From patchwork Thu Aug 2 00:57:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saravana Kannan X-Patchwork-Id: 952514 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=codeaurora.org header.i=@codeaurora.org header.b="HckZdUMO"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="HckZdUMO"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41gsH14f9lz9s4s for ; Thu, 2 Aug 2018 10:58:05 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732308AbeHBCq1 (ORCPT ); Wed, 1 Aug 2018 22:46:27 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:55276 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730632AbeHBCq1 (ORCPT ); Wed, 1 Aug 2018 22:46:27 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id A1B1960B12; Thu, 2 Aug 2018 00:57:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1533171475; bh=8DU0v405rtpXJJvz0LYhPf3/Smuaf/SxDQdZlxWMUac=; h=From:To:Cc:Subject:Date:From; b=HckZdUMO0VcdHYa4/NSs6cyB+IwWVGQ+GRm0nQzzSezfU1ing2XCOiZoDZlzpx49E H7WHBG1j3NDxUdU9H5OAjVPuL4BhCFwz0ZtkV/a6KcOPfQf8GmGwtgwI7gIaoP6S3D XMYf645om3Nyywk9aRQbBW0Lg1P90v/C2zVLKYrY= X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=2.0 tests=ALL_TRUSTED,BAYES_00, DKIM_SIGNED, T_DKIM_INVALID autolearn=no autolearn_force=no version=3.4.0 Received: from skannan1-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: skannan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 8C56160B13; Thu, 2 Aug 2018 00:57:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1533171475; bh=8DU0v405rtpXJJvz0LYhPf3/Smuaf/SxDQdZlxWMUac=; h=From:To:Cc:Subject:Date:From; b=HckZdUMO0VcdHYa4/NSs6cyB+IwWVGQ+GRm0nQzzSezfU1ing2XCOiZoDZlzpx49E H7WHBG1j3NDxUdU9H5OAjVPuL4BhCFwz0ZtkV/a6KcOPfQf8GmGwtgwI7gIaoP6S3D XMYf645om3Nyywk9aRQbBW0Lg1P90v/C2zVLKYrY= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8C56160B13 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=skannan@codeaurora.org From: Saravana Kannan To: MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Rob Herring , Mark Rutland Cc: Saravana Kannan , georgi.djakov@linaro.org, vincent.guittot@linaro.org, daidavid1@codeaurora.org, bjorn.andersson@linaro.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] PM / devfreq: Add devfreq driver for interconnect bandwidth voting Date: Wed, 1 Aug 2018 17:57:42 -0700 Message-Id: <1533171465-25508-2-git-send-email-skannan@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This driver registers itself as a devfreq device that allows devfreq governors to make bandwidth votes for an interconnect path. This allows applying various policies for different interconnect paths using devfreq governors. Example uses: * Use the devfreq performance governor to set the CPU to DDR interconnect path for maximum performance. * Use the devfreq performance governor to set the GPU to DDR interconnect path for maximum performance. * Use the CPU frequency to device frequency mapping governor to scale the DDR frequency based on the needs of the CPUs' current frequency. Signed-off-by: Saravana Kannan --- Documentation/devicetree/bindings/devfreq/icbw.txt | 21 ++++ drivers/devfreq/Kconfig | 13 +++ drivers/devfreq/Makefile | 1 + drivers/devfreq/devfreq_icbw.c | 116 +++++++++++++++++++++ 4 files changed, 151 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/icbw.txt create mode 100644 drivers/devfreq/devfreq_icbw.c diff --git a/Documentation/devicetree/bindings/devfreq/icbw.txt b/Documentation/devicetree/bindings/devfreq/icbw.txt new file mode 100644 index 0000000..36cf045 --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/icbw.txt @@ -0,0 +1,21 @@ +Interconnect bandwidth device + +icbw is a device that represents an interconnect path that connects two +devices. This device is typically used to vote for BW requirements between +two devices. Eg: CPU to DDR, GPU to DDR, etc + +Required properties: +- compatible: Must be "devfreq-icbw" +- interconnects: Pairs of phandles and interconnect provider specifier + to denote the edge source and destination ports of + the interconnect path. See