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* Re: [PATCH v2 003/110] audit: widen ino fields to u64
From: Jeff Layton @ 2026-03-03 11:04 UTC (permalink / raw)
  To: Paul Moore
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, David Howells, Paulo Alcantara, Andreas Dilger,
	Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, James Morris, Serge E. Hallyn, Mimi Zohar,
	Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <CAHC9VhRnmBuXEKkUPQhJ_LDzcksjoAJL-ne6mFoJdR1hnDdzsg@mail.gmail.com>

On Mon, 2026-03-02 at 18:44 -0500, Paul Moore wrote:
> On Mon, Mar 2, 2026 at 3:25 PM Jeff Layton <jlayton@kernel.org> wrote:
> > 
> > inode->i_ino is being widened from unsigned long to u64. The audit
> > subsystem uses unsigned long ino in struct fields, function parameters,
> > and local variables that store inode numbers from arbitrary filesystems.
> > On 32-bit platforms this truncates inode numbers that exceed 32 bits,
> > which will cause incorrect audit log entries and broken watch/mark
> > comparisons.
> > 
> > Widen all audit ino fields, parameters, and locals to u64, and update
> > the inode format string from %lu to %llu to match.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> >  include/linux/audit.h   | 2 +-
> >  kernel/audit.h          | 9 ++++-----
> >  kernel/audit_fsnotify.c | 4 ++--
> >  kernel/audit_watch.c    | 8 ++++----
> >  kernel/auditsc.c        | 2 +-
> >  5 files changed, 12 insertions(+), 13 deletions(-)
> 
> We should also update audit_hash_ino() in kernel/audit.h.  It is a
> *very* basic hash function, so I think leaving the function as-is and
> just changing the inode parameter from u32 to u64 should be fine.

It is indeed very simple. Here it is today:

	static inline int audit_hash_ino(u32 ino)                            
	{                                                                    
	        return (ino & (AUDIT_INODE_BUCKETS-1));                      
	}       

It doesn't look like changing the argument type will make any material
difference. Given that it should still work without that change, can we
leave this cleanup for you to do in a follow-on patchset?

-- 
Jeff Layton <jlayton@kernel.org>

^ permalink raw reply

* Re: [PATCH v3 07/18] rtla: Add strscpy() and replace strncpy() calls
From: Wander Lairson Costa @ 2026-03-03 11:02 UTC (permalink / raw)
  To: Tomas Glozar
  Cc: Steven Rostedt, Crystal Wood, Ivan Pravdin, Costa Shulyupin,
	John Kacur, Tiezhu Yang, Haiyong Sun, Daniel Wagner,
	Daniel Bristot de Oliveira,
	open list:Real-time Linux Analysis (RTLA) tools,
	open list:Real-time Linux Analysis (RTLA) tools,
	open list:BPF [MISC]:Keyword:(?:b|_)bpf(?:b|_)
In-Reply-To: <CAP4=nvR1YMQerrJUfKG6a1WaR_ajhOda=Ee5Jit-U=mB6Y9uWA@mail.gmail.com>

On Mon, Mar 2, 2026 at 11:33 AM Tomas Glozar <tglozar@redhat.com> wrote:
>
> čt 15. 1. 2026 v 18:26 odesílatel Wander Lairson Costa
> <wander@redhat.com> napsal:
> >
> > Introduce a userspace strscpy() implementation that matches the Linux
> > kernel's strscpy() semantics. The function is built on top of glibc's
> > strlcpy() and provides guaranteed NUL-termination along with proper
> > truncation detection through its return value.
> >
> > The previous strncpy() calls had potential issues: strncpy() does not
> > guarantee NUL-termination when the source string length equals or
> > exceeds the destination buffer size. This required defensive patterns
> > like pre-zeroing buffers or manually setting the last byte to NUL.
> > The new strscpy() function always NUL-terminates the destination buffer
> > unless the size is zero, and returns -E2BIG on truncation, making error
> > handling cleaner and more consistent with kernel code.
> >
> > Note that unlike the kernel's strscpy(), this implementation uses
> > strlcpy() internally, which reads the entire source string to determine
> > its length. The kernel avoids this to prevent potential DoS attacks from
> > extremely long untrusted strings. This is harmless for a userspace CLI
> > tool like rtla where input sources are bounded and trusted.
> >
>
> strlcpy() was only added in glibc 2.38 [1]. It is thus not available
> on systems with older glibc, like RHEL 9. Using it for strscpy()
> implementation causes RTLA to fail to build on those systems.
>

Thanks for pointing this. I will fix that in v4.

> [1] https://www.gnu.org/software/gnulib/manual/html_node/strlcpy.html
>
> > Replace all strncpy() calls in rtla with strscpy(), using sizeof() for
> > buffer sizes instead of magic constants to ensure the sizes stay in
> > sync with the actual buffer declarations. Also remove a now-redundant
> > memset() call that was previously needed to work around strncpy()
> > behavior.
> >
> > Signed-off-by: Wander Lairson Costa <wander@redhat.com>
> > ---
> >  tools/tracing/rtla/src/timerlat_aa.c |  6 ++---
> >  tools/tracing/rtla/src/utils.c       | 34 ++++++++++++++++++++++++++--
> >  tools/tracing/rtla/src/utils.h       |  1 +
> >  3 files changed, 36 insertions(+), 5 deletions(-)
> >
>
> Tomas
>


^ permalink raw reply

* Re: [PATCH v2 001/110] vfs: introduce kino_t typedef and PRIino format macro
From: Jan Kara @ 2026-03-03 11:00 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, David Howells, Paulo Alcantara, Andreas Dilger,
	Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260302-iino-u64-v2-1-e5388800dae0@kernel.org>

On Mon 02-03-26 15:23:45, Jeff Layton wrote:
> Introduce a kino_t typedef and PRIino format macro to enable a
> bisect-clean transition of i_ino from unsigned long to u64.
> 
> kino_t is initially defined as unsigned long (matching the original
> i_ino type), and PRIino is "l" (the format length modifier for
> unsigned long). A later patch will change these to u64 and "ll"
> respectively once all format strings have been updated to use PRIino.
> 
> The PRIino macro is a length modifier, not a complete format specifier.
> It is used as: "%" PRIino "u" for decimal, "%" PRIino "x" for hex, etc.
> This follows the pattern used by userspace PRIu64/PRIx64 macros.
> 
> Format strings using i_ino should be updated to use PRIino instead of
> a hard-coded length modifier to ensure warning-free compilation on
> both 32-bit and 64-bit architectures throughout the transition.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Yeah, as a temporary solution for bisectability this looks fine to me. Feel
free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  include/linux/fs.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 8b3dd145b25ec12b00ac1df17a952d9116b88047..e38bc5ece1f360d679a8f30b8171292f7a65c218 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -758,6 +758,9 @@ struct inode_state_flags {
>  	enum inode_state_flags_enum __state;
>  };
>  
> +typedef unsigned long	kino_t;
> +#define PRIino		"l"
> +
>  /*
>   * Keep mostly read-only and often accessed (especially for
>   * the RCU path lookup and 'stat' data) fields at the beginning
> @@ -783,7 +786,7 @@ struct inode {
>  #endif
>  
>  	/* Stat data, not accessed from path walking */
> -	unsigned long		i_ino;
> +	kino_t			i_ino;
>  	/*
>  	 * Filesystems may only read i_nlink directly.  They shall use the
>  	 * following functions for modification:
> 
> -- 
> 2.53.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply

* Re: [PATCH v2 002/110] vfs: widen inode hash/lookup functions to u64
From: Jan Kara @ 2026-03-03 10:59 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, David Howells, Paulo Alcantara, Andreas Dilger,
	Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260302-iino-u64-v2-2-e5388800dae0@kernel.org>

On Mon 02-03-26 15:23:46, Jeff Layton wrote:
> Change the inode hash/lookup VFS API functions to accept u64 parameters
> instead of unsigned long for inode numbers and hash values. This is
> preparation for widening i_ino itself to u64, which will allow
> filesystems to store full 64-bit inode numbers on 32-bit architectures.
> 
> Since unsigned long implicitly widens to u64 on all architectures, this
> change is backward-compatible with all existing callers.
> 
> In dump_mapping(), change the local ino variable to kino_t and use the
> PRIino format macro, since this variable holds an i_ino value. In
> init_special_inode(), also switch to PRIino.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply

* Re: [PATCH v2 000/110] vfs: change inode->i_ino from unsigned long to u64
From: Jeff Layton @ 2026-03-03 10:58 UTC (permalink / raw)
  To: David Howells
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, Paulo Alcantara, Andreas Dilger, Jan Kara,
	Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <1787281.1772535332@warthog.procyon.org.uk>

On Tue, 2026-03-03 at 10:55 +0000, David Howells wrote:
> Jeff Layton <jlayton@kernel.org> wrote:
> 
> > This version splits the change up to be more bisectable. It first adds a
> > new kino_t typedef and a new "PRIino" macro to hold the width specifier
> > for format strings. The conversion is done, and then everything is
> > changed to remove the new macro and typedef.
> 
> Why remove the typedef?  It might be better to keep it.
> 

Why? After this change, internel kernel inodes will be u64's -- full
stop. I don't see what the macro or typedef will buy us at that point.
-- 
Jeff Layton <jlayton@kernel.org>

^ permalink raw reply

* Re: [PATCH v2 000/110] vfs: change inode->i_ino from unsigned long to u64
From: David Howells @ 2026-03-03 10:55 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, David Howells, Paulo Alcantara, Andreas Dilger,
	Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260302-iino-u64-v2-0-e5388800dae0@kernel.org>

Jeff Layton <jlayton@kernel.org> wrote:

> This version splits the change up to be more bisectable. It first adds a
> new kino_t typedef and a new "PRIino" macro to hold the width specifier
> for format strings. The conversion is done, and then everything is
> changed to remove the new macro and typedef.

