From mboxrd@z Thu Jan 1 00:00:00 1970 From: mturquette@linaro.org (Mike Turquette) Date: Wed, 20 Mar 2013 08:03:15 -0700 Subject: [RESEND PATCH 1/3] clk: Remove _clk_reparent from API and restructure code In-Reply-To: <51498BD0.7010508@ti.com> References: <1363116050-3882-1-git-send-email-ulf.hansson@stericsson.com> <1363116050-3882-2-git-send-email-ulf.hansson@stericsson.com> <20130319212053.8663.63425@quantum> <51498BD0.7010508@ti.com> Message-ID: <20130320150315.11073.85260@quantum> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting Rajendra Nayak (2013-03-20 03:13:36) > On Wednesday 20 March 2013 03:15 PM, Ulf Hansson wrote: > > On 19 March 2013 22:20, Mike Turquette wrote: > >> Quoting Ulf Hansson (2013-03-12 12:20:48) > >>> From: Ulf Hansson > >>> > >>> There shall be no reason for keeping this API available for clock > >>> providers. So we remove it from the API and restrcuture the code so > >>> for example the COMMON_CLK_DEBUG part is separated. > >>> > >> > >> Hi Ulf, > >> > >> There is one reason to keep this api. OMAP currently uses it to change > >> the parent of a PLL during .set_rate. This is kind of a legacy > >> mechanism however, and the reentrancy series I posted actually takes > >> care of this one corner case: > >> http://article.gmane.org/gmane.linux.kernel/1448449 > > > > Hi Mike, > > > > It was a while ago I created this patch, so I guess this has beed > > merged without me noticing, sorry. > > > >> > >> Let me see how the OMAP folks feel about taking that patch in, which > >> eliminates the only external user of the API. +Rajendra & Benoit > >> > > > > I have no problem rebasing the patch and keep the API, if that is the > > easiest way forward. > > Ulf, It would be good if you could keep the api for now. I seemed to have > missed out on Mikes patch getting rid of the the api from OMAP PLL .set_rate. > I will take a stab at that to get rid of that api along with the other OMAP > only things that exist today as part of Common clk. > Rajendra, Yeah, the patch I linked to above was actually just "example code" showing how to reentrantly call clk_set_parent from within a .set_rate callback. It's no suprise you missed it since the patch $SUBJECT starts with "HACK:" ;-) The trick is to recognize that OMAP's PLLs are mux clocks and have them properly support clk_set_parent. This would have made my life easier in the bad days of DPLL cascading back in 2011. > regards, > Rajendra > > > Although, I guess in the end you want to remove these kind of internal > > clk API functions. So, if we get ack from Rajendra & Benoit, it is > > better to remove the API right? > > Ulf, Correct, as we discussed at LCA I do want to get rid of all of these internal accessor functions. Thanks, Mike > > Kind regards > > Ulf Hansson > > > >> Thanks, > >> Mike > >> > >>> This patch will also make it possible to hold the spinlock over the > >>> actual update of the clock tree topology, which could not be done > >>> before when both debugfs updates and clock rate updates was done > >>> within the same function. > >>> > >>> Signed-off-by: Ulf Hansson > >>> --- > >>> drivers/clk/clk.c | 82 ++++++++++++++++++++++++------------------ > >>> include/linux/clk-provider.h | 1 - > >>> 2 files changed, 48 insertions(+), 35 deletions(-) > >>> > >>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > >>> index 593a2e4..2e10cc1 100644 > >>> --- a/drivers/clk/clk.c > >>> +++ b/drivers/clk/clk.c > >>> @@ -284,6 +284,39 @@ out: > >>> } > >>> > >>> /** > >>> + * clk_debug_reparent - reparent clk node in the debugfs clk tree > >>> + * @clk: the clk being reparented > >>> + * @new_parent: the new clk parent, may be NULL > >>> + * > >>> + * Rename clk entry in the debugfs clk tree if debugfs has been > >>> + * initialized. Otherwise it bails out early since the debugfs clk tree > >>> + * will be created lazily by clk_debug_init as part of a late_initcall. > >>> + * > >>> + * Caller must hold prepare_lock. > >>> + */ > >>> +static void clk_debug_reparent(struct clk *clk, struct clk *new_parent) > >>> +{ > >>> + struct dentry *d; > >>> + struct dentry *new_parent_d; > >>> + > >>> + if (!inited) > >>> + return; > >>> + > >>> + if (new_parent) > >>> + new_parent_d = new_parent->dentry; > >>> + else > >>> + new_parent_d = orphandir; > >>> + > >>> + d = debugfs_rename(clk->dentry->d_parent, clk->dentry, > >>> + new_parent_d, clk->name); > >>> + if (d) > >>> + clk->dentry = d; > >>> + else > >>> + pr_debug("%s: failed to rename debugfs entry for %s\n", > >>> + __func__, clk->name); > >>> +} > >>> + > >>> +/** > >>> * clk_debug_init - lazily create the debugfs clk tree visualization > >>> * > >>> * clks are often initialized very early during boot before memory can > >>> @@ -338,6 +371,9 @@ static int __init clk_debug_init(void) > >>> late_initcall(clk_debug_init); > >>> #else > >>> static inline int clk_debug_register(struct clk *clk) { return 0; } > >>> +static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) > >>> +{ > >>> +} > >>> #endif > >>> > >>> /* caller must hold prepare_lock */ > >>> @@ -1179,16 +1215,8 @@ out: > >>> return ret; > >>> } > >>> > >>> -void __clk_reparent(struct clk *clk, struct clk *new_parent) > >>> +static void clk_reparent(struct clk *clk, struct clk *new_parent) > >>> { > >>> -#ifdef CONFIG_COMMON_CLK_DEBUG > >>> - struct dentry *d; > >>> - struct dentry *new_parent_d; > >>> -#endif > >>> - > >>> - if (!clk || !new_parent) > >>> - return; > >>> - > >>> hlist_del(&clk->child_node); > >>> > >>> if (new_parent) > >>> @@ -1196,28 +1224,7 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) > >>> else > >>> hlist_add_head(&clk->child_node, &clk_orphan_list); > >>> > >>> -#ifdef CONFIG_COMMON_CLK_DEBUG > >>> - if (!inited) > >>> - goto out; > >>> - > >>> - if (new_parent) > >>> - new_parent_d = new_parent->dentry; > >>> - else > >>> - new_parent_d = orphandir; > >>> - > >>> - d = debugfs_rename(clk->dentry->d_parent, clk->dentry, > >>> - new_parent_d, clk->name); > >>> - if (d) > >>> - clk->dentry = d; > >>> - else > >>> - pr_debug("%s: failed to rename debugfs entry for %s\n", > >>> - __func__, clk->name); > >>> -out: > >>> -#endif > >>> - > >>> clk->parent = new_parent; > >>> - > >>> - __clk_recalc_rates(clk, POST_RATE_CHANGE); > >>> } > >>> > >>> static int __clk_set_parent(struct clk *clk, struct clk *parent) > >>> @@ -1329,7 +1336,9 @@ int clk_set_parent(struct clk *clk, struct clk *parent) > >>> } > >>> > >>> /* propagate rate recalculation downstream */ > >>> - __clk_reparent(clk, parent); > >>> + clk_reparent(clk, parent); > >>> + clk_debug_reparent(clk, parent); > >>> + __clk_recalc_rates(clk, POST_RATE_CHANGE); > >>> > >>> out: > >>> mutex_unlock(&prepare_lock); > >>> @@ -1453,14 +1462,19 @@ int __clk_init(struct device *dev, struct clk *clk) > >>> hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node) { > >>> if (orphan->ops->get_parent) { > >>> i = orphan->ops->get_parent(orphan->hw); > >>> - if (!strcmp(clk->name, orphan->parent_names[i])) > >>> - __clk_reparent(orphan, clk); > >>> + if (!strcmp(clk->name, orphan->parent_names[i])) { > >>> + clk_reparent(orphan, clk); > >>> + clk_debug_reparent(orphan, clk); > >>> + __clk_recalc_rates(orphan, POST_RATE_CHANGE); > >>> + } > >>> continue; > >>> } > >>> > >>> for (i = 0; i < orphan->num_parents; i++) > >>> if (!strcmp(clk->name, orphan->parent_names[i])) { > >>> - __clk_reparent(orphan, clk); > >>> + clk_reparent(orphan, clk); > >>> + clk_debug_reparent(orphan, clk); > >>> + __clk_recalc_rates(orphan, POST_RATE_CHANGE); > >>> break; > >>> } > >>> } > >>> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h > >>> index 4989b8a..87a7c2c 100644 > >>> --- a/include/linux/clk-provider.h > >>> +++ b/include/linux/clk-provider.h > >>> @@ -359,7 +359,6 @@ struct clk *__clk_lookup(const char *name); > >>> */ > >>> int __clk_prepare(struct clk *clk); > >>> void __clk_unprepare(struct clk *clk); > >>> -void __clk_reparent(struct clk *clk, struct clk *new_parent); > >>> unsigned long __clk_round_rate(struct clk *clk, unsigned long rate); > >>> > >>> struct of_device_id; > >>> -- > >>> 1.7.10