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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 2D089C43603 for ; Mon, 16 Dec 2019 01:00:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1747206A5 for ; Mon, 16 Dec 2019 01:00:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="bjI9t4/S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726380AbfLPBAF (ORCPT ); Sun, 15 Dec 2019 20:00:05 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:57344 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726373AbfLPBAF (ORCPT ); Sun, 15 Dec 2019 20:00:05 -0500 Received: from epcas1p1.samsung.com (unknown [182.195.41.45]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20191216010000epoutp01be481ef6267ee5d0e8b1029ebe2552ba~gtDLb8iTS1899318993epoutp01_ for ; Mon, 16 Dec 2019 01:00:00 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20191216010000epoutp01be481ef6267ee5d0e8b1029ebe2552ba~gtDLb8iTS1899318993epoutp01_ DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1576458000; bh=UHz8miwCsStCk7x4OhXxqR1MgVUMnyw8pTG8bj8lXKw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=bjI9t4/Su8furkVauRwFhKB366NtzDJoMdJaj5AkdxeEU4eOzzsdKmSXiC0ZmfM0w perEZqzMNHhzGCW2tm5OKhoUcU70Ze+E5jHkDXijjMwSdOxXo0F7V/q5PVtPI0Eddz jLjMj8EXikZsiDev+NVakj6dHmCTHCqyr+AdQWSA= Received: from epsnrtp4.localdomain (unknown [182.195.42.165]) by epcas1p4.samsung.com (KnoxPortal) with ESMTP id 20191216005959epcas1p43d9f20c8a1dfc59693da8c7b774e0d8e~gtDKpg9vw0859708597epcas1p4O; Mon, 16 Dec 2019 00:59:59 +0000 (GMT) Received: from epsmges1p1.samsung.com (unknown [182.195.40.157]) by epsnrtp4.localdomain (Postfix) with ESMTP id 47bjbw0mR4zMqYkh; Mon, 16 Dec 2019 00:59:56 +0000 (GMT) Received: from epcas1p4.samsung.com ( [182.195.41.48]) by epsmges1p1.samsung.com (Symantec Messaging Gateway) with SMTP id 60.FA.57028.C07D6FD5; Mon, 16 Dec 2019 09:59:56 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas1p4.samsung.com (KnoxPortal) with ESMTPA id 20191216005955epcas1p48aeb95c6015292220cf0498396290b8e~gtDHT4JKR0322803228epcas1p4B; Mon, 16 Dec 2019 00:59:55 +0000 (GMT) Received: from epsmgms1p2new.samsung.com (unknown [182.195.42.42]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20191216005955epsmtrp18de3761690431996684448af40d7d9ed~gtDHSzmXU2772127721epsmtrp1C; Mon, 16 Dec 2019 00:59:55 +0000 (GMT) X-AuditID: b6c32a35-50bff7000001dec4-2b-5df6d70cb118 Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgms1p2new.samsung.com (Symantec Messaging Gateway) with SMTP id 1D.2B.06569.B07D6FD5; Mon, 16 Dec 2019 09:59:55 +0900 (KST) Received: from [10.113.221.102] (unknown [10.113.221.102]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20191216005955epsmtip2fb5fbd6c8e8081be254d754781d77dd6~gtDG_HOFo0385803858epsmtip2N; Mon, 16 Dec 2019 00:59:55 +0000 (GMT) Subject: Re: [PATCH RFC v6 2/9] PM / devfreq: Add generic imx bus scaling driver From: Chanwoo Choi To: Leonard Crestez , Georgi Djakov , Rob Herring Cc: Alexandre Bailon , "Rafael J. Wysocki" , Jacky Bai , Anson Huang , Abel Vesa , Krzysztof Kozlowski , MyungJoo Ham , Kyungmin Park , Saravana Kannan , Mark Rutland , Viresh Kumar , Shawn Guo , Dong Aisheng , Fabio Estevam , Stephen Boyd , Michael Turquette , Matthias Kaehlcke , Angus Ainslie , Martin Kepplinger , Silvano di Ninno , linux-pm@vger.kernel.org, kernel@pengutronix.de, linux-imx@nxp.