From patchwork Mon Jun 17 02:58:23 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Turquette X-Patchwork-Id: 2730221 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 760A69F96B for ; Mon, 17 Jun 2013 03:02:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5FAAC2017B for ; Mon, 17 Jun 2013 03:02:31 +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 2D0D820174 for ; Mon, 17 Jun 2013 03:02:30 +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 1UoPge-0003sX-2t; Mon, 17 Jun 2013 03:00:57 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoPgJ-0003JU-Od; Mon, 17 Jun 2013 03:00:35 +0000 Received: from mail-pb0-x22c.google.com ([2607:f8b0:400e:c01::22c]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UoPfk-0003EY-F5 for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2013 03:00:03 +0000 Received: by mail-pb0-f44.google.com with SMTP id uo1so2296062pbc.17 for ; Sun, 16 Jun 2013 19:59:38 -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=bfmfVABmhP3wsQv+UfjPTOVBEA91yiR+GGz3K4PrMYo=; b=pwRAsMa5r1/nVfEc1aiM/f4e8x+1MFLEgI50Ta8ipCBk5ZsvtInNwsnL/CAtsWwuCL o5MXEmdPyDkCzAKvnUjqTwOxjw4sSCvjYNtqG5AU/e8QEto63fbZt7bdONu/6fy8MAVi N27X/QxbjkqxMckIx9xPBUCylkvuevkjNz3beTIwLNeMSVZ5SOxbNOlOx9+qkWan/lF/ Wa+wgoZCylCSF8iIrAk30Ul7TKtVQIbnpvPyWHMXnALQXRwH8AsbOaoHRNsoAAkzZ1hN qGTkTuSaOvXxULB7i5AMtVEGppxTLHOF7vmYC4sTMcAH9XtUHcIiSIdq9BwJnPeZXkuJ nlwQ== X-Received: by 10.68.245.200 with SMTP id xq8mr11270956pbc.32.1371437977925; Sun, 16 Jun 2013 19:59:37 -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 vu5sm12836936pab.10.2013.06.16.19.59.36 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 16 Jun 2013 19:59:37 -0700 (PDT) From: Mike Turquette To: linux-kernel@vger.kernel.org Subject: [PATCH v2 3/5] clk: dt: binding for basic multiplexer clock Date: Sun, 16 Jun 2013 19:58:23 -0700 Message-Id: <1371437905-15567-4-git-send-email-mturquette@linaro.org> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1371437905-15567-1-git-send-email-mturquette@linaro.org> References: <1371437905-15567-1-git-send-email-mturquette@linaro.org> X-Gm-Message-State: ALoCoQkua+9aPBUe9nlvIRCAEVhoIYSG63jd0dAb+LtVKgWkqXPw2BrlZj5Me07TwJKvx7nl64FB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130616_230000_735498_08CA8E58 X-CRM114-Status: GOOD ( 19.85 ) X-Spam-Score: -1.9 (-) Cc: Mike Turquette , =?UTF-8?q?Heiko=20St=C3=BCbner?= , devicetree-discuss@lists.ozlabs.org, Stephen Boyd , 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=-5.3 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 multiplexer, plus the setup function to register the clock. Based on the existing fixed-clock binding. Includes minor beautification of clk-provider.h where some whitespace is added and of_fixed_factor_clock_setup is relocated to maintain a consistent style. Signed-off-by: Mike Turquette --- Changes since v1: * pass shift value into clk_register_mux_table * s/multiplexor/multiplexer/ * removed debug prints * mask is u32, shift is u8 * DT property names use dashes instead of underscores * DT property names are more verbose * shift property is optional in binding and can be auto-generated from a full 32-bit mask .../devicetree/bindings/clock/mux-clock.txt | 77 ++++++++++++++++++++++ drivers/clk/clk-mux.c | 62 ++++++++++++++++- include/linux/clk-provider.h | 5 +- 3 files changed, 142 insertions(+), 2 deletions(-) create mode 100644 Documentation/devicetree/bindings/clock/mux-clock.txt diff --git a/Documentation/devicetree/bindings/clock/mux-clock.txt b/Documentation/devicetree/bindings/clock/mux-clock.txt new file mode 100644 index 0000000..8fa370e --- /dev/null +++ b/Documentation/devicetree/bindings/clock/mux-clock.txt @@ -0,0 +1,77 @@ +Binding for simple mux clock. + +This binding uses the common clock binding[1]. It assumes a +register-mapped multiplexer with multiple input clock signals or +parents, one of which can be selected as output. This clock does not +gate or adjust the parent rate via a divider or multiplier. + +By default the "clocks" property lists the parents in the same order +as they are programmed into the regster. E.g: + + clocks = <&foo_clock>, <&bar_clock>, <&baz_clock>; + +results in programming the register as follows: + +register value selected parent clock +0 foo_clock +1 bar_clock +2 baz_clock + +Some clock controller IPs do not allow a value of zero to be programmed +into the register, instead indexing begins at 1. The optional property +"index_one" modified the scheme as follows: + +register value selected clock parent +1 foo_clock +2 bar_clock +3 baz_clock + +Additionally an optional table of bit and parent pairs may be supplied +like so: + + table = <&foo_clock 0x0>, <&bar_clock, 0x2>, <&baz_clock, 0x4>; + +where the first value in the pair is the parent clock and the second +value is the bitfield to be programmed into the register. + +The binding must provide the register to control the mux and the mask +for the corresponding control bits. Optionally the number of bits to +shift that mask if necessary. If the shift value is missing it is the +same as supplying a zero shift. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : shall be "mux-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : link phandles of parent clocks +- reg : base address for register controlling adjustable mux +- bit-mask : arbitrary bitmask for programming the adjustable mux + +Optional properties: +- clock-output-names : From common clock binding. +- table : array of integer pairs defining parents & bitfield values +- bit-shift : number of bits to shift the bit-mask, defaults to + (ffs(mask) - 1) if not present +- index-starts-at-one : valid input select programming starts at 1, not + zero + +Examples: + clock: clock@4a008100 { + compatible = "mux-clock"; + #clock-cells = <0>; + clocks = <&clock_foo>, <&clock_bar>, <&clock_baz>; + reg = <0x4a008100 0x4> + mask = <0x3>; + index_one; + }; + + clock: clock@4a008100 { + #clock-cells = <0>; + compatible = "mux-clock"; + clocks = <&clock_foo>, <&clock_bar>, <&clock_baz>; + reg = <0x4a008100 0x4>; + mask = <0x3>; + shift = <0>; + table = <&clock_foo 1>, <&clock_bar 2>, <&clock_baz 3>; + }; diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index 614444c..a640228 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -1,7 +1,7 @@ /* * Copyright (C) 2011 Sascha Hauer, Pengutronix * Copyright (C) 2011 Richard Zhao, Linaro - * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd + * Copyright (C) 2011-2013 Mike Turquette, Linaro Ltd * * 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 @@ -16,6 +16,8 @@ #include #include #include +#include +#include /* * DOC: basic adjustable multiplexer clock that cannot gate @@ -166,3 +168,61 @@ struct clk *clk_register_mux(struct device *dev, const char *name, flags, reg, shift, mask, clk_mux_flags, NULL, lock); } + +#ifdef CONFIG_OF +/** + * of_mux_clk_setup() - Setup function for simple mux rate clock + */ +void of_mux_clk_setup(struct device_node *node) +{ + struct clk *clk; + const char *clk_name = node->name; + void __iomem *reg; + int num_parents; + const char **parent_names; + int i; + u8 clk_mux_flags = 0; + u32 mask = 0; + u8 shift = 0; + + of_property_read_string(node, "clock-output-names", &clk_name); + + num_parents = of_clk_get_parent_count(node); + if (num_parents < 1) { + pr_err("%s: mux-clock %s must have parent(s)\n", + __func__, node->name); + return; + } + + parent_names = kzalloc((sizeof(char*) * num_parents), + GFP_KERNEL); + + for (i = 0; i < num_parents; i++) + parent_names[i] = of_clk_get_parent_name(node, i); + + reg = of_iomap(node, 0); + + if (of_property_read_u32(node, "bit-mask", &mask)) { + pr_err("%s: missing bit-mask property for %s\n", __func__, node->name); + return; + } + + if (of_property_read_u8(node, "bit-shift", &shift)) { + shift = __ffs(mask); + pr_debug("%s: bit-shift property defaults to 0x%x for %s\n", + __func__, shift, node->name); + } + + if (of_property_read_bool(node, "index-starts-at-one")) + clk_mux_flags |= CLK_MUX_INDEX_ONE; + + clk = clk_register_mux_table(NULL, clk_name, parent_names, num_parents, + 0, reg, shift, mask, clk_mux_flags, + NULL, NULL); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); +} +EXPORT_SYMBOL_GPL(of_mux_clk_setup); +CLK_OF_DECLARE(mux_clk, "mux-clock", of_mux_clk_setup); +#endif diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 8730cb9..24a04b8 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -340,7 +340,7 @@ struct clk *clk_register_mux_table(struct device *dev, const char *name, void __iomem *reg, u8 shift, u32 mask, u8 clk_mux_flags, u32 *table, spinlock_t *lock); -void of_fixed_factor_clk_setup(struct device_node *node); +void of_mux_clk_setup(struct device_node *node); /** * struct clk_fixed_factor - fixed multiplier and divider clock @@ -361,10 +361,13 @@ struct clk_fixed_factor { }; extern struct clk_ops clk_fixed_factor_ops; + struct clk *clk_register_fixed_factor(struct device *dev, const char *name, const char *parent_name, unsigned long flags, unsigned int mult, unsigned int div); +void of_fixed_factor_clk_setup(struct device_node *node); + /*** * struct clk_composite - aggregate clock of mux, divider and gate clocks *