From patchwork Thu Sep 11 14:26:19 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomeu Vizoso X-Patchwork-Id: 4888271 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6BF8FC0338 for ; Thu, 11 Sep 2014 14:29:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8A7A320272 for ; Thu, 11 Sep 2014 14:29:32 +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 B6E18201EF for ; Thu, 11 Sep 2014 14:29:27 +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 1XS5LI-0001IF-Qs; Thu, 11 Sep 2014 14:27:24 +0000 Received: from mail-wi0-x229.google.com ([2a00:1450:400c:c05::229]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XS5L0-0000ib-2m for linux-arm-kernel@lists.infradead.org; Thu, 11 Sep 2014 14:27:07 +0000 Received: by mail-wi0-f169.google.com with SMTP id cc10so1229299wib.0 for ; Thu, 11 Sep 2014 07:26:41 -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=wepUwSNRDq60Qi85Yptn/xVrz7PwXlrzeiKNSGu+AjI=; b=0KU8+gq6GySsYTBOQNntibbzGYCwZDJizoyrNIDYdXm2yvkgex/DdM4KljYqH09fO3 HcLgq2vKhM31oddrXkYVAV6/5nbCAljunpmuznIa2dMINHZvcA/ho/nBLp7lc0t7i6ed mGAmWy/za020K0W8wbjmgX503rhihvXtBuHnLPfcZ6eWsawKAYfAeLNPQk4QJvHZUrKk G4rsMKDt2IF8v2XEioORsUOeIemMEbb0OO+H/RCCLDv2hZPCVVusWdnsKSh8gY6u0boI GP5xHC1YpSGo7gs5B1LUjspxqu0aIgiXU0s5QdB1rvQAn/0AlCRXYdm4IR4GEqk/8RPu ZmUQ== X-Received: by 10.180.88.167 with SMTP id bh7mr7906246wib.12.1410445601807; Thu, 11 Sep 2014 07:26:41 -0700 (PDT) Received: from localhost.localdomain (37-48-42-23.tmcz.cz. [37.48.42.23]) by mx.google.com with ESMTPSA id ka3sm1421242wjc.3.2014.09.11.07.26.39 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Sep 2014 07:26:40 -0700 (PDT) From: Tomeu Vizoso To: Mike Turquette Subject: [PATCH v11 5/9] clk: Add floor and ceiling constraints to clock rates Date: Thu, 11 Sep 2014 16:26:19 +0200 Message-Id: <1410445583-18626-3-git-send-email-tomeu.vizoso@collabora.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1410445583-18626-1-git-send-email-tomeu.vizoso@collabora.com> References: <1410445421-18362-1-git-send-email-tomeu.vizoso@collabora.com> <1410445583-18626-1-git-send-email-tomeu.vizoso@collabora.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140911_072706_274220_30A4150D X-CRM114-Status: GOOD ( 18.89 ) X-Spam-Score: -0.7 (/) Cc: Tomeu Vizoso , Stephen Warren , Peter De Schrijver , linux-kernel@vger.kernel.org, tomasz.figa@gmail.com, rabin@rab.in, Thierry Reding , Javier Martinez Canillas , 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=-4.3 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_NONE,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 Tested-by: Heiko Stuebner --- v9: * Apply first all the floor constraints, then the ceiling constraints. * WARN on ceiling constraints below the current floor, for a given user clk v5: * Move the storage of constraints to the per-user clk struct, as suggested by Stephen Warren. --- drivers/clk/clk.c | 43 +++++++++++++++++++++++++++++++++++++++++++ drivers/clk/clk.h | 1 + drivers/clk/clkdev.c | 2 +- include/linux/clk-private.h | 5 +++++ include/linux/clk.h | 18 ++++++++++++++++++ 5 files changed, 68 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 61a3492..3a961c6 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -560,6 +560,8 @@ struct clk *__clk_create_clk(struct clk_core *clk_core, const char *dev, clk->dev_id = dev; clk->con_id = con; + hlist_add_head(&clk->child_node, &clk_core->per_user_clks); + return clk; } @@ -1625,6 +1627,7 @@ 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 clk *clk_user; int ret = 0; if (!clk) @@ -1633,6 +1636,15 @@ 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(clk_user, &clk->per_user_clks, child_node) { + rate = max(rate, clk_user->floor_constraint); + } + + hlist_for_each_entry(clk_user, &clk->per_user_clks, child_node) { + if (clk_user->ceiling_constraint > 0) + rate = min(rate, clk_user->ceiling_constraint); + } + /* bail early if nothing to do */ if (rate == clk_provider_get_rate(clk)) goto out; @@ -1699,6 +1711,29 @@ int clk_set_rate(struct clk *clk_user, unsigned long rate) } EXPORT_SYMBOL_GPL(clk_set_rate); +int clk_set_floor_rate(struct clk *clk_user, unsigned long rate) +{ + struct clk_core *clk = clk_to_clk_core(clk_user); + + clk_user->floor_constraint = rate; + return clk_provider_set_rate(clk, clk_provider_get_rate(clk)); +} +EXPORT_SYMBOL_GPL(clk_set_floor_rate); + +int clk_set_ceiling_rate(struct clk *clk_user, unsigned long rate) +{ + struct clk_core *clk = clk_to_clk_core(clk_user); + + WARN(rate > 0 && rate < clk_user->floor_constraint, + "clk %s dev %s con %s: new ceiling %lu lower than existing floor %lu\n", + __clk_get_name(clk), clk_user->dev_id, clk_user->con_id, rate, + clk_user->floor_constraint); + + clk_user->ceiling_constraint = rate; + return clk_provider_set_rate(clk, clk_provider_get_rate(clk)); +} +EXPORT_SYMBOL_GPL(clk_set_ceiling_rate); + struct clk_core *clk_provider_get_parent(struct clk_core *clk) { struct clk_core *parent; @@ -2043,6 +2078,8 @@ int __clk_init(struct device *dev, struct clk_core *clk) } } + INIT_HLIST_HEAD(&clk->per_user_clks); + /* * optional platform-specific magic * @@ -2493,6 +2530,12 @@ 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) +{ + hlist_del(&clk_user->child_node); + 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 f7b352a..89193de 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -270,7 +270,7 @@ 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 ce6a528..8126046 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 per_user_clks; unsigned int notifier_count; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; @@ -62,6 +63,10 @@ struct clk { unsigned int enable_count; void *last_disable; + + unsigned long floor_constraint; + unsigned long ceiling_constraint; + struct hlist_node child_node; }; /* 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