From patchwork Sat Jun 17 10:29:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Oltmanns X-Patchwork-Id: 13283498 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BB0BEB64D9 for ; Sat, 17 Jun 2023 10:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235819AbjFQK3x (ORCPT ); Sat, 17 Jun 2023 06:29:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235928AbjFQK3m (ORCPT ); Sat, 17 Jun 2023 06:29:42 -0400 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [IPv6:2001:67c:2050:0:465::101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C247210D; Sat, 17 Jun 2023 03:29:40 -0700 (PDT) Received: from smtp202.mailbox.org (smtp202.mailbox.org [IPv6:2001:67c:2050:b231:465::202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4Qjshx5qbfz9srL; Sat, 17 Jun 2023 12:29:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oltmanns.dev; s=MBO0001; t=1686997777; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=piM6ASDgch6PVWDiOGs21ydWS2z+iDsSfAmRcYpzIiU=; b=SoeQ25K1x4Jyzd4FS1IvZAluHv1wt/1WmOU6WfxqI2hVmUtcpkpSmDzpBPxIGwUkpD09OJ kcrjWcXjSFxaF9Tnrvrlq45WwAAxPjDOhi7dFDNI7nijOFpgv8omIcPwsPtlrfbaRvzpep tMsKn7f43UUYpeeLOzTUpjV6f14RYkaO6it/9hYCXCIUgp9WbbMt5FxWMXM8eK/WrVlQ5q GizaP4RyglSSJxUjfSszx2ajfe9jaBr9ybx+mOcQ7eSFYR+Kki5GB52wiYQa0zewF67Oq6 ZmEkzyr4qda6nvUNXIHp/aHh2yjuPTLHyY2aB+dOXOiCzx/aHM1RBdT6GIVrNw== From: Frank Oltmanns To: Michael Turquette , Stephen Boyd Cc: Frank Oltmanns , "A . s . Dong" , Abel Vesa , Fabio Estevam , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, NXP Linux Team , Peng Fan , Pengutronix Kernel Team , Sascha Hauer , Shawn Guo , Elaine Zhang Subject: [PATCH v4 1/2] clk: fractional-divider: Improve approximation when zero based and export Date: Sat, 17 Jun 2023 12:29:18 +0200 Message-ID: <20230617102919.27564-2-frank@oltmanns.dev> In-Reply-To: <20230617102919.27564-1-frank@oltmanns.dev> References: <20230617102919.27564-1-frank@oltmanns.dev> MIME-Version: 1.0 X-Rspamd-Queue-Id: 4Qjshx5qbfz9srL Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Consider the CLK_FRAC_DIVIDER_ZERO_BASED flag when finding the best approximation for m and n. By doing so, increase the range of valid values for the numerator and denominator by 1. Furthermore, export the approximation function so that users of this function can be compiled as modules. Cc: A.s. Dong Signed-off-by: Frank Oltmanns --- drivers/clk/clk-fractional-divider.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c index 479297763e70..5067e067e906 100644 --- a/drivers/clk/clk-fractional-divider.c +++ b/drivers/clk/clk-fractional-divider.c @@ -123,6 +123,7 @@ void clk_fractional_divider_general_approximation(struct clk_hw *hw, unsigned long *m, unsigned long *n) { struct clk_fractional_divider *fd = to_clk_fd(hw); + unsigned long max_m, max_n; /* * Get rate closer to *parent_rate to guarantee there is no overflow @@ -138,10 +139,17 @@ void clk_fractional_divider_general_approximation(struct clk_hw *hw, rate <<= scale - fd->nwidth; } - rational_best_approximation(rate, *parent_rate, - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), - m, n); + if (fd->flags & CLK_FRAC_DIVIDER_ZERO_BASED) { + max_m = 1 << fd->mwidth; + max_n = 1 << fd->nwidth; + } else { + max_m = GENMASK(fd->mwidth - 1, 0); + max_n = GENMASK(fd->nwidth - 1, 0); + } + + rational_best_approximation(rate, *parent_rate, max_m, max_n, m, n); } +EXPORT_SYMBOL_GPL(clk_fractional_divider_general_approximation); static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) @@ -169,13 +177,18 @@ static int clk_fd_set_rate(struct clk_hw *hw, unsigned long rate, { struct clk_fractional_divider *fd = to_clk_fd(hw); unsigned long flags = 0; - unsigned long m, n; + unsigned long m, n, max_m, max_n; u32 mmask, nmask; u32 val; - rational_best_approximation(rate, parent_rate, - GENMASK(fd->mwidth - 1, 0), GENMASK(fd->nwidth - 1, 0), - &m, &n); + if (fd->flags & CLK_FRAC_DIVIDER_ZERO_BASED) { + max_m = 1 << fd->mwidth; + max_n = 1 << fd->nwidth; + } else { + max_m = GENMASK(fd->mwidth - 1, 0); + max_n = GENMASK(fd->nwidth - 1, 0); + } + rational_best_approximation(rate, parent_rate, max_m, max_n, &m, &n); if (fd->flags & CLK_FRAC_DIVIDER_ZERO_BASED) { m--;