From patchwork Tue Jan 21 13:41:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 1226556 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4828pd2gz3z9sRG for ; Wed, 22 Jan 2020 00:42:01 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729162AbgAUNlv (ORCPT ); Tue, 21 Jan 2020 08:41:51 -0500 Received: from mga17.intel.com ([192.55.52.151]:4186 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729140AbgAUNlt (ORCPT ); Tue, 21 Jan 2020 08:41:49 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jan 2020 05:41:49 -0800 X-IronPort-AV: E=Sophos;i="5.70,346,1574150400"; d="scan'208";a="399667390" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jan 2020 05:41:45 -0800 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 6AE5F20AF3; Tue, 21 Jan 2020 15:41:39 +0200 (EET) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1ittn3-0005K2-Tk; Tue, 21 Jan 2020 15:41:57 +0200 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 Subject: [PATCH v4 5/6] at24: Support probing while off Date: Tue, 21 Jan 2020 15:41:56 +0200 Message-Id: <20200121134157.20396-6-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200121134157.20396-1-sakari.ailus@linux.intel.com> References: <20200121134157.20396-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@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 | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 0681d5fdd538a..5fc1162b67618 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -564,6 +564,7 @@ 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; @@ -701,19 +702,24 @@ static int at24_probe(struct i2c_client *client) i2c_set_clientdata(client, at24); - /* enable runtime pm */ - pm_runtime_set_active(dev); + low_power = acpi_dev_state_low_power(&client->dev); + if (!low_power) + 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); - pm_runtime_idle(dev); - if (err) { - pm_runtime_disable(dev); - return -ENODEV; + if (!low_power) { + err = at24_read(at24, 0, &test_byte, 1); + pm_runtime_idle(dev); + if (err) { + pm_runtime_disable(dev); + return -ENODEV; + } } if (writable) @@ -728,8 +734,12 @@ static int at24_probe(struct i2c_client *client) static int at24_remove(struct i2c_client *client) { + bool low_power; + pm_runtime_disable(&client->dev); - 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; } @@ -743,6 +753,7 @@ static struct i2c_driver at24_driver = { .probe_new = at24_probe, .remove = at24_remove, .id_table = at24_ids, + .probe_low_power = true, }; static int __init at24_init(void)