From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A22CC04AA7 for ; Mon, 13 May 2019 13:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E4F520657 for ; Mon, 13 May 2019 13:47:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729745AbfEMNrs (ORCPT ); Mon, 13 May 2019 09:47:48 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:44035 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728904AbfEMNrr (ORCPT ); Mon, 13 May 2019 09:47:47 -0400 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1hQBIq-0001mO-DH; Mon, 13 May 2019 15:47:40 +0200 Message-ID: <1557755257.4442.8.camel@pengutronix.de> Subject: Re: Hardware-accelerated video decoders used through a firmware instead of hardware registers From: Philipp Zabel To: Paul Kocialkowski , Nicolas Dufresne , Hans Verkuil , Sakari Ailus , Mauro Carvalho Chehab Cc: Laurent Pinchart , Maxime Ripard , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, Linus Torvalds , Thierry Reding , Tiffany Lin , Andrew-CT Chen Date: Mon, 13 May 2019 15:47:37 +0200 In-Reply-To: References: <19804f842e80f1f8bd85b8eb49e75e149abf0062.camel@bootlin.com> <69c10fdd26566049c523d4c8cfb1b8c35018b738.camel@ndufresne.ca> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Sun, 2019-05-12 at 18:32 +0200, Paul Kocialkowski wrote: [...] > I would be curious to know what the situation is on the i.MX6 coda > block, which also seems pretty obscure. FWIW, I had started collecting things I learned about the BIT processor in the CODA IP cores, mostly by looking at the firmware files distributed by Freescale/NXP: https://github.com/pH5/coda-bits It is a somewhat strange custom 16-bit DSP architecture. There is a rudimentary start for a disassembler in there as well, but large parts of the instruction set are still completely unknown, and I have no idea how the address generator / DMA units or bitstream accelerators work. I would be delighted if somebody would like to pick up analyzing the BIT processor ISA further. I think it could be fruitful to start systematically throwing instructions at it and see what happens, to learn more. I haven't had much motivation to play with this, recently. About the internal connections and available accelerator units, there is a block diagram in the i.MX53 TRM, but I am not aware of any register level description for any of these. regards Philipp