From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1819AC636CA for ; Sat, 17 Jul 2021 12:19:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEDB860233 for ; Sat, 17 Jul 2021 12:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233327AbhGQMWZ (ORCPT ); Sat, 17 Jul 2021 08:22:25 -0400 Received: from gloria.sntech.de ([185.11.138.130]:34092 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbhGQMWW (ORCPT ); Sat, 17 Jul 2021 08:22:22 -0400 Received: from ip5f5aa64a.dynamic.kabel-deutschland.de ([95.90.166.74] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m4jHq-00051D-Eo; Sat, 17 Jul 2021 14:19:18 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Andy Shevchenko , Elaine Zhang , Stephen Boyd , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, Andy Shevchenko Cc: Michael Turquette Subject: Re: [PATCH v2 1/3] clk: fractional-divider: Export approximation algo to the CCF users Date: Sat, 17 Jul 2021 14:19:17 +0200 Message-ID: <10550544.QTc0DxZM9B@diego> In-Reply-To: <20210716133448.24890-1-andriy.shevchenko@linux.intel.com> References: <20210716133448.24890-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, 16. Juli 2021, 15:34:46 CEST schrieb Andy Shevchenko: > At least one user currently duplicates some functions that are provided > by fractional divider module. Let's export approximation algo and replace > the open-coded variant. > > As a bonus the exported function will get better documentation in place. > > Signed-off-by: Andy Shevchenko on Rockchip rk3288 and rk3399 Tested-by: Heiko Stuebner Also for dropping the Rockchip-specific copy in favor of the main implementation Acked-by: Heiko Stuebner > --- > v2: fixed compilation error (LKP), successfully compile-tested on x86 > 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( >