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: 256211 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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 04B8FC433E0 for ; Mon, 10 Aug 2020 14:25:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4A8D2070B 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)