From patchwork Tue Jun 27 10:40:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abel Vesa X-Patchwork-Id: 13294336 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86FC7EB64D9 for ; Tue, 27 Jun 2023 10:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230401AbjF0Kkr (ORCPT ); Tue, 27 Jun 2023 06:40:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229647AbjF0Kkq (ORCPT ); Tue, 27 Jun 2023 06:40:46 -0400 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11815E5B for ; Tue, 27 Jun 2023 03:40:45 -0700 (PDT) Received: by mail-wr1-x42e.google.com with SMTP id ffacd0b85a97d-307d58b3efbso3847294f8f.0 for ; Tue, 27 Jun 2023 03:40:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1687862443; x=1690454443; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=XNWf4XrzpOMeSduBCIvkxhctVOzqSSmAJ8R1LK8bH5w=; b=v0kohGNzQndW2yQwqx2w8zwRIoXdd0x63JIBhZR/Qo1PuXH+wh4+0Vqs7AaTXb8vAH tBlwNu76zMuSVaeWkKEVoV6AUIvN3mBi2M2bpMG3H5LQZyPBpPgtxwWx7Kby0/bm/1Pd 4wurTqEtwjL1R9QnX50LRsLPVET4OTGm43r/yftAsap1BE7kiz2XO+eRaQ6DnXsLkO6e 1m3/jDV2SokiIMCqdeQCb1xWVYEOA5mepuT9JhQSe38lAln9ZreztOarjZuSLm6gPh2k Ph3wGYfXlSxmd7kd8iZvPmRJRpwlz9Z1lIDKH9zdpt6GQzGj7sA9MrcxPemGfUdQALCH k/2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687862443; x=1690454443; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=XNWf4XrzpOMeSduBCIvkxhctVOzqSSmAJ8R1LK8bH5w=; b=CsmbhnW6HTnPiA7D9Ht+HXRXPrmz+Yu2MVDY75wNzLA4TGuHU7J7D8oq5mOKz02oMD lesQxRAdxBStgLAXB4H93PRF8FHa/0ZGotqOGWz2vSeRFKrMLlSb16Clyw6YZdrCZZQf KInIEj0gQDCcgtQLZp2Cn73CZqvZpmJXJI4x2d6fbDjwxlKjnVhj4i+BxLx0RzdWoC+1 RkqLYktslRbXDw9d0On4Dk0widDcvj0/T5TEGEAz4P/x5roGmtgvtYEXMciRDbVMZ6LC z1in9K2CXFIu3U+fn9NVnOcQztgit3ROApTXB7hoP9pbPZKBVq5YrH1MrPI2CL9VfMTc xRGw== X-Gm-Message-State: AC+VfDycgv3p1uq76pBRtOddz/Gz8Ewg+/GxLbwjTcGh+r7EQXFAj6Ah wlQQ55DaD95oj/WkRYW2pCg5+g== X-Google-Smtp-Source: ACHHUZ4RWdwlfmE4HxDH85NtG4N+3LRB9BQsLJLeEYH8wtwl67F/1B1j3/l4x4dNuo9wx0QB51ijpQ== X-Received: by 2002:a5d:4ad0:0:b0:313:f98a:1fd3 with SMTP id y16-20020a5d4ad0000000b00313f98a1fd3mr2072465wrs.27.1687862443390; Tue, 27 Jun 2023 03:40:43 -0700 (PDT) Received: from hackbox.lan ([62.231.110.100]) by smtp.gmail.com with ESMTPSA id a10-20020adfdd0a000000b0030af15d7e41sm10203750wrm.4.2023.06.27.03.40.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Jun 2023 03:40:42 -0700 (PDT) From: Abel Vesa To: "Rafael J . Wysocki" , Kevin Hilman , Ulf Hansson , avel Machek , Len Brown , Greg Kroah-Hartman , Bjorn Andersson , Andy Gross , Konrad Dybcio , Mike Turquette , Stephen Boyd , Taniya Das Cc: linux-pm@vger.kernel.org, Linux Kernel Mailing List , linux-arm-msm@vger.kernel.org Subject: [RFC PATCH 1/2] PM: domains: Allow devices attached to genpd to be managed by HW Date: Tue, 27 Jun 2023 13:40:32 +0300 Message-Id: <20230627104033.3345659-1-abel.vesa@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Ulf Hansson Some power-domains may be capable of relying on the HW to control the power for a device that's hooked up to it. Typically, for these kinds of configurations the device doesn't really need to be attached to a PM domain (genpd), from Linux point of view. However, in some cases the behaviour of the power-domain and its device can be changed in runtime. To allow a consumer driver to change the behaviour of the PM domain for its device, let's provide a new function, dev_pm_genpd_set_hwmode(). Moreover, let's add a corresponding optional genpd callback, ->set_hwmode_dev(), which the genpd provider should implement if it can support switching between HW controlled mode and SW controlled mode. Signed-off-by: Ulf Hansson --- drivers/base/power/domain.c | 66 +++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 15 +++++++++ 2 files changed, 