor (ISP) driver - -Copyright (C) 2010 Nokia Corporation -Copyright (C) 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/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 [2]. - - -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. - - -Events -====== - -The OMAP 3 ISP driver does support the V4L2 event interface on CCDC and -statistics (AEWB, AF and histogram) subdevs. - -The CCDC subdev produces V4L2_EVENT_FRAME_SYNC type event on HS_VS -interrupt which is used to signal frame start. Earlier version of this -driver used V4L2_EVENT_OMAP3ISP_HS_VS for this purpose. The event is -triggered exactly when the reception of the first line of the frame starts -in the CCDC module. The event can be subscribed on the CCDC subdev. - -(When using parallel interface one must pay account to correct configuration -of the VS signal polarity. This is automatically correct when using the serial -receivers.) - -Each of the statistics subdevs is able to produce events. An event is -generated whenever a statistics buffer can be dequeued by a user space -application using the VIDIOC_OMAP3ISP_STAT_REQ IOCTL. The events available -are: - - V4L2_EVENT_OMAP3ISP_AEWB - V4L2_EVENT_OMAP3ISP_AF - V4L2_EVENT_OMAP3ISP_HIST - -The type of the event data is struct omap3isp_stat_event_status for these -ioctls. If there is an error calculating the statistics, there will be an -event as usual, but no related statistics buffer. In this case -omap3isp_stat_event_status.buf_err is set to non-zero. - - -Private IOCTLs -============== - -The OMAP 3 ISP driver supports standard V4L2 IOCTLs and controls where -possible and practical. Much of the functions provided by the ISP, however, -does not fall under the standard IOCTLs --- gamma tables and configuration of -statistics collection are examples of such. - -In general, there is a private ioctl for configuring each of the blocks -containing hardware-dependent functions. - -The following private IOCTLs are supported: - - VIDIOC_OMAP3ISP_CCDC_CFG - VIDIOC_OMAP3ISP_PRV_CFG - VIDIOC_OMAP3ISP_AEWB_CFG - VIDIOC_OMAP3ISP_HIST_CFG - VIDIOC_OMAP3ISP_AF_CFG - VIDIOC_OMAP3ISP_STAT_REQ - VIDIOC_OMAP3ISP_STAT_EN - -The parameter structures used by these ioctls are described in -include/linux/omap3isp.h. The detailed functions of the ISP itself related to -a given ISP block is described in the Technical Reference Manuals (TRMs) --- -see the end of the document for those. - -While it is possible to use the ISP driver without any use of these private -IOCTLs it is not possible to obtain optimal image quality this way. The AEWB, -AF and histogram modules cannot be used without configuring them using the -appropriate private IOCTLs. - - -CCDC and preview block IOCTLs -============================= - -The VIDIOC_OMAP3ISP_CCDC_CFG and VIDIOC_OMAP3ISP_PRV_CFG IOCTLs are used to -configure, enable and disable functions in the CCDC and preview blocks, -respectively. Both IOCTLs control several functions in the blocks they -control. VIDIOC_OMAP3ISP_CCDC_CFG IOCTL accepts a pointer to struct -omap3isp_ccdc_update_config as its argument. Similarly VIDIOC_OMAP3ISP_PRV_CFG -accepts a pointer to struct omap3isp_prev_update_config. The definition of -both structures is available in [1]. - -The update field in the structures tells whether to update the configuration -for the specific function and the flag tells whether to enable or disable the -function. - -The update and flag bit masks accept the following values. Each separate -functions in the CCDC and preview blocks is associated with a flag (either -disable or enable; part of the flag field in the structure) and a pointer to -configuration data for the function. - -Valid values for the update and flag fields are listed here for -VIDIOC_OMAP3ISP_CCDC_CFG. Values may be or'ed to configure more than one -function in the same IOCTL call. - - OMAP3ISP_CCDC_ALAW - OMAP3ISP_CCDC_LPF - OMAP3ISP_CCDC_BLCLAMP - OMAP3ISP_CCDC_BCOMP - OMAP3ISP_CCDC_FPC - OMAP3ISP_CCDC_CULL - OMAP3ISP_CCDC_CONFIG_LSC - OMAP3ISP_CCDC_TBL_LSC - -The corresponding values for the