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Tue, 01 Apr 2014 01:43:05 +0900 (KST) From: Sylwester Nawrocki To: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC v4 2/2] clk: Add handling of clk parent and rate assigned from DT Date: Mon, 31 Mar 2014 18:41:56 +0200 Message-id: <1396284116-19178-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1396284116-19178-1-git-send-email-s.nawrocki@samsung.com> References: <1396284116-19178-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrPLMWRmVeSWpSXmKPExsVy+t9jAV2p2ZbBBksPsFnMP3KO1aL/zUJW iwN/djBaNC9ez2ZxtukNu0XnxCXsFpseX2O1uLxrDpvF7cu8FmuP3GW3WHr9IpPF0wkX2Sxa 9x5ht/i7fROLxeE37awWMya/ZLNYP+M1i4Ogx5p5axg9Wpp72Dwu9/UyeczumMnqsWlVJ5vH nWt72Dz2z13D7rF5Sb1H/18Dj74tqxg9Pm+SC+CO4rJJSc3JLEst0rdL4MpYvXguc8F1r4qD J4IaGF9bdTFyckgImEi8ubibDcIWk7hwbz2YLSSwiFFi2ZaELkYuILuDSWLngTtMIAk2AUOJ 3qN9jCC2iICNRM+Wk4wgRcwC85kljj85AdYtLBAucfzIElYQm0VAVaLn8m52EJtXwE3izsd9 QA0cQNsUJOZMsgEJcwq4Syza9pURYrGbxNynm5gnMPIuYGRYxSiaWpBcUJyUnmuoV5yYW1ya l66XnJ+7iREc7M+kdjCubLA4xCjAwajEw2tRbhksxJpYVlyZe4hRgoNZSYT3yHSgEG9KYmVV alF+fFFpTmrxIUZpDhYlcd4DrdaBQgLpiSWp2ampBalFMFkmDk6pBsZdmyalR+T+8tdfPCco R4KzdZfN2wCbGabHbvTO9pBe4HfvwS8/161ygVK9bNtmv+3ZuGzzVIcT52q703TetvzqT3dt r5z64NaH3J5TMR91nv5bk8dyuVyyRm6zY4/Mf79Vn1Uz5cPr936wZ1WoEHzJmGCipCdfx+13 hXfP4jPejWfWRgWY7lRiKc5INNRiLipOBADbP39McgIAAA== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140331_124328_418435_BE7439E2 X-CRM114-Status: GOOD ( 24.17 ) X-Spam-Score: -7.5 (-------) Cc: mark.rutland@arm.com, mturquette@linaro.org, gregkh@linuxfoundation.org, t.figa@samsung.com, sw0312.kim@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, s.hauer@pengutronix.de, linux-arm-kernel@lists.infradead.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=-4.8 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 function 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 v3: - added detailed description of the assigned-clocks subnode, - clk-conf.c is now excluded when CONFIG_OF is not set, - s/of_clk_device_setup/of_clk_device_init, - added missing 'static inline' to the function stub definition. 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 | 42 ++++++++++ drivers/base/dd.c | 7 ++ drivers/clk/Makefile | 3 + drivers/clk/clk-conf.c | 87 ++++++++++++++++++++ drivers/clk/clk.c | 10 ++- 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 -- 1.7.9.5 diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index 700e7aa..59fbb4e 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -132,3 +132,45 @@ 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). + + 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 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/dd.c b/drivers/base/dd.c index 0605176..4c633e7 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -278,6 +279,12 @@ static int really_probe(struct device *dev, struct device_driver *drv) if (ret) goto probe_failed; + if (dev->of_node) { + ret = of_clk_device_init(dev->of_node); + if (ret) + goto probe_failed; + } + if (driver_sysfs_add(dev)) { printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n", __func__, dev_name(dev)); diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 85a33e6..5ec53cb 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..a2e992e --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,87 @@ +/* + * 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_device_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_device_init(struct device_node *node) +{ + struct property *prop; + const __be32 *cur; + int rc, index, num_parents; + struct clk *clk, *pclk; + u32 rate; + + 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); + else + pr_debug("clk: set %s as parent of %s\n", + __clk_get_name(pclk), __clk_get_name(clk)); + } + + 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); + else + pr_debug("clk: set rate of clock %s to %lu\n", + __clk_get_name(clk), clk_get_rate(clk)); + } + index++; + } + + return 0; +} diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index dff0373..ea6d8bd 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -10,6 +10,7 @@ */ #include +#include #include #include #include @@ -2620,7 +2621,15 @@ 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_device_init(np); + list_del(&clk_provider->node); kfree(clk_provider); is_init_done = true; @@ -2635,7 +2644,6 @@ 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..51b9c01 --- /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_device_init(struct device_node *node); +#else +static inline int of_clk_device_init(struct device_node *node) +{ + return 0; +} +#endif