From patchwork Fri Sep 14 12:46:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Lad, Prabhakar" X-Patchwork-Id: 1458731 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id A505540220 for ; Fri, 14 Sep 2012 12:54:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753465Ab2INMyM (ORCPT ); Fri, 14 Sep 2012 08:54:12 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:36503 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957Ab2INMyK (ORCPT ); Fri, 14 Sep 2012 08:54:10 -0400 Received: by dady13 with SMTP id y13so2404259dad.19 for ; Fri, 14 Sep 2012 05:54:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=ciA7g0c5qkJYnpLSwzg2S0u65kDeMY6qzJj1iAfBUA8=; b=VenY7q+okZdVHs+4+7UkKeYE7kHeuIkI+mgmdYJGf0Q+f07O9dtEeYEk4wG9N2Hi22 mcCEXHKA21tpXhwpM9K1ZhVg4R/xO9P0sHkM6RhCPemMn9CfLlgL+yziVhMt1x04mSuP SLBVS9zXECjDPzqPZhPouLYIk7QmP7kI6hmbLIHr9talIe6ghZ5CgOtCFLC2P/wLcBvO fXsOKJf/j94zTflwMlRuIVxHSMmBfpwfxIWB/k76UO6Y8ZmSzDHFNoaRQBWAN25u97RA /tGaPilttRnVG2hgs7pGQmYGMt6gGEU/qBtDsV9UC6y5e3btESpXdLOTS78HTbLeCEZr 2vyg== Received: by 10.68.231.130 with SMTP id tg2mr5065808pbc.70.1347627250202; Fri, 14 Sep 2012 05:54:10 -0700 (PDT) Received: from localhost.localdomain ([122.166.13.141]) by mx.google.com with ESMTPS id gv1sm939033pbc.38.2012.09.14.05.54.06 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 14 Sep 2012 05:54:09 -0700 (PDT) From: Prabhakar Lad To: LMML Cc: LKML , Mauro Carvalho Chehab , DLOS , Manjunath Hadli , "Lad, Prabhakar" , Rob Landley , Subject: [PATCH 14/14] [media] davinci: vpfe: Add documentation Date: Fri, 14 Sep 2012 18:16:44 +0530 Message-Id: <1347626804-5703-15-git-send-email-prabhakar.lad@ti.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1347626804-5703-1-git-send-email-prabhakar.lad@ti.com> References: <1347626804-5703-1-git-send-email-prabhakar.lad@ti.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Manjunath Hadli Add documentation on the Davinci VPFE driver. Document the subdevs, and private IOTCLs the driver implements Signed-off-by: Manjunath Hadli Signed-off-by: Lad, Prabhakar Cc: Rob Landley Cc: --- Documentation/video4linux/davinci-vpfe-mc.txt | 95 +++++++++++++++++++++++++ 1 files changed, 95 insertions(+), 0 deletions(-) create mode 100644 Documentation/video4linux/davinci-vpfe-mc.txt diff --git a/Documentation/video4linux/davinci-vpfe-mc.txt b/Documentation/video4linux/davinci-vpfe-mc.txt new file mode 100644 index 0000000..9dfc4f9 --- /dev/null +++ b/Documentation/video4linux/davinci-vpfe-mc.txt @@ -0,0 +1,95 @@ +Davinci Video processing Front End (VPFE) driver + +Copyright (C) 2012 Texas Instruments Inc + +Contacts: Manjunath Hadli + + +Introduction +============ + +This file documents the Texas Instruments Davinci Video processing Front End +(VPFE) driver located under drivers/media/platform/davinci. The original driver +exists for Davinci VPFE, which is now being changed to Media Controller +Framework. + +Currently the driver has been successfully used on the following +version of Davinci: + + DM365/DM368 + +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 Davinci VPFE is split into V4L2 subdevs, each of the blocks inside the VPFE +having one subdev to represent it. Each of the subdevs provide a V4L2 subdev +interface to userspace. + + DAVINCI CCDC + DAVINCI PREVIEWER + DAVINCI RESIZER + +Each possible link in the VPFE is modeled by a link in the Media controller +interface. For an example program see [1]. + + +Private IOCTLs +============== + +The Davinci Video processing Front End (VPFE) driver supports standard V4L2 +IOCTLs and controls where possible and practical. Much of the functions provided +by the VPFE, however, does not fall under the standard IOCTL's. + +In general, there is a private ioctl for configuring each of the blocks +containing hardware-dependent functions. + +The following private IOCTLs are supported: + + VIDIOC_VPFE_CCDC_[S/G]_RAW_PARAMS + VIDIOC_VPFE_PRV_[S/G]_CONFIG + VIDIOC_VPFE_RSZ_[S/G]_CONFIG + +The parameter structures used by these ioctl's are described in +include/linux/davinci_vpfe.h and include/linux/dm365_ccdc.h. + +The VIDIOC_VPFE_CCDC_S_RAW_PARAMS, VIDIOC_VPFE_PRV_S_CONFIG and +VIDIOC_VPFE_RSZ_S_CONFIG are used to configure, enable and disable functions in +the CCDC, preview and resizer blocks respectively. These IOCTL's control several +functions in the blocks they control. VIDIOC_VPFE_CCDC_S_RAW_PARAMS IOCTL +accepts a pointer to struct ccdc_config_params_raw as its argument. Similarly +VIDIOC_VPFE_PRV_S_CONFIG accepts a pointer to struct vpfe_prev_config. And +VIDIOC_VPFE_RSZ_S_CONFIG accepts a pointer to struct vpfe_rsz_config as its +argument. Similarly VIDIOC_VPFE_CCDC_G_RAW_PARAMS, VIDIOC_VPFE_PRV_G_CONFIG and +VIDIOC_VPFE_RSZ_G_CONFIG are used to get the current configuration set +in the CCDC, preview and resizer blocks respectively. + +The detailed functions of the VPFE itself related to a given VPFE block is +described in the Technical Reference Manuals (TRMs) --- see the end of the +document for those. + + +Technical reference manuals (TRMs) and other documentation +========================================================== + +Davinci DM365 TRM: + +Referenced MARCH 2009-REVISED JUNE 2011 + +Davinci DM368 TRM: + +Referenced APRIL 2010-REVISED JUNE 2011 + +Davinci Video Processing Front End (VPFE) DM36x + + + +References +========== + +[1] http://git.ideasonboard.org/?p=media-ctl.git;a=summary +[2] include/linux/davinci_vpfe.h & include/linux/dm365_ccdc.h