From patchwork Fri Feb 5 13:25:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 377292 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=ham 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 6979FC433E0 for ; Fri, 5 Feb 2021 22:41:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24E5F64E0A for ; Fri, 5 Feb 2021 22:41:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231492AbhBEWl2 (ORCPT ); Fri, 5 Feb 2021 17:41:28 -0500 Received: from mga03.intel.com ([134.134.136.65]:3425 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229785AbhBEN2w (ORCPT ); Fri, 5 Feb 2021 08:28:52 -0500 IronPort-SDR: x5pevTuE5EHdXLMUh/y0TebDoTBBidkkChawExMcuPToW66pUkgQGhZZCtT+GiPChTlhmKnvSk Z8ElkppSJ/cA== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="181495980" X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="181495980" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:24:55 -0800 IronPort-SDR: gfp2U/xboQ5uRr6A/nV02d4+tku7J8fLeCZ4JSb7z1Cd9N5VhWaoqoOP2SX+P4+9xrueqrAdCp ttcbiT3HZfGw== X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="576645181" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:24:53 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 892E020757; Fri, 5 Feb 2021 15:24:51 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1l816f-0005GI-Ai; Fri, 05 Feb 2021 15:25:05 +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 v10 2/7] i2c: Allow an ACPI driver to manage the device's power state during probe Date: Fri, 5 Feb 2021 15:25:00 +0200 Message-Id: <20210205132505.20173-3-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210205132505.20173-1-sakari.ailus@linux.intel.com> References: <20210205132505.20173-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@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 Reviewed-by: Tomasz Figa Acked-by: Wolfram Sang --- 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..7bab8b9126ee6 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.state_for_enumeration >= adev->power.state; +} +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 */ From patchwork Fri Feb 5 13:25:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 377291 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=ham 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 9948BC433E6 for ; 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d="scan'208";a="373390607" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:24:53 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 90B8420D38; Fri, 5 Feb 2021 15:24:51 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1l816f-0005GL-C1; Fri, 05 Feb 2021 15:25:05 +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 v10 3/7] Documentation: ACPI: Document _DSE object usage for enum power state Date: Fri, 5 Feb 2021 15:25:01 +0200 Message-Id: <20210205132505.20173-4-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210205132505.20173-1-sakari.ailus@linux.intel.com> References: <20210205132505.20173-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Document the use of the _DSE object for setting desirable power state during probe. Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa --- Documentation/firmware-guide/acpi/index.rst | 1 + .../firmware-guide/acpi/low-power-probe.rst | 69 +++++++++++++++++++ 2 files changed, 70 insertions(+) create mode 100644 Documentation/firmware-guide/acpi/low-power-probe.rst diff --git a/Documentation/firmware-guide/acpi/index.rst b/Documentation/firmware-guide/acpi/index.rst index f72b5f1769fb2..d02712acccbc0 100644 --- a/Documentation/firmware-guide/acpi/index.rst +++ b/Documentation/firmware-guide/acpi/index.rst @@ -25,5 +25,6 @@ ACPI Support acpi-lid lpit video_extension + low-power-probe extcon-intel-int3496 intel-pmc-mux diff --git a/Documentation/firmware-guide/acpi/low-power-probe.rst b/Documentation/firmware-guide/acpi/low-power-probe.rst new file mode 100644 index 0000000000000..b96804d959a6c --- /dev/null +++ b/Documentation/firmware-guide/acpi/low-power-probe.rst @@ -0,0 +1,69 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================================== +Probing