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Organization: Samsung Electronics Message-ID: <25e3177f-e2b9-6be4-cfb8-24f87ccba45b@samsung.com> Date: Mon, 16 Dec 2019 10:06:31 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:59.0) Gecko/20100101 Thunderbird/59.0 MIME-Version: 1.0 In-Reply-To: <047990a5-263d-d447-7f0a-77a99e4b1f63@samsung.com> Content-Language: en-US Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA02TfUwbZRzHfXrX67GsenYgj406uGHMmGw9oPhgB5JsmjNbIjrmH4uE3eCk pK/2WiZb1DrtWJvJRrAqhb04ZIEC2doSxhYYE+oQJkzUdYtscaYzGXWCyEtwE2Pb6yL/fX6/ fL+/tycPiSm6ZEqyymjlLUZOTxOr8J6h9aqs1dcXS1U9dThauDIK0OkfvgFo3n0BQ+FfJgE6 11iOTgTHpcgXmMTR5/1+Annd53F09epZGRo7cE+G2m7NSpE/HJIi1/12DM19EgSo9fqEBIXa 6qVo7mwYoInRl9Hkh20E6hj/mkDH5t0YcvQHZcg1uEygf0M+HN3tTkWtLSEM+RbYoqdYt6sN sJ3HOwE7c8MhY5vsEzh70m9j/V4nwd4M9RFs4KsPWN90r4Q9sqxi7w+lsHXdXsDO+Z8plu/S bdbyXAVvSeON5aaKKmNlAb1tR9mWMnWeisli8tELdJqRM/AF9NbtxVmvVOmj96DTqjm9LZoq 5gSB3lS42WKyWfk0rUmwFtC8uUJvzjdvFDiDYDNWbiw3GV5kVKpsdVS4W6dt/rva3Mm+2+Sr w+2gXuMCSSSkcuHUR06pC6wiFVQvgFP2RokY/AWgo7ZDGlMpqEUAf7r0/kPHTGAh4egH8Nps HSEGM1HR0CweU62h3oBfnmmPM0FlwoG7N4gYJ1P74dGxA5IYY9RnMvjAnR/jx6h0eG0pDGIs pwphw7Iz7sWpZ2Hznw3xKVKoN+FIz8cJzeNwpPFOXJNEvQQvd0RkYs1U+POdE4n6a+G5P5qx 2HCQ6iJhcOwLTFxhK7ztbJKKvAZGhrtlIivh1JGDCd4P20eChGg+BGD3wPcJQw4caG2IdiCj HdbDMxc2iel0eP7BMSA2fhROLxyWxiSQksNDBxWiZB388fYtichPwpZaJ3EU0J4V63hWrOBZ sYLn/2YnAe4FT/BmwVDJC4yZWfnYfhD/KpnqXvDp+PZBQJGAXi0v0i2WKqRctVBjGASQxOhk Ob9hrlQhr+Bq9vEWU5nFpueFQaCOXrseU6aUm6Ifz2gtY9TZOTk5KJfJUzMMnSonlyZKFVQl Z+V1PG/mLQ99EjJJaQfb9nx3Ki/S9zp6xDgMX+XuvXXx8oiutiR8UTi+N2O4T72za+Zpqigg 1VZf2dWy02Ke3jdAMb9mthZmvBcZifyT4QnkuZ4r2bvDVfP2b5pSDb68JeXbDUt2w3zJJW8T o+nc/U7278nyRv50cFF5eO3zSzf3jJ5yaHId3Yr0nKx1r5loXNByTCZmEbj/ANRVUPJABAAA X-Brightmail-Tracker: H4sIAAAAAAAAA02Sa0hTYRzGeXfOzo6rQ29T8dWk6eiCq9RW1AtdCZRDn6IoumA29KDhpmPH rSwoiyycZJnMcC61UplzoNvES2XlvFSWysSmZBGxIWbZBdNStMs2Ar/9eJ7nB/8Pf5qQlAuj 6NPZuZw2W6mSUWKypUsm3bRsZDYlccG2Bs+87AO4bqgH4B/GBwT2vh8DuLU8DVd1Dwix3TlG 4tsdDgpbje0kHhxsEuH+y59F2PLuuxA7vB4hNszXE3j6ejfAtSNuAfZYSoR4uskLsLsvCY9d slC4YaCTwnd+GAlc0NEtwgbXIoV/e+wknmiOwLX3PQS2z7B7o1mjwQJYW6UNsF9HC0RsRb6b ZKsdOtZhLaTYt55HFOusucjav7QJ2BuLiex8Vzhb3GwF7LRj9QHmuHhnOqc6ree0CbtPiTPN c3qNjT1bYS8m80HJDgMIoRHcir46Z4QGIKYl8CFArrZOYbCIRGXuHsIA6H8cirq6+OBmCqAP j/so/yYUHkR3G+tJP1NQjp5MjAbyMHgeLYw/I/wCAU0i5Ctyk0H7lQB9af8UMFbAWPT6lxf4 mYG7UeliYSAn4Vpk/lYauCIcHkHtNV5BcLMSvSj3BTYhcA/qbZgU+ZmA69FC5RAR5Aj0xlcl CLIUtU6ZiZsg1LRENy1RTEsU0xKlGpBWEMlpeHWGmt+sUWRzZ+J5pZrXZWfEp+WoHSDwMHJ5 G3j+PNUFIA1ky5m9WbMpEqFSz+epXQDRhCyM4TZMp0iYdGXeOU6bk6rVqTjeBVbRpCyCkeb0 HpPADGUul8VxGk77vxXQIVH5IDYn7mP3xha94pai70/+utxCJ+TfJqelS7fPgft55bO6mPph qepwuCKrOnrSqdHvPyzPIMXDuv7fI4l1zTajIe5V1BbsM19TxGxjDpXBF+5lNQ2WfZ3OkyU3 Cp86VeZig+tetLGp0dcznsT0wp/WXVcvnEhgiq4km5MGmo/KSD5TuVlOaHnlX+jR8R8sAwAA X-CMS-MailID: 20191216005955epcas1p48aeb95c6015292220cf0498396290b8e X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: SVC_REQ_APPROVE CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20191114201049epcas5p4a24607634af7b31e6a2dbdb4166dd862 References: <8734a934-79e2-7445-c3e5-a0bb59afd4a8@samsung.com> <047990a5-263d-d447-7f0a-77a99e4b1f63@samsung.