From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 24C26C5518A for ; Fri, 24 Apr 2020 04:56:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 084AC2076C for ; Fri, 24 Apr 2020 04:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726520AbgDXE4p (ORCPT ); Fri, 24 Apr 2020 00:56:45 -0400 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:38804 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726298AbgDXE4l (ORCPT ); Fri, 24 Apr 2020 00:56:41 -0400 Received: from pps.filterd (m0167088.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03O4o4ds030564; Fri, 24 Apr 2020 00:56:27 -0400 Received: from nwd2mta3.analog.com ([137.71.173.56]) by mx0a-00128a01.pphosted.com with ESMTP id 30fud7n63y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Apr 2020 00:56:27 -0400 Received: from ASHBMBX9.ad.analog.com (ashbmbx9.ad.analog.com [10.64.17.10]) by nwd2mta3.analog.com (8.14.7/8.14.7) with ESMTP id 03O4uQ89016518 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=FAIL); Fri, 24 Apr 2020 00:56:26 -0400 Received: from ASHBCASHYB5.ad.analog.com (10.64.17.133) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Fri, 24 Apr 2020 00:56:25 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBCASHYB5.ad.analog.com (10.64.17.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Fri, 24 Apr 2020 00:56:25 -0400 Received: from zeus.spd.analog.com (10.64.82.11) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.1.1779.2 via Frontend Transport; Fri, 24 Apr 2020 00:56:24 -0400 Received: from localhost.localdomain ([10.48.65.12]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 03O4uGpn017534; Fri, 24 Apr 2020 00:56:23 -0400 From: Alexandru Ardelean To: , CC: , , , "Alexandru Ardelean" Subject: [PATCH v4 4/7] iio: core: register chardev only if needed Date: Fri, 24 Apr 2020 07:56:39 +0300 Message-ID: <20200424045642.4903-5-alexandru.ardelean@analog.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200424045642.4903-1-alexandru.ardelean@analog.com> References: <20200424045642.4903-1-alexandru.ardelean@analog.com> MIME-Version: 1.0 Content-Type: text/plain X-ADIRoutedOnPrem: True X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-24_01:2020-04-23,2020-04-24 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 mlxlogscore=999 priorityscore=1501 clxscore=1015 impostorscore=0 suspectscore=0 phishscore=0 mlxscore=0 lowpriorityscore=0 bulkscore=0 adultscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004240035 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The final intent is to localize all buffer ops into the industrialio-buffer.c file, to be able to add support for multiple buffers per IIO device. We only need a chardev if we need to support buffers and/or events. With this change, a chardev will be created only if an IIO buffer is attached OR an event_interface is configured. Otherwise, no chardev will be created, and the IIO device will get registered with the 'device_add()' call. Quite a lot of IIO devices don't really need a chardev, so this is a minor improvement to the IIO core, as the IIO device will take up (slightly) fewer resources. Signed-off-by: Alexandru Ardelean --- drivers/iio/industrialio-core.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index bac865ff673e..03f5b5baeb94 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1676,6 +1676,15 @@ static int iio_check_unique_scan_index(struct iio_dev *indio_dev) static const struct iio_buffer_setup_ops noop_ring_setup_ops; +static const struct file_operations iio_event_fileops = { + .release = iio_chrdev_release, + .open = iio_chrdev_open, + .owner = THIS_MODULE, + .llseek = noop_llseek, + .unlocked_ioctl = iio_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) { int ret; @@ -1726,11 +1735,18 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) indio_dev->setup_ops == NULL) indio_dev->setup_ops = &noop_ring_setup_ops; - cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); + if (indio_dev->buffer) + cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); + else if (indio_dev->event_interface) + cdev_init(&indio_dev->chrdev, &iio_event_fileops); indio_dev->chrdev.owner = this_mod; - ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); + if (indio_dev->buffer || indio_dev->event_interface) + ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); + else + ret = device_add(&indio_dev->dev); + if (ret < 0) goto error_unreg_eventset; @@ -1754,7 +1770,10 @@ EXPORT_SYMBOL(__iio_device_register); **/ void iio_device_unregister(struct iio_dev *indio_dev) { - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); + if (indio_dev->buffer || indio_dev->event_interface) + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); + else + device_del(&indio_dev->dev); mutex_lock(&indio_dev->info_exist_lock); -- 2.17.1