From patchwork Tue Sep 23 18:44:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomeu Vizoso X-Patchwork-Id: 4958971 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 95A36BEEA5 for ; Tue, 23 Sep 2014 18:48:03 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 86D4E2025A for ; Tue, 23 Sep 2014 18:48:02 +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 287C220259 for ; Tue, 23 Sep 2014 18:48:01 +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 1XWV5j-000534-FD; Tue, 23 Sep 2014 18:45:35 +0000 Received: from mail-wi0-x22c.google.com ([2a00:1450:400c:c05::22c]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XWV5I-0003X7-PM for linux-arm-kernel@lists.infradead.org; Tue, 23 Sep 2014 18:45:10 +0000 Received: by mail-wi0-f172.google.com with SMTP id em10so5525299wid.11 for ; Tue, 23 Sep 2014 11:44:46 -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=48ycR6npy6zsvrK0flz9SFs6zDf8kLjbN/C8LNd+/0M=; b=Zr4F6JebPZrJw2PqgM8ill9BuYS5IT/4fAoaFef4R9vx4hAcq5vr0vBZ6zYfaVQbDn XaWtpQryBhWYyHO/G0tAhzLCLOZUtUooO6y0wABqR7GmICzBbcG/vH5cPsVH7G1Lt7a2 T4KaMDjB4cPL4SVJIoFK/fZ6cOaKTgBIDFVzZsVgxqcvNWvRFTZpr1nKCu0VPOutYZ/6 ntI+nqT9beUqGX/DO1B3tb+4VZbZwz1MrSOtJLi4l95VSS+ktJ9Wk01NzP+bm8tVuDBF uLhG0oKdRuVr/5BFXucZq2T6BZBkcDFrzNBnSLDiYhqn6WquMFoIIbW242b8uKqWpxYC 1Saw== X-Received: by 10.180.86.33 with SMTP id m1mr24621957wiz.11.1411497886768; Tue, 23 Sep 2014 11:44:46 -0700 (PDT) Received: from cizrna.lan (37-48-33-192.tmcz.cz. [37.48.33.192]) by mx.google.com with ESMTPSA id pn5sm16871650wjc.4.2014.09.23.11.44.43 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Sep 2014 11:44:45 -0700 (PDT) From: Tomeu Vizoso To: Mike Turquette Subject: [PATCH v13 5/9] clk: Add floor and ceiling constraints to clock rates Date: Tue, 23 Sep 2014 20:44:13 +0200 Message-Id: <1411497857-24726-3-git-send-email-tomeu.vizoso@collabora.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1411497857-24726-1-git-send-email-tomeu.vizoso@collabora.com> References: <1411497613-24049-1-git-send-email-tomeu.vizoso@collabora.com> <1411497857-24726-1-git-send-email-tomeu.vizoso@collabora.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140923_114509_158086_9062410D X-CRM114-Status: GOOD ( 18.91 ) X-Spam-Score: 0.0 (/) Cc: Russell King , 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=-2.5 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 b34922e..11ab923 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; } @@ -1669,6 +1671,7 @@ 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) @@ -1677,6 +1680,15 @@ 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; @@ -1743,6 +1755,29 @@ 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; @@ -2094,6 +2129,8 @@ int __clk_init(struct device *dev, struct clk_core *clk) } } + INIT_HLIST_HEAD(&clk->per_user_clks); + /* * optional platform-specific magic * @@ -2500,6 +2537,12 @@ 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 8699a9b..a555e58 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -292,7 +292,7 @@ void clk_put(struct clk *clk) #if defined(CONFIG_COMMON_CLK) struct clk_core *core = clk_to_clk_core(clk); - kfree(clk); + __clk_free_clk(clk); clk_provider_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