VIDIOC_OMAP3ISP_PRV_CFG are here: - - OMAP3ISP_PREV_LUMAENH - OMAP3ISP_PREV_INVALAW - OMAP3ISP_PREV_HRZ_MED - OMAP3ISP_PREV_CFA - OMAP3ISP_PREV_CHROMA_SUPP - OMAP3ISP_PREV_WB - OMAP3ISP_PREV_BLKADJ - OMAP3ISP_PREV_RGB2RGB - OMAP3ISP_PREV_COLOR_CONV - OMAP3ISP_PREV_YC_LIMIT - OMAP3ISP_PREV_DEFECT_COR - OMAP3ISP_PREV_GAMMABYPASS - OMAP3ISP_PREV_DRK_FRM_CAPTURE - OMAP3ISP_PREV_DRK_FRM_SUBTRACT - OMAP3ISP_PREV_LENS_SHADING - OMAP3ISP_PREV_NF - OMAP3ISP_PREV_GAMMA - -The associated configuration pointer for the function may not be NULL when -enabling the function. When disabling a function the configuration pointer is -ignored. - - -Statistic blocks IOCTLs -======================= - -The statistics subdevs do offer more dynamic configuration options than the -other subdevs. They can be enabled, disable and reconfigured when the pipeline -is in streaming state. - -The statistics blocks always get the input image data from the CCDC (as the -histogram memory read isn't implemented). The statistics are dequeueable by -the user from the statistics subdev nodes using private IOCTLs. - -The private IOCTLs offered by the AEWB, AF and histogram subdevs are heavily -reflected by the register level interface offered by the ISP hardware. There -are aspects that are purely related to the driver implementation and these are -discussed next. - -VIDIOC_OMAP3ISP_STAT_EN ------------------------ - -This private IOCTL enables/disables a statistic module. If this request is -done before streaming, it will take effect as soon as the pipeline starts to -stream. If the pipeline is already streaming, it will take effect as soon as -the CCDC becomes idle. - -VIDIOC_OMAP3ISP_AEWB_CFG, VIDIOC_OMAP3ISP_HIST_CFG and VIDIOC_OMAP3ISP_AF_CFG ------------------------------------------------------------------------------ - -Those IOCTLs are used to configure the modules. They require user applications -to have an in-depth knowledge of the hardware. Most of the fields explanation -can be found on OMAP's TRMs. The two following fields common to all the above -configure private IOCTLs require explanation for better understanding as they -are not part of the TRM. - -omap3isp_[h3a_af/h3a_aewb/hist]_config.buf_size: - -The modules handle their buffers internally. The necessary buffer size for the -module's data output depends on the requested configuration. Although the -driver supports reconfiguration while streaming, it does not support a -reconfiguration which requires bigger buffer size than what is already -internally allocated if the module is enabled. It will return -EBUSY on this -case. In order to avoid such condition, either disable/reconfigure/enable the -module or request the necessary buffer size during the first configuration -while the module is disabled. - -The internal buffer size allocation considers the requested configuration's -minimum buffer size and the value set on buf_size field. If buf_size field is -out of [minimum, maximum] buffer size range, it's clamped to fit in there. -The driver then selects the biggest value. The corrected buf_size value is -written back to user application. - -omap3isp_[h3a_af/h3a_aewb/hist]_config.config_counter: - -As the configuration doesn't take effect synchronously to the request, the -driver must provide a way to track this information to provide more accurate -data. After a configuration is requested, the config_counter returned to user -space application will be an unique value associated to that request. When -user application receives an event for buffer availability or when a new -buffer is requested, this config_counter is used to match a buffer data and a -configuration. - -VIDIOC_OMAP3ISP_STAT_REQ ------------------------- - -Send to user space the oldest data available in the internal buffer queue and -discards such buffer afterwards. The field omap3isp_stat_data.frame_number -matches with the video buffer's field_count. - - -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 -========== - -[1] include/linux/omap3isp.h - -[2] http://git.ideasonboard.org/?p=media-ctl.git;a=summary |