From patchwork Mon Aug 10 14:27:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707513 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 16498618 for ; Mon, 10 Aug 2020 14:25:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0812B2070B for ; Mon, 10 Aug 2020 14:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727778AbgHJOZf (ORCPT ); Mon, 10 Aug 2020 10:25:35 -0400 Received: from mga01.intel.com ([192.55.52.88]:45121 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727017AbgHJOYt (ORCPT ); Mon, 10 Aug 2020 10:24:49 -0400 IronPort-SDR: fmnMgSU1eGDFHffPoQ8Z7ySs3KSf39qQZE/m70MMsTU5K9/NL9biIjEhO8JmLovc0cfU/j/bdl pFNqzRQ6XLHA== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="171579268" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="171579268" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:48 -0700 IronPort-SDR: YPl2fZSOAy/e24cOsyis2lgV58Q+EebSHq2FtPjmpDgwqTwRi6JPwKGv1w2wD8V5dxRmZwRLD+ gLTO5k8u7hoQ== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="494329333" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:44 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 9EABA2056B; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003Er-5a; Mon, 10 Aug 2020 17:27:48 +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 v5 1/6] i2c: Allow driver to manage the device's power state during probe Date: Mon, 10 Aug 2020 17:27:42 +0300 Message-Id: <20200810142747.12400-2-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org 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 --- drivers/i2c/i2c-core-base.c | 17 ++++++++++++++--- include/linux/i2c.h | 14 ++++++++++++++ 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 34a9609f256da..cde9cf49a07e6 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -436,6 +436,14 @@ static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) return irq > 0 ? irq : -ENXIO; } +static bool allow_low_power_probe(struct device *dev) +{ + struct i2c_driver *driver = to_i2c_driver(dev->driver); + + return driver->flags & I2C_DRV_FL_ALLOW_LOW_POWER_PROBE && + device_property_present(dev, "allow-low-power-probe"); +} + static int i2c_device_probe(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); @@ -514,7 +522,8 @@ 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, + !allow_low_power_probe(&client->dev)); if (status) goto err_clear_wakeup_irq; @@ -536,7 +545,8 @@ 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, + !allow_low_power_probe(&client->dev)); err_clear_wakeup_irq: dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); @@ -562,7 +572,8 @@ static int i2c_device_remove(struct device *dev) status = driver->remove(client); } - dev_pm_domain_detach(&client->dev, true); + dev_pm_domain_detach(&client->dev, + !allow_low_power_probe(&client->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 fc55ea41d3237..6824719c24ebe 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 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; + + unsigned int flags; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) From patchwork Mon Aug 10 14:27:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707511 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B3DDF913 for ; Mon, 10 Aug 2020 14:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A2DA2076B for ; Mon, 10 Aug 2020 14:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727027AbgHJOYt (ORCPT ); Mon, 10 Aug 2020 10:24:49 -0400 Received: from mga03.intel.com ([134.134.136.65]:56256 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726894AbgHJOYs (ORCPT ); Mon, 10 Aug 2020 10:24:48 -0400 IronPort-SDR: Q6qhjOhwX5w3g9Js3r/Kzd5OinMCB92ibjBfPAf7cUVPRjTHORfqVr91rbN6tjV+u3ptamZ5jG WVLDbuLtS+TA== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="153507698" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="153507698" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:47 -0700 IronPort-SDR: fPzusWNHyWNEmQYBc8qacLEKeHJ3SdFpLaooHQVPjcP9POizRzPhmeoroT5+BHdY9rKTcC44tt OeyladIgWf5Q== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="294400874" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:43 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id A4D4C20728; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003Eu-6y; Mon, 10 Aug 2020 17:27:48 +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 v5 2/6] ACPI: Add a convenience function to tell a device is in low power state Date: Mon, 10 Aug 2020 17:27:43 +0300 Message-Id: <20200810142747.12400-3-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@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) From patchwork Mon Aug 10 14:27:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707523 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C49A0913 for ; Mon, 10 Aug 2020 14:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B25FA2078D for ; Mon, 10 Aug 2020 14:25:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726963AbgHJOYs (ORCPT ); Mon, 10 Aug 2020 10:24:48 -0400 Received: from mga04.intel.com ([192.55.52.120]:28442 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726910AbgHJOYs (ORCPT ); Mon, 10 Aug 2020 10:24:48 -0400 IronPort-SDR: sB39yN+BVDu2PoWjFb+GvvuwE1xCzGOF9zhlrYpHtajDLw82dcwzNdyBRKMi1WHilBONsBlZaQ ft10DzkhgKjw== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="150973817" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="150973817" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:46 -0700 IronPort-SDR: 6faF++bStC7CbW7JmF76TSaiiQB8K0ag+qY7CtjTExBsoF8Z8QYg8tL18A5c35oN0yfmKcaQeX o5OJad2qHQyQ== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="308086172" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:43 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id ACC8F209D1; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003Ex-88; Mon, 10 Aug 2020 17:27:48 +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 v5 3/6] ov5670: Support probe whilst the device is in a low power state Date: Mon, 10 Aug 2020 17:27:44 +0300 Message-Id: <20200810142747.12400-4-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org 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. Signed-off-by: Sakari Ailus --- drivers/media/i2c/ov5670.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c index f26252e35e08d..1f75b888d2a18 100644 --- a/drivers/media/i2c/ov5670.c +++ b/drivers/media/i2c/ov5670.c @@ -2456,6 +2456,7 @@ 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); @@ -2472,11 +2473,14 @@ 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); @@ -2513,10 +2517,10 @@ 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); @@ -2558,7 +2562,7 @@ static const struct dev_pm_ops ov5670_pm_ops = { #ifdef CONFIG_ACPI static const struct acpi_device_id ov5670_acpi_ids[] = { - {"INT3479"}, + { "INT3479" }, { /* sentinel */ } }; @@ -2573,6 +2577,7 @@ 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 Mon Aug 10 14:27:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707499 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C89F0618 for ; Mon, 10 Aug 2020 14:24:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B17D6207DA for ; Mon, 10 Aug 2020 14:24:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbgHJOYt (ORCPT ); Mon, 10 Aug 2020 10:24:49 -0400 Received: from mga05.intel.com ([192.55.52.43]:5304 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726897AbgHJOYs (ORCPT ); Mon, 10 Aug 2020 10:24:48 -0400 IronPort-SDR: W6DyI0fS2XxlYkJaglwXzF7uqVXGVze2ajKL6b8rklgjoaAlORi+dxr6jEgAkpZVSAK5gcdMNk UYl6+JFqcQcw== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="238371926" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="238371926" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:46 -0700 IronPort-SDR: 52m5sVXupHSldNjkls906YBK8xA0kbrQeZ5AX59IHpMo+rS4hYsYQRa2rKzREw1s9Lushq1iYD pAD0Y7os7POQ== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="277292106" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:43 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id B48DF20AC3; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003F0-9I; Mon, 10 Aug 2020 17:27:48 +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 v5 4/6] media: i2c: imx319: Support probe while the device is off Date: Mon, 10 Aug 2020 17:27:45 +0300 Message-Id: <20200810142747.12400-5-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Rajmohan Mani Tell ACPI device PM code that the driver supports the device being powered off when the driver's probe function is entered. Signed-off-by: Rajmohan Mani Signed-off-by: Sakari Ailus --- drivers/media/i2c/imx319.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c index 17c2e4b41221e..dc5ebff6a85a3 100644 --- a/drivers/media/i2c/imx319.c +++ b/drivers/media/i2c/imx319.c @@ -2424,6 +2424,7 @@ static struct imx319_hwcfg *imx319_get_hwcfg(struct device *dev) static int imx319_probe(struct i2c_client *client) { struct imx319 *imx319; + bool low_power; int ret; u32 i; @@ -2436,11 +2437,14 @@ static int imx319_probe(struct i2c_client *client) /* Initialize subdev */ v4l2_i2c_subdev_init(&imx319->sd, client, &imx319_subdev_ops); - /* Check module identity */ - ret = imx319_identify_module(imx319); - if (ret) { - dev_err(&client->dev, "failed to find sensor: %d", ret); - goto error_probe; + low_power = acpi_dev_state_low_power(&client->dev); + if (!low_power) { + /* Check module identity */ + ret = imx319_identify_module(imx319); + if (ret) { + dev_err(&client->dev, "failed to find sensor: %d", ret); + goto error_probe; + } } imx319->hwcfg = imx319_get_hwcfg(&client->dev); @@ -2493,10 +2497,10 @@ static int imx319_probe(struct i2c_client *client) goto error_media_entity; /* - * 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); @@ -2536,7 +2540,7 @@ static const struct dev_pm_ops imx319_pm_ops = { }; static const struct acpi_device_id imx319_acpi_ids[] = { - { "SONY319A" }, + { "SONY319A", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(acpi, imx319_acpi_ids); @@ -2549,6 +2553,7 @@ static struct i2c_driver imx319_i2c_driver = { }, .probe_new = imx319_probe, .remove = imx319_remove, + .flags = I2C_DRV_FL_ALLOW_LOW_POWER_PROBE, }; module_i2c_driver(imx319_i2c_driver); From patchwork Mon Aug 10 14:27:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707507 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DA5D0618 for ; Mon, 10 Aug 2020 14:25:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C55822078E for ; Mon, 10 Aug 2020 14:25:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727108AbgHJOZX (ORCPT ); Mon, 10 Aug 2020 10:25:23 -0400 Received: from mga03.intel.com ([134.134.136.65]:56256 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727044AbgHJOYw (ORCPT ); Mon, 10 Aug 2020 10:24:52 -0400 IronPort-SDR: rpYu62zuQPYzHm/5gR14LAIr0MV/9pwXFr2Mh5BSz9FhLHo5PwjvVW9+UTbenJm/XjlUUhSfBV