From patchwork Thu Jul 31 11:39:39 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomeu Vizoso X-Patchwork-Id: 4655321 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F22FF9F2B8 for ; Thu, 31 Jul 2014 11:43:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EEE112017A for ; Thu, 31 Jul 2014 11:43:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EA6AE2011B for ; Thu, 31 Jul 2014 11:43:16 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XCojb-000220-AP; Thu, 31 Jul 2014 11:41:23 +0000 Received: from mail-wg0-x232.google.com ([2a00:1450:400c:c00::232]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XCoiz-0001bv-EI for linux-arm-kernel@lists.infradead.org; Thu, 31 Jul 2014 11:40:46 +0000 Received: by mail-wg0-f50.google.com with SMTP id n12so2659948wgh.9 for ; Thu, 31 Jul 2014 04:40:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=4cAQuiu+ZNgCc9Z9o2A39hayqI2sL1J62jwIR78jcXA=; b=pTPEE4vlMKL339UULU9ltcolHpm1HGMWY7CUqQsPkQiqsYqtY3PsvqjKQZSago/R56 MUGQ035QnsIDt+DyQHYRe7rtvdPz382vuBN0NRdgaxLGlYDmKSghCKfoCBFz/AUiYMOA 7VDGocL/d1E0ivMStbFE3le00yKzZbwmTSqwYB3A7Wn9viqK+KjbVcarQ4mk9wY+5JpL g/Ak2wHCjyq20OATMGlwkzBZw/EjYCLpxqJIrRuu/uxWAPb3CikKWxdrOBwwhGeV3juq VCoWKKbjgZuMnjP+Med1fOCgIuUEVtgreWMgonS27xGXvj2iL2ze+mI6RJI9oNZevhb0 7lzg== X-Received: by 10.180.78.169 with SMTP id c9mr15055348wix.68.1406806821639; Thu, 31 Jul 2014 04:40:21 -0700 (PDT) Received: from cizrna.lan (37-48-39-114.tmcz.cz. [37.48.39.114]) by mx.google.com with ESMTPSA id k6sm12815328wjq.5.2014.07.31.04.40.19 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 31 Jul 2014 04:40:20 -0700 (PDT) From: Tomeu Vizoso To: Mike Turquette Subject: [PATCH v4 RESEND 6/6] clk: Add floor and ceiling constraints to clock rates Date: Thu, 31 Jul 2014 13:39:39 +0200 Message-Id: <1406806779-26939-6-git-send-email-tomeu.vizoso@collabora.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1406806779-26939-1-git-send-email-tomeu.vizoso@collabora.com> References: <1406806779-26939-1-git-send-email-tomeu.vizoso@collabora.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140731_044045_832586_E128A8E7 X-CRM114-Status: GOOD ( 19.79 ) X-Spam-Score: -0.7 (/) Cc: Tomeu Vizoso , Stephen Warren , Tomasz Figa , linux-kernel@vger.kernel.org, rabin@rab.in, Thierry Reding , Peter De Schrijver , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Adds a way for clock consumers to set maximum and minimum rates. This can be used for thermal drivers to set ceiling rates, or by misc. drivers to set floor rates to assure a minimum performance level. Signed-off-by: Tomeu Vizoso --- drivers/clk/clk.c | 103 ++++++++++++++++++++++++++++++++++++++++++++ drivers/clk/clk.h | 1 + drivers/clk/clkdev.c | 2 +- include/linux/clk-private.h | 1 + include/linux/clk.h | 18 ++++++++ 5 files changed, 124 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f1cdc01..90db677 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -23,6 +23,19 @@ #include "clk.h" +enum constraint_type { + CONSTRAINT_FLOOR, + CONSTRAINT_CEILING, +}; + +struct rate_constraint { + struct hlist_node node; + const char *dev_id; + const char *con_id; + enum constraint_type type; + unsigned long rate; +}; + static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -1653,6 +1666,7 @@ static void clk_change_rate(struct clk_core *clk) int clk_provider_set_rate(struct clk_core *clk, unsigned long rate) { struct clk_core *top, *fail_clk; + struct rate_constraint *constraint; int ret = 0; if (!clk) @@ -1661,6 +1675,17 @@ int clk_provider_set_rate(struct clk_core *clk, unsigned long rate) /* prevent racing with updates to the clock topology */ clk_prepare_lock(); + hlist_for_each_entry(constraint, &clk->rate_constraints, node) { + switch (constraint->type) { + case CONSTRAINT_FLOOR: + rate = max(rate, constraint->rate); + break; + case CONSTRAINT_CEILING: + rate = min(rate, constraint->rate); + break; + } + } + /* bail early if nothing to do */ if (rate == clk_provider_get_rate(clk)) goto out; @@ -1727,6 +1752,65 @@ int clk_set_rate(struct clk *clk_user, unsigned long rate) } EXPORT_SYMBOL_GPL(clk_set_rate); +static struct rate_constraint *__ensure_constraint(struct clk *clk_user, + enum constraint_type type) +{ + struct clk_core *clk = clk_to_clk_core(clk_user); + struct