Why remove the typedef?  It might be better to keep it.

David


^ permalink raw reply

* Re: [PATCH v2 001/110] vfs: introduce kino_t typedef and PRIino format macro
From: Jeff Layton @ 2026-03-03 10:53 UTC (permalink / raw)
  To: Darrick J. Wong, Theodore Tso
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Muchun Song, Oscar Salvador, David Hildenbrand,
	David Howells, Paulo Alcantara, Andreas Dilger, Jan Kara,
	Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Martin Schiller,
	Eric Paris, Joerg Reuter, Marcel Holtmann, Johan Hedberg,
	Luiz Augusto von Dentz, Oliver Hartkopp, Marc Kleine-Budde,
	David Ahern, Neal Cardwell, Steffen Klassert, Herbert Xu,
	Remi Denis-Courmont, Marcelo Ricardo Leitner, Xin Long,
	Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260303042546.GF13868@frogsfrogsfrogs>

On Mon, 2026-03-02 at 20:25 -0800, Darrick J. Wong wrote:
> On Mon, Mar 02, 2026 at 08:25:56PM -0500, Theodore Tso wrote:
> > On Mon, Mar 02, 2026 at 03:23:45PM -0500, Jeff Layton wrote:
> > > The PRIino macro is a length modifier, not a complete format specifier.
> > > It is used as: "%" PRIino "u" for decimal, "%" PRIino "x" for hex, etc.
> > > This follows the pattern used by userspace PRIu64/PRIx64 macros.
> > 
> > For the record, I really hate the inttypes.h format specifiers, but I
> > agree that we should forward the example of the C99 spec, for better
> > or for worse.
> > 
> > That being said, the userspace PRIu64, et. al macros are complete
> > format specifiers, not just a length modifier.  And I think this
> > results in less ugly format specifiers in our kernel code.
> 
> Yeah, I don't like "ino=%" PRIino "u, lolz\n" either.  I'd rather have
> the whole format in the PRIino definition -- it /is/ unsigned long
> after all.
> 

Like I said to Ted, this is just temporary scaffolding for the change.
The PRIino macro is removed in the end. Given that, perhaps you can
overlook the bikeshed's color in this instance?
-- 
Jeff Layton <jlayton@kernel.org>

^ permalink raw reply

* Re: [PATCH v2 001/110] vfs: introduce kino_t typedef and PRIino format macro
From: Jeff Layton @ 2026-03-03 10:52 UTC (permalink / raw)
  To: Theodore Tso
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Muchun Song, Oscar Salvador, David Hildenbrand,
	David Howells, Paulo Alcantara, Andreas Dilger, Jan Kara,
	Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260303012556.GA6520@macsyma-wired.lan>

On Mon, 2026-03-02 at 20:25 -0500, Theodore Tso wrote:
> On Mon, Mar 02, 2026 at 03:23:45PM -0500, Jeff Layton wrote:
> > The PRIino macro is a length modifier, not a complete format specifier.
> > It is used as: "%" PRIino "u" for decimal, "%" PRIino "x" for hex, etc.
> > This follows the pattern used by userspace PRIu64/PRIx64 macros.
> 
> For the record, I really hate the inttypes.h format specifiers, but I
> agree that we should forward the example of the C99 spec, for better
> or for worse.
> 
> That being said, the userspace PRIu64, et. al macros are complete
> format specifiers, not just a length modifier.  And I think this
> results in less ugly format specifiers in our kernel code.
> 
> ---- cut here ---
> #!/bin/sh
> cat <<EOF > /tmp/blah.c
> #include <inttypes.h>
> #include <stdio.h>
> 
> int main(int arg, char **argv)
> {
>         printf("PRIu64 is %s\n", PRIu64);
>         printf("PRId64 is %s\n", PRId64);
>         printf("PRIx64 is %s\n", PRIx64);
>         return 0;
> }
> EOF
> 
> clang -m32 -o /tmp/blah /tmp/blah.c
> /tmp/blah
> ---- cut here ---
> 
> % /tmp/blah.sh
> PRIu64 is llu
> PRId64 is lld
> PRIx64 is llx
> 

I originally had them that way, but ended up going with just a single
"PRIino" macro since it was simpler.

If we were going to keep these macros in perpetuity then I'd be
inclined to follow your suggestion, but since they're just temporary
scaffolding to make this change, maybe I can ask you to overlook this
preference for now?

-- 
Jeff Layton <jlayton@kernel.org>

^ permalink raw reply

* Re: [PATCH v2 000/110] vfs: change inode->i_ino from unsigned long to u64
From: David Howells @ 2026-03-03 10:48 UTC (permalink / raw)
  To: Jeff Layton, Alexander Viro, Christian Brauner, Jan Kara,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers, Dan Williams,
	Matthew Wilcox, Eric Biggers, Theodore Y. Ts'o, Muchun Song,
	Oscar Salvador, David Hildenbrand, David Howells, Paulo Alcantara,
	Andreas Dilger, Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust,
	Anna Schumaker, Chuck Lever, NeilBrown, Olga Kornievskaia,
	Dai Ngo, Tom Talpey, Steve French, Ronnie Sahlberg,
	Shyam Prasad N, Bharath SM, Alexander Aring, Ryusuke Konishi,
	Viacheslav Dubeyko, Eric Van Hensbergen, Latchesar Ionkov,
	Dominique Martinet, Christian Schoenebeck, David Sterba,
	Marc Dionne, Ian Kent, Luis de Bethencourt, Salah Triki,
	Tigran A. Aivazian, Ilya Dryomov, Alex Markuze, Jan Harkes, coda,
	Nicolas Pitre, Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	Marc Kleine-Budde, David Ahern, Neal Cardwell, Steffen Klassert,
	Herbert Xu, Remi Denis-Courmont, Marcelo Ricardo Leitner,
	Xin Long, Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend
  Cc: linux-fsdevel, linux-kernel, linux-trace-kernel, nvdimm, fsverity,
	linux-mm, netfs, linux-ext4, linux-f2fs-devel, linux-nfs,
	linux-cifs, samba-technical, linux-nilfs, v9fs, linux-afs, autofs,
	ceph-devel, codalist, ecryptfs, linux-mtd, jfs-discussion, ntfs3,
	ocfs2-devel, devel, linux-unionfs, apparmor,
	linux-security-module, linux-integrity, selinux, amd-gfx,
	dri-devel, linux-media, linaro-mm-sig, netdev, linux-perf-users,
	linux-fscrypt, linux-xfs, linux-hams, linux-x25, audit,
	linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260302-iino-u64-v2-0-e5388800dae0@kernel.org>

Jeff Layton <jlayton@kernel.org> wrote:

> This version splits the change up to be more bisectable. It first adds a
> new kino_t typedef and a new "PRIino" macro to hold the width specifier
> for format strings. The conversion is done, and then everything is
> changed to remove the new macro and typedef.

Why remove the typedef?  It might be better to keep it.

David


^ permalink raw reply

* Re: [PATCH] tracing: Fix WARN_ON in tracing_buffers_mmap_close
From: Lorenzo Stoakes @ 2026-03-03 10:19 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Vincent Donnefort, Qing Wang, Masami Hiramatsu, Mathieu Desnoyers,
	linux-kernel, linux-trace-kernel, syzbot+3b5dd2030fe08afdf65d,
	linux-mm, Andrew Morton, Vlastimil Babka, David Hildenbrand
In-Reply-To: <20260302115220.163f1249@gandalf.local.home>

On Mon, Mar 02, 2026 at 11:52:20AM -0500, Steven Rostedt wrote:
> On Mon, 2 Mar 2026 12:13:24 +0000
> Lorenzo Stoakes <lorenzo.stoakes@oracle.com> wrote:
>
> Hi Lorenzo,
>
> Thanks for looking into this.
>
> > > But looking at the various flags, I see there's a VM_SPECIAL. I'm wondering
> > > if that is what we should use?
> >
> > VM_SPECIAL is not a VMA flag, it's a bitmask of all the flags which cause us not
> > to permit things like splitting/merging of VMAs (because we can't safely do
> > them), i.e. that are one or more of:
>
> Yep, I knew it wasn't a flag, and actually picked it because it looked to
> have the flags we may have wanted.

Yeah you shouldn't set that is TL;DR on that :P

>
> >
> >         VM_IO - Memory-mapped I/O range.
> >
> >     VM_PFNMAP - A mapping without struct folio's/page's backing them, e.g. perhaps a
> >                 raw kernel mapping.
> >
> >   VM_MIXEDMAP - A combination of page/folio-backed memory and/or PFN-backed memory.
> >
> > VM_DONTEXPAND - Disallow expansion of memory in mremap().
> >
> > You already set VM_DONTEXPAND so you get these semantics already.
> >
> > Setting VM_IO just to trigger a failure case in madvise() feels like a hack? I
> > guess it'd do the trick though, but you're not going to be able to reclaim that
> > memory, and you might get some unexpected behaviour in code paths that assume
> > VM_IO means it's memory-mapped I/O... (for instance GUP will stop working, if
> > you need that).
>
> Well, we don't reclaim that memory anyway.

OK so maybe not such an issue then! As long as GUP not working with it wouldn't
break anything?

>
> >
> > I'd take a step back and wonder why you are wanting to not allow copying on
> > fork? Is this kernel-allocated memory? In which case you should set VM_MIXEDMAP
> > or VM_PFNMAP as appropriate... If not and it has a folio etc. then it seems like
> > strange semantics.
> >
> > Are you really bothered also by users doing strange things? Maybe the solution
> > is to tolerate a fork-copy even if it's broken? I presume somethings straight up
> > breaks right now?
>
> Yeah, right now the accounting gets screwed up as the mappings get out of
> sync when it is forked.

Ack, is that in a way that could screw up things from a kernel point of view at
all? Presumably there was some report that triggered this work, like an assert
fail or something, or a warning?

If a user is explicitly going to an ftrace buffer and madvise()'ing it in random
ways they've only themselves to blame for being so stupid :)

As long as it's not exploitable in some way I don't think that's too much of an
issue?

It'd be nice to keep the semantics of 'don't copy on fork' if we could, even if
some crazy users might override it with madvise().

>
> >
> > Without more context that I don't really have much time to acquire it's hard to
> > know what to advise.
>
> Fair enough, let me explain everything then ;-)
>
> This is a mapping of the ftrace ring buffer to user space. Until recently,
> the only way user space could get access to the ftrace ring buffer was to
> either read it, or splice() it to a file/pipe/whatever.
>
> The way the ftrace ring buffer works is that it is made up of a bunch of
> sub-buffers (must be multiple of PAGE_SIZE and usually is a single page).
> There is one sub-buffer called the "reader-page" which writers never write
> to (with an exception out of scope for understanding the mappings).
>
> The "reader-page" is a sub-buffer that belongs to the reader. When the
> reader is finish with it and wants to read more of the buffer, an operation
> is performed to swap the current reader-page with one of the pages that the
> writers have. The new page is now owned by the reader and writers will
> leave it alone. This allows readers to do a zero copy splice of the data in
> the ring buffer.
>
> Now we added a feature to memory map this buffer to user space. The
> reader-page and writer sub-buffers are all mapped read-only into the user's
> memory address.
>
> Another page is mapped called the "meta page" which tells user space how to
> read the buffer (which sub-buffer is the current reader-page and the order
> of the write sub-buffers).
>
> The read-page is what user space will read directly, and when it is done,
> it does an ioctl() on the file descriptor for the buffer:
>
>   /sys/kernel/tracing/per_cpu/cpu*/trace_pipe_raw
>
> One command of the ioctl() will tell the kernel to swap the reader-page with
> a writer sub-buffer. The meta page is updated and the user space
> application can read that.
>
> Now the meta page is unique per ring buffer and not per process. If there's
> a fork, any change to the meta page will affect all processes that have
> this mapped.
>
> If two processes map the same buffer, one process will see any updates in
> its meta page that another process does to it.
>
> Now there is nothing wrong with doing that, accept the user space processes
> will likely get confused. And we currently allow two separate tasks to mmap
> it at the same time (maybe we shouldn't have!).
>
> What we didn't allow was forking, as the code didn't update the proper
> accounting. It needs to know that the buffer is mapped because it handles
> splice differently. As the pages are mapped to user space, the kernel can't
> just allow splice to steal a page and send it off to whatever pipe. Instead
> it makes a copy of the page (basically killing the performance splice()
> gives it in the first place).
>
> We originally added the DONTFORK so that we didn't need to handle the fork
> case, but I'm guessing that you are suggesting that we should do that
> instead of preventing it from being duplicated on fork. Am I correct?

Thanks for that!

Kind of separate from the question, but I mean if it's kernel-allocated memory
which you're managing separately it should surely be VM_PFNMAP?

It depends if you want to have a refcounted folio underneath though. If you do
then yeah don't do that :)

In general I'd suggest supporting the fork case if you can, or just let things
be wrong if a user does something crazy and undoes the VM_DONTCOPY flag.

>
> -- Steve
>

Cheers, Lorenzo

^ permalink raw reply

* Re: [PATCH v2 004/110] net: change sock.sk_ino and sock_i_ino() to u64
From: Marc Kleine-Budde @ 2026-03-03 10:03 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Alexander Viro, Christian Brauner, Jan Kara, Steven Rostedt,
	Masami Hiramatsu, Mathieu Desnoyers, Dan Williams, Matthew Wilcox,
	Eric Biggers, Theodore Y. Ts'o, Muchun Song, Oscar Salvador,
	David Hildenbrand, David Howells, Paulo Alcantara, Andreas Dilger,
	Jan Kara, Jaegeuk Kim, Chao Yu, Trond Myklebust, Anna Schumaker,
	Chuck Lever, NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey,
	Steve French, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
	Alexander Aring, Ryusuke Konishi, Viacheslav Dubeyko,
	Eric Van Hensbergen, Latchesar Ionkov, Dominique Martinet,
	Christian Schoenebeck, David Sterba, Marc Dionne, Ian Kent,
	Luis de Bethencourt, Salah Triki, Tigran A. Aivazian,
	Ilya Dryomov, Alex Markuze, Jan Harkes, coda, Nicolas Pitre,
	Tyler Hicks, Amir Goldstein, Christoph Hellwig,
	John Paul Adrian Glaubitz, Yangtao Li, Mikulas Patocka,
	David Woodhouse, Richard Weinberger, Dave Kleikamp,
	Konstantin Komarov, Mark Fasheh, Joel Becker, Joseph Qi,
	Mike Marshall, Martin Brandenburg, Miklos Szeredi, Anders Larsen,
	Zhihao Cheng, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
	John Johansen, Paul Moore, James Morris, Serge E. Hallyn,
	Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg, Fan Wu,
	Stephen Smalley, Ondrej Mosnacek, Casey Schaufler, Alex Deucher,
	Christian König, David Airlie, Simona Vetter, Sumit Semwal,
	Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
	David S. Miller, Jakub Kicinski, Simon Horman, Oleg Nesterov,
	Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
	Ian Rogers, Adrian Hunter, James Clark, Darrick J. Wong,
	Martin Schiller, Eric Paris, Joerg Reuter, Marcel Holtmann,
	Johan Hedberg, Luiz Augusto von Dentz, Oliver Hartkopp,
	David Ahern, Neal Cardwell, Steffen Klassert, Herbert Xu,
	Remi Denis-Courmont, Marcelo Ricardo Leitner, Xin Long,
	Magnus Karlsson, Maciej Fijalkowski, Stanislav Fomichev,
	Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer,
	John Fastabend, linux-fsdevel, linux-kernel, linux-trace-kernel,
	nvdimm, fsverity, linux-mm, netfs, linux-ext4, linux-f2fs-devel,
	linux-nfs, linux-cifs, samba-technical, linux-nilfs, v9fs,
	linux-afs, autofs, ceph-devel, codalist, ecryptfs, linux-mtd,
	jfs-discussion, ntfs3, ocfs2-devel, devel, linux-unionfs,
	apparmor, linux-security-module, linux-integrity, selinux,
	amd-gfx, dri-devel, linux-media, linaro-mm-sig, netdev,
	linux-perf-users, linux-fscrypt, linux-xfs, linux-hams, linux-x25,
	audit, linux-bluetooth, linux-can, linux-sctp, bpf
In-Reply-To: <20260302-iino-u64-v2-4-e5388800dae0@kernel.org>

[-- Attachment #1: Type: text/plain, Size: 1275 bytes --]

On 02.03.2026 15:23:48, Jeff Layton wrote:
> inode->i_ino is being converted to a u64. sock.sk_ino (which caches the
> inode number) must also be widened to avoid truncation on 32-bit
> architectures where unsigned long is only 32 bits.
>
> Change sk_ino from unsigned long to u64, and update the return type
> of sock_i_ino() to match. Fix all format strings that print the
> result of sock_i_ino() (%lu -> %llu), and widen the intermediate
> variables and function parameters in the diag modules that were
> using int to hold the inode number.
>
> Note that the UAPI socket diag structures (inet_diag_msg.idiag_inode,
> unix_diag_msg.udiag_ino, etc.) are all __u32 and cannot be changed
> without breaking the ABI. The assignments to those fields will
> silently truncate, which is the existing behavior.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  net/can/bcm.c                | 2 +-

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
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[-- Attachment #2: signature.asc --]
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^ permalink raw reply

* Re: [PATCH 6.12.y] tracing: Fix to clear fprobe after unregister_fprobe() when module unloading
From: Masami Hiramatsu @ 2026-03-03  8:36 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Sasha Levin
  Cc: Masami Hiramatsu (Google), stable, Steven Rostedt,
	Mathieu Desnoyers, linux-kernel, linux-trace-kernel
In-Reply-To: <177177399650.99709.12415733322341955461.stgit@devnote2>

Hi Greg and Sasha,

This patch is not able to be applied to upstream because fprobe
implementation was changed in v6.14 by commit 4346ba160409 ("fprobe:
Rewrite fprobe on function-graph tracer"). So this is only for 6.12.y.

Please tell me if I need more work for merging this fix in stable tree.

Thank you,

On Mon, 23 Feb 2026 00:26:36 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu <mhiramat@kernel.org>
> 
> Clear fprobe after unregister_fprobe() for preventing double
> unregistering fprobe.
> 
> Without this fix, test.d/dynevent/add_remove_tprobe_module.tc test
> case of ftracetest caused a kernel panic as below on 6.12.y.
> 
> This is only happens on 6.12.y because this bug was introduced by
> commit 5ba4f58ec2de ("tracing: tprobe-events: Fix to clean up tprobe
> correctly when module unload"). This fix expects that the new fprobe
> implementation based on fgraph, but on 6.12.y, fprobe is still using
> ftrace.
> 
>  ------------[ cut here ]------------
>  WARNING: CPU: 0 PID: 156 at kernel/trace/ftrace.c:378 __unregister_ftrace_function+0x154/0x170
>  Modules linked in: [last unloaded: trace_events_sample]
>  CPU: 0 UID: 0 PID: 156 Comm: ftracetest Not tainted 6.12.74 #1
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
>  RIP: 0010:__unregister_ftrace_function+0x154/0x170
>  Code: 85 30 ff ff ff c6 05 fd d5 85 01 01 48 c7 c7 eb 8e 14 82 be 39 01 00 00 48 c7 c2 dd bd 1c 82 e8 52 12 93 00 e9 0c ff ff ff 90 <0f> 0b 90 b8 f0 ff ff ff 5b e9 be 8b 95 00 cc 66 66 66 66 2e 0f 1f
>  RSP: 0018:ffffc900005c3b48 EFLAGS: 00010246
>  RAX: 0000000000000000 RBX: ffff8880054ba818 RCX: 7a7d3ccd1e752c00
>  RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8880054ba818
>  RBP: 0000000000000000 R08: 000000000000017b R09: 0000000000000000
>  R10: 0000000000000002 R11: 0000000000000000 R12: ffff8880048216d0
>  R13: ffff8880052f7850 R14: ffff8880054ba818 R15: ffffffff8124e160
>  FS:  000000002de743c0(0000) GS:ffff88807d800000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 000000002de8b898 CR3: 0000000005b3a000 CR4: 00000000000006b0
>  Call Trace:
>   <TASK>
>   ftrace_shutdown+0x25/0x260
>   ? __pfx_dyn_event_open+0x10/0x10
>   unregister_ftrace_function+0x2a/0x140
>   ? __pfx_dyn_event_open+0x10/0x10
>   unregister_fprobe+0x57/0x90
>   trace_fprobe_release+0x56/0x150
>   dyn_event_open+0x99/0xe0
>   do_dentry_open+0x14a/0x3e0
>   vfs_open+0x2c/0xe0
>   path_openat+0xca5/0xf10
>   ? __lock_acquire+0xd38/0x2af0
>   ? __create_object+0x36/0x100
>   ? __create_object+0x36/0x100
>   do_filp_open+0xb5/0x160
>   do_sys_openat2+0x7f/0xd0
>   __x64_sys_openat+0x81/0xa0
>   do_syscall_64+0xec/0x1d0
>   ? exc_page_fault+0x92/0x110
>   entry_SYSCALL_64_after_hwframe+0x77/0x7f
>  RIP: 0033:0x4aa9cb
>  Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25
>  RSP: 002b:00007ffce30daf50 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>  RAX: ffffffffffffffda RBX: 000000002de79bd0 RCX: 00000000004aa9cb
>  RDX: 0000000000000241 RSI: 000000002deb08f0 RDI: 00000000ffffff9c
>  RBP: 000000002deb08f0 R08: 0000000000000000 R09: 0000000000000000
>  R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000241
>  R13: 000000002deb08f0 R14: 00007ffce30db3f8 R15: 0000000000000000
>   </TASK>
>  irq event stamp: 147361
>  hardirqs last  enabled at (147373): [<ffffffff81128511>] __console_unlock+0x81/0xd0
>  hardirqs last disabled at (147386): [<ffffffff811284f6>] __console_unlock+0x66/0xd0
>  softirqs last  enabled at (146866): [<ffffffff8109a74f>] handle_softirqs+0x34f/0x3b0
>  softirqs last disabled at (146861): [<ffffffff8109a956>] __irq_exit_rcu+0x66/0xd0
>  ---[ end trace 0000000000000000 ]---
>  BUG: kernel NULL pointer dereference, address: 000000000000002e
>  #PF: supervisor read access in kernel mode
>  #PF: error_code(0x0000) - not-present page
>  PGD 8000000005af0067 P4D 8000000005af0067 PUD 55d7067 PMD 0
>  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
>  CPU: 0 UID: 0 PID: 156 Comm: ftracetest Tainted: G        W          6.12.74 #1
>  Tainted: [W]=WARN
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
>  RIP: 0010:trace_fprobe_release+0x78/0x150
>  Code: 4c 89 f7 e8 ba e2 ff ff ba f0 01 00 00 4c 89 f7 31 f6 e8 9b 64 8d 00 48 8b bb 10 02 00 00 48 85 ff 74 21 4c 8d b3 10 02 00 00 <48> 8b 77 30 31 d2 e8 8d cf f8 ff 49 c7 06 00 00 00 00 49 c7 46 08
>  RSP: 0018:ffffc900005c3be8 EFLAGS: 00010282
>  RAX: ffff8880054ba818 RBX: ffff8880054ba800 RCX: 0000000000000000
>  RDX: 0000000000000000 RSI: 0000000000000000 RDI: fffffffffffffffe
>  RBP: 00000000fffffff0 R08: 000000000000017b R09: 0000000000000000
>  R10: ffff8880054ba818 R11: 0000000000000000 R12: ffff8880048216d0
>  R13: ffff8880052f7850 R14: ffff8880054baa10 R15: ffffffff8124e160
>  FS:  000000002de743c0(0000) GS:ffff88807d800000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 000000000000002e CR3: 0000000005b3a000 CR4: 00000000000006b0
>  Call Trace:
>   <TASK>
>   dyn_event_open+0x99/0xe0
>   do_dentry_open+0x14a/0x3e0
>   vfs_open+0x2c/0xe0
>   path_openat+0xca5/0xf10
>   ? __lock_acquire+0xd38/0x2af0
>   ? __create_object+0x36/0x100
>   ? __create_object+0x36/0x100
>   do_filp_open+0xb5/0x160
>   do_sys_openat2+0x7f/0xd0
>   __x64_sys_openat+0x81/0xa0
>   do_syscall_64+0xec/0x1d0
>   ? exc_page_fault+0x92/0x110
>   entry_SYSCALL_64_after_hwframe+0x77/0x7f
>  RIP: 0033:0x4aa9cb
>  Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25
>  RSP: 002b:00007ffce30daf50 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
>  RAX: ffffffffffffffda RBX: 000000002de79bd0 RCX: 00000000004aa9cb
>  RDX: 0000000000000241 RSI: 000000002deb08f0 RDI: 00000000ffffff9c
>  RBP: 000000002deb08f0 R08: 0000000000000000 R09: 0000000000000000
>  R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000241
>  R13: 000000002deb08f0 R14: 00007ffce30db3f8 R15: 0000000000000000
>   </TASK>
>  Modules linked in: [last unloaded: trace_events_sample]
>  CR2: 000000000000002e
>  ---[ end trace 0000000000000000 ]---
> 
> Fixes: 5ba4f58ec2de ("tracing: tprobe-events: Fix to clean up tprobe correctly when module unload")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
>  kernel/trace/trace_fprobe.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
> index 440dbfa6bbfd..2cf5036c825d 100644
> --- a/kernel/trace/trace_fprobe.c
> +++ b/kernel/trace/trace_fprobe.c
> @@ -984,6 +984,7 @@ static int __tracepoint_probe_module_cb(struct notifier_block *self,
>  			}
>  		} else if (val == MODULE_STATE_GOING && tp_mod->mod == tf->mod) {
>  			unregister_fprobe(&tf->fp);
> +			memset(&tf->fp, 0, sizeof(tf->fp));
>  			if (trace_fprobe_is_tracepoint(tf)) {
>  				tracepoint_probe_unregister(tf->tpoint,
>  					tf->tpoint->probestub, NULL);
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

^ permalink raw reply

* Re: [PATCH 09/12] dt-bindings: input: Document hid-over-spi DT schema
From: Rob Herring (Arm) @ 2026-03-03  7:24 UTC (permalink / raw)
  To: Jingyuan Liang
  Cc: Mark Brown, Benjamin Tissoires, Mathieu Desnoyers,
	Jarrett Schultz, Dmitry Torokhov, Jonathan Corbet, Jiri Kosina,
	linux-doc, linux-input, hbarnor, Steven Rostedt, Dmitry Antipov,
	linux-spi, linux-trace-kernel, Krzysztof Kozlowski,
	Masami Hiramatsu, devicetree, Conor Dooley, linux-kernel
In-Reply-To: <20260303-send-upstream-v1-9-1515ba218f3d@chromium.org>


On Tue, 03 Mar 2026 06:13:01 +0000, Jingyuan Liang wrote:
> Documentation describes the required and optional properties for
> implementing Device Tree for a Microsoft G6 Touch Digitizer that
> supports HID over SPI Protocol 1.0 specification.
> 
> The properties are common to HID over SPI.
> 
> Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
> Signed-off-by: Jarrett Schultz <jaschultz@microsoft.com>
> Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
> ---
>  .../devicetree/bindings/input/hid-over-spi.yaml    | 153 +++++++++++++++++++++
>  1 file changed, 153 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:
./Documentation/devicetree/bindings/input/hid-over-spi.yaml:67:6: [warning] wrong indentation: expected 6 but found 5 (indentation)
./Documentation/devicetree/bindings/input/hid-over-spi.yaml:89:15: [error] empty value in block mapping (empty-values)
./Documentation/devicetree/bindings/input/hid-over-spi.yaml:153:7: [error] no new line character at the end of file (new-line-at-end-of-file)
./Documentation/devicetree/bindings/input/hid-over-spi.yaml:91:16: [error] syntax error: mapping values are not allowed here (syntax)

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/input/hid-over-spi.yaml: ignoring, error parsing file
./Documentation/devicetree/bindings/input/hid-over-spi.yaml:91:16: mapping values are not allowed here
make[2]: *** Deleting file 'Documentation/devicetree/bindings/input/hid-over-spi.example.dts'
Documentation/devicetree/bindings/input/hid-over-spi.yaml:91:16: mapping values are not allowed here
make[2]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/input/hid-over-spi.example.dts] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/builds/robherring/dt-review-ci/linux/Makefile:1559: dt_binding_check] Error 2
make: *** [Makefile:248: __sub-make] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/20260303-send-upstream-v1-9-1515ba218f3d@chromium.org

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.


^ permalink raw reply

* [PATCH 12/12] HID: spi-hid: add quirkis to support mode switch for Ilitek touch
From: Jingyuan Liang @ 2026-03-03  6:13 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Add quirks to support mode switch among Ilitek normal, debug and test mode
and allow delay before send output reports.
Add a shared variable to configure response timeout value for Ilitek
touch controllers.

Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-core.c | 84 +++++++++++++++++++++++++++++++++++++-
 drivers/hid/spi-hid/spi-hid-core.h |  4 ++
 drivers/hid/spi-hid/spi-hid.h      |  6 +++
 3 files changed, 93 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 893a0d4642d2..736e51f10cfc 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -22,6 +22,7 @@
 
 #include <linux/completion.h>
 #include <linux/crc32.h>
+#include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
@@ -45,9 +46,14 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
+#include "../hid-ids.h"
 #include "spi-hid.h"
 #include "spi-hid-core.h"
 
+/* quirks to control the device */
+#define SPI_HID_QUIRK_MODE_SWITCH	BIT(0)
+#define SPI_HID_QUIRK_READ_DELAY	BIT(1)
+
 /* Protocol constants */
 #define SPI_HID_READ_APPROVAL_CONSTANT		0xff
 #define SPI_HID_INPUT_HEADER_SYNC_BYTE		0x5a
@@ -86,6 +92,16 @@
 #define SPI_HID_CREATE_DEVICE	4
 #define SPI_HID_ERROR	5
 
+static const struct spi_hid_quirks {
+	__u16 idVendor;
+	__u16 idProduct;
+	__u32 quirks;
+} spi_hid_quirks[] = {
+	{ USB_VENDOR_ID_ILITEK, HID_ANY_ID,
+		SPI_HID_QUIRK_MODE_SWITCH | SPI_HID_QUIRK_READ_DELAY },
+	{ 0, 0 }
+};
+
 /* Processed data from input report header */
 struct spi_hid_input_header {
 	u8 version;
@@ -112,6 +128,27 @@ struct spi_hid_output_report {
 
 static struct hid_ll_driver spi_hid_ll_driver;
 
+/**
+ * spi_hid_lookup_quirk: return any quirks associated with a SPI HID device
+ * @idVendor: the 16-bit vendor ID
+ * @idProduct: the 16-bit product ID
+ *
+ * Returns: a u32 quirks value.
+ */
+static u32 spi_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
+{
+	u32 quirks = 0;
+	int n;
+
+	for (n = 0; spi_hid_quirks[n].idVendor; n++)
+		if (spi_hid_quirks[n].idVendor == idVendor &&
+		    (spi_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
+		     spi_hid_quirks[n].idProduct == idProduct))
+			quirks = spi_hid_quirks[n].quirks;
+
+	return quirks;
+}
+
 static void spi_hid_populate_read_approvals(const struct spi_hid_conf *conf,
 					    u8 *header_buf, u8 *body_buf)
 {
@@ -382,6 +419,9 @@ static int spi_hid_send_output_report(struct spi_hid *shid,
 	u8 padding;
 	int error;
 
+	if (shid->quirks & SPI_HID_QUIRK_READ_DELAY)
+		usleep_range(2000, 2100);
+
 	guard(mutex)(&shid->output_lock);
 	if (report->content_length > shid->desc.max_output_length) {
 		dev_err(dev, "Output report too big, content_length 0x%x.",
@@ -406,18 +446,38 @@ static int spi_hid_send_output_report(struct spi_hid *shid,
 	return error;
 }
 
+static const u32 spi_hid_get_timeout(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+	u32 timeout;
+
+	timeout = READ_ONCE(shid->ops->response_timeout_ms);
+
+	if (timeout < SPI_HID_RESP_TIMEOUT || timeout > 10000) {
+		dev_dbg(dev, "Response timeout is out of range, using default %d",
+			SPI_HID_RESP_TIMEOUT);
+		timeout = SPI_HID_RESP_TIMEOUT;
+	}
+
+	return timeout;
+}
+
 static int spi_hid_sync_request(struct spi_hid *shid,
 				struct spi_hid_output_report *report)
 {
 	struct device *dev = &shid->spi->dev;
+	u32 timeout = SPI_HID_RESP_TIMEOUT;
 	int error;
 
 	error = spi_hid_send_output_report(shid, report);
 	if (error)
 		return error;
 
+	if (shid->quirks & SPI_HID_QUIRK_MODE_SWITCH)
+		timeout = spi_hid_get_timeout(shid);
+
 	error = wait_for_completion_interruptible_timeout(&shid->output_done,
-							  msecs_to_jiffies(SPI_HID_RESP_TIMEOUT));
+							  msecs_to_jiffies(timeout));
 	if (error == 0) {
 		dev_err(dev, "Response timed out.");
 		return -ETIMEDOUT;
@@ -561,6 +621,8 @@ static int spi_hid_create_device(struct spi_hid *shid)
 	hid->vendor = shid->desc.vendor_id;
 	hid->product = shid->desc.product_id;
 
+	shid->quirks = spi_hid_lookup_quirk(hid->vendor, hid->product);
+
 	snprintf(hid->name, sizeof(hid->name), "spi %04X:%04X",
 		 hid->vendor, hid->product);
 	strscpy(hid->phys, dev_name(&shid->spi->dev), sizeof(hid->phys));
@@ -836,6 +898,24 @@ static irqreturn_t spi_hid_dev_irq(int irq, void *_shid)
 		goto out;
 	}
 
+	if (shid->quirks & SPI_HID_QUIRK_MODE_SWITCH) {
+		/*
+		 * Update reset_pending on mode transitions inferred from
+		 * response timeout (entering/exiting a mode).
+		 */
+		u32 timeout = spi_hid_get_timeout(shid);
+		bool mode_enabled = timeout > SPI_HID_RESP_TIMEOUT;
+
+		if (mode_enabled != shid->prev_mode_enabled) {
+			if (mode_enabled)
+				set_bit(SPI_HID_RESET_PENDING, &shid->flags);
+			else
+				clear_bit(SPI_HID_RESET_PENDING, &shid->flags);
+		}
+
+		shid->prev_mode_enabled = mode_enabled;
+	}
+
 	if (shid->input_message.status < 0) {
 		dev_warn(dev, "Error reading header: %d.",
 			 shid->input_message.status);
@@ -1190,6 +1270,8 @@ static int spi_hid_dev_init(struct spi_hid *shid)
 	struct device *dev = &spi->dev;
 	int error;
 
+	shid->ops->custom_init(shid->ops);
+
 	shid->ops->assert_reset(shid->ops);
 
 	shid->ops->sleep_minimal_reset_delay(shid->ops);
diff --git a/drivers/hid/spi-hid/spi-hid-core.h b/drivers/hid/spi-hid/spi-hid-core.h
index 88e9020d37aa..8441dbad95d4 100644
--- a/drivers/hid/spi-hid/spi-hid-core.h
+++ b/drivers/hid/spi-hid/spi-hid-core.h
@@ -62,6 +62,10 @@ struct spi_hid {
 	u16 response_length;
 	u16 bufsize;
 
+	bool prev_mode_enabled;	/* Previous device mode tracked for SPI_HID_QUIRK_MODE_SWITCH. */
+
+	unsigned long quirks;	/* Various quirks. */
+
 	enum hidspi_power_state power_state;
 
 	u8 reset_attempts;	/* The number of reset attempts. */
diff --git a/drivers/hid/spi-hid/spi-hid.h b/drivers/hid/spi-hid/spi-hid.h
index 5651c7fb706a..3c0369bdb4ab 100644
--- a/drivers/hid/spi-hid/spi-hid.h
+++ b/drivers/hid/spi-hid/spi-hid.h
@@ -25,6 +25,9 @@ struct spi_hid_conf {
  * @power_down: do sequencing to power down the device
  * @assert_reset: do sequencing to assert the reset line
  * @deassert_reset: do sequencing to deassert the reset line
+ * @sleep_minimal_reset_delay: minimal sleep delay during reset
+ * @custom_init: customized device init
+ * @response_timeout_ms: output report response timeout in ms
  */
 struct spihid_ops {
 	int (*power_up)(struct spihid_ops *ops);
@@ -32,6 +35,9 @@ struct spihid_ops {
 	int (*assert_reset)(struct spihid_ops *ops);
 	int (*deassert_reset)(struct spihid_ops *ops);
 	void (*sleep_minimal_reset_delay)(struct spihid_ops *ops);
+	int (*custom_init)(struct spihid_ops *ops);
+
+	u32 response_timeout_ms;
 };
 
 int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 11/12] HID: spi-hid: add panel follower support
From: Jingyuan Liang @ 2026-03-03  6:13 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Add support to spi-hid to be a panel follower.

Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-core.c | 199 +++++++++++++++++++++++++++++--------
 drivers/hid/spi-hid/spi-hid-core.h |   7 ++
 2 files changed, 163 insertions(+), 43 deletions(-)

diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 797ba99394f9..893a0d4642d2 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -238,21 +238,21 @@ static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state
 	}
 }
 
-static void spi_hid_suspend(struct spi_hid *shid)
+static int spi_hid_suspend(struct spi_hid *shid)
 {
 	int error;
 	struct device *dev = &shid->spi->dev;
 
 	guard(mutex)(&shid->power_lock);
 	if (shid->power_state == HIDSPI_OFF)
-		return;
+		return 0;
 
 	if (shid->hid) {
 		error = hid_driver_suspend(shid->hid, PMSG_SUSPEND);
 		if (error) {
 			dev_err(dev, "%s failed to suspend hid driver: %d",
 				__func__, error);
-			return;
+			return error;
 		}
 	}
 
@@ -270,21 +270,22 @@ static void spi_hid_suspend(struct spi_hid *shid)
 			dev_err(dev, "%s: could not power down.", __func__);
 			shid->regulator_error_count++;
 			shid->regulator_last_error = error;
-			return;
+			return error;
 		}
 
 		shid->power_state = HIDSPI_OFF;
 	}
+	return 0;
 }
 
-static void spi_hid_resume(struct spi_hid *shid)
+static int spi_hid_resume(struct spi_hid *shid)
 {
 	int error;
 	struct device *dev = &shid->spi->dev;
 
 	guard(mutex)(&shid->power_lock);
 	if (shid->power_state == HIDSPI_ON)
-		return;
+		return 0;
 
 	enable_irq(shid->spi->irq);
 
@@ -298,7 +299,7 @@ static void spi_hid_resume(struct spi_hid *shid)
 			dev_err(dev, "%s: could not power up.", __func__);
 			shid->regulator_error_count++;
 			shid->regulator_last_error = error;
-			return;
+			return error;
 		}
 		shid->power_state = HIDSPI_ON;
 
@@ -307,10 +308,13 @@ static void spi_hid_resume(struct spi_hid *shid)
 
 	if (shid->hid) {
 		error = hid_driver_reset_resume(shid->hid);
-		if (error)
+		if (error) {
 			dev_err(dev, "%s: failed to reset resume hid driver: %d.",
 				__func__, error);
+			return error;
+		}
 	}
+	return 0;
 }
 
 static void spi_hid_stop_hid(struct spi_hid *shid)
@@ -1171,6 +1175,132 @@ const struct attribute_group *spi_hid_groups[] = {
 };
 EXPORT_SYMBOL_GPL(spi_hid_groups);
 
+/*
+ * At the end of probe we initialize the device:
+ *   0) assert reset, bias the interrupt line
+ *   1) sleep minimal reset delay
+ *   2) request IRQ
+ *   3) power up the device
+ *   4) deassert reset (high)
+ * After this we expect an IRQ with a reset response.
+ */
+static int spi_hid_dev_init(struct spi_hid *shid)
+{
+	struct spi_device *spi = shid->spi;
+	struct device *dev = &spi->dev;
+	int error;
+
+	shid->ops->assert_reset(shid->ops);
+
+	shid->ops->sleep_minimal_reset_delay(shid->ops);
+
+	error = devm_request_threaded_irq(dev, spi->irq, NULL, spi_hid_dev_irq,
+					  IRQF_ONESHOT, dev_name(&spi->dev), shid);
+	if (error) {
+		dev_err(dev, "%s: unable to request threaded IRQ.", __func__);
+		return error;
+	}
+	if (device_may_wakeup(dev)) {
+		error = dev_pm_set_wake_irq(dev, spi->irq);
+		if (error) {
+			dev_err(dev, "%s: failed to set wake IRQ.", __func__);
+			return error;
+		}
+	}
+
+	error = shid->ops->power_up(shid->ops);
+	if (error) {
+		dev_err(dev, "%s: could not power up.", __func__);
+		shid->regulator_error_count++;
+		shid->regulator_last_error = error;
+		return error;
+	}
+
+	shid->ops->deassert_reset(shid->ops);
+
+	return 0;
+}
+
+static void spi_hid_panel_follower_work(struct work_struct *work)
+{
+	struct spi_hid *shid = container_of(work, struct spi_hid,
+					    panel_follower_work);
+	int error;
+
+	if (!shid->desc.hid_version)
+		error = spi_hid_dev_init(shid);
+	else
+		error = spi_hid_resume(shid);
+	if (error)
+		dev_warn(&shid->spi->dev, "Power on failed: %d", error);
+	else
+		WRITE_ONCE(shid->panel_follower_work_finished, true);
+
+	/*
+	 * The work APIs provide a number of memory ordering guarantees
+	 * including one that says that memory writes before schedule_work()
+	 * are always visible to the work function, but they don't appear to
+	 * guarantee that a write that happened in the work is visible after
+	 * cancel_work_sync(). We'll add a write memory barrier here to match
+	 * with spi_hid_panel_unpreparing() to ensure that our write to
+	 * panel_follower_work_finished is visible there.
+	 */
+	smp_wmb();
+}
+
+static int spi_hid_panel_follower_resume(struct drm_panel_follower *follower)
+{
+	struct spi_hid *shid = container_of(follower, struct spi_hid, panel_follower);
+
+	/*
+	 * Powering on a touchscreen can be a slow process. Queue the work to
+	 * the system workqueue so we don't block the panel's power up.
+	 */
+	WRITE_ONCE(shid->panel_follower_work_finished, false);
+	schedule_work(&shid->panel_follower_work);
+
+	return 0;
+}
+
+static int spi_hid_panel_follower_suspend(struct drm_panel_follower *follower)
+{
+	struct spi_hid *shid = container_of(follower, struct spi_hid, panel_follower);
+
+	cancel_work_sync(&shid->panel_follower_work);
+
+	/* Match with shid_core_panel_follower_work() */
+	smp_rmb();
+	if (!READ_ONCE(shid->panel_follower_work_finished))
+		return 0;
+
+	return spi_hid_suspend(shid);
+}
+
+static const struct drm_panel_follower_funcs
+				spi_hid_panel_follower_prepare_funcs = {
+	.panel_prepared = spi_hid_panel_follower_resume,
+	.panel_unpreparing = spi_hid_panel_follower_suspend,
+};
+
+static int spi_hid_register_panel_follower(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+
+	shid->panel_follower.funcs = &spi_hid_panel_follower_prepare_funcs;
+
+	/*
+	 * If we're not in control of our own power up/power down then we can't
+	 * do the logic to manage wakeups. Give a warning if a user thought
+	 * that was possible then force the capability off.
+	 */
+	if (device_can_wakeup(dev)) {
+		dev_warn(dev, "Can't wakeup if following panel\n");
+		device_set_wakeup_capable(dev, false);
+	}
+
+	return drm_panel_add_follower(dev, &shid->panel_follower);
+}
+
 int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 		       struct spi_hid_conf *conf)
 {
@@ -1190,6 +1320,7 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	shid->ops = ops;
 	shid->conf = conf;
 	set_bit(SPI_HID_RESET_PENDING, &shid->flags);
+	shid->is_panel_follower = drm_is_panel_follower(&spi->dev);
 
 	spi_set_drvdata(spi, shid);
 
@@ -1202,6 +1333,7 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	init_completion(&shid->output_done);
 
 	INIT_WORK(&shid->reset_work, spi_hid_reset_work);
+	INIT_WORK(&shid->panel_follower_work, spi_hid_panel_follower_work);
 
 	/*
 	 * We need to allocate the buffer without knowing the maximum
@@ -1212,42 +1344,18 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	if (error)
 		return error;
 
-	/*
-	 * At the end of probe we initialize the device:
-	 *   0) assert reset, bias the interrupt line
-	 *   1) sleep minimal reset delay
-	 *   2) request IRQ
-	 *   3) power up the device
-	 *   4) deassert reset (high)
-	 * After this we expect an IRQ with a reset response.
-	 */
-
-	shid->ops->assert_reset(shid->ops);
-
-	shid->ops->sleep_minimal_reset_delay(shid->ops);
-
-	error = devm_request_threaded_irq(dev, spi->irq, NULL, spi_hid_dev_irq,
-					  IRQF_ONESHOT, dev_name(&spi->dev), shid);
-	if (error) {
-		dev_err(dev, "%s: unable to request threaded IRQ.", __func__);
-		return error;
-	}
-	if (device_may_wakeup(dev)) {
-		error = dev_pm_set_wake_irq(dev, spi->irq);
+	if (shid->is_panel_follower) {
+		error = spi_hid_register_panel_follower(shid);
 		if (error) {
-			dev_err(dev, "%s: failed to set wake IRQ.", __func__);
+			dev_err(dev, "%s: could not add panel follower.", __func__);
 			return error;
 		}
+	} else {
+		error = spi_hid_dev_init(shid);
+		if (error)
+			return error;
 	}
 
