From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A624941212 for ; Wed, 15 Nov 2023 19:24:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jEIW/Yce" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55677C433C7; Wed, 15 Nov 2023 19:24:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700076285; bh=EYLa1g5TuWQJuHidIG4ASDu3Zb84iFt/TDnZ9KSTOv0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jEIW/YceuNHo2GompMLLI/sK5dM6GiOvl8O/+hzuFUIBT5Pov1ZsF4o9KEKjPLuvq gmXkZ8YqUFWn3ixk48rszE7oXHemMEX3E+lw7i3eIL6nTvkSENwt3wPhX1OOabw9vG +C+G63ZvVKfG3Kl3NVyF9uaifyeavH/Pdad4L6Hg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Claudiu Beznea , Geert Uytterhoeven , Sasha Levin Subject: [PATCH 6.5 168/550] clk: renesas: rzg2l: Fix computation formula Date: Wed, 15 Nov 2023 14:12:32 -0500 Message-ID: <20231115191612.357569639@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191600.708733204@linuxfoundation.org> References: <20231115191600.708733204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Claudiu Beznea [ Upstream commit a2b23159499efd36b2d63b3c4534075d12ddc97a ] According to the hardware manual for RZ/G2L (r01uh0914ej0130-rzg2l-rzg2lc.pdf), the computation formula for PLL rate is as follows: Fout = ((m + k/65536) * Fin) / (p * 2^s) and k has values in the range [-32768, 32767]. Dividing k by 65536 with integer arithmetic gives zero all the time, causing slight differences b/w what has been set vs. what is displayed. Thus, get rid of this and decompose the formula before dividing k by 65536. Fixes: ef3c613ccd68a ("clk: renesas: Add CPG core wrapper for RZ/G2L SoC") Signed-off-by: Claudiu Beznea Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230929053915.1530607-6-claudiu.beznea@bp.renesas.com Signed-off-by: Geert Uytterhoeven Signed-off-by: Sasha Levin --- drivers/clk/renesas/rzg2l-cpg.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c index 03028362cf619..a3b20c898a391 100644 --- a/drivers/clk/renesas/rzg2l-cpg.c +++ b/drivers/clk/renesas/rzg2l-cpg.c @@ -43,7 +43,7 @@ #define GET_SHIFT(val) ((val >> 12) & 0xff) #define GET_WIDTH(val) ((val >> 8) & 0xf) -#define KDIV(val) FIELD_GET(GENMASK(31, 16), val) +#define KDIV(val) ((s16)FIELD_GET(GENMASK(31, 16), val)) #define MDIV(val) FIELD_GET(GENMASK(15, 6), val) #define PDIV(val) FIELD_GET(GENMASK(5, 0), val) #define SDIV(val) FIELD_GET(GENMASK(2, 0), val) @@ -702,18 +702,18 @@ static unsigned long rzg2l_cpg_pll_clk_recalc_rate(struct clk_hw *hw, struct pll_clk *pll_clk = to_pll(hw); struct rzg2l_cpg_priv *priv = pll_clk->priv; unsigned int val1, val2; - unsigned int mult = 1; - unsigned int div = 1; + u64 rate; if (pll_clk->type != CLK_TYPE_SAM_PLL) return parent_rate; val1 = readl(priv->base + GET_REG_SAMPLL_CLK1(pll_clk->conf)); val2 = readl(priv->base + GET_REG_SAMPLL_CLK2(pll_clk->conf)); - mult = MDIV(val1) + KDIV(val1) / 65536; - div = PDIV(val1) << SDIV(val2); - return DIV_ROUND_CLOSEST_ULL((u64)parent_rate * mult, div); + rate = mul_u64_u32_shr(parent_rate, (MDIV(val1) << 16) + KDIV(val1), + 16 + SDIV(val2)); + + return DIV_ROUND_CLOSEST_ULL(rate, PDIV(val1)); } static const struct clk_ops rzg2l_cpg_pll_ops = { -- 2.42.0