From: Mike Turquette <mturquette@linaro.org> To: Stephen Boyd <sboyd@codeaurora.org>, Tomasz Figa <tomasz.figa@gmail.com> Cc: linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, James Hogan <james.hogan@imgtec.com>, Saravana Kannan <skannan@codeaurora.org>, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 04/14] clk: Add set_rate_and_parent() op Date: Thu, 08 Aug 2013 22:32:03 -0700 [thread overview] Message-ID: <20130809053203.5348.40567@quantum> (raw) In-Reply-To: <20130725164542.GF29694@codeaurora.org> Quoting Stephen Boyd (2013-07-25 09:45:42) > On 07/25, Tomasz Figa wrote: > > On Wednesday 24 of July 2013 17:43:32 Stephen Boyd wrote: > > > Some of Qualcomm's clocks can change their parent and rate at the > > > same time with a single register write. Add support for this > > > hardware to the common clock framework by adding a new > > > set_rate_and_parent() op. When the clock framework determines > > > that both the parent and the rate are going to change during > > > clk_set_rate() it will call the .set_rate_and_parent() op if > > > available and fall back to calling .set_parent() followed by > > > .set_rate() otherwise. > > > > This is strange. Does you hardware support switching parent and rate > > separately or you always need to set both and so all the fuss here? > > It supports setting the parent or setting the rate, or setting > both at the same time. I think that setting parent and rate at the same time is a common enough case to merit handling it in the clock core. Probably this design will become more common in time. Regards, Mike > > > > > If the latter is the case, then maybe you can simply keep parent index and > > rate cached inside driver data of your clock driver and use them on any > > .set_rate() or .set_parent() calls? > > This will not work. In fact, doing that would cause us to > overclock hardware for a short time between switching the parent > and the rate. > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > hosted by The Linux Foundation
WARNING: multiple messages have this Message-ID (diff)
From: mturquette@linaro.org (Mike Turquette) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v1 04/14] clk: Add set_rate_and_parent() op Date: Thu, 08 Aug 2013 22:32:03 -0700 [thread overview] Message-ID: <20130809053203.5348.40567@quantum> (raw) In-Reply-To: <20130725164542.GF29694@codeaurora.org> Quoting Stephen Boyd (2013-07-25 09:45:42) > On 07/25, Tomasz Figa wrote: > > On Wednesday 24 of July 2013 17:43:32 Stephen Boyd wrote: > > > Some of Qualcomm's clocks can change their parent and rate at the > > > same time with a single register write. Add support for this > > > hardware to the common clock framework by adding a new > > > set_rate_and_parent() op. When the clock framework determines > > > that both the parent and the rate are going to change during > > > clk_set_rate() it will call the .set_rate_and_parent() op if > > > available and fall back to calling .set_parent() followed by > > > .set_rate() otherwise. > > > > This is strange. Does you hardware support switching parent and rate > > separately or you always need to set both and so all the fuss here? > > It supports setting the parent or setting the rate, or setting > both at the same time. I think that setting parent and rate at the same time is a common enough case to merit handling it in the clock core. Probably this design will become more common in time. Regards, Mike > > > > > If the latter is the case, then maybe you can simply keep parent index and > > rate cached inside driver data of your clock driver and use them on any > > .set_rate() or .set_parent() calls? > > This will not work. In fact, doing that would cause us to > overclock hardware for a short time between switching the parent > and the rate. > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > hosted by The Linux Foundation
next prev parent reply other threads:[~2013-08-09 5:32 UTC|newest] Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-25 0:43 [PATCH v1 00/14] Add support for MSM's mmio clocks Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 01/14] clk: fixed-rate: Export clk_fixed_rate_register() Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-08-03 3:32 ` Mike Turquette 2013-08-03 3:32 ` Mike Turquette 2013-07-25 0:43 ` [PATCH v1 02/14] clk: Add of_init_clk_data() to parse common clock bindings Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 8:21 ` Tomasz Figa 2013-07-25 8:21 ` Tomasz Figa 2013-07-25 16:36 ` Stephen Boyd 2013-07-25 16:36 ` Stephen Boyd 2013-08-03 1:06 ` Mike Turquette 2013-08-03 1:06 ` Mike Turquette 2013-07-25 0:43 ` [PATCH v1 03/14] clk: Add of_clk_match() for device drivers Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 8:12 ` Tomasz Figa 2013-07-25 8:12 ` Tomasz Figa 2013-07-25 16:36 ` Stephen Boyd 2013-07-25 16:36 ` Stephen Boyd 2013-08-12 20:23 ` Mike Turquette 2013-08-12 20:23 ` Mike Turquette 2013-08-13 5:48 ` Stephen Boyd 2013-08-13 5:48 ` Stephen Boyd 2013-08-15 5:02 ` Mike Turquette 2013-08-15 5:02 ` Mike Turquette 2013-08-16 1:31 ` Stephen Boyd 2013-08-16 1:31 ` Stephen Boyd 2013-08-16 3:44 ` Mike Turquette 2013-08-16 3:44 ` Mike Turquette 2013-08-16 16:43 ` Kumar Gala 2013-08-16 16:43 ` Kumar Gala 2013-08-16 17:16 ` Kumar Gala 2013-08-16 17:16 ` Kumar Gala 2013-07-25 0:43 ` [PATCH v1 04/14] clk: Add set_rate_and_parent() op Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 8:26 ` Tomasz Figa 2013-07-25 8:26 ` Tomasz Figa 2013-07-25 8:26 ` Tomasz Figa 2013-07-25 16:45 ` Stephen Boyd 2013-07-25 16:45 ` Stephen Boyd 2013-08-09 5:32 ` Mike Turquette [this message] 2013-08-09 5:32 ` Mike Turquette 2013-08-09 9:11 ` James Hogan 2013-08-09 9:11 ` James Hogan 2013-08-09 9:11 ` James Hogan 2013-07-25 0:43 ` [PATCH v1 05/14] clk: msm: Add support for phase locked loops (PLLs) Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 8:29 ` Tomasz Figa 2013-07-25 8:29 ` Tomasz Figa 2013-07-25 16:37 ` Stephen Boyd 2013-07-25 16:37 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 06/14] clk: msm: Add support for root clock generators (RCGs) Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 07/14] clk: msm: Add support for branches/gate clocks Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 08/14] clk: msm: Add MSM clock driver Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 8:32 ` Tomasz Figa 2013-07-25 8:32 ` Tomasz Figa 2013-07-25 16:40 ` Stephen Boyd 2013-07-25 16:40 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 09/14] clk: msm: Add support for MSM8960's global clock controller (GCC) Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-08-08 17:00 ` Mark Rutland 2013-08-08 17:00 ` Mark Rutland 2013-08-08 17:00 ` Mark Rutland 2013-08-13 5:03 ` Stephen Boyd 2013-08-13 5:03 ` Stephen Boyd 2013-08-13 5:03 ` Stephen Boyd 2013-08-13 14:24 ` Mike Turquette 2013-08-13 14:24 ` Mike Turquette 2013-08-13 14:24 ` Mike Turquette 2013-08-13 18:42 ` Stephen Boyd 2013-08-13 18:42 ` Stephen Boyd 2013-08-13 18:42 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 10/14] clk: msm: Add support for MSM8960's multimedia clock controller (MMCC) Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-08-08 17:02 ` Mark Rutland 2013-08-08 17:02 ` Mark Rutland 2013-08-08 17:02 ` Mark Rutland 2013-07-25 0:43 ` [PATCH v1 11/14] ARM: dts: msm: Add MSM8960 GCC DT nodes Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 12/14] ARM: dts: msm: Add MSM8960 MMCC " Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 13/14] clk: msm: Add MSM8974 GCC data Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd 2013-07-25 0:43 ` [PATCH v1 14/14] ARM: dts: msm: Add clock entries for MSM8960 uart device Stephen Boyd 2013-07-25 0:43 ` Stephen Boyd
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