From ee708e6baacd3afdace9b721c25fbbe106cebb94 Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Mon, 15 Feb 2021 12:40:38 +0200 Subject: iio: buffer: introduce support for attaching more IIO buffers With this change, calling iio_device_attach_buffer() will actually attach more buffers. Right now this doesn't do any validation of whether a buffer is attached twice; maybe that can be added later (if needed). Attaching a buffer more than once should yield noticeably bad results. The first buffer is the legacy buffer, so a reference is kept to it. At this point, accessing the data for the extra buffers (that are added after the first one) isn't possible yet. The iio_device_attach_buffer() is also changed to return an error code, which for now is -ENOMEM if the array could not be realloc-ed for more buffers. To adapt to this new change iio_device_attach_buffer() is called last in all place where it's called. The realloc failure is a bit difficult to handle during un-managed calls when unwinding, so it's better to have this as the last error in the setup_buffer calls. At this point, no driver should call iio_device_attach_buffer() directly, it should call one of the {devm_}iio_triggered_buffer_setup() or devm_iio_kfifo_buffer_setup() or devm_iio_dmaengine_buffer_setup() functions. This makes iio_device_attach_buffer() a bit easier to handle. Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20210215104043.91251-20-alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron --- include/linux/iio/buffer_impl.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/iio/buffer_impl.h') diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index 41044320e581..768b90c64412 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -112,6 +112,9 @@ struct iio_buffer { /* @demux_bounce: Buffer for doing gather from incoming scan. */ void *demux_bounce; + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ + struct list_head attached_entry; + /* @buffer_list: Entry in the devices list of current buffers. */ struct list_head buffer_list; -- cgit v1.2.3