From 32f171724e5cbecc80594fb6eced057cfdd6eb6f Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Mon, 15 Feb 2021 12:40:29 +0200 Subject: [PATCH] iio: core: rework iio device group creation Up until now, the device groups that an IIO device had were limited to 6. Two of these groups would account for buffer attributes (the buffer/ and scan_elements/ directories). Since we want to add multiple buffers per IIO device, this number may not be enough, when adding a second buffer. So, this change reallocates the groups array whenever an IIO device group is added, via a iio_device_register_sysfs_group() helper. This also means that the groups array should be assigned to 'indio_dev.dev.groups' really late, right before {cdev_}device_add() is called to do the entire setup. And we also must take care to free this array when the sysfs resources are being cleaned up. With this change we can also move the 'groups' & 'groupcounter' fields to the iio_dev_opaque object. Up until now, this didn't make a whole lot of sense (especially since we weren't sure how multibuffer support would look like in the end). But doing it now kills one birds with one stone. An alternative, would be to add a configurable Kconfig symbol CONFIG_IIO_MAX_BUFFERS_PER_DEVICE (or something like that) and compute a static maximum of the groups we can support per IIO device. But that would probably annoy a few people since that would make the system less configurable. Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20210215104043.91251-11-alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/iio_core.h | 3 +++ drivers/iio/industrialio-buffer.c | 12 ++++++++++-- drivers/iio/industrialio-core.c | 30 +++++++++++++++++++++++++++--- drivers/iio/industrialio-event.c | 5 ++++- drivers/iio/industrialio-trigger.c | 6 ++---- include/linux/iio/iio-opaque.h | 4 ++++ include/linux/iio/iio.h | 5 ----- 7 files changed, 50 insertions(+), 15 deletions(-) diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h index fced02cadcc3c1..7d5b179c1fe731 100644 --- a/drivers/iio/iio_core.h +++ b/drivers/iio/iio_core.h @@ -46,6 +46,9 @@ int __iio_add_chan_devattr(const char *postfix, struct list_head *attr_list); void iio_free_chan_devattr_list(struct list_head *attr_list); +int iio_device_register_sysfs_group(struct iio_dev *indio_dev, + const struct attribute_group *group); + ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals); /* Event interface flags */ diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 2f7426a2f47ca5..cc846988fdb9a7 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1287,7 +1287,9 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, buffer->buffer_group.name = "buffer"; buffer->buffer_group.attrs = attr; - indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group; + ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); + if (ret) + goto error_free_buffer_attrs; attrcount = 0; INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); @@ -1330,14 +1332,20 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, 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; + + ret = iio_device_register_sysfs_group(indio_dev, &buffer->scan_el_group); + if (ret) + goto error_free_scan_el_attrs; return 0; +error_free_scan_el_attrs: + kfree(buffer->scan_el_group.attrs); error_free_scan_mask: bitmap_free(buffer->scan_mask); error_cleanup_dynamic: iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); +error_free_buffer_attrs: kfree(buffer->buffer_group.attrs); return ret; diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 92efbc24509848..924f3a16712535 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1454,6 +1454,25 @@ static ssize_t iio_store_timestamp_clock(struct device *dev, return len; } +int iio_device_register_sysfs_group(struct iio_dev *indio_dev, + const struct attribute_group *group) +{ + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); + const struct attribute_group **new, **old = iio_dev_opaque->groups; + unsigned int cnt = iio_dev_opaque->groupcounter; + + new = krealloc(old, sizeof(*new) * (cnt + 2), GFP_KERNEL); + if (!new) + return -ENOMEM; + + new[iio_dev_opaque->groupcounter++] = group; + new[iio_dev_opaque->groupcounter] = NULL; + + iio_dev_opaque->groups = new; + + return 