From patchwork Fri Jan 22 15:57:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Ardelean X-Patchwork-Id: 12040089 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 4DAC3C433E9 for ; Fri, 22 Jan 2021 17:31:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DEDB23A79 for ; Fri, 22 Jan 2021 17:31:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729584AbhAVR2S (ORCPT ); Fri, 22 Jan 2021 12:28:18 -0500 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:15408 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729107AbhAVP4U (ORCPT ); Fri, 22 Jan 2021 10:56:20 -0500 Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 10MFV0ma019193; Fri, 22 Jan 2021 10:55:24 -0500 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com with ESMTP id 3668rbtjpv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 22 Jan 2021 10:55:24 -0500 Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 10MFtNK8002553 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 22 Jan 2021 10:55:23 -0500 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.721.2; Fri, 22 Jan 2021 10:55:22 -0500 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.721.2 via Frontend Transport; Fri, 22 Jan 2021 10:55:22 -0500 Received: from localhost.localdomain ([10.48.65.12]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 10MFtF56014933; Fri, 22 Jan 2021 10:55:20 -0500 From: Alexandru Ardelean To: , CC: , , , , , Alexandru Ardelean Subject: [PATCH v2 03/12] iio: buffer: rework buffer & scan_elements dir creation Date: Fri, 22 Jan 2021 17:57:56 +0200 Message-ID: <20210122155805.83012-4-alexandru.ardelean@analog.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210122155805.83012-1-alexandru.ardelean@analog.com> References: <20210122155805.83012-1-alexandru.ardelean@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343,18.0.737 definitions=2021-01-22_11:2021-01-22,2021-01-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 phishscore=0 malwarescore=0 impostorscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 adultscore=0 mlxlogscore=758 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101220087 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org When adding more than one IIO buffer per IIO device, we will need to create a buffer & scan_elements directory for each buffer. We also want to move the 'scan_elements' to be a sub-directory of the 'buffer' folder. The format we want to reach is, for a iio:device0 folder, for 2 buffers [for example], we have a 'buffer0' and a 'buffer1' subfolder, and each with it's own 'scan_elements' subfolder. So, for example: iio:device0/buffer0 scan_elements/ iio:device0/buffer1 scan_elements/ The other attributes under 'bufferX' would remain unchanged. However, we would also need to symlink back to the old 'buffer' & 'scan_elements' folders, to keep backwards compatibility. Doing all these, require that we maintain the kobjects for each 'bufferX' and 'scan_elements' so that we can symlink them back. We also need to implement the sysfs_ops for these folders. Signed-off-by: Alexandru Ardelean --- drivers/iio/industrialio-buffer.c | 195 +++++++++++++++++++++++++++--- drivers/iio/industrialio-core.c | 24 ++-- include/linux/iio/buffer_impl.h | 14 ++- include/linux/iio/iio.h | 2 +- 4 files changed, 200 insertions(+), 35 deletions(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 0412c4fda4c1..0f470d902790 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1175,8 +1175,6 @@ static ssize_t iio_buffer_store_enable(struct device *dev, return (ret < 0) ? ret : len; } -static const char * const iio_scan_elements_group_name = "scan_elements"; - static ssize_t iio_buffer_show_watermark(struct device *dev, struct device_attribute *attr, char *buf) @@ -1252,6 +1250,124 @@ static struct attribute *iio_buffer_attrs[] = { &dev_attr_data_available.attr, }; +#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) + +static ssize_t iio_buffer_dir_attr_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, buffer_dir); + struct device_attribute *dattr; + + dattr = to_dev_attr(attr); + + return dattr->show(&buffer->indio_dev->dev, dattr, buf); +} + +static ssize_t iio_buffer_dir_attr_store(struct kobject *kobj, + struct attribute *attr, + const char *buf, + size_t len) +{ + struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, buffer_dir); + struct device_attribute *dattr; + + dattr = to_dev_attr(attr); + + return dattr->store(&buffer->indio_dev->dev, dattr, buf, len); +} + +static const struct sysfs_ops iio_buffer_dir_sysfs_ops = { + .show = iio_buffer_dir_attr_show, + .store = iio_buffer_dir_attr_store, +}; + +static struct kobj_type iio_buffer_dir_ktype = { + .sysfs_ops = &iio_buffer_dir_sysfs_ops, +}; + +static ssize_t iio_scan_el_dir_attr_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, scan_el_dir); + struct device_attribute *dattr = to_dev_attr(attr); + + return dattr->show(&buffer->indio_dev->dev, dattr, buf); +} + +static ssize_t