-	error = shid->ops->power_up(shid->ops);
-	if (error) {
-		dev_err(dev, "%s: could not power up.", __func__);
-		return error;
-	}
-
-	shid->ops->deassert_reset(shid->ops);
-
 	dev_dbg(dev, "%s: d3 -> %s.", __func__,
 		spi_hid_power_mode_string(shid->power_state));
 
@@ -1261,6 +1369,9 @@ void spi_hid_core_remove(struct spi_device *spi)
 	struct device *dev = &spi->dev;
 	int error;
 
+	if (shid->is_panel_follower)
+		drm_panel_remove_follower(&shid->panel_follower);
+
 	spi_hid_stop_hid(shid);
 
 	shid->ops->assert_reset(shid->ops);
@@ -1274,18 +1385,20 @@ static int spi_hid_core_pm_suspend(struct device *dev)
 {
 	struct spi_hid *shid = dev_get_drvdata(dev);
 
-	spi_hid_suspend(shid);
+	if (shid->is_panel_follower)
+		return 0;
 
-	return 0;
+	return spi_hid_suspend(shid);
 }
 
 static int spi_hid_core_pm_resume(struct device *dev)
 {
 	struct spi_hid *shid = dev_get_drvdata(dev);
 
-	spi_hid_resume(shid);
+	if (shid->is_panel_follower)
+		return 0;
 
-	return 0;
+	return spi_hid_resume(shid);
 }
 
 const struct dev_pm_ops spi_hid_core_pm = {
diff --git a/drivers/hid/spi-hid/spi-hid-core.h b/drivers/hid/spi-hid/spi-hid-core.h
index 2bfdfbe6d7fc..88e9020d37aa 100644
--- a/drivers/hid/spi-hid/spi-hid-core.h
+++ b/drivers/hid/spi-hid/spi-hid-core.h
@@ -7,6 +7,8 @@
 #include <linux/hid-over-spi.h>
 #include <linux/spi/spi.h>
 
+#include <drm/drm_panel.h>
+
 /* Protocol message size constants */
 #define SPI_HID_READ_APPROVAL_LEN		5
 #define SPI_HID_OUTPUT_HEADER_LEN		8
@@ -53,6 +55,10 @@ struct spi_hid {
 	struct spi_hid_input_buf *input;	/* Input buffer. */
 	struct spi_hid_input_buf *response;	/* Response buffer. */
 
+	struct drm_panel_follower panel_follower;
+	bool	is_panel_follower;
+	bool	panel_follower_work_finished;
+
 	u16 response_length;
 	u16 bufsize;
 
@@ -63,6 +69,7 @@ struct spi_hid {
 	unsigned long flags;	/* device flags. */
 
 	struct work_struct reset_work;
+	struct work_struct panel_follower_work;
 
 	/* Control lock to make sure one output transaction at a time. */
 	struct mutex output_lock;

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 10/12] HID: spi-hid: add power management implementation
From: Jingyuan Liang @ 2026-03-03  6:13 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Implement HID over SPI driver power management callbacks.

Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-acpi.c |   1 +
 drivers/hid/spi-hid/spi-hid-core.c | 107 +++++++++++++++++++++++++++++++++++++
 drivers/hid/spi-hid/spi-hid-of.c   |   1 +
 drivers/hid/spi-hid/spi-hid.h      |   1 +
 4 files changed, 110 insertions(+)

diff --git a/drivers/hid/spi-hid/spi-hid-acpi.c b/drivers/hid/spi-hid/spi-hid-acpi.c
index 612e74fe72f9..2c1e4de99fea 100644
--- a/drivers/hid/spi-hid/spi-hid-acpi.c
+++ b/drivers/hid/spi-hid/spi-hid-acpi.c
@@ -238,6 +238,7 @@ static struct spi_driver spi_hid_acpi_driver = {
 	.driver = {
 		.name	= "spi_hid_acpi",
 		.owner	= THIS_MODULE,
+		.pm	= &spi_hid_core_pm,
 		.acpi_match_table = ACPI_PTR(spi_hid_acpi_match),
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 		.dev_groups = spi_hid_groups,
diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 02beb209a92d..797ba99394f9 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -35,6 +35,8 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/pm_wakeirq.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/string.h>
@@ -236,6 +238,81 @@ static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state
 	}
 }
 
+static void spi_hid_suspend(struct spi_hid *shid)
+{
+	int error;
+	struct device *dev = &shid->spi->dev;
+
+	guard(mutex)(&shid->power_lock);
+	if (shid->power_state == HIDSPI_OFF)
+		return;
+
+	if (shid->hid) {
+		error = hid_driver_suspend(shid->hid, PMSG_SUSPEND);
+		if (error) {
+			dev_err(dev, "%s failed to suspend hid driver: %d",
+				__func__, error);
+			return;
+		}
+	}
+
+	disable_irq(shid->spi->irq);
+
+	clear_bit(SPI_HID_READY, &shid->flags);
+
+	if (!device_may_wakeup(dev)) {
+		set_bit(SPI_HID_RESET_PENDING, &shid->flags);
+
+		shid->ops->assert_reset(shid->ops);
+
+		error = shid->ops->power_down(shid->ops);
+		if (error) {
+			dev_err(dev, "%s: could not power down.", __func__);
+			shid->regulator_error_count++;
+			shid->regulator_last_error = error;
+			return;
+		}
+
+		shid->power_state = HIDSPI_OFF;
+	}
+}
+
+static void spi_hid_resume(struct spi_hid *shid)
+{
+	int error;
+	struct device *dev = &shid->spi->dev;
+
+	guard(mutex)(&shid->power_lock);
+	if (shid->power_state == HIDSPI_ON)
+		return;
+
+	enable_irq(shid->spi->irq);
+
+	if (!device_may_wakeup(dev)) {
+		shid->ops->assert_reset(shid->ops);
+
+		shid->ops->sleep_minimal_reset_delay(shid->ops);
+
+		error = shid->ops->power_up(shid->ops);
+		if (error) {
+			dev_err(dev, "%s: could not power up.", __func__);
+			shid->regulator_error_count++;
+			shid->regulator_last_error = error;
+			return;
+		}
+		shid->power_state = HIDSPI_ON;
+
+		shid->ops->deassert_reset(shid->ops);
+	}
+
+	if (shid->hid) {
+		error = hid_driver_reset_resume(shid->hid);
+		if (error)
+			dev_err(dev, "%s: failed to reset resume hid driver: %d.",
+				__func__, error);
+	}
+}
+
 static void spi_hid_stop_hid(struct spi_hid *shid)
 {
 	struct hid_device *hid = shid->hid;
@@ -1155,6 +1232,13 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 		dev_err(dev, "%s: unable to request threaded IRQ.", __func__);
 		return error;
 	}
+	if (device_may_wakeup(dev)) {
+		error = dev_pm_set_wake_irq(dev, spi->irq);
+		if (error) {
+			dev_err(dev, "%s: failed to set wake IRQ.", __func__);
+			return error;
+		}
+	}
 
 	error = shid->ops->power_up(shid->ops);
 	if (error) {
@@ -1186,6 +1270,29 @@ void spi_hid_core_remove(struct spi_device *spi)
 }
 EXPORT_SYMBOL_GPL(spi_hid_core_remove);
 
+static int spi_hid_core_pm_suspend(struct device *dev)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	spi_hid_suspend(shid);
+
+	return 0;
+}
+
+static int spi_hid_core_pm_resume(struct device *dev)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	spi_hid_resume(shid);
+
+	return 0;
+}
+
+const struct dev_pm_ops spi_hid_core_pm = {
+	SYSTEM_SLEEP_PM_OPS(spi_hid_core_pm_suspend, spi_hid_core_pm_resume)
+};
+EXPORT_SYMBOL_GPL(spi_hid_core_pm);
+
 MODULE_DESCRIPTION("HID over SPI transport driver");
 MODULE_AUTHOR("Dmitry Antipov <dmanti@microsoft.com>");
 MODULE_LICENSE("GPL");
diff --git a/drivers/hid/spi-hid/spi-hid-of.c b/drivers/hid/spi-hid/spi-hid-of.c
index a20c8146230b..bc1d3c5a4dda 100644
--- a/drivers/hid/spi-hid/spi-hid-of.c
+++ b/drivers/hid/spi-hid/spi-hid-of.c
@@ -227,6 +227,7 @@ static struct spi_driver spi_hid_of_driver = {
 	.driver = {
 		.name	= "spi_hid_of",
 		.owner	= THIS_MODULE,
+		.pm	= &spi_hid_core_pm,
 		.of_match_table = of_match_ptr(spi_hid_of_match),
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 		.dev_groups = spi_hid_groups,
diff --git a/drivers/hid/spi-hid/spi-hid.h b/drivers/hid/spi-hid/spi-hid.h
index 1fdd45262647..5651c7fb706a 100644
--- a/drivers/hid/spi-hid/spi-hid.h
+++ b/drivers/hid/spi-hid/spi-hid.h
@@ -40,5 +40,6 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 void spi_hid_core_remove(struct spi_device *spi);
 
 extern const struct attribute_group *spi_hid_groups[];
+extern const struct dev_pm_ops spi_hid_core_pm;
 
 #endif /* SPI_HID_H */

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 09/12] dt-bindings: input: Document hid-over-spi DT schema
From: Jingyuan Liang @ 2026-03-03  6:13 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Dmitry Antipov, Jarrett Schultz
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Documentation describes the required and optional properties for
implementing Device Tree for a Microsoft G6 Touch Digitizer that
supports HID over SPI Protocol 1.0 specification.