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi, Also, I think that 'devfreq' word is not proper for device driver name. imx-bus.c or imx-noc.c or others to inform the role of this driver of developer. And, I have a question. This driver adds the devfreq device with either passive governor or userspace governor. As I understood, the devfreq device with passive governor will be operated with imx8m-ddrc.c driver. But, when is operating with userspace governor? I think that you better to add the explanation to description for two scenarios how to operate with interconnect provider on either passive governor or userspace governor usage case. On 12/13/19 10:51 AM, Chanwoo Choi wrote: > On 12/13/19 10:30 AM, Chanwoo Choi wrote: >> Hi, >> >> On 11/15/19 5:09 AM, Leonard Crestez wrote: >>> Add initial support for dynamic frequency switching on pieces of the imx >>> interconnect fabric. >>> >>> All this driver does is set a clk rate based on an opp table, it does >>> not map register areas. >>> >>> Signed-off-by: Leonard Crestez >>> --- >>> drivers/devfreq/Kconfig | 9 ++ >>> drivers/devfreq/Makefile | 1 + >>> drivers/devfreq/imx-devfreq.c | 150 ++++++++++++++++++++++++++++++++++ >>> 3 files changed, 160 insertions(+) >>> create mode 100644 drivers/devfreq/imx-devfreq.c >>> >>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>> index 923a6132e741..fef5ce831e90 100644 >>> --- a/drivers/devfreq/Kconfig >>> +++ b/drivers/devfreq/Kconfig >>> @@ -98,10 +98,19 @@ config ARM_IMX8M_DDRC_DEVFREQ >>> select DEVFREQ_GOV_USERSPACE >>> help >>> This adds the DEVFREQ driver for the i.MX8M DDR Controller. It allows >>> adjusting DRAM frequency. >>> >>> +config ARM_IMX_DEVFREQ >>> + tristate "i.MX Generic DEVFREQ Driver" >>> + depends on ARCH_MXC || COMPILE_TEST >>> + select DEVFREQ_GOV_PASSIVE >>> + select DEVFREQ_GOV_USERSPACE >>> + help >>> + This adds the generic DEVFREQ driver for i.MX interconnects. It >>> + allows adjusting NIC/NOC frequency. >>> + >>> config ARM_TEGRA_DEVFREQ >>> tristate "NVIDIA Tegra30/114/124/210 DEVFREQ Driver" >>> depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \ >>> ARCH_TEGRA_132_SOC || ARCH_TEGRA_124_SOC || \ >>> ARCH_TEGRA_210_SOC || \ >>> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile >>> index 3eb4d5e6635c..61d0edee16f7 100644 >>> --- a/drivers/devfreq/Makefile >>> +++ b/drivers/devfreq/Makefile >>> @@ -8,10 +8,11 @@ obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o >>> obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o >>> >>> # DEVFREQ Drivers >>> obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o >>> obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o >>> +obj-$(CONFIG_ARM_IMX_DEVFREQ) += imx-devfreq.o >>> obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o >>> obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o >>> obj-$(CONFIG_ARM_TEGRA20_DEVFREQ) += tegra20-devfreq.o >>> >>> # DEVFREQ Event Drivers >>> diff --git a/drivers/devfreq/imx-devfreq.c b/drivers/devfreq/imx-devfreq.c >>> new file mode 100644 >>> index 000000000000..620b344e87aa >>> --- /dev/null >>> +++ b/drivers/devfreq/imx-devfreq.c >>> @@ -0,0 +1,150 @@ >>> +// SPDX-License-Identifier: GPL-2.0 >>> +/* >>> + * Copyright 2019 NXP >>> + */ >>> + >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +struct imx_devfreq { >>> + struct devfreq_dev_profile profile; >>> + struct devfreq *devfreq; >>> + struct clk *clk; >>> + struct devfreq_passive_data passive_data; >>> +}; >>> + >>> +static int imx_devfreq_target(struct device *dev, >>> + unsigned long *freq, u32 flags) >> >> Don't use space for the indentation. Please use only tab. >> >>> +{ >>> + struct imx_devfreq *priv = dev_get_drvdata(dev); >>> + struct dev_pm_opp *new_opp; >>> + unsigned long new_freq; >>> + int ret; >>> + >>> + new_opp = devfreq_recommended_opp(dev, freq, flags); >>> + if (IS_ERR(new_opp)) { >>> + ret = PTR_ERR(new_opp); >>> + dev_err(dev, "failed to get recommended opp: %d\n", ret); >>> + return ret; >>> + } >>> + new_freq = dev_pm_opp_get_freq(new_opp); >>> + dev_pm_opp_put(new_opp); >>> + >>> + return clk_set_rate(priv->clk, new_freq); >>> +} >>> + >>> +static int imx_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) >>> +{ >>> + struct imx_devfreq *priv = dev_get_drvdata(dev); >>> + >>> + *freq = clk_get_rate(priv->clk); >>> + >>> + return 0; >>> +} >>> + >>> +static int imx_devfreq_get_dev_status(struct device *dev, >>> + struct devfreq_dev_status *stat) >> >> ditto. Please use tab for the indentation. >> >>> +{ >>> + struct imx_devfreq *priv = dev_get_drvdata(dev); >>> + >>> + stat->busy_time = 0; >>> + stat->total_time = 0; >>> + stat->current_frequency = clk_get_rate(priv->clk); >>> + >>> + return 0; >>> +} >>> + >>> +static void imx_devfreq_exit(struct device *dev) >>> +{ >>> + dev_pm_opp_of_remove_table(dev); >>> +} >>> + >>> +static int imx_devfreq_probe(struct platform_device *pdev) >>> +{ >>> + struct device *dev = &pdev->dev; >>> + struct imx_devfreq *priv; >> >> How about changing the variable name 'priv' to 'imx' or 'imx_data'? >> because it is not easy to catch the role of 'priv' from variable name. >> >>> + const char *gov = DEVFREQ_GOV_USERSPACE; >>> + void *govdata = NULL; >> >> How about changing the variable name 'govdata' to 'gov_data'? >> - govdata -> gov_data >> >>> + int ret; >>> + >>> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); >>> + if (!priv) >>> + return -ENOMEM; >>> + >>> + priv->clk = devm_clk_get(dev, NULL); >> >> nitpick: because the clock-name is not mandatory. >> Don't need to specify the clock name to inform the role of clock >> of