From patchwork Mon May 19 17:22:51 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: 4204731 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 81C62BEEAB for ; Mon, 19 May 2014 17:28:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 49EF3201F2 for ; Mon, 19 May 2014 17:28:58 +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 0FAD5201E7 for ; Mon, 19 May 2014 17:28:57 +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 1WmRKh-0004uP-U5; Mon, 19 May 2014 17:26:39 +0000 Received: from mailout4.samsung.com ([203.254.224.34]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WmRKc-0004hf-Og for linux-arm-kernel@lists.infradead.org; Mon, 19 May 2014 17:26:36 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout4.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N5U00FOR0FNCK80@mailout4.samsung.com> for linux-arm-kernel@lists.infradead.org; Tue, 20 May 2014 02:26:12 +0900 (KST) X-AuditID: cbfee61a-b7fef6d00000200b-62-537a3eb30257 Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id 2C.65.08203.3BE3A735; Tue, 20 May 2014 02:26:11 +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 <0N5U00B010A9ZE00@mmp1.samsung.com>; Tue, 20 May 2014 02:26:11 +0900 (KST) From: Sylwester Nawrocki To: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, mturquette@linaro.org Subject: [PATCH/RFC V6 2/2] clk: Add handling of clk parent and rate assigned from DT Date: Mon, 19 May 2014 19:22:51 +0200 Message-id: <1400520171-6698-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1400520171-6698-1-git-send-email-s.nawrocki@samsung.com> References: <1400520171-6698-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrBLMWRmVeSWpSXmKPExsVy+t9jAd3NdlXBBrOWWFrMP3KO1aL/zUJW iwN/djBanG16w26x6fE1VovLu+awWdy+zGux9shddoul1y8yWTydcJHNYsL0tSwWrXuPsFsc ftPOajFj8ks2i/UzXrM48HusmbeG0aOluYfN43JfL5PHplWdbB53ru1h89i8pN6jb8sqRo/P m+QCOKK4bFJSczLLUov07RK4Mu7dn89ccCGhouPIEbYGxrU+XYycHBICJhINHetYIWwxiQv3 1rN1MXJxCAksYpTonj6fEcLpYJJ4c/EsI0gVm4ChRO/RPjBbRCBWYsOzvWBFzAK7mSTWfzoC NkpYIFzi/qvZLCA2i4CqRGP3TyYQm1fAVWL1qnVANgfQOgWJOZNsQMKcAm4ST99MYwUJCwGV nHvgMYGRdwEjwypG0dSC5ILipPRcQ73ixNzi0rx0veT83E2M4PB9JrWDcWWDxSFGAQ5GJR7e A+JVwUKsiWXFlbmHGCU4mJVEeN1MgEK8KYmVValF+fFFpTmpxYcYpTlYlMR5D7RaBwoJpCeW pGanphakFsFkmTg4pRoYC5RFOszCpO+sb76S1SH3apc0y34dq+r5m688fGZ0atYt5WM/z9/c 9dzh1qkoZebjb04s+PfCxCOgUuy1yYoMnutxJ4qlH3tG7vJsKllX45Tz4/LNb9u9l7ofrc67 Ejuh/Y1ivlFj0hmerxuX1n7vVWW+myVaf+fXxYVyfbv4KzwytscJXxXRV2Ipzkg01GIuKk4E ABQ9uCxbAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140519_102635_153244_FFD5582E X-CRM114-Status: GOOD ( 29.41 ) X-Spam-Score: -5.7 (-----) Cc: mark.rutland@arm.com, linux@arm.linux.org.uk, pawel.moll@arm.com, t.figa@samsung.com, sw0312.kim@samsung.com, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, robh+dt@kernel.org, Sylwester Nawrocki , galak@codeaurora.org, grant.likely@linaro.org, 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=-2.5 required=5.0 tests=BAYES_00,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 v5: - updated the DT binding description (dropped 'assigned-clocks' node); - fixed detecting of null phandles (ENOENT error handling); - modified of_clk_init() to account for that the clocks property may now contain a clock specifier with a phandle that points to our node; 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 | 32 +++++ drivers/base/platform.c | 5 + drivers/clk/Makefile | 3 + drivers/clk/clk-conf.c | 141 ++++++++++++++++++++ drivers/clk/clk.c | 27 +++- include/linux/clk/clk-conf.h | 20 +++ 6 files changed, 225 insertions(+), 3 deletions(-) create mode 100644 drivers/clk/clk-conf.c create mode 100644 include/linux/clk/clk-conf.h -- 1.7.9.5 diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index 700e7aa..bee649b 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -132,3 +132,35 @@ 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 default parent clocks +and clock frequecies. Such a configuration can be specified in a device 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 consumes +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 similarly specified in the clock provider node. diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5b47210..f622733 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -486,6 +487,10 @@ static int platform_drv_probe(struct device *_dev) struct platform_device *dev = to_platform_device(_dev); int ret; + ret = of_clk_set_defaults(_dev->of_node, false); + 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..0bf26d5 --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,141 @@ +/* + * 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 +#include "clk.h" + +static int __set_clk_parents(struct device_node *node, bool self_consumer) +{ + struct of_phandle_args clkspec; + int index, rc, num_parents; + struct clk *clk, *pclk; + + 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++) { + rc = of_parse_phandle_with_args(node, "clock-parents", + "#clock-cells", index, &clkspec); + if (rc < 0) { + /* skip empty (null) phandles */ + if (rc == -ENOENT) + continue; + else + return rc; + } + if (clkspec.np == node && !self_consumer) + return 0; + pclk = of_clk_get_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + return PTR_ERR(pclk); + } + + rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", + index, &clkspec); + if (rc < 0) + goto err; + if (clkspec.np == node && !self_consumer) { + rc = 0; + goto err; + } + clk = of_clk_get_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + rc = PTR_ERR(pclk); + goto err; + } + + 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); + clk_put(clk); + clk_put(pclk); + } + return 0; +err: + clk_put(pclk); + return rc; +} + +static int __set_clk_rates(struct device_node *node, bool self_consumer) +{ + struct of_phandle_args clkspec; + struct property *prop; + const __be32 *cur; + int rc, index = 0; + struct clk *clk; + u32 rate; + + of_property_for_each_u32(node, "clock-rates", prop, cur, rate) { + if (rate) { + rc = of_parse_phandle_with_args(node, "clocks", + "#clock-cells", index, &clkspec); + if (rc < 0) { + /* skip empty (null) phandles */ + if (rc == -ENOENT) + continue; + else + return rc; + } + if (clkspec.np == node && !self_consumer) + return 0; + + clk = of_clk_get_by_clkspec(&clkspec); + 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); + clk_put(clk); + } + index++; + } + return 0; +} + +/** + * of_clk_set_defaults() - parse and set assigned clocks configuration + * @node: device node to apply clock settings for + * @self_consumer: true to indicate @node may also consume clocks it supplies + * + * This function parses 'clock-parents' and 'clock-rates' properties and sets + * any specified clock parents and rates. The @self_consumer argument should be + * set to true if @node may be also a clock supplier of any clock listed in its + * 'clocks' or 'clock-parents' properties. Otherwise the functions exits as soon + * as it determines the @node is also a supplier of any of the clocks. + */ +int of_clk_set_defaults(struct device_node *node, bool self_consumer) +{ + int rc; + + if (!node) + return 0; + + rc = __set_clk_parents(node, self_consumer); + if (rc < 0) + return rc; + + return __set_clk_rates(node, self_consumer); +} diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index dff0373..3a8947d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -10,6 +10,7 @@ */ #include +#include #include #include #include @@ -2429,6 +2430,7 @@ int of_clk_add_provider(struct device_node *np, void *data) { struct of_clk_provider *cp; + int ret; cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); if (!cp) @@ -2443,7 +2445,11 @@ int of_clk_add_provider(struct device_node *np, mutex_unlock(&of_clk_mutex); pr_debug("Added clock from %s\n", np->full_name); - return 0; + ret = of_clk_set_defaults(np, true); + if (ret < 0) + of_clk_del_provider(np); + + return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider); @@ -2558,10 +2564,23 @@ static LIST_HEAD(clk_provider_list); */ static int parent_ready(struct device_node *np) { + struct of_phandle_args clkspec; int i = 0; while (true) { - struct clk *clk = of_clk_get(np, i); + struct clk *clk; + + int rc = of_parse_phandle_with_args(np, "clocks", + "#clock-cells", i, &clkspec); + if (!rc) { + if (clkspec.np == np) { + i++; + continue; + } + clk = of_clk_get_by_clkspec(&clkspec); + } else { + clk = ERR_PTR(rc); + } /* this parent is ready we can check the next one */ if (!IS_ERR(clk)) { @@ -2620,7 +2639,10 @@ 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); + of_clk_set_defaults(np, true); + list_del(&clk_provider->node); kfree(clk_provider); is_init_done = true; @@ -2635,7 +2657,6 @@ 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..0a1f311 --- /dev/null +++ b/include/linux/clk/clk-conf.h @@ -0,0 +1,20 @@ +/* + * 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_set_defaults(struct device_node *node, bool self_consumer); +#else +static inline int of_clk_set_defaults(struct device_node *node, + bool self_consumer) +{ + return 0; +} +#endif