From patchwork Fri Jun 21 06:14:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Turquette X-Patchwork-Id: 2760391 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 A63A59F756 for ; Fri, 21 Jun 2013 06:23:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A5DFF201B1 for ; Fri, 21 Jun 2013 06:23:21 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 84E99201AF for ; Fri, 21 Jun 2013 06:23:20 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Upukb-0006cE-2d; Fri, 21 Jun 2013 06:23:13 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UpukY-0000wY-J2; Fri, 21 Jun 2013 06:23:10 +0000 Received: from mail-pa0-x22f.google.com ([2607:f8b0:400e:c03::22f]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UpukU-0000wC-O5 for linux-arm-kernel@lists.infradead.org; Fri, 21 Jun 2013 06:23:07 +0000 Received: by mail-pa0-f47.google.com with SMTP id kl14so7299941pab.6 for ; Thu, 20 Jun 2013 23:22:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :x-gm-message-state; bh=zfuGkiec986uL/gnDHiJD2KbL0Qeskp9KOlICUOtstg=; b=cmgja+AzsuLBYV42/2F+Uo5x11QwgZlmEMRk4qidJ7oQCwQx0iCRGspZkpxMkf81E1 c2bCfUPTGCTbmNA3Aro3WLswVC5cWhixwD0zAnKRVNjYaoDAM6RKPqDpTUQIvQDc1Ue/ Q9Qher48soryaMcoK9Do+F/zKau726A9vu5IGop5A2qcunrsv+XCbErKVU4YzDHva6Go uGwS3NfyASmt7/RlZwpSaatnINsj7bKhY+RUiFHJvlA6Yzigtk2FihqXwCbS3xP7qJkO IUVwEbbZ4flXiO8NFNhsbYj2XHBulQtzcfqudf8EluF3nO9gELT7crMsHqZv8f24GUxu KY1Q== X-Received: by 10.68.129.10 with SMTP id ns10mr10911648pbb.13.1371795278479; Thu, 20 Jun 2013 23:14:38 -0700 (PDT) Received: from localhost.localdomain (c-50-152-203-145.hsd1.ca.comcast.net. [50.152.203.145]) by mx.google.com with ESMTPSA id tq3sm4250612pab.7.2013.06.20.23.14.36 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 20 Jun 2013 23:14:37 -0700 (PDT) From: Mike Turquette To: linux-kernel@vger.kernel.org Subject: [PATCH v3 5/5] clk: dt: binding for basic gate clock Date: Thu, 20 Jun 2013 23:14:16 -0700 Message-Id: <1371795256-16703-6-git-send-email-mturquette@linaro.org> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1371795256-16703-1-git-send-email-mturquette@linaro.org> References: <1371795256-16703-1-git-send-email-mturquette@linaro.org> X-Gm-Message-State: ALoCoQmX7Y+yNiP7wCz7fxqt81KV8bBgwn9w0y0W1LLbMBblmdSjyExmo9vYj0B2RWUPXxp74V1c X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130621_022306_985616_2B8A3E6D X-CRM114-Status: GOOD ( 17.65 ) X-Spam-Score: -1.9 (-) Cc: Mike Turquette , =?UTF-8?q?Heiko=20St=C3=BCbner?= , devicetree-discuss@lists.ozlabs.org, Stephen Boyd , Tero Kristo , Haojian Zhuang , Matt Sealey , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 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=-5.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, 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 Device Tree binding for the basic clock gate, plus the setup function to register the clock. Based on the existing fixed-clock binding. A different approach to this was proposed in 2012[1] and a similar binding was proposed more recently[2] if anyone wants some extra reading. [1] http://article.gmane.org/gmane.linux.documentation/5679 [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2012-December/137878.html Tero Kristo contributed helpful bug fixes to this patch. Signed-off-by: Mike Turquette --- Changes since v2: * added hiword-mask property to the binding * changed bit-shift property from u8 to u32 in the dt binding .../devicetree/bindings/clock/gate-clock.txt | 36 ++++++++++++++++++ drivers/clk/clk-gate.c | 43 ++++++++++++++++++++++ include/linux/clk-provider.h | 2 + 3 files changed, 81 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/gate-clock.txt diff --git a/Documentation/devicetree/bindings/clock/gate-clock.txt b/Documentation/devicetree/bindings/clock/gate-clock.txt new file mode 100644 index 0000000..1c0d4d5 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/gate-clock.txt @@ -0,0 +1,36 @@ +Binding for simple gate clock. + +This binding uses the common clock binding[1]. It assumes a +register-mapped clock gate controlled by a single bit that has only one +input clock or parent. By default setting the specified bit gates the +clock signal and clearing the bit ungates it. + +The binding must provide the register to control the gate and the bit +shift for the corresponding gate control bit. Some clocks set the bit to +gate the clock signal, and clear it to ungate the clock signal. The +optional "set-bit-to-disable" specifies this behavior. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : shall be "gate-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : link to phandle of parent clock +- reg : base address for register controlling adjustable gate +- bit-shift : bit shift for programming the clock gate + +Optional properties: +- clock-output-names : from common clock binding. +- set-bit-to-disable : inverts default gate programming. Setting the bit + gates the clock and clearing the bit ungates the clock. +- hiword-mask : lower half of the register controls the gate, upper half + of the register indicates bits that were updated in the lower half + +Examples: + clock_foo: clock_foo@4a008100 { + compatible = "gate-clock"; + #clock-cells = <0>; + clocks = <&clock_bar>; + reg = <0x4a008100 0x4> + bit-shift = <3> + }; diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c index 790306e..cd595ec 100644 --- a/drivers/clk/clk-gate.c +++ b/drivers/clk/clk-gate.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include /** * DOC: basic gatable clock which can gate and ungate it's ouput @@ -161,3 +163,44 @@ struct clk *clk_register_gate(struct device *dev, const char *name, return clk; } + +#ifdef CONFIG_OF +/** + * of_gate_clk_setup() - Setup function for simple gate rate clock + */ +void of_gate_clk_setup(struct device_node *node) +{ + struct clk *clk; + const char *clk_name = node->name; + void __iomem *reg; + const char *parent_name; + u8 clk_gate_flags = 0; + u32 bit_idx = 0; + + of_property_read_string(node, "clock-output-names", &clk_name); + + parent_name = of_clk_get_parent_name(node, 0); + + reg = of_iomap(node, 0); + + if (of_property_read_u32(node, "bit-shift", &bit_idx)) { + pr_err("%s: missing bit-shift property for %s\n", + __func__, node->name); + return; + } + + if (of_property_read_bool(node, "set-bit-to-disable")) + clk_gate_flags |= CLK_GATE_SET_TO_DISABLE; + + if (of_property_read_bool(node, "hiword-mask")) + clk_gate_flags |= CLK_GATE_HIWORD_MASK; + + clk = clk_register_gate(NULL, clk_name, parent_name, 0, reg, (u8) bit_idx, + clk_gate_flags, NULL); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); +} +EXPORT_SYMBOL_GPL(of_gate_clk_setup); +CLK_OF_DECLARE(gate_clk, "gate-clock", of_gate_clk_setup); +#endif diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 723ce69..4aeaedb 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -232,6 +232,8 @@ struct clk *clk_register_gate(struct device *dev, const char *name, void __iomem *reg, u8 bit_idx, u8 clk_gate_flags, spinlock_t *lock); +void of_gate_clk_setup(struct device_node *node); + struct clk_div_table { unsigned int val; unsigned int div;