From patchwork Tue Sep 1 21:03:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749497 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 B007B109B for ; Tue, 1 Sep 2020 21:04:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E0C7208CA for ; Tue, 1 Sep 2020 21:04:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728597AbgIAVDg (ORCPT ); Tue, 1 Sep 2020 17:03:36 -0400 Received: from mga17.intel.com ([192.55.52.151]:33538 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727788AbgIAVDb (ORCPT ); Tue, 1 Sep 2020 17:03:31 -0400 IronPort-SDR: OyCpsOA8RbAtMmfUBtqEtmxtavtewVM4aDBoXC31T/9tkDUI3ay5oscbH4qCH6ZSuqxmAHeEMd +5jMM/7sPrxg== X-IronPort-AV: E=McAfee;i="6000,8403,9731"; a="137318127" X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="137318127" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:30 -0700 IronPort-SDR: GZpsDaftDbWT47dNxsqframCcitgW8UaL1G4CGS9SVlB3eV2H5ighxl4XVKjeIPLeLEA9lt8ga cXdgKkUnN2OA== X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="331197427" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:26 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 75BE1205F7; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002DL-Ab; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 1/6] i2c: Allow an ACPI driver to manage the device's power state during probe Date: Wed, 2 Sep 2020 00:03:28 +0300 Message-Id: <20200901210333.8462-2-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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 | 19 ++++++++++++++++--- include/linux/i2c.h | 14 ++++++++++++++ 2 files changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 34a9609f256da..da5f6d642bd76 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -436,6 +436,16 @@ 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 && + !acpi_dev_get_property(ACPI_COMPANION(dev), + "allow-low-power-probe", ACPI_TYPE_ANY, + NULL); +} + static int i2c_device_probe(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); @@ -514,7 +524,8 @@ 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 +547,8 @@ 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 +574,8 @@ 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..f8c3257a8bb25 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) From patchwork Tue Sep 1 21:03:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749501 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 B9780618 for ; Tue, 1 Sep 2020 21:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A66AC207D3 for ; Tue, 1 Sep 2020 21:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729095AbgIAVED (ORCPT ); Tue, 1 Sep 2020 17:04:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:20771 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728237AbgIAVDg (ORCPT ); Tue, 1 Sep 2020 17:03:36 -0400 IronPort-SDR: DRQZ3nzC2auRw4bi9+lQ/PTkVFwUD4zH7DO3Cn9H+PCH9h1SgKMys56APxDOG3CoM404+n2YRM D57QWsvwnfMA== X-IronPort-AV: E=McAfee;i="6000,8403,9731"; a="158268523" X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="158268523" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:29 -0700 IronPort-SDR: uZ3+1zzBrRusLUt/WYH4PBQalrYNbZEe1XagkRO/QpAUURsefRyznweaSgxvWVd4IxtASVtcS8 3Gwgss/diRMg== X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="314874352" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:26 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 7D9042269A; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002DO-Bx; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 2/6] ACPI: Add a convenience function to tell a device is in low power state Date: Wed, 2 Sep 2020 00:03:29 +0300 Message-Id: <20200901210333.8462-3-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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 Tue Sep 1 21:03:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749507 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 B7EC7109B for ; Tue, 1 Sep 2020 21:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D8F4207D3 for ; Tue, 1 Sep 2020 21:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729188AbgIAVEP (ORCPT ); Tue, 1 Sep 2020 17:04:15 -0400 Received: from mga01.intel.com ([192.55.52.88]:43615 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727927AbgIAVDd (ORCPT ); Tue, 1 Sep 2020 17:03:33 -0400 IronPort-SDR: 4VybYq7qwrbGHLHrQxy9tIVWCpGrKnzHvHe2dYUWK/LLF6hIEpQU6YkOEB414bR+I7IhT2PMyx ZFwTxqX83xlQ== X-IronPort-AV: E=McAfee;i="6000,8403,9731"; a="175317803" X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="175317803" 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; 01 Sep 2020 14:03:32 -0700 IronPort-SDR: ELaLDu3ELT71dl+CWOO/vukOarvEKPuJIVxFjlx1xbJCXoRPjrtUc1Mp8hfJsDarRHodJGWFLo La7mrwkGnEeg== X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="501886792" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:27 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 85C97226B7; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002DR-DA; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 3/6] ov5670: Support probe whilst the device is in a low power state Date: Wed, 2 Sep 2020 00:03:30 +0300 Message-Id: <20200901210333.8462-4-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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. Also do identification on the first access of the device, whether in probe or when starting streaming. Signed-off-by: Sakari Ailus --- 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 f26252e35e08d..74b0325c22565 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) @@ -2270,6 +2272,32 @@ 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) { @@ -2278,6 +2306,10 @@ 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); @@ -2401,27 +2433,6 @@ 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, }; @@ -2456,6 +2467,7 @@ 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 +2484,14 @@ 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 +2528,10 @@ 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 +2573,7 @@ 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 +2588,7 @@ 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 Tue Sep 1 21:03:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749505 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 06EE3109B for ; 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d="scan'208";a="297450122" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:26 