From patchwork Thu Apr 8 11:42:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 418512 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=-24.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 E84A9C43460 for ; Thu, 8 Apr 2021 11:42:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B92F6611B0 for ; Thu, 8 Apr 2021 11:42:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230291AbhDHLmj (ORCPT ); Thu, 8 Apr 2021 07:42:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:39212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230411AbhDHLmj (ORCPT ); Thu, 8 Apr 2021 07:42:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7BF3D61154; Thu, 8 Apr 2021 11:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617882148; bh=NLEKXcnL6UX8xrVKZbjL6ed/FTM/FhsKqG6UtL4kOJA=; h=From:To:Subject:Date:In-Reply-To:References:From; b=rXzzwvzoHagt5SEJpt8RGbz9SeAID3O5kcyDJhfW0inz6Bz0EXIZwpEQg5DM+DoZT GvCM5MKEtJ63K8HI5/JmR9wwMjMwwUyxghZb1oggpK9dCnjvSKr1nsKazwSBeq/acZ Oxf1dn035P6wMGOQwUPD1v1a01hg/ZnNbo41o5Vv32CdZirtwWRThHuW6sJzWqZO6l ZX2VIkjbDYgVPXNgLU1PHTx6hivFbpzfqhN5XPTHD89qL1luUfgnDh5yaiuAM8r3oo gAMGaepZZVUy/MuJgIBBhiAIRqRMpjAeIgQed+Bfj9KvJx1p0I+rQCqbNLinrGEwg0 hgEjmSI9bQVqg== Received: by pali.im (Postfix) id AFB27EDE; Thu, 8 Apr 2021 13:42:26 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: linux-pm@vger.kernel.org, Viresh Kumar Subject: [RESEND PATCH mvebu v3 02/10] cpufreq: armada-37xx: Fix setting TBG parent for load levels Date: Thu, 8 Apr 2021 13:42:15 +0200 Message-Id: <20210408114223.8471-2-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210408114223.8471-1-pali@kernel.org> References: <20210408114223.8471-1-pali@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Marek Behún With CPU frequency determining software [1] we have discovered that after this driver does one CPU frequency change, the base frequency of the CPU is set to the frequency of TBG-A-P clock, instead of the TBG that is parent to the CPU. This can be reproduced on EspressoBIN and Turris MOX: cd /sys/devices/system/cpu/cpufreq/policy0 echo powersave >scaling_governor echo performance >scaling_governor Running the mhz tool before this driver is loaded reports 1000 MHz, and after loading the driver and executing commands above the tool reports 800 MHz. The change of TBG clock selector is supposed to happen in function armada37xx_cpufreq_dvfs_setup. Before the function returns, it does this: parent = clk_get_parent(clk); clk_set_parent(clk, parent); The armada-37xx-periph clock driver has the .set_parent method implemented correctly for this, so if the method was actually called, this would work. But since the introduction of the common clock framework in commit b2476490ef11 ("clk: introduce the common clock..."), the clk_set_parent function checks whether the parent is actually changing, and if the requested new parent is same as the old parent (which is obviously the case for the code above), the .set_parent method is not called at all. This patch fixes this issue by filling the correct TBG clock selector directly in the armada37xx_cpufreq_dvfs_setup during the filling of other registers at the same address. But the determination of CPU TBG index cannot be done via the common clock framework, therefore we need to access the North Bridge Peripheral Clock registers directly in this driver. [1] https://github.com/wtarreau/mhz Signed-off-by: Marek Behún Acked-by: Gregory CLEMENT Tested-by: Pali Rohár Tested-by: Tomasz Maciej Nowak Tested-by: Anders Trier Olesen Tested-by: Philip Soares Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx") Cc: stable@vger.kernel.org --- drivers/cpufreq/armada-37xx-cpufreq.c | 35 ++++++++++++++++++--------- 1 file changed, 23 insertions(+), 12 deletions(-) diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c index b4af4094309b..b8dc6c849579 100644 --- a/drivers/cpufreq/armada-37xx-cpufreq.c +++ b/drivers/cpufreq/armada-37xx-cpufreq.c @@ -25,6 +25,10 @@ #include "cpufreq-dt.h" +/* Clk register set */ +#define ARMADA_37XX_CLK_TBG_SEL 0 +#define ARMADA_37XX_CLK_TBG_SEL_CPU_OFF 22 + /* Power management in North Bridge register set */ #define ARMADA_37XX_NB_L0L1 0x18 #define ARMADA_37XX_NB_L2L3 0x1C @@ -120,10 +124,15 @@ static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq) * will be configured then the DVFS will be enabled. */ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base, - struct clk *clk, u8 *divider) + struct regmap *clk_base, u8 *divider) { + u32 cpu_tbg_sel; int load_lvl; - struct clk *parent; + + /* Determine to which TBG clock is CPU connected */ + regmap_read(clk_base, ARMADA_37XX_CLK_TBG_SEL, &cpu_tbg_sel); + cpu_tbg_sel >>= ARMADA_37XX_CLK_TBG_SEL_CPU_OFF; + cpu_tbg_sel &= ARMADA_37XX_NB_TBG_SEL_MASK; for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) { unsigned int reg, mask, val, offset = 0; @@ -142,6 +151,11 @@ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base, mask = (ARMADA_37XX_NB_CLK_SEL_MASK << ARMADA_37XX_NB_CLK_SEL_OFF); + /* Set TBG index, for all levels we use the same TBG */ + val = cpu_tbg_sel << ARMADA_37XX_NB_TBG_SEL_OFF; + mask = (ARMADA_37XX_NB_TBG_SEL_MASK + << ARMADA_37XX_NB_TBG_SEL_OFF); + /* * Set cpu divider based on the pre-computed array in * order to have balanced step. @@ -160,14 +174,6 @@ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base, regmap_update_bits(base, reg, mask, val); } - - /* - * Set cpu clock source, for all the level we keep the same - * clock source that the one already configured. For this one - * we need to use the clock framework - */ - parent = clk_get_parent(clk); - clk_set_parent(clk, parent); } /* @@ -358,11 +364,16 @@ static int __init armada37xx_cpufreq_driver_init(void) struct platform_device *pdev; unsigned long freq; unsigned int cur_frequency, base_frequency; - struct regmap *nb_pm_base, *avs_base; + struct regmap *nb_clk_base, *nb_pm_base, *avs_base; struct device *cpu_dev; int load_lvl, ret; struct clk *clk, *parent; + nb_clk_base = + syscon_regmap_lookup_by_compatible("marvell,armada-3700-periph-clock-nb"); + if (IS_ERR(nb_clk_base)) + return -ENODEV; + nb_pm_base = syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm"); @@ -439,7 +450,7 @@ static int __init armada37xx_cpufreq_driver_init(void) armada37xx_cpufreq_avs_configure(avs_base, dvfs); armada37xx_cpufreq_avs_setup(avs_base, dvfs); - armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider); + armada37xx_cpufreq_dvfs_setup(nb_pm_base, nb_clk_base, dvfs->divider); clk_put(clk); for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;