Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756527Ab3FFBju (ORCPT ); Wed, 5 Jun 2013 21:39:50 -0400 Received: from mail-ea0-f171.google.com ([209.85.215.171]:51553 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755983Ab3FFBjs (ORCPT ); Wed, 5 Jun 2013 21:39:48 -0400 MIME-Version: 1.0 In-Reply-To: <1369056507-32521-1-git-send-email-james.hogan@imgtec.com> References: <1369056507-32521-1-git-send-email-james.hogan@imgtec.com> Date: Thu, 6 Jun 2013 09:39:46 +0800 Message-ID: Subject: Re: [PATCH v4 0/5] clk: implement remuxing during set_rate From: Haojian Zhuang To: James Hogan Cc: Mike Turquette , "linux-arm-kernel@lists.infradead.org" , Stephen Boyd , "linux-kernel@vger.kernel.org" , Saravana Kannan Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5014 Lines: 109 On Mon, May 20, 2013 at 9:28 PM, James Hogan wrote: > This patchset adds support for automatic selection of the best parent > for a clock mux, i.e. the one which can provide the closest clock rate > to that requested. It can be disabled by a new CLK_SET_RATE_NO_REPARENT > flag (which is set for all uses of clk_register_mux(). > > This works by way of adding a new op, determine_rate, similar to > round_rate but with an extra parameter to allow the clock driver to > optionally select a different parent clock. This is used in > clk_calc_new_rates to decide whether to initiate a set_parent operation. > > Changes in v4: > > * rebased on clk-next ("clk: sun5i: Add compatibles for Allwinner A13"). > * replace __clk_set_parent_no_recalc with __clk_set_parent. > * never pass NULL to determine_rate's best_parent_clk parameter, and > slight refactor of __clk_round_rate to use local copy of clk->parent. > * a few new comments around use of clk::new_child. > * new patch (patch 2) split out of patch 3 to avoid having to declare > static __clk_set_parent() at the top of clk.c, and to ease readability > of patch 3. > > Changes in v3: > > * rebased on v3.10-rc1. > * remove double underscore prefix from clk_get_parent_by_index() > * store new_parent_index in struct clk too (calculated from > clk_fetch_parent_index, and passed through __clk_set_parent_no_recalc > to __clk_set_parent). > * allow determine_rate to satisfy recalc_rate check in __clk_init. > * rename/invert CLK_SET_RATE_REMUX to CLK_SET_RATE_NO_REPARENT and move > to patch 3. > * patch 3: add CLK_SET_RATE_NO_REPARENT flag to all callers of > clk_register_mux. If you don't mind your clocks being reparented in > response to set_rate please let me know and I'll drop the relevant > portion of the patch. > > Changes in v2: > > I've moved the mux determine_rate implementation into a core helper, but > I haven't pushed it fully into the core, as I think it just wouldn't > work correctly for more complex clocks, e.g. if you (theoretically) had > a combined mux and divide, you'd want to intercept the determine_rate > and ask for a larger rate from the parent clocks, then return the > divided rate. This should be possible by wrapping the mux determine_rate > helper. > > Patch 1 still exports the __clk_get_parent_by_index as it seems like it > might be a useful thing for clock implementations to have access to if > they ever wanted to do something more fancy with changing clock parents. > > I haven't made any attempt to implement the atomic set_parent+set_rate > as I don't have hardware that could take proper advantage of it, but it > shouldn't be too difficult for others to implement if they wanted since > they're fairly close to one another (in clk_change_rate()). > > * switched to using new determine_rate op rather than adding an argument > to round_rate. > * moved mux implementation into a single helper which should be usable > from more complex clocks which can mux. > * rewrite main implementation so that no changes are made until after > the PRE notifications have been sent, and in a way that should ensure > correct notifications without duplicates, and I think should be safe > in the event of a notification failing. > * various tidy ups and fixes. > > James Hogan (5): > clk: abstract parent cache > clk: move some parent related functions upwards > clk: add support for clock reparent on set_rate > clk: add CLK_SET_RATE_NO_REPARENT flag > clk: clk-mux: implement remuxing on set_rate > > Documentation/clk.txt | 4 + > arch/arm/mach-imx/clk.h | 5 +- > drivers/clk/clk-mux.c | 1 + > drivers/clk/clk.c | 416 ++++++++++++++++++++++------------- > drivers/clk/mmp/clk-mmp2.c | 39 ++-- > drivers/clk/mmp/clk-pxa168.c | 40 ++-- > drivers/clk/mmp/clk-pxa910.c | 31 ++- > drivers/clk/mxs/clk.h | 4 +- > drivers/clk/samsung/clk.h | 2 +- > drivers/clk/spear/spear1310_clock.c | 179 +++++++-------- > drivers/clk/spear/spear1340_clock.c | 97 ++++---- > drivers/clk/spear/spear3xx_clock.c | 57 +++-- > drivers/clk/spear/spear6xx_clock.c | 35 +-- > drivers/clk/sunxi/clk-sunxi.c | 3 +- > drivers/clk/tegra/clk-tegra114.c | 36 ++- > drivers/clk/tegra/clk-tegra20.c | 6 +- > drivers/clk/tegra/clk-tegra30.c | 33 ++- > drivers/clk/versatile/clk-vexpress.c | 4 +- > include/linux/clk-private.h | 3 + > include/linux/clk-provider.h | 12 + > 20 files changed, 614 insertions(+), 393 deletions(-) > > -- > 1.8.1.2 Tested-by: Haojian Zhuang Pass test on MMP & Hisilicon SoC. Regards Haojian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/