From patchwork Sun Oct 7 09:38:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Jernej_=C5=A0krabec?= X-Patchwork-Id: 10629507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AE6F8112B for ; Sun, 7 Oct 2018 09:42:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0E5A29190 for ; Sun, 7 Oct 2018 09:42:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94BF6291AF; Sun, 7 Oct 2018 09:42:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2C4EF29190 for ; Sun, 7 Oct 2018 09:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726874AbeJGQqG (ORCPT ); Sun, 7 Oct 2018 12:46:06 -0400 Received: from mailoutvs53.siol.net ([185.57.226.244]:39583 "EHLO mail.siol.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725994AbeJGQqF (ORCPT ); Sun, 7 Oct 2018 12:46:05 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.siol.net (Postfix) with ESMTP id C85B9520BC5; Sun, 7 Oct 2018 11:39:20 +0200 (CEST) X-Virus-Scanned: amavisd-new at psrvmta10.zcs-production.pri Received: from mail.siol.net ([127.0.0.1]) by localhost (psrvmta10.zcs-production.pri [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id dQnvNgxfUEiy; Sun, 7 Oct 2018 11:39:20 +0200 (CEST) Received: from mail.siol.net (localhost [127.0.0.1]) by mail.siol.net (Postfix) with ESMTPS id 70ECC520BC6; Sun, 7 Oct 2018 11:39:20 +0200 (CEST) Received: from localhost.localdomain (cpe1-8-82.cable.triera.net [213.161.8.82]) (Authenticated sender: 031275009) by mail.siol.net (Postfix) with ESMTPSA id D9EF6520BC5; Sun, 7 Oct 2018 11:39:17 +0200 (CEST) From: Jernej Skrabec To: maxime.ripard@bootlin.com, wens@csie.org Cc: robh+dt@kernel.org, sboyd@kernel.org, airlied@linux.ie, architt@codeaurora.org, a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-sunxi@googlegroups.com Subject: [PATCH v2 02/29] clk: sunxi-ng: Adjust MP clock parent rate when allowed Date: Sun, 7 Oct 2018 11:38:38 +0200 Message-Id: <20181007093905.11253-3-jernej.skrabec@siol.net> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181007093905.11253-1-jernej.skrabec@siol.net> References: <20181007093905.11253-1-jernej.skrabec@siol.net> MIME-Version: 1.0 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently MP clocks don't consider adjusting parent rate even if they are allowed to do so. Such behaviour considerably lowers amount of possible rates, which is very inconvenient when such clock is used for pixel clock, for example. In order to improve the situation, adjusting parent rate is considered when allowed. This code is inspired by clk_divider_bestdiv() function, which does basically the same thing for different clock type. Signed-off-by: Jernej Skrabec --- drivers/clk/sunxi-ng/ccu_mp.c | 64 +++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 2 deletions(-) diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c index 5d0af4051737..0357349eb767 100644 --- a/drivers/clk/sunxi-ng/ccu_mp.c +++ b/drivers/clk/sunxi-ng/ccu_mp.c @@ -40,6 +40,61 @@ static void ccu_mp_find_best(unsigned long parent, unsigned long rate, *p = best_p; } +static unsigned long ccu_mp_find_best_with_parent_adj(struct clk_hw *hw, + unsigned long *parent, + unsigned long rate, + unsigned int max_m, + unsigned int max_p) +{ + unsigned long parent_rate_saved; + unsigned long parent_rate, now; + unsigned long best_rate = 0; + unsigned int _m, _p, div; + unsigned long maxdiv; + + parent_rate_saved = *parent; + + /* + * The maximum divider we can use without overflowing + * unsigned long in rate * m * p below + */ + maxdiv = max_m * max_p; + maxdiv = min(ULONG_MAX / rate, maxdiv); + + for (_p = 1; _p <= max_p; _p <<= 1) { + for (_m = 1; _m <= max_m; _m++) { + div = _m * _p; + + if (div > maxdiv) + break; + + if (rate * div == parent_rate_saved) { + /* + * It's the most ideal case if the requested + * rate can be divided from parent clock without + * needing to change parent rate, so return the + * divider immediately. + */ + *parent = parent_rate_saved; + return rate; + } + + parent_rate = clk_hw_round_rate(hw, rate * div); + now = parent_rate / div; + + if (now <= rate && now > best_rate) { + best_rate = now; + *parent = parent_rate; + + if (now == rate) + return rate; + } + } + } + + return best_rate; +} + static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux, struct clk_hw *hw, unsigned long *parent_rate, @@ -56,8 +111,13 @@ static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux, max_m = cmp->m.max ?: 1 << cmp->m.width; max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1); - ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p); - rate = *parent_rate / p / m; + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { + ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p); + rate = *parent_rate / p / m; + } else { + rate = ccu_mp_find_best_with_parent_adj(hw, parent_rate, rate, + max_m, max_p); + } if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV) rate /= cmp->fixed_post_div;