From patchwork Wed Aug 26 11:54:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 251695 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 346ABC433DF for ; Wed, 26 Aug 2020 11:53:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 078FC20707 for ; Wed, 26 Aug 2020 11:53:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729022AbgHZLxU (ORCPT ); Wed, 26 Aug 2020 07:53:20 -0400 Received: from mga04.intel.com ([192.55.52.120]:56886 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729178AbgHZLvE (ORCPT ); Wed, 26 Aug 2020 07:51:04 -0400 IronPort-SDR: DomxA95qKQGfaottZvVOOwd3LkuKx71s7AfMijDih4aOGW+V2q+2cUV91H32qc//XEgwbzu9tz iwHrZ3gHH1bA== X-IronPort-AV: E=McAfee;i="6000,8403,9724"; a="153697662" X-IronPort-AV: E=Sophos;i="5.76,355,1592895600"; d="scan'208";a="153697662" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2020 04:50:56 -0700 IronPort-SDR: 5dw5ztxdXOWsP6enz2cfMRr+3xabuDaa7MmRSVDufBGKov0zWvp3DM1ONSf+raLra36oj7SzW9 oJHCyd4xkrWw== X-IronPort-AV: E=Sophos;i="5.76,355,1592895600"; d="scan'208";a="499691353" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2020 04:50:53 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 5EE3F20623; Wed, 26 Aug 2020 14:50:51 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kAu0e-0001bM-OH; Wed, 26 Aug 2020 14:54:32 +0300 From: Sakari Ailus To: linux-i2c@vger.kernel.org Cc: Wolfram Sang , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, Bingbu Cao , linux-media@vger.kernel.org, Chiranjeevi Rapolu , Hyungwoo Yang , Bartosz Golaszewski , Arnd Bergmann , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , rajmohan.mani@intel.com, Tomasz Figa , "Qiu, Tian Shu" Subject: [PATCH v6 2/6] ACPI: Add a convenience function to tell a device is in low power state Date: Wed, 26 Aug 2020 14:54:28 +0300 Message-Id: <20200826115432.6103-3-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200826115432.6103-1-sakari.ailus@linux.intel.com> References: <20200826115432.6103-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Add a convenience function to tell whether a device is in low power state, primarily for use in drivers' probe or remove functions on busses where the custom is to power on the device for the duration of both. Returns false on non-ACPI systems. Suggested-by: Mika Westerberg Signed-off-by: Sakari Ailus Reviewed-by: Rafael J. Wysocki --- drivers/acpi/device_pm.c | 31 +++++++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++++ 2 files changed, 36 insertions(+) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 94d91c67aeaeb..e3c488d4af0d4 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1344,4 +1344,35 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on) return 1; } EXPORT_SYMBOL_GPL(acpi_dev_pm_attach); + +/** + * acpi_dev_state_low_power - Check the current ACPI power state of a device. + * @dev: Physical device the ACPI power state of which to check + * + * On a system without ACPI, return false. On a system with ACPI, return true if + * the current ACPI power state of the device is not D0, or false otherwise. + * + * Note that the power state of a device is not well-defined after it has been + * passed to acpi_device_set_power() and before that function returns, so it is + * not valid to ask for the ACPI power state of the device in that time frame. + */ +bool acpi_dev_state_low_power(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + int power_state; + int ret; + + if (!adev) + return false; + + ret = acpi_device_get_power(adev, &power_state); + if (ret) { + dev_dbg(dev, "Cannot obtain power state (%d)\n", ret); + return false; + } + + return power_state != ACPI_STATE_D0; +} +EXPORT_SYMBOL_GPL(acpi_dev_state_low_power); + #endif /* CONFIG_PM */ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 1e4cdc6c7ae20..276f6af99779f 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -976,6 +976,7 @@ int acpi_dev_resume(struct device *dev); int acpi_subsys_runtime_suspend(struct device *dev); int acpi_subsys_runtime_resume(struct device *dev); int acpi_dev_pm_attach(struct device *dev, bool power_on); +bool acpi_dev_state_low_power(struct device *dev); #else static inline int acpi_dev_runtime_suspend(struct device *dev) { return 0; } static inline int acpi_dev_runtime_resume(struct device *dev) { return 0; } @@ -985,6 +986,10 @@ static inline int acpi_dev_pm_attach(struct device *dev, bool power_on) { return 0; } +static inline bool acpi_dev_state_low_power(struct device *dev) +{ + return false; +} #endif #if defined(CONFIG_ACPI) && defined(CONFIG_PM_SLEEP)