81 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 5cb2023581d4..23286853d1d0 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -541,6 +541,72 @@ void dev_pm_genpd_synced_poweroff(struct device *dev) } EXPORT_SYMBOL_GPL(dev_pm_genpd_synced_poweroff); +/** + * dev_pm_genpd_set_hwmode - Set the HW mode for the device and its PM domain. + * + * @dev: Device for which the HW-mode should be changed. + * @enable: Value to set or unset the HW-mode. + * + * Some PM domains can rely on HW signals to control the power for a device. To + * allow a consumer driver to switch the behaviour for its device in runtime, + * which may be beneficial from a latency or energy point of view, this function + * may be called. + * + * It is assumed that the users guarantee that the genpd wouldn't be detached + * while this routine is getting called. + * + * Returns 0 on success and negative error values on failures. + */ +int dev_pm_genpd_set_hwmode(struct device *dev, bool enable) +{ + struct generic_pm_domain *genpd; + int ret = 0; + + genpd = dev_to_genpd_safe(dev); + if (!genpd) + return -ENODEV; + + if (!genpd->set_hwmode_dev) + return -EOPNOTSUPP; + + genpd_lock(genpd); + + if (dev_gpd_data(dev)->hw_mode == enable) + goto out; + + ret = genpd->set_hwmode_dev(genpd, dev, enable); + if (!ret) + dev_gpd_data(dev)->hw_mode = enable; + +out: + genpd_unlock(genpd); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_genpd_set_hwmode); + +/** + * dev_pm_genpd_get_hwmode - Get the HW mode setting for the device. + * + * @dev: Device for which the current HW-mode setting should be fetched. + * + * This helper function allows consumer drivers to fetch the current HW mode + * setting of its the device. + * + * It is assumed that the users guarantee that the genpd wouldn't be detached + * while this routine is getting called. + */ +bool dev_pm_genpd_get_hwmode(struct device *dev) +{ + struct generic_pm_domain *genpd; + + genpd = dev_to_genpd_safe(dev); + if (!genpd) + return false; + + return dev_gpd_data(dev)->hw_mode; +} +EXPORT_SYMBOL_GPL(dev_pm_genpd_get_hwmode); + static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) { unsigned int state_idx = genpd->state_idx; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index f776fb93eaa0..8f60c36851d5 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -146,6 +146,8 @@ struct generic_pm_domain { int (*set_performance_state)(struct generic_pm_domain *genpd, unsigned int state); struct gpd_dev_ops dev_ops; + int (*set_hwmode_dev)(struct generic_pm_domain *domain, + struct device *dev, bool enable); int (*attach_dev)(struct generic_pm_domain *domain, struct device *dev); void (*detach_dev)(struct generic_pm_domain *domain, @@ -208,6 +210,7 @@ struct generic_pm_domain_data { unsigned int performance_state; unsigned int default_pstate; unsigned int rpm_pstate; + bool hw_mode; void *data; }; @@ -237,6 +240,8 @@ int dev_pm_genpd_remove_notifier(struct device *dev); void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next); ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev); void dev_pm_genpd_synced_poweroff(struct device *dev); +int dev_pm_genpd_set_hwmode(struct device *dev, bool enable); +bool dev_pm_genpd_get_hwmode(struct device *dev); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -305,6 +310,16 @@ static inline ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev) static inline void dev_pm_genpd_synced_poweroff(struct device *dev) { } +static inline int dev_pm_genpd_set_hwmode(struct device *dev, bool enable) +{ + return -EOPNOTSUPP; +} + +static inline bool dev_pm_genpd_get_hwmode(struct device *dev) +{ + return false; +} + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif