From patchwork Tue Jan 5 10:22:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 357878 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=-11.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 EE0C4C43331 for ; Tue, 5 Jan 2021 10:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCDCD2250E for ; Tue, 5 Jan 2021 10:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728437AbhAEKXu (ORCPT ); Tue, 5 Jan 2021 05:23:50 -0500 Received: from esa.microchip.iphmx.com ([68.232.154.123]:16875 "EHLO esa.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727710AbhAEKXt (ORCPT ); Tue, 5 Jan 2021 05:23:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1609842228; x=1641378228; h=from:to:cc:subject:date:message-id:mime-version; bh=Hkq9Fwje5+PfX7EUjvA17my8iHwo8jNIb8URrp0sN64=; b=fVMvPz403XyDiWm3MHWB+6h+KMz0a8yYRLuRctDXKCSEd8+OO3gyYX7y eJlSkn4TgmBs+mMMIRTrDV16QkPJVYeLFClUiH55ryGWWZZgpJM/qCpUS dnS0kLm79CZ7nUzGFhCtzhRx2nPJyDl9w00qjjSgEaMUp56PAhEFGbPQZ ykPup78r1yS5bxZZADjzUQlErHWfGHj6128dlfk+tAciCw+hZAwB2yark 4rP+/nZRA6X/f+iH1E9i88A7UY0V1rg1masZHuQL++8ZoDuqXq9E8iXne VC56s+aC1fw3A7ClKcKXBMwJj3qu41RhtP6HWQQfTNyciAeP0YXADuJuT Q==; IronPort-SDR: uuQx6/QlC7K8+eVFrX3SEi3SEAM2C3EVR/WcmpYwoSRpliYH0HmOp5YdaoeugvK3KZZ4JhkLig Qneo/htWieBAj9LJSjcP5GimFqUD9K7j9uXTlmnyxSie9YjyWSRqee9BHzOL0g1+WFVHHq50j1 scH8QkvHoW29Xm5QPvZthlcN6V6cv86V6g0prseppv3G87UHHTdK8evP0lwhSp2sMz0OiBx5Ks VHBgufPSK1FZy4TaXfIKyH0UYuT+2+V3NVZDRrNd9Tju63vLVUX0eWlSVWwEoA58juI9CJbr3f kDU= X-IronPort-AV: E=Sophos;i="5.78,476,1599548400"; d="scan'208";a="99023594" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 05 Jan 2021 03:22:33 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 5 Jan 2021 03:22:32 -0700 Received: from m18063-ThinkPad-T460p.microchip.com (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server id 15.1.1979.3 via Frontend Transport; Tue, 5 Jan 2021 03:22:30 -0700 From: Claudiu Beznea To: , , CC: , , , Claudiu Beznea Subject: [PATCH 0/3] cpufreq: sama7g5: add support for sama7g5 Date: Tue, 5 Jan 2021 12:22:24 +0200 Message-ID: <1609842147-8161-1-git-send-email-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi, SAMA7G5 supports run-time changes of CPU frequency. This is done by changing CPU's PLL. The block diagram explaining the relation b/w CPU clock and its PLL is as follows: +--------------> cpuck | +------+ | +-----+ cpupllck --> | pres |--+--> | div |---> mck +------+ +-----+ where cpuck is the CPU's clock and mck is the system master clock 0 that feeds some other IPs. All the IPs feed by mck are glich free aware. Because MCK is also feed by cpuplllk the CPUFreq driver needs also to handle this clock to avoid its under/over clocking: every time the CPUFreq's .target_index API is called: - the mck frequency is adjusted to avoid its overclocking/underclocking - then the cpuck frequency is increased/lowered - then mck frequency is adjusted to keep the initial 200MHz frequency Thank you, Claudiu Beznea Claudiu Beznea (3): dt-bindings: cpufreq: sama7g5-cpufreq: add dt bindings documentation cpufreq: sama7g5: add cpufreq driver MAINTAINERS: add sama7g5 cpufreq .../bindings/cpufreq/cpufreq-sama7g5.yaml | 80 +++++ MAINTAINERS | 6 + drivers/cpufreq/Kconfig.arm | 9 + drivers/cpufreq/Makefile | 1 + drivers/cpufreq/cpufreq-dt-platdev.c | 2 + drivers/cpufreq/sama7g5-cpufreq.c | 371 +++++++++++++++++++++ 6 files changed, 469 insertions(+) create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-sama7g5.yaml create mode 100644 drivers/cpufreq/sama7g5-cpufreq.c