I²C devices in low power state +====================================== + +Introduction +============ + +In some cases it may be preferred to leave certain devices powered off for the +entire system bootup if powering on these devices has adverse side effects, +beyond just powering on the said device. + +How it works +============ + +The _DSE (Device State for Enumeration) object that evaluates to integer 0 may +be used to tell Linux the highest allowed D state for a device during probe. If +the driver indicates its support for this by setting the +I2C_DRV_FL_ALLOW_LOW_POWER_PROBE flag in struct i2c_driver.flags field and the +_DSE object evaluates to integer higher than the D state of the device, the +device will not be powered on (put in D0 state) for probe. + +The D states and thus also the allowed values for _DSE are listed below. Refer +to [1] for more information on device power states. + +.. code-block:: text + + Number State Description + 0 D0 Device fully powered on + 1 D1 + 2 D2 + 3 D3hot + 4 D3cold Off + +The downside is that as the device is not powered on, even if there's a problem +with the device, the driver likely probes just fine but the first user will +find out the device doesn't work, instead of a failure at probe time. This +feature should thus be used sparingly. + +References +========== + +[1] https://uefi.org/specifications/ACPI/6.4/02_Definition_of_Terms/Definition_of_Terms.html#device-power-state-definitions + +Example +======= + +An ASL example describing an ACPI device using _DSE object to tell Operating +System the device should remain powered off during probe looks like this. Some +objects not relevant from the example point of view have been omitted. + +.. code-block:: text + + Device (CAM0) + { + Name (_HID, "SONY319A") + Name (_UID, Zero) + Name (_CRS, ResourceTemplate () + { + I2cSerialBus(0x0020, ControllerInitiated, 0x00061A80, + AddressingMode7Bit, "\\_SB.PCI0.I2C0", + 0x00, ResourceConsumer) + }) + Name (_DSE, 0, NotSerialized) + { + Return (0x4) + } + } From patchwork Fri Feb 5 13:25:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 377295 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 31C9FC433DB for ; Fri, 5 Feb 2021 13:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD45A64E0B for ; Fri, 5 Feb 2021 13:33:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230120AbhBENc5 (ORCPT ); Fri, 5 Feb 2021 08:32:57 -0500 Received: from mga06.intel.com ([134.134.136.31]:30367 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229876AbhBEN2w (ORCPT ); Fri, 5 Feb 2021 08:28:52 -0500 IronPort-SDR: FE//1QypzqFqykF/01P6B/ckCA2gSfl8TbSGn2pUqj0tP9Z4+izrEAr7ckV4eqTGOjJfOd2Cin xItxGjuHArNA== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="242934115" X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="242934115" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:25:02 -0800 IronPort-SDR: T7mKaIz0pmfvEp8hRidWDEmtu19qLnpFj0GErgx1gj8tjrNndc9/6aqeK8yskSaM2n09k8F3Yz ZRYdEx+6/qlQ== X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="508536741" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:24:58 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 9F0CE20EFD; Fri, 5 Feb 2021 15:24:51 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1l816f-0005GR-Dv; Fri, 05 Feb 2021 15:25:05 +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 v10 5/7] ov5670: Support probe whilst the device is in a low power state Date: Fri, 5 Feb 2021 15:25:03 +0200 Message-Id: <20210205132505.20173-6-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210205132505.20173-1-sakari.ailus@linux.intel.com> References: <20210205132505.20173-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Tell ACPI device PM code that the driver supports the device being in a low power state when the driver's probe function is entered. Also do identification on the first access of the device, whether in probe or when starting streaming. Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa --- drivers/media/i2c/ov5670.c | 76 +++++++++++++++++++++++--------------- 1 file changed, 46 insertions(+), 30 deletions(-) diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c index 866c8c2e8f59a..eb0d599f3318b 100644 --- a/drivers/media/i2c/ov5670.c +++ b/drivers/media/i2c/ov5670.c @@ -1832,6 +1832,8 @@ struct ov5670 { /* Streaming on/off */ bool streaming; + /* True if the device has been identified */ + bool identified; }; #define to_ov5670(_sd) container_of(_sd, struct ov5670, sd) @@ -2271,6 +2273,32 @@ static int ov5670_get_skip_frames(struct v4l2_subdev *sd, u32 *frames) return 0; } +/* Verify chip ID */ +static int ov5670_identify_module(struct ov5670 *ov5670) +{ + struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd); + int ret; + u32 val; + + if (ov5670->identified) + return 0; + + ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID, + OV5670_REG_VALUE_24BIT, &val); + if (ret) + return ret; + + if (val != OV5670_CHIP_ID) { + dev_err(&client->dev, "chip id mismatch: %x!=%x\n", + OV5670_CHIP_ID, val); + return -ENXIO; + } + + ov5670->identified = true; + + return 0; +} + /* Prepare streaming by writing default values and customized values */ static int ov5670_start_streaming(struct ov5670 *ov5670) { @@ -2279,6 +2307,10 @@ static int ov5670_start_streaming(struct ov5670 *ov5670) int link_freq_index; int ret; + ret = ov5670_identify_module(ov5670); + if (ret) + return ret; + /* Get out of from software reset */ ret = ov5670_write_reg(ov5670, OV5670_REG_SOFTWARE_RST, OV5670_REG_VALUE_08BIT, OV5670_SOFTWARE_RST); @@ -2400,27 +2432,6 @@ static int __maybe_unused ov5670_resume(struct device *dev) return 0; } -/* Verify chip ID */ -static int ov5670_identify_module(struct ov5670 *ov5670) -{ - struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd); - int ret; - u32 val; - - ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID, - OV5670_REG_VALUE_24BIT, &val); - if (ret) - return ret; - - if (val != OV5670_CHIP_ID) { - dev_err(&client->dev, "chip id mismatch: %x!=%x\n", - OV5670_CHIP_ID, val); - return -ENXIO; - } - - return 0; -} - static const struct v4l2_subdev_video_ops ov5670_video_ops = { .s_stream = ov5670_set_stream, }; @@ -2455,6 +2466,7 @@ static int ov5670_probe(struct i2c_client *client) struct ov5670 *ov5670; const char *err_msg; u32 input_clk = 0; + bool low_power; int ret; device_property_read_u32(&client->dev, "clock-frequency", &input_clk); @@ -2471,11 +2483,14 @@ static int ov5670_probe(struct i2c_client *client) /* Initialize subdev */ v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops); - /* Check module identity */ - ret = ov5670_identify_module(ov5670); - if (ret) { - err_msg = "ov5670_identify_module() error"; - goto error_print; + low_power = acpi_dev_state_low_power(&client->dev); + if (!low_power) { + /* Check module identity */ + ret = ov5670_identify_module(ov5670); + if (ret) { + err_msg = "ov5670_identify_module() error"; + goto error_print; + } } mutex_init(&ov5670->mutex); @@ -2512,10 +2527,10 @@ static int ov5670_probe(struct i2c_client *client) ov5670->streaming = false; /* - * Device is already turned on by i2c-core with ACPI domain PM. - * Enable runtime PM and turn off the device. + * Don't set the device's state to active if it's in a low power state. */ - pm_runtime_set_active(&client->dev); + if (!low_power) + pm_runtime_set_active(&client->dev); pm_runtime_enable(&client->dev); pm_runtime_idle(&client->dev); @@ -2557,7 +2572,7 @@ static const struct dev_pm_ops ov5670_pm_ops = { #ifdef CONFIG_ACPI static const struct acpi_device_id ov5670_acpi_ids[] = { - {"INT3479"}, + { "INT3479" }, { /* sentinel */ } }; @@ -2572,6 +2587,7 @@ static struct i2c_driver ov5670_i2c_driver = { }, .probe_new = ov5670_probe, .remove = ov5670_remove, + .flags = I2C_DRV_FL_ALLOW_LOW_POWER_PROBE, }; module_i2c_driver(ov5670_i2c_driver); From patchwork Fri Feb 5 13:25:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 377294 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 C9F84C433E0 for ; Fri, 5 Feb 2021 13:36:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E72E64F9F for ; Fri, 5 Feb 2021 13:36:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230243AbhBENfH (ORCPT ); Fri, 5 Feb 2021 08:35:07 -0500 Received: from mga09.intel.com ([134.134.136.24]:26783 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229986AbhBENcR (ORCPT ); Fri, 5 Feb 2021 08:32:17 -0500 IronPort-SDR: G9HSbYOHf+zjsiFuHRdL+Ci5DUgBv9+0ButCcvbE8HE3aOrG2gLQRT1BUQMSiBCGNFFXUkC8KV mITvep/RDx2g== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="181578728" X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="181578728" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:25:01 -0800 IronPort-SDR: SVoxw9OfMZrC1wXygP9As+pPtInJSF7e03U1YzeFhiToz+fW9LiChSsdA7BMCqI6HNA7EralAs YfvjIXRMh0qg== X-IronPort-AV: E=Sophos;i="5.81,154,1610438400"; d="scan'208";a="357959766" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2021 05:24:58 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id B1680216F2; Fri, 5 Feb 2021 15:24:51 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1l816f-0005GX-G0; Fri, 05 Feb 2021 15:25:05 +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 v10 7/7] at24: Support probing while off Date: Fri, 5 Feb 2021 15:25:05 +0200 Message-Id: <20210205132505.20173-8-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210205132505.20173-1-sakari.ailus@linux.intel.com> References: <20210205132505.20173-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org In certain use cases (where the chip is part of a camera module, and the camera module is wired together with a camera privacy LED), powering on the device during probe is undesirable. Add support for the at24 to execute probe while being powered off. For this to happen, a hint in form of a device property is required from the firmware. Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa --- drivers/misc/eeprom/at24.c | 43 +++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 926408b41270c..69a5e4023d9e1 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -595,6 +595,7 @@ static int at24_probe(struct i2c_client *client) bool i2c_fn_i2c, i2c_fn_block; unsigned int i, num_addresses; struct at24_data *at24; + bool off_during_probe; struct regmap *regmap; bool writable; u8 test_byte; @@ -750,14 +751,16 @@ static int at24_probe(struct i2c_client *client) i2c_set_clientdata(client, at24); - err = regulator_enable(at24->vcc_reg); - if (err) { - dev_err(dev, "Failed to enable vcc regulator\n"); - return err; - } + off_during_probe = acpi_dev_state_low_power(&client->dev); + if (!off_during_probe) { + err = regulator_enable(at24->vcc_reg); + if (err) { + dev_err(dev, "Failed to enable vcc regulator\n"); + return err; + } - /* enable runtime pm */ - pm_runtime_set_active(dev); + pm_runtime_set_active(dev); + } pm_runtime_enable(dev); at24->nvmem = devm_nvmem_register(dev, &nvmem_config); @@ -768,14 +771,17 @@ static int at24_probe(struct i2c_client *client) } /* - * Perform a one-byte test read to verify that the - * chip is functional. + * Perform a one-byte test read to verify that the chip is functional, + * unless powering on the device is to be avoided during probe (i.e. + * it's powered off right now). */ - err = at24_read(at24, 0, &test_byte, 1); - if (err) { - pm_runtime_disable(dev); - regulator_disable(at24->vcc_reg); - return -ENODEV; + if (!off_during_probe) { + err = at24_read(at24, 0, &test_byte, 1); + if (err) { + pm_runtime_disable(dev); + regulator_disable(at24->vcc_reg); + return -ENODEV; + } } pm_runtime_idle(dev); @@ -795,9 +801,11 @@ static int at24_remove(struct i2c_client *client) struct at24_data *at24 = i2c_get_clientdata(client); pm_runtime_disable(&client->dev); - if (!pm_runtime_status_suspended(&client->dev)) - regulator_disable(at24->vcc_reg); - pm_runtime_set_suspended(&client->dev); + if (!acpi_dev_state_low_power(&client->dev)) { + if (!pm_runtime_status_suspended(&client->dev)) + regulator_disable(at24->vcc_reg); + pm_runtime_set_suspended(&client->dev); + } return 0; } @@ -834,6 +842,7 @@ static struct i2c_driver at24_driver = { .probe_new = at24_probe, .remove = at24_remove, .id_table = at24_ids, + .flags = I2C_DRV_FL_ALLOW_LOW_POWER_PROBE, }; static int __init at24_init(void)