From 32f171724e5cbecc80594fb6eced057cfdd6eb6f Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Mon, 15 Feb 2021 12:40:29 +0200 Subject: 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 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/iio/iio_core.h') diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h index fced02cadcc3..7d5b179c1fe7 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 */ -- cgit v1.2.3-58-ga151