From patchwork Wed Apr 9 11:26:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sylwester Nawrocki/Kernel \\(PLT\\) /SRPOL/Staff Engineer/Samsung Electronics" X-Patchwork-Id: 3954751 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 A189DBFF02 for ; Wed, 9 Apr 2014 11:29:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 37A9220444 for ; Wed, 9 Apr 2014 11:29:01 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (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 7AC9420435 for ; Wed, 9 Apr 2014 11:28:59 +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 1WXqfd-000192-OS; Wed, 09 Apr 2014 11:27:58 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WXqfQ-00072n-HT; Wed, 09 Apr 2014 11:27:44 +0000 Received: from mailout1.samsung.com ([203.254.224.24]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WXqfD-00070O-2k for linux-arm-kernel@lists.infradead.org; Wed, 09 Apr 2014 11:27:34 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N3R004FCH5APK30@mailout1.samsung.com> for linux-arm-kernel@lists.infradead.org; Wed, 09 Apr 2014 20:27:10 +0900 (KST) X-AuditID: cbfee61a-b7fb26d00000724f-b1-53452e8e6ff2 Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id 25.E7.29263.E8E25435; Wed, 09 Apr 2014 20:27:10 +0900 (KST) Received: from amdc1344.digital.local ([106.116.147.32]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0N3R00H4WH485K60@mmp1.samsung.com>; Wed, 09 Apr 2014 20:27:10 +0900 (KST) From: Sylwester Nawrocki To: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Subject: [PATCH RFC v5 2/2] clk: Add handling of clk parent and rate assigned from DT Date: Wed, 09 Apr 2014 13:26:30 +0200 Message-id: <1397042790-10636-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1397042790-10636-1-git-send-email-s.nawrocki@samsung.com> References: <1397042790-10636-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrLLMWRmVeSWpSXmKPExsVy+t9jAd0+Pddgg/8b1C0e3Gplsph/5Byr Rf+bhawWB/7sYLRoXryezeJs0xt2i86JS9gtNj2+xmpxedccNovbl3kt1h65y26x9PpFJoun Ey6yWUxaO5XRonXvEXaLv9s3sVgcftPOajFj8ks2iyVPO9gs1s94zeIg4rFm3hpGj5bmHjaP y329TB7PXk5m8pjdMZPVY9OqTjaPO9f2sHnsn7uG3WPzknqP3uZ3bB79fw08+rasYvQ4fmM7 k8fnTXIBfFFcNimpOZllqUX6dglcGXdbbzEWvPaumHtboYHxqnUXIweHhICJxPPtvF2MnECm mMSFe+vZuhi5OIQEFjFKrGrbwgThdDBJbHh7lhWkik3AUKL3aB8jiC0i4CLR+WAdC0gRs8A9 Zonj5+ewgCSEBcIluk/8ZgOxWQRUJU4+ewBm8wq4Sbw58psRYrOCxJxJNiBhTgF3iW1fm8Fm CgGVfLg+n2kCI+8CRoZVjKKpBckFxUnpuYZ6xYm5xaV56XrJ+bmbGMGR8kxqB+PKBotDjAIc jEo8vIqWLsFCrIllxZW5hxglOJiVRHifs7kGC/GmJFZWpRblxxeV5qQWH2KU5mBREuc90God KCSQnliSmp2aWpBaBJNl4uCUamCs0Fp/lv28yQQu1+da3T6zS40uLFuRwlq+ZHmYoU9buJhq 0RL+KzsMzOIuMm148SFwQn3i6b9BClyeHBaSCyYEP1x34m/Ud63CN8m5r9fFpe9P0ek68rzK StB+13RfiXPRloGBf/KdZjPnL2M2WjI3+sHFbk39Rf69K2fIuE1zCeb9Hef9g0uJpTgj0VCL uag4EQC1V+QmkAIAAA== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140409_072732_909374_DD1AEDAA X-CRM114-Status: GOOD ( 24.10 ) X-Spam-Score: -7.2 (-------) Cc: mark.rutland@arm.com, pdeschrijver@nvidia.com, mturquette@linaro.org, gregkh@linuxfoundation.org, s.hauer@pengutronix.de, sw0312.kim@samsung.com, linux-kernel@vger.kernel.org, t-kristo@ti.com, t.figa@samsung.com, kyungmin.park@samsung.com, robh+dt@kernel.org, laurent.pinchart@ideasonboard.com, Sylwester Nawrocki , galak@codeaurora.org, grant.likely@linaro.org, linux@arm.linux.org.uk, ben.dooks@codethink.co.uk, m.szyprowski@samsung.com 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=-4.5 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 This patch adds a helper function to configure clock parents and rates as specified in clock-parents, clock-rates DT properties for a consumer device and a call to it before driver is bound to a device. Signed-off-by: Sylwester Nawrocki --- Changes since v4: - added note explaining