From patchwork Wed Aug 16 14:57:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abel Vesa X-Patchwork-Id: 13355368 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 C562FC04A6A for ; Wed, 16 Aug 2023 14:58:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343874AbjHPO6E (ORCPT ); Wed, 16 Aug 2023 10:58:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343855AbjHPO5y (ORCPT ); Wed, 16 Aug 2023 10:57:54 -0400 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 425DF10FF for ; Wed, 16 Aug 2023 07:57:53 -0700 (PDT) Received: by mail-lj1-x236.google.com with SMTP id 38308e7fff4ca-2b703a0453fso100999111fa.3 for ; Wed, 16 Aug 2023 07:57:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1692197871; x=1692802671; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=YJy2R3P3tqw0+ESpB2MxKyE27+v98SJ0NGWR6OuPHME=; b=FFsAYIPCoql6xswQkEnqKEFXrppTVmLHlVv+VfbtsYgPHJnIYrdSYD/SO/BJtXlhoc wA+1z0Brl33kk5FQvjYbND1wQ9fwAOxMrJcAS/WU+uQbVZKjJAdVzCUgsZxc2x9n8hVI 2oRgIb+O1tc2w9KWRgn9oFyAPlavnDtio0/TDhWCwUS4OyFK/4yKNIPxxarXiu1Jjb2/ m96rlqO+sA7eQA1/eN8AuAWyiBevnw2+iwyXtjCTYASC+t9q7ywMhKt2tsedaY7JQkgU LXYANfX8hbUBSw+25eazY8KL4TfCrYl4y4goqFdAyoQMNmgfsLU3UXOsZlKIsiTQLiND cR4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692197871; x=1692802671; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=YJy2R3P3tqw0+ESpB2MxKyE27+v98SJ0NGWR6OuPHME=; b=Y5qngxgAfJ8D+JctyzvcvpeM1VbfGRThOKS02LE3Ui41lT0QpJC1i+iinaqXH9L1Lw 78I8PB1vnWJCdGpO9JNgAXrIXz60y6k7SrbEME56PlruWziM4BRp0cMIsBF8YYSyFFnY AKhKX1b3YoCCzMMipfdmcgbYCWqltiTXPvPDB8HfEWyeuyhExil5uNptQ+165akmxiiI UWMtraI7JgFxbPrjq68xn0Hcf52WBdIg9aERRf725lAssjs8UDELr2SchxDr1AN+WupE E+AKt1Gn/nfacLhSYG1EIXsBHEHbhuohJ/h1Um+NtUyLcsAVjFJKprtTsmS7caZs1Zi6 2JVQ== X-Gm-Message-State: AOJu0YzpJDYlPO9hNmQaL13X4rhya00dru+EB7nndTLEE7VVKcrGCzTu FZNAdr0AXPfAZyZl0vr04NcXMA== X-Google-Smtp-Source: AGHT+IFPyEEjR3aBCl4jPyvfEu16V/bunE3zATtqhYdZEh6WtyuA71IJB08RCkr8xn8X4letoC9xUw== X-Received: by 2002:a2e:86c2:0:b0:2b9:acad:b4b2 with SMTP id n2-20020a2e86c2000000b002b9acadb4b2mr1707919ljj.6.1692197871439; Wed, 16 Aug 2023 07:57:51 -0700 (PDT) Received: from hackbox.lan ([84.232.191.92]) by smtp.gmail.com with ESMTPSA id f16-20020a170906561000b00992076f4a01sm8610403ejq.190.2023.08.16.07.57.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Aug 2023 07:57:51 -0700 (PDT) From: Abel Vesa To: "Rafael J . Wysocki" , Kevin Hilman , Ulf Hansson , Pavel 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: [PATCH v2 1/6] PM: domains: Allow devices attached to genpd to be managed by HW Date: Wed, 16 Aug 2023 17:57:36 +0300 Message-Id: <20230816145741.1472721-2-abel.vesa@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230816145741.1472721-1-abel.vesa@linaro.org> References: <20230816145741.1472721-1-abel.vesa@linaro.org> 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. Similarly, add the dev_pm_genpd_get_hwmode() to allow consumers to read the current mode and its corresponding optional genpd callback, ->get_hwmode_dev(), which the genpd provider can also implement for reading back the mode from the hardware. Signed-off-by: Ulf Hansson Signed-off-by: Abel Vesa --- Changes since v1: * reword the commit message to mention the dev_pm_genpd_get_hwmode * add the get_hwmode_dev callback to the generic_pm_domain * call the genpd provider implementation of the get_hwmode_dev from the generic API drivers/base/power/domain.c | 69 +++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 17 +++++++++ 2 files changed, 86 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 5cb2023581d4..dfb4f1de540d 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -541,6 +541,75 @@ 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; + + if (genpd->get_hwmode_dev) + return genpd->get_hwmode_dev(genpd, dev); + + 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..36d308ba40b0 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -146,6 +146,10 @@ 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); + bool (*get_hwmode_dev)(struct generic_pm_domain *domain, + struct device *dev); int (*attach_dev)(struct generic_pm_domain *domain, struct device *dev); void (*detach_dev)(struct generic_pm_domain *domain, @@ -208,6 +212,7 @@ struct generic_pm_domain_data { unsigned int performance_state; unsigned int default_pstate; unsigned int rpm_pstate; + bool hw_mode; void *data; }; @@ -237,6 +242,8 @@ 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 +312,16 @@ 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