From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH] spmi-pmic-arb: support configurable number of peripherals Date: Wed, 14 Oct 2015 15:43:56 -0700 Message-ID: <561EDAAC.6060800@codeaurora.org> References: <1442267672-11287-1-git-send-email-sboyd@codeaurora.org> <55F77451.9070900@codeaurora.org> <1442316018.15519.4.camel@mm-sol.com> <20150915182728.GA11715@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150915182728.GA11715@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: "Ivan T. Ivanov" Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Gilad Avidov , Sagar Dharia List-Id: linux-arm-msm@vger.kernel.org On 09/15/2015 11:27 AM, Stephen Boyd wrote: > On 09/15, Ivan T. Ivanov wrote: >> On Mon, 2015-09-14 at 18:28 -0700, Stephen Boyd wrote: >>> On 09/14/2015 02:54 PM, Stephen Boyd wrote: >>>> The current driver implementation supports only 128 peripherals. >>>> Add support for more than 128 peripherals by taking a lazy >>>> caching approach to the mapping tables. Instead of reading the >>>> tables at boot given some fixed size, read them on an as needed >>>> basis and cache the results. We still assume a max number of 512 >>>> peripherals, trading off some space for simplicity. >>>> >>>> Based on a patch by Gilad Avidov and >>>> Sagar Dharia . >>>> >>>> Signed-off-by: Stephen Boyd >>>> --- >>> Hi Ivan, >>> >>> This patch causes 8916 to crash, because there isn't a mapping for ppid >>> 257 in the ppid to channel table. It seems that we're reading the revid >>> from the slave id 1 pmic by going through channel 0, which seems to be >>> setup for ppid 9 (slave id 0 and the peripheral starting at 0x900). Can >>> we stop reading the revid registers from non-zero slave id pmic devices? >>> That would be one solution to fix this problem. Or maybe we need to >>> special case this in the pmic arbiter code to fold ppid 0xN01 (slave id >>> N and address 0x100) onto channel 0 all the time? >>> >> Yes, we can. We are not using this information at the moment. >> Right now, revision read is more or less for debug purposes. >> >> Would following patch work for you? Of course it will be difficult > Yes the patch works fine. Feel free to add a > > Tested-by: Stephen Boyd > > I have to take this back. I missed the part where some pmics are on slave id 2 or slave id 4, so this check isn't going to work. I've adjusted it to use sid % 2 instead and I'll resend these two patches, but I imagine to be more robust we're going to need to add a revid node to the DT under the SID that actually has it. Then we can search the child nodes for a revid compatible node and do the rev probing stuff. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project