how to skip setting parent and rate of a clock, - moved of_clk_dev_init() calls to the platform bus, - added missing call to of_node_put(), - dropped debug traces. Changes since v3: - added detailed description of the assigned-clocks subnode, - added missing 'static inline' to the function stub definition, - clk-conf.c is now excluded when CONFIG_OF is not set, - s/of_clk_device_setup/of_clk_device_init. Changes since v2: - edited in clock-bindings.txt, added note about 'assigned-clocks' subnode which may be used to specify "global" clocks configuration at a clock provider node, - moved of_clk_device_setup() function declaration from clk-provider.h to clk-conf.h so required function stubs are available when CONFIG_COMMON_CLK is not enabled, Changes since v1: - the helper function to parse and set assigned clock parents and rates made public so it is available to clock providers to call directly; - dropped the platform bus notification and call of_clk_device_setup() is is now called from the driver core, rather than from the notification callback; - s/of_clk_get_list_entry/of_clk_get_by_property. --- .../devicetree/bindings/clock/clock-bindings.txt | 44 ++++++++++ drivers/base/platform.c | 5 ++ drivers/clk/Makefile | 3 + drivers/clk/clk-conf.c | 85 ++++++++++++++++++++ drivers/clk/clk.c | 12 ++- include/linux/clk/clk-conf.h | 19 +++++ 6 files changed, 167 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/clk-conf.c create mode 100644 include/linux/clk/clk-conf.h diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index 700e7aa..93513fc 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -132,3 +132,47 @@ clock signal, and a UART. ("pll" and "pll-switched"). * The UART has its baud clock connected the external oscillator and its register clock connected to the PLL clock (the "pll-switched" signal) + +==Assigned clock parents and rates== + +Some platforms require static initial configuration of parts of the clocks +controller. Such a configuration can be specified in a clock consumer node +through clock-parents and clock-rates DT properties. The former should +contain a list of parent clocks in form of phandle and clock specifier pairs, +the latter the list of assigned clock frequency values (one cell each). +To skip setting parent or rate of a clock its corresponding entry should be +set to 0, or can be omitted if it is not followed by any non-zero entry. + + uart@a000 { + compatible = "fsl,imx-uart"; + reg = <0xa000 0x1000>; + ... + clocks = <&clkcon 0>, <&clkcon 3>; + clock-names = "baud", "mux"; + + clock-parents = <0>, <&pll 1>; + clock-rates = <460800>; + }; + +In this example the pll is set as parent of "mux" clock and frequency of "baud" +clock is specified as 460800 Hz. + +Configuring a clock's parent and rate through the device node that uses +the clock can be done only for clocks that have a single user. Specifying +conflicting parent or rate configuration in multiple consumer nodes for +a shared clock is forbidden. + +Configuration of common clocks, which affect multiple consumer devices +can be specified in a dedicated 'assigned-clocks' subnode of a clock +provider node, e.g.: + + clkcon { + ... + #clock-cells = <1>; + + assigned-clocks { + clocks = <&clkcon 16>, <&clkcon 17>; + clock-parents = <0>, <&clkcon 1>; + clock-rates = <200000>; + }; + }; diff --git a/drivers/base/platform.c b/drivers/base/platform.c index e714709..4b95322 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -481,6 +482,10 @@ static int platform_drv_probe(struct device *_dev) struct platform_device *dev = to_platform_device(_dev); int ret; + ret = of_clk_dev_init(_dev->of_node); + if (ret < 0) + return ret; + acpi_dev_pm_attach(_dev, true); ret = drv->probe(dev); diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 5f8a287..45598f7 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -8,6 +8,9 @@ obj-$(CONFIG_COMMON_CLK) += clk-fixed-rate.o obj-$(CONFIG_COMMON_CLK) += clk-gate.o obj-$(CONFIG_COMMON_CLK) += clk-mux.o obj-$(CONFIG_COMMON_CLK) += clk-composite.o +ifeq ($(CONFIG_OF), y) +obj-$(CONFIG_COMMON_CLK) += clk-conf.o +endif # hardware specific clock types # please keep this section sorted lexicographically by file/directory path name diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c new file mode 100644 index 0000000..c0d4096 --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,85 @@ +/* + * Copyright (C) 2014 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +/** + * of_clk_dev_init() - parse and set clk configuration assigned to a device + * @node: device node to apply the configuration for + * + * This function parses 'clock-parents' and 'clock-rates' properties and sets + * any specified clock parents and rates. + */ +int of_clk_dev_init(struct device_node *node) +{ + struct property *prop; + const __be32 *cur; + int rc, index, num_parents; + struct clk *clk, *pclk; + u32 rate; + + if (!node) + return 0; + + num_parents = of_count_phandle_with_args(node, "clock-parents", + "#clock-cells"); + if (num_parents == -EINVAL) + pr_err("clk: invalid value of clock-parents property at %s\n", + node->full_name); + + for (index = 0; index < num_parents; index++) { + pclk = of_clk_get_by_property(node, "clock-parents", index); + if (IS_ERR(pclk)) { + /* skip empty (null) phandles */ + if (PTR_ERR(pclk) == -ENOENT) + continue; + + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + + return PTR_ERR(pclk); + } + + clk = of_clk_get(node, index); + if (IS_ERR(clk)) { + pr_warn("clk: couldn't get clock %d for %s\n", + index, node->full_name); + return PTR_ERR(clk); + } + + rc = clk_set_parent(clk, pclk); + if (rc < 0) + pr_err("clk: failed to reparent %s to %s: %d\n", + __clk_get_name(clk), __clk_get_name(pclk), rc); + } + + index = 0; + of_property_for_each_u32(node, "clock-rates", prop, cur, rate) { + if (rate) { + clk = of_clk_get(node, index); + if (IS_ERR(clk)) { + pr_warn("clk: couldn't get clock %d for %s\n", + index, node->full_name); + return PTR_ERR(clk); + } + + rc = clk_set_rate(clk, rate); + if (rc < 0) + pr_err("clk: couldn't set %s clock rate: %d\n", + __clk_get_name(clk), rc); + } + index++; + } + + return 0; +} diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index dff0373..0d72a4d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -10,6 +10,7 @@ */ #include +#include #include #include #include @@ -2620,7 +2621,17 @@ void __init of_clk_init(const struct of_device_id *matches) list_for_each_entry_safe(clk_provider, next, &clk_provider_list, node) { if (force || parent_ready(clk_provider->np)) { + clk_provider->clk_init_cb(clk_provider->np); + + /* Set any assigned clock parents and rates */ + np = of_get_child_by_name(clk_provider->np, + "assigned-clocks"); + if (np) { + of_clk_dev_init(np); + of_node_put(np); + } + list_del(&clk_provider->node); kfree(clk_provider); is_init_done = true; @@ -2635,7 +2646,6 @@ void __init of_clk_init(const struct of_device_id *matches) */ if (!is_init_done) force = true; - } } #endif diff --git a/include/linux/clk/clk-conf.h b/include/linux/clk/clk-conf.h new file mode 100644 index 0000000..afb4228 --- /dev/null +++ b/include/linux/clk/clk-conf.h @@ -0,0 +1,19 @@ +/* + * Copyright (C) 2014 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +struct device_node; + +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +int of_clk_dev_init(struct device_node *node); +#else +static inline int of_clk_dev_init(struct device_node *node) +{ + return 0; +} +#endif