0; +} + static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR, iio_show_timestamp_clock, iio_store_timestamp_clock); @@ -1527,8 +1546,10 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev) if (clk) iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk; - indio_dev->groups[indio_dev->groupcounter++] = - &iio_dev_opaque->chan_attr_group; + ret = iio_device_register_sysfs_group(indio_dev, + &iio_dev_opaque->chan_attr_group); + if (ret) + goto error_clear_attrs; return 0; @@ -1545,6 +1566,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list); kfree(iio_dev_opaque->chan_attr_group.attrs); iio_dev_opaque->chan_attr_group.attrs = NULL; + kfree(iio_dev_opaque->groups); } static void iio_dev_release(struct device *device) @@ -1594,7 +1616,6 @@ struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv) ALIGN(sizeof(struct iio_dev_opaque), IIO_ALIGN); dev->dev.parent = parent; - dev->dev.groups = dev->groups; dev->dev.type = &iio_device_type; dev->dev.bus = &iio_bus_type; device_initialize(&dev->dev); @@ -1857,6 +1878,9 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) indio_dev->chrdev.owner = this_mod; } + /* assign device groups now; they should be all registered now */ + indio_dev->dev.groups = iio_dev_opaque->groups; + ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev); if (ret < 0) goto error_unreg_eventset; diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index 7e532117ac5502..ea8947cc21e4d3 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -544,7 +544,10 @@ int iio_device_register_eventset(struct iio_dev *indio_dev) /* Add all elements from the list. */ list_for_each_entry(p, &ev_int->dev_attr_list, l) ev_int->group.attrs[attrn++] = &p->dev_attr.attr; - indio_dev->groups[indio_dev->groupcounter++] = &ev_int->group; + + ret = iio_device_register_sysfs_group(indio_dev, &ev_int->group); + if (ret) + goto error_free_setup_event_lines; ev_int->ioctl_handler.ioctl = iio_event_ioctl; iio_device_ioctl_handler_register(&iio_dev_opaque->indio_dev, diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index 438d5012e8b8e9..a035d5c2a44583 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -694,10 +694,8 @@ EXPORT_SYMBOL(iio_trigger_validate_own_device); int iio_device_register_trigger_consumer(struct iio_dev *indio_dev) { - indio_dev->groups[indio_dev->groupcounter++] = - &iio_trigger_consumer_attr_group; - - return 0; + return iio_device_register_sysfs_group(indio_dev, + &iio_trigger_consumer_attr_group); } void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev) diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h index 07c5a8e52ca88d..8ba13a5c7af67e 100644 --- a/include/linux/iio/iio-opaque.h +++ b/include/linux/iio/iio-opaque.h @@ -12,6 +12,8 @@ * attributes * @chan_attr_group: group for all attrs in base directory * @ioctl_handlers: ioctl handlers registered with the core handler + * @groups: attribute groups + * @groupcounter: index of next attribute group * @debugfs_dentry: device specific debugfs dentry * @cached_reg_addr: cached register address for debugfs reads * @read_buf: read buffer to be used for the initial reg read @@ -24,6 +26,8 @@ struct iio_dev_opaque { struct list_head channel_attr_list; struct attribute_group chan_attr_group; struct list_head ioctl_handlers; + const struct attribute_group **groups; + int groupcounter; #if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_dentry; unsigned cached_reg_addr; diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index e4a9822e649502..f8585d01fc76ae 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -518,8 +518,6 @@ struct iio_buffer_setup_ops { * @setup_ops: [DRIVER] callbacks to call before and after buffer * enable/disable * @chrdev: [INTERN] associated character device - * @groups: [INTERN] attribute groups - * @groupcounter: [INTERN] index of next attribute group * @flags: [INTERN] file ops related flags including busy flag. * @priv: [DRIVER] reference to driver's private information * **MUST** be accessed **ONLY** via iio_priv() helper @@ -556,9 +554,6 @@ struct iio_dev { struct mutex info_exist_lock; const struct iio_buffer_setup_ops *setup_ops; struct cdev chrdev; -#define IIO_MAX_GROUPS 6 - const struct attribute_group *groups[IIO_MAX_GROUPS + 1]; - int groupcounter; unsigned long flags; void *priv;