From patchwork Thu Jan 28 23:27:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 372869 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 668C5C433DB for ; Thu, 28 Jan 2021 23:32:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30FA464E5A for ; Thu, 28 Jan 2021 23:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231237AbhA1Xbz (ORCPT ); Thu, 28 Jan 2021 18:31:55 -0500 Received: from mga04.intel.com ([192.55.52.120]:11312 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbhA1Xam (ORCPT ); Thu, 28 Jan 2021 18:30:42 -0500 IronPort-SDR: HaSICEI2CDsE/bkTGRt+rpy2uKzq21rV/zm0+QITh7kxbUuK2A3qnlBT+iDeAjGMqZ3OOWJqVT wAMDA5TSA/xg== X-IronPort-AV: E=McAfee;i="6000,8403,9878"; a="177768135" X-IronPort-AV: E=Sophos;i="5.79,383,1602572400"; d="scan'208";a="177768135" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2021 15:27:33 -0800 IronPort-SDR: 2W9D+xilxzq2zjjp4Ijo7ih+AgkQcGcKKAMfRkI2/LhQP+R8HpnbszpbY2Dl1DYuBZTbnJZABV 2Aeq8V4Dasng== X-IronPort-AV: E=Sophos;i="5.79,383,1602572400"; d="scan'208";a="357611616" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2021 15:27:29 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id C1E1D218AC; Fri, 29 Jan 2021 01:27:27 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1l5GhF-0004FC-NR; Fri, 29 Jan 2021 01:27:29 +0200 From: Sakari Ailus To: linux-i2c@vger.kernel.org Cc: Wolfram Sang , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , rajmohan.mani@intel.com, Tomasz Figa , Bartosz Golaszewski , Bingbu Cao , Chiranjeevi Rapolu , Hyungwoo Yang , linux-media@vger.kernel.org Subject: [PATCH v9 2/7] i2c: Allow an ACPI driver to manage the device's power state during probe Date: Fri, 29 Jan 2021 01:27:24 +0200 Message-Id: <20210128232729.16064-2-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200903081550.6012-1-sakari.ailus@linux.intel.com> References: <20200903081550.6012-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Enable drivers to tell ACPI that there's no need to power on a device for probe. Drivers should still perform this by themselves if there's a need to. In some cases powering on the device during probe is undesirable, and this change enables a driver to choose what fits best for it. Add a field called "flags" into struct i2c_driver for driver flags, and a flag I2C_DRV_FL_ALLOW_LOW_POWER_PROBE to tell a driver supports probe in low power state. Signed-off-by: Sakari Ailus --- drivers/i2c/i2c-core-acpi.c | 10 ++++++++++ drivers/i2c/i2c-core-base.c | 9 ++++++--- include/linux/i2c.h | 19 +++++++++++++++++++ 3 files changed, 35 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c index 8ceaa88dd78fb..045d344dd0cb3 100644 --- a/drivers/i2c/i2c-core-acpi.c +++ b/drivers/i2c/i2c-core-acpi.c @@ -493,6 +493,16 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, } EXPORT_SYMBOL_GPL(i2c_acpi_new_device); +bool i2c_acpi_allow_low_power_probe(struct device *dev) +{ + struct i2c_driver *driver = to_i2c_driver(dev->driver); + struct acpi_device *adev = ACPI_COMPANION(dev); + + return driver->flags & I2C_DRV_FL_ALLOW_LOW_POWER_PROBE && + adev && adev->power.flags.allow_low_power_probe; +} +EXPORT_SYMBOL_GPL(i2c_acpi_allow_low_power_probe); + #ifdef CONFIG_ACPI_I2C_OPREGION static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, u8 cmd, u8 *data, u8 data_len) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 63ebf722a4248..87b84eee01da6 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -514,7 +514,8 @@ static int i2c_device_probe(struct device *dev) if (status < 0) goto err_clear_wakeup_irq; - status = dev_pm_domain_attach(&client->dev, true); + status = dev_pm_domain_attach(&client->dev, + !i2c_acpi_allow_low_power_probe(dev)); if (status) goto err_clear_wakeup_irq; @@ -536,7 +537,8 @@ static int i2c_device_probe(struct device *dev) return 0; err_detach_pm_domain: - dev_pm_domain_detach(&client->dev, true); + dev_pm_domain_detach(&client->dev, + !i2c_acpi_allow_low_power_probe(dev)); err_clear_wakeup_irq: dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); @@ -563,7 +565,8 @@ static int i2c_device_remove(struct device *dev) dev_warn(dev, "remove failed (%pe), will be ignored\n", ERR_PTR(status)); } - dev_pm_domain_detach(&client->dev, true); + dev_pm_domain_detach(&client->dev, + !i2c_acpi_allow_low_power_probe(dev)); dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 56622658b2158..1a103c5933d2f 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -11,6 +11,7 @@ #define _LINUX_I2C_H #include /* for acpi_handle */ +#include #include #include /* for struct device */ #include /* for completion */ @@ -217,6 +218,16 @@ enum i2c_alert_protocol { I2C_PROTOCOL_SMBUS_HOST_NOTIFY, }; +/** + * enum i2c_driver_flags - Flags for an I2C device driver + * + * @I2C_DRV_FL_ALLOW_LOW_POWER_PROBE: Let the ACPI driver manage the device's + * power state during probe and remove + */ +enum i2c_driver_flags { + I2C_DRV_FL_ALLOW_LOW_POWER_PROBE = BIT(0), +}; + /** * struct i2c_driver - represent an I2C device driver * @class: What kind of i2c device we instantiate (for detect) @@ -231,6 +242,7 @@ enum i2c_alert_protocol { * @detect: Callback for device detection * @address_list: The I2C addresses to probe (for detect) * @clients: List of detected clients we created (for i2c-core use only) + * @flags: A bitmask of flags defined in &enum i2c_driver_flags * * The driver.owner field should be set to the module owner of this driver. * The driver.name field should be set to the name of this driver. @@ -289,6 +301,8 @@ struct i2c_driver { int (*detect)(struct i2c_client *client, struct i2c_board_info *info); const unsigned short *address_list; struct list_head clients; + + u32 flags; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) @@ -996,6 +1010,7 @@ u32 i2c_acpi_find_bus_speed(struct device *dev); struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info); struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); +bool i2c_acpi_allow_low_power_probe(struct device *dev); #else static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c) @@ -1015,6 +1030,10 @@ static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle ha { return NULL; } +static inline bool i2c_acpi_allow_low_power_probe(struct device *dev) +{ + return false; +} #endif /* CONFIG_ACPI */ #endif /* _LINUX_I2C_H */