rate_constraint *constraint = NULL; + bool found = false; + + hlist_for_each_entry(constraint, &clk->rate_constraints, node) { + if (constraint->dev_id == clk_user->dev_id && + constraint->con_id == clk_user->con_id && + constraint->type == type) + found = true; + } + + if (!found) { + constraint = kzalloc(sizeof(*constraint), GFP_KERNEL); + if (!constraint) + return NULL; + hlist_add_head(&constraint->node, &clk->rate_constraints); + } + + return constraint; +} + +static int __clk_set_constraint(struct clk *clk_user, unsigned long rate, + enum constraint_type type) +{ + struct clk_core *clk = clk_to_clk_core(clk_user); + struct rate_constraint *constraint; + int ret; + + clk_prepare_lock(); + + constraint = __ensure_constraint(clk_user, type); + if (!constraint) + return -ENOMEM; + + constraint->rate = rate; + + /* Update the rate so the new constraint is taken into account */ + ret = clk_provider_set_rate(clk, clk_provider_get_rate(clk)); + + clk_prepare_unlock(); + + return ret; +} + +int clk_set_floor_rate(struct clk *clk_user, unsigned long rate) +{ + return __clk_set_constraint(clk_user, rate, CONSTRAINT_FLOOR); +} +EXPORT_SYMBOL_GPL(clk_set_floor_rate); + +int clk_set_ceiling_rate(struct clk *clk_user, unsigned long rate) +{ + return __clk_set_constraint(clk_user, rate, CONSTRAINT_CEILING); +} +EXPORT_SYMBOL_GPL(clk_set_ceiling_rate); + struct clk_core *clk_provider_get_parent(struct clk_core *clk) { struct clk_core *parent; @@ -2072,6 +2156,8 @@ int __clk_init(struct device *dev, struct clk_core *clk) } } + INIT_HLIST_HEAD(&clk->rate_constraints); + /* * optional platform-specific magic * @@ -2508,6 +2594,23 @@ int clk_notifier_unregister(struct clk *clk_user, struct notifier_block *nb) } EXPORT_SYMBOL_GPL(clk_notifier_unregister); +void __clk_free_clk(struct clk *clk_user) +{ + struct clk_core *clk = clk_to_clk_core(clk_user); + struct rate_constraint *constraint; + struct hlist_node *tmp; + + hlist_for_each_entry_safe(constraint, tmp, &clk->rate_constraints, node) { + if (constraint->dev_id == clk_user->dev_id && + constraint->con_id == clk_user->con_id) { + hlist_del(&constraint->node); + kfree(constraint); + } + } + + kfree(clk_user); +} + #ifdef CONFIG_OF /** * struct of_clk_provider - Clock provider registration structure diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h index 49eff38..005deb3 100644 --- a/drivers/clk/clk.h +++ b/drivers/clk/clk.h @@ -21,4 +21,5 @@ void of_clk_unlock(void); #if defined(CONFIG_COMMON_CLK) struct clk *__clk_create_clk(struct clk_core *clk_core, const char *dev, const char *con); +void __clk_free_clk(struct clk *clk_user); #endif diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 517a25b..8a6a398 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -269,7 +269,7 @@ void clk_put(struct clk *clk) #if defined(CONFIG_COMMON_CLK) clk_core_t *core = clk_to_clk_core(clk); - kfree(clk); + __clk_free_clk(clk); __clk_put(core); #else __clk_put(clk); diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index 9657fc8..a8279e1 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -48,6 +48,7 @@ struct clk_core { unsigned long accuracy; struct hlist_head children; struct hlist_node child_node; + struct hlist_head rate_constraints; unsigned int notifier_count; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; diff --git a/include/linux/clk.h b/include/linux/clk.h index f46a2eb..066b100 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -275,6 +275,24 @@ long clk_round_rate(struct clk *clk, unsigned long rate); int clk_set_rate(struct clk *clk, unsigned long rate); /** + * clk_set_floor_rate - set a minimum clock rate for a clock source + * @clk: clock source + * @rate: desired minimum clock rate in Hz + * + * Returns success (0) or negative errno. + */ +int clk_set_floor_rate(struct clk *clk, unsigned long rate); + +/** + * clk_set_ceiling_rate - set a maximum clock rate for a clock source + * @clk: clock source + * @rate: desired maximum clock rate in Hz + * + * Returns success (0) or negative errno. + */ +int clk_set_ceiling_rate(struct clk *clk, unsigned long rate); + +/** * clk_set_parent - set the parent clock source for this clock * @clk: clock source * @parent: parent clock source