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)