From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [RFC PATCH 3/6] PM / Voltagedomain: introduce voltage domain driver support Date: Mon, 10 Mar 2014 14:25:43 -0500 Message-ID: <531E11B7.6080109@ti.com> References: <1392755543-28335-1-git-send-email-nm@ti.com> <1392755543-28335-4-git-send-email-nm@ti.com> <20140224015826.GU25940@sirena.org.uk> <530B594F.2030500@ti.com> <20140303035426.GC2411@sirena.org.uk> <531DF250.5060100@ti.com> <20140310172221.GT28112@sirena.org.uk> <531DF931.1060108@ti.com> <20140310180131.GZ28112@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140310180131.GZ28112@sirena.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Mark Brown , Mike Turquette Cc: devicetree@vger.kernel.org, linux-doc@vger.kernel.org, Viresh Kumar , linux-pm@vger.kernel.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, MyungJoo Ham , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On 03/10/2014 01:01 PM, Mark Brown wrote: > On Mon, Mar 10, 2014 at 12:41:05PM -0500, Nishanth Menon wrote: > >> The only other options are: >> a) Abstract it at a higher level at "user drivers", since they are >> aware of the sequencing needs - but this partially defeats the >> purpose, unless ofcourse, we do a tricky implementation such as: >> clk a, b, c -> prenotifiers in a, postnotifiers in c (which as you >> mentioned is a little trickier to get right). >> b) introduce a higher level generic dvfs function[1] which does not >> seem very attractive either. > >> Any other suggestions other than limiting the usage(and documenting it >> so) and hoping for a future evolution to take this into consideration? > > Something might be doable with telling the clock API about maintianing > ratios between clocks? I do think we should have an idea where we'd go > with such requirements, even if we don't currently handle it, so that we > can hopefully avoid another round of refactoring everything but it > doesn't seem 100% essential, just very nice to have. > Mike, Any suggestions about the above? could we use composite clocks in some manner here(even though I think the original intent of the same was not the same)? -- Regards, Nishanth Menon