Thanks all for the replies! I composed the document for Nicolas and I hope he manages to arrange for a video interview. The two main aspects were that what Allwinner currently provides (to the developer communities) is not sufficient, and that what is needed is a direct contact from Allwinner to the linux-sunxi community in order to sort out issues as they develop.
The fact that Allwinner has been sending the OptimusBoard for testing as a server, http://www.mininodes.com/allwinner-a80-optimus-board-arrives-for-testing/ shows that they need to open up and provide support so that any server distribution would work well. The OptimusBoard with Android is not very useful for a server, and Linux 3.4 that currently runs on the A80 is not useful for a server either. The videos that Nicolas has posted on ARMDevices.net show that there might be a cultural/language barrier with the potential contact. I hope there is a response and we continue from there. Simos On Tue, Aug 5, 2014 at 5:03 AM, Chen-Yu Tsai <[email protected]> wrote: > On Tue, Aug 5, 2014 at 7:58 AM, Simos Xenitellis > <[email protected]> wrote: > > > > On Mon, Aug 4, 2014 at 11:12 PM, Maxime Ripard > > <[email protected]> wrote: > >> > >> On Mon, Aug 04, 2014 at 02:14:13AM +0300, Simos Xenitellis wrote: > >> > Hi All, > >> > > >> > Nicolas (from ARMDevices.net) has conducted quite a few interviews > with > >> > Chinese hardware companies around Shenzhen. > >> > There are several videos with Allwinner, such as > >> > > >> > > http://armdevices.net/2014/07/23/allwinner-64bit-armv8-processor-announced/ > >> > > >> > I think it would be a good opportunity to interview Allwinner about > >> > issues > >> > with source code development. At > >> > https://plus.google.com/u/0/+charbax/posts/6uqUutxjQiw (see > comments) he > >> > is > >> > OK to either mail Allwinner or arrange to visit them for a video > >> > interview. > >> > My preference would be an interview on camera and I believe it should > be > >> > feasible. > >> > There may not be immediate results out of this, however it would be > >> > great > >> > to have some official response. > >> > > >> > What's needed is to describe to Nicolas what questions to ask. > >> > I am not familiar with all important questions that can be asked so it > >> > would be good to help add to the list, and explain to Nicolas so that > he > >> > can discuss them at ease. > >> > > >> > Here is my attempt with a question. Feel free to correct me. > >> > > >> > 1. The Linux kernel holds now the hardware description of SoCs in a > data > >> > format called Device Tree (DT). There are more details about DT at > >> > > >> > > http://events.linuxfoundation.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf > >> > For example, here is the DT file for the Rockchip 3188, > >> > > >> > > https://github.com/torvalds/linux/blob/master/arch/arm/boot/dts/rk3188.dtsi > >> > > >> > While many manufacturers have provided DT files for their products, > >> > there > >> > are none yet from Allwinner. > >> > Here we can ask for Allwinner to provide them for all SoCs, or we can > >> > ask > >> > specific details that will help to produce those files. Do we have a > >> > preference? > >> > >> The only thing we need to write those are a good technical > >> documentation and board schematics. Allwinner is only really involved > >> in the former. > > > > > > For the A20, there is this document for EVB schematics, > > > https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A20-PDFs/A20_PAD_STD_V1_1.rar?raw=true > > and http://dl.linux-sunxi.org/A20/A20%20User%20Manual%202013-03-22.pdf > for > > technical documentation. > > Are these what you are referring to? > > > > If we want to make a proper question/request, we need a table with the > SoCs > > and what's missing for each one of them. > > Can someone make such a table? > > You can find what docs we have by looking through the wiki. > For instance, we are missing user manuals for A10s and A31. > > And the manuals we do have, have typos and/or are missing stuff for > vital hardware components, such as USB OTG, GMAC. Not to mention > undocumented registers for various stuff. > > Last, most of the manual is just register dumps. There is little > information regarding the actual operation of the hardware. > > >> > 2. Source code in mainline Linux. We explain why it is important, etc. > >> > > >> > There is a list of items (mainly drivers) at > >> > http://linux-sunxi.org/Linux_mainlining_effort > >> > Are these drivers without any released source code? Has the source > code > >> > been released but it needs lots of work to add to mainline? What > should > >> > we > >> > ask Allwinner to do? > >> > >> I'm not sure to get what you mean, but the drivers that got merged > >> were either: > >> - rewritten from scratch (GPIO, clocks, SPI, etc.) > >> - an adaptation to the Allwinner SoCs of already existing drivers > >> (GMAC, I2C, SATA, USB, etc.) > >> - Allwinner source code cleaned up (EMAC, MMC, etc.) > > > > > > This is very specific and useful. > > > >> > >> > >> As for the things Allwinner should do, they should move to using > >> standard Linux API. They improved a lot that aspect when developping > >> the A23 BSP, and hopefully will continue to do so. > >> > > > > With Linux API you mean that Allwinner should use much as possible from > what > > is offered at > > https://www.kernel.org/doc/htmldocs/kernel-api/ > > like the available data manipulation functions rather than > re-implementing > > them? > > Can you give some specific examples and perhaps somewhat quantify the > extent > > of the issue? > > What went well with the A23 BSP? > > Older kernels by Allwinner were based on 3.0 or 3.3, with a whole bunch > of Allwinner created APIs. With the A23 BSP, they moved to 3.4, and > backported > a lot of new frameworks from 3.8+, such as pinctrl, common clk framework, > dmaengine, ASoC. They even used Maxime's pinctrl driver as a base. > > Basing their code on newer kernel versions and common APIs makes them > easier to understand, clean up and port to mainline. > > > Cheers > ChenYu > -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