other developer/user? >> >> For example, "ddr", "bus" and so on. > > And, this driver doesn't include the 'clk_prepare_enable'. > how to enable the clock? > >> >>> + if (IS_ERR(priv->clk)) { >>> + ret = PTR_ERR(priv->clk); >>> + dev_err(dev, "failed to fetch clk: %d\n", ret); >>> + return ret; >>> + } >>> + platform_set_drvdata(pdev, priv); >>> + >>> + ret = dev_pm_opp_of_add_table(dev); >>> + if (ret < 0) { >>> + dev_err(dev, "failed to get OPP table\n"); >>> + return ret; >>> + } >>> + >>> + priv->profile.polling_ms = 1000; >>> + priv->profile.target = imx_devfreq_target; >>> + priv->profile.get_dev_status = imx_devfreq_get_dev_status; >>> + priv->profile.exit = imx_devfreq_exit; >>> + priv->profile.get_cur_freq = imx_devfreq_get_cur_freq; >>> + priv->profile.initial_freq = clk_get_rate(priv->clk); >>> + >>> + /* Handle passive devfreq parent link */ >>> + priv->passive_data.parent = devfreq_get_devfreq_by_phandle(dev, 0); >>> + if (!IS_ERR(priv->passive_data.parent)) { >>> + dev_info(dev, "setup passive link to %s\n", >>> + dev_name(priv->passive_data.parent->dev.parent)); >>> + gov = DEVFREQ_GOV_PASSIVE; >>> + govdata = &priv->passive_data; >>> + } else if (priv->passive_data.parent != ERR_PTR(-ENODEV)) { >>> + // -ENODEV means no parent: not an error. >>> + ret = PTR_ERR(priv->passive_data.parent); >>> + if (ret != -EPROBE_DEFER) >>> + dev_warn(dev, "failed to get initialize passive parent: %d\n", >>> + ret); >>> + goto err; >>> + } >> >> You better to change the exception handling as following: It is more simple. >> >> } else if (PTR_ERR(priv->passive_data.parent) == -EPROBE_DEFER) >> || PTR_ERR(priv->passive_data.parent) == -ENODEV) { >> goto err; >> } else { >> ret = PTR_ERR(priv->passive_data.parent); >> dev_err(dev, "failed to get initialize passive parent: %d\n", ret); >> goto err; >> } >> >>> + >>> + priv->devfreq = devm_devfreq_add_device(dev, &priv->profile, >>> + gov, govdata); >>> + if (IS_ERR(priv->devfreq)) { >>> + ret = PTR_ERR(priv->devfreq); >>> + dev_err(dev, "failed to add devfreq device: %d\n", ret); >>> + goto err; >>> + } >>> + >>> + return 0; >>> + >>> +err: >>> + dev_pm_opp_of_remove_table(dev); >>> + return ret; >>> +} >>> + >>> +static const struct of_device_id imx_devfreq_of_match[] = { >>> + { .compatible = "fsl,imx8m-noc", }, >>> + { .compatible = "fsl,imx8m-nic", }, >>> + { /* sentinel */ }, >>> +}; >>> +MODULE_DEVICE_TABLE(of, imx_devfreq_of_match); >>> + >>> +static struct platform_driver imx_devfreq_platdrv = { >>> + .probe = imx_devfreq_probe, >>> + .driver = { >>> + .name = "imx-devfreq", >>> + .of_match_table = of_match_ptr(imx_devfreq_of_match), >>> + }, >>> +}; >>> +module_platform_driver(imx_devfreq_platdrv); >>> + >>> +MODULE_DESCRIPTION("Generic i.MX bus frequency driver"); >> >> If this driver is for bus frequency, you better to use 'bus' for the clock-name >> for the readability. >> >>> +MODULE_AUTHOR("Leonard Crestez "); >>> +MODULE_LICENSE("GPL v2"); >>> >> >> > > -- Best Regards, Chanwoo Choi Samsung Electronics