iio_scan_el_dir_attr_store(struct kobject *kobj, + struct attribute *attr, + const char *buf, + size_t len) +{ + struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, scan_el_dir); + struct device_attribute *dattr = to_dev_attr(attr); + + return dattr->store(&buffer->indio_dev->dev, dattr, buf, len); +} + +static const struct sysfs_ops iio_scan_el_dir_sysfs_ops = { + .show = iio_scan_el_dir_attr_show, + .store = iio_scan_el_dir_attr_store, +}; + +static struct kobj_type iio_scan_el_dir_ktype = { + .sysfs_ops = &iio_scan_el_dir_sysfs_ops, +}; + +/* + * These iio_sysfs_{add,del}_attrs() are essentially re-implementations of + * sysfs_create_files() & sysfs_remove_files(), but they are meant to get + * around the const-pointer mismatch situation with using them. + * + * sysfs_{create,remove}_files() uses 'const struct attribute * const *ptr', + * while these are happy with just 'struct attribute **ptr' + */ +static int iio_sysfs_add_attrs(struct kobject *kobj, struct attribute **ptr) +{ + int err = 0; + int i; + + for (i = 0; ptr[i] && !err; i++) + err = sysfs_create_file(kobj, ptr[i]); + if (err) + while (--i >= 0) + sysfs_remove_file(kobj, ptr[i]); + return err; +} + +static void iio_sysfs_del_attrs(struct kobject *kobj, struct attribute **ptr) +{ + int i; + + for (i = 0; ptr[i]; i++) + sysfs_remove_file(kobj, ptr[i]); +} + +/** + * __iio_buffer_alloc_sysfs_and_mask() - Allocate sysfs attributes to an attached buffer + * @buffer: the buffer object for which the sysfs attributes are created for + * @indio_dev: the iio device to which the iio buffer belongs to + * + * Return 0, or negative for error. + * + * This function must be called for each single buffer. The sysfs attributes for that + * buffer will be created, and the IIO device object will be the parent kobject of that + * the kobjects created here. + * Because we need to redirect sysfs attribute to it's IIO buffer object, we need to + * implement our own sysfs_ops, and each IIO buffer will keep a kobject for the + * 'bufferX' directory and one for the 'scan_elements' directory. + * And in order to do this, this function must be called after the IIO device object + * has been added via device_add(). This fundamentally changes how sysfs attributes + * were created before (with one single IIO buffer per IIO device), where the + * sysfs attributes for the buffer were mapped as attribute groups on the IIO device + * groups object list. + * Using kobjects directly for the 'bufferX' and 'scan_elements' directories allows + * us to symlink them back to keep backwards compatibility for the old sysfs interface + * for IIO buffers while also allowing us to support multiple IIO buffers per one + * IIO device. + */ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, struct iio_dev *indio_dev) { @@ -1282,12 +1398,16 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, sizeof(struct attribute *) * attrcount); - attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL; + buffer->buffer_attrs = attr; - buffer->buffer_group.name = "buffer"; - buffer->buffer_group.attrs = attr; + ret = kobject_init_and_add(&buffer->buffer_dir, &iio_buffer_dir_ktype, + &indio_dev->dev.kobj, "buffer"); + if (ret) + goto error_buffer_free_attrs; - indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group; + ret = iio_sysfs_add_attrs(&buffer->buffer_dir, buffer->buffer_attrs); + if (ret) + goto error_buffer_kobject_put; attrcount = 0; INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); @@ -1317,32 +1437,57 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, } } - buffer->scan_el_group.name = iio_scan_elements_group_name; - - buffer->scan_el_group.attrs = kcalloc(attrcount + 1, - sizeof(buffer->scan_el_group.attrs[0]), - GFP_KERNEL); - if (buffer->scan_el_group.attrs == NULL) { + buffer->scan_el_attrs = kcalloc(attrcount + 1, + sizeof(buffer->scan_el_attrs[0]), + GFP_KERNEL); + if (buffer->scan_el_attrs == NULL) { ret = -ENOMEM; goto error_free_scan_mask; } - attrn = 0; + ret = kobject_init_and_add(&buffer->scan_el_dir, &iio_scan_el_dir_ktype, + &indio_dev->dev.kobj, "scan_elements"); + if (ret) + goto error_free_scan_attrs; + + attrn = 0; list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l) - buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr; - indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group; + buffer->scan_el_attrs[attrn++] = &p->dev_attr.attr; + + ret = iio_sysfs_add_attrs(&buffer->scan_el_dir, buffer->scan_el_attrs); + if (ret) + goto error_scan_kobject_put; return 0; +error_scan_kobject_put: + kobject_put(&buffer->scan_el_dir); +error_free_scan_attrs: + kfree(buffer->scan_el_attrs); error_free_scan_mask: bitmap_free(buffer->scan_mask); error_cleanup_dynamic: + iio_sysfs_del_attrs(&buffer->buffer_dir, buffer->buffer_attrs); iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); - kfree(buffer->buffer_group.attrs); +error_buffer_kobject_put: + kobject_put(&buffer->buffer_dir); +error_buffer_free_attrs: + kfree(buffer->buffer_attrs); return ret; } +/** + * iio_buffer_alloc_sysfs_and_mask() - Allocate sysfs attributes to attached buffers + * @indio_dev: the iio device for which to create the buffer sysfs attributes + * + * Return 0, or negative for error. + * + * If the IIO device has no buffer attached, no sysfs attributes will be created. + * This function must be called after the IIO device object has been created and + * registered with device_add(). See __iio_buffer_alloc_sysfs_and_mask() for more + * details. + */ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) { struct iio_buffer *buffer = indio_dev->buffer; @@ -1364,14 +1509,28 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev); } +/** + * __iio_buffer_free_sysfs_and_mask() - Free sysfs objects for a single IIO buffer + * @buffer: the iio buffer for which to destroy the objects + */ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) { + iio_sysfs_del_attrs(&buffer->scan_el_dir, buffer->scan_el_attrs); + kobject_put(&buffer->scan_el_dir); + kfree(buffer->scan_el_attrs); bitmap_free(buffer->scan_mask); - kfree(buffer->buffer_group.attrs); - kfree(buffer->scan_el_group.attrs); + iio_sysfs_del_attrs(&buffer->buffer_dir, buffer->buffer_attrs); iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); + kobject_put(&buffer->buffer_dir); + kfree(buffer->buffer_attrs); } +/** + * iio_buffer_free_sysfs_and_mask() - Free sysfs objects for all IIO buffers + * @indio_dev: the iio device for which to destroy the objects + * + * If the IIO device has no buffer attached, nothing will be done. + */ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) { struct iio_buffer *buffer = indio_dev->buffer; diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 0a6fd299a978..95d66745f118 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1817,18 +1817,11 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) iio_device_register_debugfs(indio_dev); - ret = iio_buffer_alloc_sysfs_and_mask(indio_dev); - if (ret) { - dev_err(indio_dev->dev.parent, - "Failed to create buffer sysfs interfaces\n"); - goto error_unreg_debugfs; - } - ret = iio_device_register_sysfs(indio_dev); if (ret) { dev_err(indio_dev->dev.parent, "Failed to register sysfs interfaces\n"); - goto error_buffer_free_sysfs; + goto error_unreg_debugfs; } ret = iio_device_register_eventset(indio_dev); if (ret) { @@ -1857,14 +1850,21 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) if (ret < 0) goto error_unreg_eventset; + ret = iio_buffer_alloc_sysfs_and_mask(indio_dev); + if (ret) { + dev_err(indio_dev->dev.parent, + "Failed to create buffer sysfs interfaces\n"); + goto error_device_del; + } + return 0; +error_device_del: + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); error_unreg_eventset: iio_device_unregister_eventset(indio_dev); error_free_sysfs: iio_device_unregister_sysfs(indio_dev); -error_buffer_free_sysfs: - iio_buffer_free_sysfs_and_mask(indio_dev); error_unreg_debugfs: iio_device_unregister_debugfs(indio_dev); return ret; @@ -1880,6 +1880,8 @@ void iio_device_unregister(struct iio_dev *indio_dev) struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_ioctl_handler *h, *t; + iio_buffer_free_sysfs_and_mask(indio_dev); + cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); mutex_lock(&indio_dev->info_exist_lock); @@ -1897,8 +1899,6 @@ void iio_device_unregister(struct iio_dev *indio_dev) iio_buffer_wakeup_poll(indio_dev); mutex_unlock(&indio_dev->info_exist_lock); - - iio_buffer_free_sysfs_and_mask(indio_dev); } EXPORT_SYMBOL(iio_device_unregister); diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index 67d73d465e02..77e169e51434 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -103,14 +103,20 @@ struct iio_buffer { /* @scan_el_dev_attr_list: List of scan element related attributes. */ struct list_head scan_el_dev_attr_list; - /* @buffer_group: Attributes of the buffer group. */ - struct attribute_group buffer_group; + /* @buffer_dir: kobject for the 'buffer' directory of this buffer */ + struct kobject buffer_dir; + + /* @buffer_attrs: Attributes of the buffer group. */ + struct attribute **buffer_attrs; + + /* @scan_el_dir: kobject for the 'scan_elements' directory of this buffer */ + struct kobject scan_el_dir; /* - * @scan_el_group: Attribute group for those attributes not + * @scan_el_attrs: Array of attributes for those attributes not * created from the iio_chan_info array. */ - struct attribute_group scan_el_group; + struct attribute **scan_el_attrs; /* @attrs: Standard attributes of the buffer. */ const struct attribute **attrs; diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index e4a9822e6495..59b317dc45b8 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -556,7 +556,7 @@ struct iio_dev { struct mutex info_exist_lock; const struct iio_buffer_setup_ops *setup_ops; struct cdev chrdev; -#define IIO_MAX_GROUPS 6 +#define IIO_MAX_GROUPS 4 const struct attribute_group *groups[IIO_MAX_GROUPS + 1]; int groupcounter;