From patchwork Thu Jul 22 19:50:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 12394579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B56FC4338F for ; Thu, 22 Jul 2021 19:51:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E0F0660EB2 for ; Thu, 22 Jul 2021 19:51:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E0F0660EB2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=wjWtpjNIIcWFDKcncj4XRRkeaTL8CY4JNv0+TCCbHAw=; b=eTgI0tg5OVs8yA tt9Jvlm7IatBtaMmcPxhM2lbXAQFGV4eMMNiTNChwad/SXkYLwlsumXM9HdlLtaX+Ouva06EmvU55 S510Qk61SFHVflRN+qDoShm2hP5PEXqIQcJ+uEJcZLGJa19g1LPkyJDoblzBP1qSXhgutSQ9N/Eww bQT9TrqFl1snv71u8dHTc5iNsF/lV7id8bNHW0OuT8R0Q4FavviKTwTTuP6/gjf7GV52GYN3YEN7j nd8aCxHQ5FZ1FFmqQYVtBES9b+xTBc0XpLBQCyFNJXz8qSYqf7fk8s7X273dF+ypyeYVJrlno5s9R vFZyyZkkK+FNVrHVrmwA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6ej5-002cRJ-AM; Thu, 22 Jul 2021 19:51:23 +0000 Received: from mga11.intel.com ([192.55.52.93]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6ei0-002c1M-SV; Thu, 22 Jul 2021 19:50:18 +0000 X-IronPort-AV: E=McAfee;i="6200,9189,10053"; a="208617267" X-IronPort-AV: E=Sophos;i="5.84,261,1620716400"; d="scan'208";a="208617267" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jul 2021 12:50:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,261,1620716400"; d="scan'208";a="470781627" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga008.fm.intel.com with ESMTP; 22 Jul 2021 12:49:57 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id EF735E7; Thu, 22 Jul 2021 22:50:24 +0300 (EEST) From: Andy Shevchenko To: "Rafael J. Wysocki" , Andy Shevchenko , Heiko Stuebner , Elaine Zhang , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-clk@vger.kernel.org, linux-imx@nxp.com, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Cc: "Rafael J. Wysocki" , Len Brown , Michael Turquette , Stephen Boyd , Abel Vesa , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Lee Jones Subject: [PATCH v3 1/4] clk: fractional-divider: Export approximation algorithm to the CCF users Date: Thu, 22 Jul 2021 22:50:07 +0300 Message-Id: <20210722195010.45940-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210722_125016_976494_5A040CA0 X-CRM114-Status: GOOD ( 17.74 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org At least one user currently duplicates some functions that are provided by fractional divider module. Let's export approximation algorithm and replace the open-coded variant. As a bonus the exported function will get better documentation in place. Signed-off-by: Andy Shevchenko Tested-by: Heiko Stuebner Acked-by: Heiko Stuebner --- v3: added tags (Heiko) drivers/clk/clk-fractional-divider.c | 11 +++++++---- drivers/clk/clk-fractional-divider.h | 9 +++++++++ drivers/clk/rockchip/clk.c | 17 +++-------------- 3 files changed, 19 insertions(+), 18 deletions(-) create mode 100644 drivers/clk/clk-fractional-divider.h diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c index b1e556f20911..535d299af646 100644 --- a/drivers/clk/clk-fractional-divider.c +++ b/drivers/clk/clk-fractional-divider.c @@ -14,6 +14,8 @@ #include #include +#include "clk-fractional-divider.h" + static inline u32 clk_fd_readl(struct clk_fractional_divider *fd) { if (fd->flags & CLK_FRAC_DIVIDER_BIG_ENDIAN) @@ -68,9 +70,10 @@ static unsigned long clk_fd_recalc_rate(struct clk_hw *hw, return ret; } -static void clk_fd_general_approximation(struct clk_hw *hw, unsigned long rate, - unsigned long *parent_rate, - unsigned long *m, unsigned long *n) +void clk_fractional_divider_general_approximation(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate, + unsigned long *m, unsigned long *n) { struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long scale; @@ -102,7 +105,7 @@ static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate, if (fd->approximation) fd->approximation(hw, rate, parent_rate, &m, &n); else - clk_fd_general_approximation(hw, rate, parent_rate, &m, &n); + clk_fractional_divider_general_approximation(hw, rate, parent_rate, &m, &n); ret = (u64)*parent_rate * m; do_div(ret, n); diff --git a/drivers/clk/clk-fractional-divider.h b/drivers/clk/clk-fractional-divider.h new file mode 100644 index 000000000000..4fa359a12ef4 --- /dev/null +++ b/drivers/clk/clk-fractional-divider.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +struct clk_hw; + +void clk_fractional_divider_general_approximation(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate, + unsigned long *m, + unsigned long *n); diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c index 049e5e0b64f6..b7be7e11b0df 100644 --- a/drivers/clk/rockchip/clk.c +++ b/drivers/clk/rockchip/clk.c @@ -22,6 +22,8 @@ #include #include #include + +#include "../clk-fractional-divider.h" #include "clk.h" /* @@ -178,10 +180,8 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate, unsigned long *m, unsigned long *n) { - struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long p_rate, p_parent_rate; struct clk_hw *p_parent; - unsigned long scale; p_rate = clk_hw_get_rate(clk_hw_get_parent(hw)); if ((rate * 20 > p_rate) && (p_rate % rate != 0)) { @@ -190,18 +190,7 @@ static void rockchip_fractional_approximation(struct clk_hw *hw, *parent_rate = p_parent_rate; } - /* - * Get rate closer to *parent_rate to guarantee there is no overflow - * for m and n. In the result it will be the nearest rate left shifted - * by (scale - fd->nwidth) bits. - */ - scale = fls_long(*parent_rate / rate - 1); - if (scale > fd->nwidth) - rate <<= scale - fd->nwidth; - - rational_best_approximation(rate, *parent_rate, - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), - m, n); + clk_fractional_divider_general_approximation(hw, rate, parent_rate, m, n); } static struct clk *rockchip_clk_register_frac_branch(