also: + Documentation/devicetree/bindings/interconnect/interconnect.txt +- interconnect-names: Must have one entry with the name "path". + +Example: + + qcom,cpubw { + compatible = "devfreq-icbw"; + interconnects = <&snoc MASTER_APSS_1 &bimc SLAVE_EBI_CH0>; + interconnect-names = "path"; + }; diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 3d9ae68..590370e 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -121,6 +121,19 @@ config ARM_RK3399_DMC_DEVFREQ It sets the frequency for the memory controller and reads the usage counts from hardware. +config DEVFREQ_ICBW + bool "DEVFREQ device for making bandwidth votes on interconnect paths" + select DEVFREQ_GOV_PERFORMANCE + select DEVFREQ_GOV_POWERSAVE + select DEVFREQ_GOV_USERSPACE + default n + help + Different devfreq governors use this devfreq device to make + bandwidth votes for interconnect paths between different devices + (Eg: CPU to DDR, GPU to DDR, etc). This driver provides a generic + interface so that the devfreq governors can be shared across SoCs + and architectures. + source "drivers/devfreq/event/Kconfig" endif # PM_DEVFREQ diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile index e9dc3e9..b302c5cf 100644 --- a/drivers/devfreq/Makefile +++ b/drivers/devfreq/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_DEVFREQ_GOV_CPUFREQ_MAP) += governor_cpufreq_map.o obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o +obj-$(CONFIG_DEVFREQ_ICBW) += devfreq_icbw.o # DEVFREQ Event Drivers obj-$(CONFIG_PM_DEVFREQ_EVENT) += event/ diff --git a/drivers/devfreq/devfreq_icbw.c b/drivers/devfreq/devfreq_icbw.c new file mode 100644 index 0000000..231fb21 --- /dev/null +++ b/drivers/devfreq/devfreq_icbw.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2013-2014, 2018, The Linux Foundation. All rights reserved. + */ + +#define pr_fmt(fmt) "icbw: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct dev_data { + struct icc_path *path; + u32 cur_ab; + u32 cur_pb; + unsigned long gov_ab; + struct devfreq *df; + struct devfreq_dev_profile dp; +}; + +static int icbw_target(struct device *dev, unsigned long *freq, u32 flags) +{ + struct dev_data *d = dev_get_drvdata(dev); + int ret; + u32 new_pb = *freq, new_ab = d->gov_ab; + + if (d->cur_pb == new_pb && d->cur_ab == new_ab) + return 0; + + dev_dbg(dev, "BW KBps: AB: %u PB: %u\n", new_ab, new_pb); + + ret = icc_set(d->path, new_ab, new_pb); + if (ret) { + dev_err(dev, "bandwidth request failed (%d)\n", ret); + } else { + d->cur_pb = new_pb; + d->cur_ab = new_ab; + } + + return ret; +} + +static int icbw_get_dev_status(struct device *dev, + struct devfreq_dev_status *stat) +{ + struct dev_data *d = dev_get_drvdata(dev); + + stat->private_data = &d->gov_ab; + return 0; +} + +static int devfreq_icbw_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dev_data *d; + struct devfreq_dev_profile *p; + + d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL); + if (!d) + return -ENOMEM; + dev_set_drvdata(dev, d); + + p = &d->dp; + p->polling_ms = 50; + p->target = icbw_target; + p->get_dev_status = icbw_get_dev_status; + + d->path = of_icc_get(dev, "path"); + if (IS_ERR(d->path)) { + dev_err(dev, "Unable to register interconnect path\n"); + return -ENODEV; + } + + d->df = devfreq_add_device(dev, p, "performance", NULL); + if (IS_ERR(d->df)) { + icc_put(d->path); + return PTR_ERR(d->df); + } + + return 0; +} + +static int devfreq_icbw_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dev_data *d = dev_get_drvdata(dev); + + devfreq_remove_device(d->df); + icc_put(d->path); + return 0; +} + +static const struct of_device_id icbw_match_table[] = { + { .compatible = "devfreq-icbw" }, + {} +}; + +static struct platform_driver icbw_driver = { + .probe = devfreq_icbw_probe, + .remove = devfreq_icbw_remove, + .driver = { + .name = "devfreq-icbw", + .of_match_table = icbw_match_table, + }, +}; + +module_platform_driver(icbw_driver); +MODULE_DESCRIPTION("Interconnect bandwidth voting driver"); +MODULE_LICENSE("GPL v2");