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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 89220D111A8 for ; Thu, 27 Nov 2025 20:34:19 +0000 (UTC) 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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+FzMW7Nv8LbKc1Eg5ZLPhQBqNpFvbVdSbRkWtpr/EkQ=; b=TJG6zpB68A7Sxt ZEN1rJ5MFHsqW/3fGIM2uSAniSvEp8CMFM2GBDA/ebx+ZJLjbPQY/o35dTsG6o0nTYxOyp08eRlH6 mFhA5ku86CI07pgzv6wA4V/LwWRhIrMRW9ufxdDLCEvv+5NG6NGkmkA35muERTXoARLEdBGV6yyy1 zvMsfajF1dwRM1HDwIeBfjthojAgCJI3BuixctOgunSHHTYCk1XuWeRX/EVbfSm6i0z/+KnTE0vBh u60KKc30f487D5Oep+AopCQZvvL1ld4Ib56SsLhtB4GOFxG8TgVeLw7IK2M079Moqbi5Rq6vas5Z4 yjhJv3vYaBxXinBvC+MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vOigp-0000000HCcP-1R9t; Thu, 27 Nov 2025 20:34:07 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vOigm-0000000HCc4-1l0i for linux-riscv@lists.infradead.org; Thu, 27 Nov 2025 20:34:05 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4726E436CA; Thu, 27 Nov 2025 20:34:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99949C4CEF8; Thu, 27 Nov 2025 20:34:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764275643; bh=iaUkQzHWoFtelBiaVO6hPpyfUhchc6MEcbKNHDj+YO8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WfAQPPNrkwDVGw1LMaEzzsxYcumtf2XjM0DixGYbmPfpXORU9ijySXiOMMY5bM3x5 cKGV3KOAC1wchviAmtEagCtsi1DFDsbi1xtvLxzVZ/lCo8wyaPwSMBOLxAO4vH5/vw cO/hxQYAtt62LYFyXXXDpinq6jreqVvkRuVa/HV93Nu83g9LI+8JnxJ7XgF2Dxa+Qc Ucn6o148G+8yHwZhgVsVqlAvKJpLJay2xm41q9DO1TGff5Z+PBCeJYLEPFJSIhvVXH ARAAMl/Sq6a3H85AjcpxC3JC5MPS7QFFD/+qi5T6FSuuCltobAZqCqjRycKQGclY5K fDnL/MsLvN9FQ== Date: Thu, 27 Nov 2025 14:33:58 -0600 From: Drew Fustini To: Yao Zi Subject: Re: [PATCH 6/7] clk: thead: th1520-ap: Support CPU frequency scaling Message-ID: References: <20251120131416.26236-1-ziyao@disroot.org> <20251120131416.26236-7-ziyao@disroot.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20251120131416.26236-7-ziyao@disroot.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251127_123404_498703_4292CD5B X-CRM114-Status: GOOD ( 13.97 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rob Herring , Conor Dooley , Albert Ou , Alexandre Ghiti , devicetree@vger.kernel.org, Stephen Boyd , Michael Turquette , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-clk@vger.kernel.org, Guo Ren , Han Gao , Han Gao , Palmer Dabbelt , Paul Walmsley , Krzysztof Kozlowski , Fu Wei Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Nov 20, 2025 at 01:14:15PM +0000, Yao Zi wrote: > On TH1520 SoC, c910_clk feeds the CPU cluster. It could be glitchlessly > reparented to one of the two PLLs: either to cpu_pll0 indirectly through > c910_i0_clk, or to cpu_pll1 directly. > > To achieve glitchless rate change, customized clock operations are > implemented for c910_clk: on rate change, the PLL not currently in use > is configured to the requested rate first, then c910_clk reparents to > it. > > Additionally, c910_bus_clk, which in turn takes c910_clk as parent, > has a frequency limit of 750MHz. A clock notifier is registered on > c910_clk to adjust c910_bus_clk on c910_clk rate change. > > Signed-off-by: Yao Zi > --- > drivers/clk/thead/clk-th1520-ap.c | 148 +++++++++++++++++++++++++++++- > 1 file changed, 146 insertions(+), 2 deletions(-) [...] > +/* > + * c910_clk could be reparented glitchlessly for DVFS. There are two parents, > + * - c910_i0_clk, dervided from cpu_pll0_clk or osc_24m. Typo: 'derived' instead of 'dervided'. [...] Unless there are other comments that require changes, I can fix up the typo when applied. Reviewed-by: Drew Fustini _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv