From mboxrd@z Thu Jan 1 00:00:00 1970 From: skannan@codeaurora.org (Saravana Kannan) Date: Fri, 22 Apr 2011 17:48:23 -0700 Subject: [PATCH RFC] clk: add support for automatic parent handling In-Reply-To: References: <1303308457-7501-1-git-send-email-u.kleine-koenig@pengutronix.de> <20110420185922.GD31131@pengutronix.de> <20110421074214.GE15233@pengutronix.de> <20110421120656.GF15233@pengutronix.de> <4DB20091.1070509@codeaurora.org> Message-ID: <4DB221D7.4030703@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/22/2011 03:55 PM, Thomas Gleixner wrote: > On Fri, 22 Apr 2011, Saravana Kannan wrote: > >> On 04/22/2011 09:57 AM, Thomas Gleixner wrote: >>> On Fri, 22 Apr 2011, Colin Cross wrote: >>> >>>> On Fri, Apr 22, 2011 at 2:51 AM, Thomas Gleixner >>>> wrote: >>>>> Another thing I'm pondering is to provide the ability to maintain >>>>> separate clk trees. So you can have individual domains which have >>>>> their per clk tree locking. Would that make sense ? >>>> >>>> Clock trees are likely to be linked somewhere - an external clock chip >>>> that drives the main clock input on the SoC, or an SoC clock output >>>> that drives a chip with an internal clock tree. Domains would have to >>>> be dynamically managed to ensure two clocks from different clock chips >>>> that become linked are moved under the same clock lock. Probably >>>> easier to keep a global lock. >>> >>> Ok. It's easy enough to split later if the need arises. >> >> MSM certainly has the need for having independent clock trees. I would like >> support for this to be in from the start otherwise it's going to really screw >> clocks in one of the trees. > > Are they completely independent or do you need a global > synchronization mechanism between those clock trees as well ? > > Thanks, > > tglx They are completely independent. No synchronization is needed between these clock trees. It's basically a bunch of clocks controlled by another processor that has it's own set of PLLs, etc. -Saravana -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.