From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbcGOD2W (ORCPT ); Thu, 14 Jul 2016 23:28:22 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:50215 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752201AbcGOD2T (ORCPT ); Thu, 14 Jul 2016 23:28:19 -0400 Date: Thu, 14 Jul 2016 21:28:14 -0600 From: Jason Gunthorpe To: Andrey Pronin Cc: Peter Huewe , Jarkko Sakkinen , Marcel Selhorst , tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, groeck@chromium.org, smbarber@chromium.org, dianders@chromium.org Subject: Re: [PATCH 0/2] tpm: add driver for cr50 on SPI Message-ID: <20160715032814.GG9347@obsidianresearch.com> References: <1468549218-19215-1-git-send-email-apronin@chromium.org> <9A3CFCAE-F2FD-438D-A32B-AD59E0362E71@gmx.de> <20160715025026.GA21375@apronin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160715025026.GA21375@apronin> User-Agent: Mutt/1.5.23 (2014-03-12) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.151 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 14, 2016 at 07:50:26PM -0700, Andrey Pronin wrote: > Yes, it has a TCG-compliant interface, however, there are several things > specific to this device: > - need to ensure a certain delay between spi transactions, or else > the chip can miss several first bytes. > - if there is no spi activity for this chip, it may go to sleep, and > needs to be waken up before sending further commands. > - it has some vendor-specific registers accessible from spi bus. This all needs to be commented clearly in the driver.. The chip sounds pretty broken... Jason