From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: msm8909 support in a recent kernel Date: Tue, 5 Dec 2017 18:45:50 -0800 Message-ID: <20171206024550.GG4283@codeaurora.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:53666 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753808AbdLFCpw (ORCPT ); Tue, 5 Dec 2017 21:45:52 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Will Newton Cc: linux-arm-msm@vger.kernel.org On 12/01, Will Newton wrote: > On Wed, Nov 29, 2017 at 6:50 PM, Stephen Boyd wrote: > > > It's not completely insane to support this SoC upstream though. You'd > > have to bring in the pinctrl and clk drivers, which may be a bit of > > effort. After that it should mostly be enabling various devices by > > adding DT nodes and testing things out. It looks like this is 32-bit, so > > getting SMP support may require some tweaks to the smp_ops code for qcom > > platforms. You're right that it isn't too different from msm8916, so it > > may be that most of the driver support for that SoC transfers over > > nicely to this one. > > I've started from the 8916 drivers and started to port in the changes > from the 3.18 tree that seem relevant. I have a kernel that boots and > talks over the serial. I've done a bunch of pinctrl although it is not > complete yet. I've had a look at the clocks and got the PLL working > but I think I'm probably missing a document that describes the > clocking architecture in more detail (I have the register reference > but that's a bit of a worm's eye view). > > The current issue I am experiencing is the first write to an SPMI > channel causes the board to reset. I suspect this means that I have > not setup clocks correctly somewhere? The SPMI controller typically always has clks enabled, so I would be surprised if the clk was off. More likely, you're attempting to read/write a channel that is locked down and triggering an access control violation. Something configured incorrectly in DT perhaps? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project