[PATCH] Docs/driver-api/uio-howto: document mmap_prepare callback

From: Doehyun Baek

Date: Mon Jun 22 2026 - 14:19:51 EST


The UIO howto still documents an mmap callback in struct uio_info.
That field was replaced by mmap_prepare, which takes a struct
vm_area_desc.

A UIO driver following the current howto no longer builds because
struct uio_info has no mmap member. Update the documented callback
signature and matching text to match the current API.

Fixes: 933f05f58ac6 ("uio: replace deprecated mmap hook with mmap_prepare in uio_info")
Signed-off-by: Doehyun Baek <doehyunbaek@xxxxxxxxx>
---
Documentation/driver-api/uio-howto.rst | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst
index 907ffa3b38f5..c08472dfbcfe 100644
--- a/Documentation/driver-api/uio-howto.rst
+++ b/Documentation/driver-api/uio-howto.rst
@@ -246,10 +246,10 @@ the members are required, others are optional.
hardware interrupt number. The flags given here will be used in the
call to :c:func:`request_irq()`.

-- ``int (*mmap)(struct uio_info *info, struct vm_area_struct *vma)``:
+- ``int (*mmap_prepare)(struct uio_info *info, struct vm_area_desc *desc)``:
Optional. If you need a special :c:func:`mmap()`
function, you can set it here. If this pointer is not NULL, your
- :c:func:`mmap()` will be called instead of the built-in one.
+ ``mmap_prepare`` will be called instead of the built-in one.

- ``int (*open)(struct uio_info *info, struct inode *inode)``:
Optional. You might want to have your own :c:func:`open()`,

base-commit: 1dc18801be29bc54709aa355b8acd80e183b03cd
--
2.43.0