mKX3Lxiid+8Q== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="153507716" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="153507716" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:52 -0700 IronPort-SDR: x/YOt9P9ugGVaDpvEZRLNPB2ntcRgY0meK8NTZAuwGdrYvtVS4HqkLkhqM2g8H7C6Mj5gQV0mg oo0Vf7yEldAw== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="324454005" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:48 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id BF0CE20BAE; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003F3-Ad; Mon, 10 Aug 2020 17:27:48 +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 v5 5/6] at24: Support probing while off Date: Mon, 10 Aug 2020 17:27:46 +0300 Message-Id: <20200810142747.12400-6-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org 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 --- drivers/misc/eeprom/at24.c | 40 ++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 2591c21b2b5d8..e597a8861e817 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -561,6 +561,7 @@ 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 low_power; struct regmap *regmap; bool writable; u8 test_byte; @@ -698,25 +699,30 @@ 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; - } + low_power = acpi_dev_state_low_power(&client->dev); + if (!low_power) { + 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); /* - * 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 (!low_power) { + 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); @@ -734,11 +740,14 @@ static int at24_probe(struct i2c_client *client) static int at24_remove(struct i2c_client *client) { struct at24_data *at24 = i2c_get_clientdata(client); + bool low_power; pm_runtime_disable(&client->dev); if (!pm_runtime_status_suspended(&client->dev)) regulator_disable(at24->vcc_reg); - pm_runtime_set_suspended(&client->dev); + low_power = acpi_dev_state_low_power(&client->dev); + if (!low_power) + pm_runtime_set_suspended(&client->dev); return 0; } @@ -775,6 +784,7 @@ 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) From patchwork Mon Aug 10 14:27:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11707503 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 64C72618 for ; Mon, 10 Aug 2020 14:24:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54D382070B for ; Mon, 10 Aug 2020 14:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbgHJOY4 (ORCPT ); Mon, 10 Aug 2020 10:24:56 -0400 Received: from mga18.intel.com ([134.134.136.126]:26240 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727061AbgHJOYy (ORCPT ); Mon, 10 Aug 2020 10:24:54 -0400 IronPort-SDR: qNzIV5FkwiWh+2U9XevxgSWdLP6YZABwDHEN3kBcQWu3dZ5erAooH2CPBtfMElTI2d09phIRC9 fL0d+RyY4wWQ== X-IronPort-AV: E=McAfee;i="6000,8403,9708"; a="141147154" X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="141147154" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:53 -0700 IronPort-SDR: Cbfr4X4RiO57NQGiwjxsRxZOEYXtBlVUul/a9/rIV2xjPCkEFWfkezRP9cFsrssD2MtUuN/m2C 21rbVghlHELg== X-IronPort-AV: E=Sophos;i="5.75,457,1589266800"; d="scan'208";a="438711300" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 07:24:49 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id C9A4720BC0; Mon, 10 Aug 2020 17:24:41 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1k58mC-0003F6-Bp; Mon, 10 Aug 2020 17:27:48 +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 v5 6/6] Documentation: ACPI: Document allow-low-power-probe _DSD property Date: Mon, 10 Aug 2020 17:27:47 +0300 Message-Id: <20200810142747.12400-7-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200810142747.12400-1-sakari.ailus@linux.intel.com> References: <20200810142747.12400-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Document the probe-low-power _DSD property and how it is used with I²C drivers. Signed-off-by: Sakari Ailus --- .../acpi/dsd/allow-low-power-probe.rst | 28 +++++++++++++++++++ Documentation/firmware-guide/acpi/index.rst | 1 + 2 files changed, 29 insertions(+) create mode 100644 Documentation/firmware-guide/acpi/dsd/allow-low-power-probe.rst diff --git a/Documentation/firmware-guide/acpi/dsd/allow-low-power-probe.rst b/Documentation/firmware-guide/acpi/dsd/allow-low-power-probe.rst new file mode 100644 index 0000000000000..6fcc89162b898 --- /dev/null +++ b/Documentation/firmware-guide/acpi/dsd/allow-low-power-probe.rst @@ -0,0 +1,28 @@ +.. 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. Linux recognizes the _DSD property +"allow-low-power-probe" that can be used for this purpose. + +How it works +============ + +The property "allow-low-power-probe" boolean property may be used to tell Linux +that the I²C framework should instruct the kernel ACPI framework to leave the +device in the low power state. 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 "allow-low-power-probe" property is present, the device will not +be powered on for probe. + +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. diff --git a/Documentation/firmware-guide/acpi/index.rst b/Documentation/firmware-guide/acpi/index.rst index ad3b5afdae77e..0070fcde9e669 100644 --- a/Documentation/firmware-guide/acpi/index.rst +++ b/Documentation/firmware-guide/acpi/index.rst @@ -11,6 +11,7 @@ ACPI Support dsd/graph dsd/data-node-references dsd/leds + dsd/allow-low-power-probe enumeration osi method-customizing