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 9098022845; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002DU-Ec; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 4/6] media: i2c: imx319: Support probe while the device is off Date: Wed, 2 Sep 2020 00:03:31 +0300 Message-Id: <20200901210333.8462-5-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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 | 74 +++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 29 deletions(-) diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c index 17c2e4b41221e..6b63bb0abb138 100644 --- a/drivers/media/i2c/imx319.c +++ b/drivers/media/i2c/imx319.c @@ -140,6 +140,8 @@ struct imx319 { /* Streaming on/off */ bool streaming; + /* True if the device has been identified */ + bool identified; }; static const struct imx319_reg imx319_global_regs[] = { @@ -2084,6 +2086,31 @@ imx319_set_pad_format(struct v4l2_subdev *sd, return 0; } +/* Verify chip ID */ +static int imx319_identify_module(struct imx319 *imx319) +{ + struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); + int ret; + u32 val; + + if (imx319->identified) + return 0; + + ret = imx319_read_reg(imx319, IMX319_REG_CHIP_ID, 2, &val); + if (ret) + return ret; + + if (val != IMX319_CHIP_ID) { + dev_err(&client->dev, "chip id mismatch: %x!=%x", + IMX319_CHIP_ID, val); + return -EIO; + } + + imx319->identified = true; + + return 0; +} + /* Start streaming */ static int imx319_start_streaming(struct imx319 *imx319) { @@ -2091,6 +2118,10 @@ static int imx319_start_streaming(struct imx319 *imx319) const struct imx319_reg_list *reg_list; int ret; + ret = imx319_identify_module(imx319); + if (ret) + return ret; + /* Global Setting */ reg_list = &imx319_global_setting; ret = imx319_write_regs(imx319, reg_list->regs, reg_list->num_of_regs); @@ -2210,26 +2241,6 @@ static int __maybe_unused imx319_resume(struct device *dev) return ret; } -/* Verify chip ID */ -static int imx319_identify_module(struct imx319 *imx319) -{ - struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); - int ret; - u32 val; - - ret = imx319_read_reg(imx319, IMX319_REG_CHIP_ID, 2, &val); - if (ret) - return ret; - - if (val != IMX319_CHIP_ID) { - dev_err(&client->dev, "chip id mismatch: %x!=%x", - IMX319_CHIP_ID, val); - return -EIO; - } - - return 0; -} - static const struct v4l2_subdev_core_ops imx319_subdev_core_ops = { .subscribe_event = v4l2_ctrl_subdev_subscribe_event, .unsubscribe_event = v4l2_event_subdev_unsubscribe, @@ -2424,6 +2435,7 @@ 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 +2448,14 @@ 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 +2508,10 @@ 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 +2551,7 @@ 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 +2564,7 @@ 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 Tue Sep 1 21:03:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749491 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 94804618 for ; Tue, 1 Sep 2020 21:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86E4A208DB for ; Tue, 1 Sep 2020 21:03:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729064AbgIAVDu (ORCPT ); Tue, 1 Sep 2020 17:03:50 -0400 Received: from mga09.intel.com ([134.134.136.24]:20771 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727877AbgIAVDo (ORCPT ); Tue, 1 Sep 2020 17:03:44 -0400 IronPort-SDR: /ksGbEdlpP3JN4ounv2MaK6sK9XgdnRfSJf4dCgZsNcloAWLJV8efYtoB9A2FA707a7vBWCIzB DOL4Sq3u/ghA== X-IronPort-AV: E=McAfee;i="6000,8403,9731"; a="158268531" X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="158268531" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:36 -0700 IronPort-SDR: 764LiWsGV0/21jDQZo7DjZZRST2Xen6I/uGUqvg2RVQ1crH+LPERDgAi6l6uOxy00wVvJpIcFD 2W4Rh99vo5xw== X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="375289675" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:31 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 99ECE228DC; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002DX-Fy; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 5/6] at24: Support probing while off Date: Wed, 2 Sep 2020 00:03:32 +0300 Message-Id: <20200901210333.8462-6-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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 | 43 +++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 2591c21b2b5d8..a343e55e41126 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); @@ -736,9 +742,11 @@ 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; } @@ -775,6 +783,7 @@ 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 Tue Sep 1 21:03:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11749489 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 2F918618 for ; Tue, 1 Sep 2020 21:03:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22310208CA for ; Tue, 1 Sep 2020 21:03:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728799AbgIAVDh (ORCPT ); Tue, 1 Sep 2020 17:03:37 -0400 Received: from mga12.intel.com ([192.55.52.136]:23422 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728098AbgIAVDf (ORCPT ); Tue, 1 Sep 2020 17:03:35 -0400 IronPort-SDR: +Mr+6vVp5TJcvdxd+Pd3f/P+4f6nPYNghpaOWlLO115JuqYUs+Q5Z+8QnWapQEHZRPjVuPZK6H z8D2hMACKukw== X-IronPort-AV: E=McAfee;i="6000,8403,9731"; a="136786013" X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="136786013" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:35 -0700 IronPort-SDR: XEZWkK12m3NRurgxOZ0Ler6s1GjrNyuUSTV2HECMOdTxCR64tDMXiREISajPYuDtfexl3iBdJk Xnq+rSUltiSA== X-IronPort-AV: E=Sophos;i="5.76,380,1592895600"; d="scan'208";a="477343364" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2020 14:03:31 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id A383722AF1; Wed, 2 Sep 2020 00:03:24 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1kDDRF-0002Da-HG; Wed, 02 Sep 2020 00:03:33 +0300 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 v7 6/6] Documentation: ACPI: Document allow-low-power-probe _DSD property Date: Wed, 2 Sep 2020 00:03:33 +0300 Message-Id: <20200901210333.8462-7-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200901210333.8462-1-sakari.ailus@linux.intel.com> References: <20200901210333.8462-1-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