From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Walleij Subject: Re: [PATCH v2 bus+gpio 1/4] bus: Add support for Moxtet bus Date: Fri, 9 Nov 2018 10:59:20 +0100 Message-ID: References: <20181102103539.6077-1-marek.behun@nic.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20181102103539.6077-1-marek.behun@nic.cz> Sender: linux-kernel-owner@vger.kernel.org To: marek.behun@nic.cz Cc: ext Tony Lindgren , Shawn Guo , Rob Herring , "open list:GPIO SUBSYSTEM" , "linux-kernel@vger.kernel.org" List-Id: linux-gpio@vger.kernel.org On Fri, Nov 2, 2018 at 11:35 AM Marek Beh=C3=BAn wrote= : > On the Turris Mox router different modules can be connected to the main > CPU board: currently a module with a SFP cage, a module with MiniPCIe > connector, a 4-port switch module, an 8-port switch module, and a 4-port > USB3 module. > > For example: > [CPU]-[PCIe]-[8-port switch]-[8-port switch]-[SFP] > > Each of this modules has an input and output shift register, and these > are connected via SPI to the CPU board. > > Via SPI we are able to discover which modules are connected, in which > order, and we can also read some information about the modules or > configure them. > From each module 8 bits can be read (of which low 4 bits identify the > module) and 8 bits can be written. > > For example from the module with a SFP cage we can read the LOS, > TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and > RATE-SELECT signals. > > This driver creates a new bus type, called "moxtet". For each Mox module > it finds via SPI, it creates a new device on the moxtet bus so that > drivers can be written for them. > > The topology of how Mox modules are connected can then be read by > listing /sys/bus/moxtet/devices. > > Signed-off-by: Marek Beh=C3=BAn This looks fine to me. Maybe strange with "gpio" in the subject of the mail? Consider adding sysfs ABI documentation in Documentation/ABI/testing/* Acked-by: Linus Walleij Yours, Linus Walleij