The properties are common to HID over SPI.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Jarrett Schultz <jaschultz@microsoft.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 .../devicetree/bindings/input/hid-over-spi.yaml    | 153 +++++++++++++++++++++
 1 file changed, 153 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.yaml b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
new file mode 100644
index 000000000000..b623629ed9d3
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
@@ -0,0 +1,153 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/hid-over-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: HID over SPI Devices
+
+maintainers:
+  - Benjamin Tissoires <benjamin.tissoires@redhat.com>
+  - Jiri Kosina <jkosina@suse.cz>
+
+description: |+
+  HID over SPI provides support for various Human Interface Devices over the
+  SPI bus. These devices can be for example touchpads, keyboards, touch screens
+  or sensors.
+
+  The specification has been written by Microsoft and is currently available here:
+  https://www.microsoft.com/en-us/download/details.aspx?id=103325
+
+  If this binding is used, the kernel module spi-hid will handle the communication
+  with the device and the generic hid core layer will handle the protocol.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - microsoft,g6-touch-digitizer
+          - const: hid-over-spi
+      - description: Just "hid-over-spi" alone is allowed, but not recommended.
+        const: hid-over-spi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+    description:
+      GPIO specifier for the digitizer's reset pin (active low). The line must
+      be flagged with GPIO_ACTIVE_LOW.
+
+  vdd-supply:
+    description:
+      Regulator for the VDD supply voltage.
+
+  input-report-header-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+      A value to be included in the Read Approval packet, listing an address of
+      the input report header to be put on the SPI bus. This address has 24
+      bits.
+
+  input-report-body-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+     A value to be included in the Read Approval packet, listing an address of
+      the input report body to be put on the SPI bus. This address has 24 bits.
+
+  output-report-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+      A value to be included in the Output Report sent by the host, listing an
+      address where the output report on the SPI bus is to be written to. This
+      address has 24 bits.
+
+  post-power-on-delay-ms:
+    description:
+      Optional time in ms required by the device after enabling its regulators
+      or powering it on, before it is ready for communication.
+
+  minimal-reset-delay-ms:
+    description:
+      Optional minimum amount of time in ms that device needs to be in reset
+      state for the reset to take effect.
+
+  read-opcode:
+  $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      Value to be used in Read Approval packets. 1 byte.
+
+  write-opcode:
+  $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      Value to be used in Write Approval packets. 1 byte.
+
+  hid-over-spi-flags:
+  $ref: /schemas/types.yaml#/definitions/uint16
+    description:
+      16 bits.
+      Bits 0-12 - Reserved (must be 0)
+      Bit 13 - SPI Write Mode. Possible values -
+        * 0b0- Writes are carried out in Single-SPI mode
+        * 0b1- Writes are carried out in the Multi-SPI mode specified by bits
+               14-15
+      Bits 14-15 - Multi-SPI Mode. Possible values -
+        * 0b00- Single SPI
+        * 0b01- Dual SPI
+        * 0b10- Quad SPI
+
+required:
+  - compatible
+  - interrupts
+  - reset-gpios
+  - vdd-supply
+  - input-report-header-address
+  - input-report-body-address
+  - output-report-address
+  - read-opcode
+  - write-opcode
+  - hid-over-spi-flags
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      hid@0 {
+        compatible = "hid-over-spi";
+        reg = <0x0>;
+        interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
+        reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
+        vdd-supply = <&pm8350c_l3>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&ts_d6_reset_assert &ts_d6_int_bias>;
+        input-report-header-address = <0x1000>;
+        input-report-body-address = <0x1004>;
+        output-report-address = <0x2000>;
+        read-opcode = <0x0b>;
+        write-opcode = <0x02>;
+        hid-over-spi-flags = <0x0000>;
+        post-power-on-delay-ms = <5>;
+        minimal-reset-delay-ms = <5>;
+      };
+    };
\ No newline at end of file

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 08/12] HID: spi_hid: add device tree support for SPI over HID
From: Jingyuan Liang @ 2026-03-03  6:13 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Jarrett Schultz, Dmitry Antipov
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

From: Jarrett Schultz <jaschultz@microsoft.com>

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/Kconfig      |  15 +++
 drivers/hid/spi-hid/Makefile     |   1 +
 drivers/hid/spi-hid/spi-hid-of.c | 243 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 259 insertions(+)

diff --git a/drivers/hid/spi-hid/Kconfig b/drivers/hid/spi-hid/Kconfig
index 114b1e00da39..76a2cd587a3e 100644
--- a/drivers/hid/spi-hid/Kconfig
+++ b/drivers/hid/spi-hid/Kconfig
@@ -25,6 +25,21 @@ config SPI_HID_ACPI
 	  will be called spi-hid-acpi. It will also build/depend on the
 	  module spi-hid.
 
+config SPI_HID_OF
+	tristate "HID over SPI transport layer Open Firmware driver"
+	depends on OF
+	select SPI_HID_CORE
+	help
+	  Say Y here if you use a keyboard, a touchpad, a touchscreen, or any
+	  other HID based devices which are connected to your computer via SPI.
+	  This driver supports Open Firmware (Device Tree)-based systems.
+
+	  If unsure, say N.
+
+	  This support is also available as a module.  If so, the module
+	  will be called spi-hid-of. It will also build/depend on the
+	  module spi-hid.
+
 config SPI_HID_CORE
 	tristate
 endif
diff --git a/drivers/hid/spi-hid/Makefile b/drivers/hid/spi-hid/Makefile
index 753c7b7a7844..fe627fd378e3 100644
--- a/drivers/hid/spi-hid/Makefile
+++ b/drivers/hid/spi-hid/Makefile
@@ -8,3 +8,4 @@
 obj-$(CONFIG_SPI_HID_CORE)	+= spi-hid.o
 spi-hid-objs 			= spi-hid-core.o
 obj-$(CONFIG_SPI_HID_ACPI)	+= spi-hid-acpi.o
+obj-$(CONFIG_SPI_HID_OF)	+= spi-hid-of.o
diff --git a/drivers/hid/spi-hid/spi-hid-of.c b/drivers/hid/spi-hid/spi-hid-of.c
new file mode 100644
index 000000000000..a20c8146230b
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-of.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID over SPI protocol, Open Firmware related code
+ *
+ * Copyright (c) 2021 Microsoft Corporation
+ *
+ * This code was forked out of the HID over SPI core code, which is partially
+ * based on "HID over I2C protocol implementation:
+ *
+ * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ * Copyright (c) 2012 Red Hat, Inc
+ *
+ * which in turn is partially based on "USB HID support for Linux":
+ *
+ * Copyright (c) 1999 Andreas Gal
+ * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ * Copyright (c) 2007-2008 Oliver Neukum
+ * Copyright (c) 2006-2010 Jiri Kosina
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+
+#include "spi-hid.h"
+
+/* Config structure is filled with data from Device Tree */
+struct spi_hid_of_config {
+	struct spihid_ops ops;
+
+	struct spi_hid_conf property_conf;
+	u32 post_power_on_delay_ms;
+	u32 minimal_reset_delay_ms;
+	struct gpio_desc *reset_gpio;
+	struct regulator *supply;
+	bool supply_enabled;
+};
+
+static int spi_hid_of_populate_config(struct spi_hid_of_config *conf,
+				      struct device *dev)
+{
+	int error;
+	u32 val;
+
+	error = device_property_read_u32(dev, "input-report-header-address",
+					 &val);
+	if (error) {
+		dev_err(dev, "Input report header address not provided.");
+		return -ENODEV;
+	}
+	conf->property_conf.input_report_header_address = val;
+
+	error = device_property_read_u32(dev, "input-report-body-address", &val);
+	if (error) {
+		dev_err(dev, "Input report body address not provided.");
+		return -ENODEV;
+	}
+	conf->property_conf.input_report_body_address = val;
+
+	error = device_property_read_u32(dev, "output-report-address", &val);
+	if (error) {
+		dev_err(dev, "Output report address not provided.");
+		return -ENODEV;
+	}
+	conf->property_conf.output_report_address = val;
+
+	error = device_property_read_u32(dev, "read-opcode", &val);
+	if (error) {
+		dev_err(dev, "Read opcode not provided.");
+		return -ENODEV;
+	}
+	conf->property_conf.read_opcode = val;
+
+	error = device_property_read_u32(dev, "write-opcode", &val);
+	if (error) {
+		dev_err(dev, "Write opcode not provided.");
+		return -ENODEV;
+	}
+	conf->property_conf.write_opcode = val;
+
+	error = device_property_read_u32(dev, "post-power-on-delay-ms", &val);
+	if (error) {
+		dev_err(dev, "post-power-on-delay-ms not provided, using 10.");
+		val = 10;
+	}
+	conf->post_power_on_delay_ms = val;
+
+	error = device_property_read_u32(dev, "minimal-reset-delay-ms", &val);
+	if (error) {
+		dev_err(dev, "minimal-reset-delay-ms not provided, using 100.");
+		val = 100;
+	}
+	conf->minimal_reset_delay_ms = val;
+
+	/* FIXME: not reading hid-over-spi-flags, multi-fragment not supported */
+
+	conf->supply = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(conf->supply)) {
+		if (PTR_ERR(conf->supply) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get regulator: %ld.",
+				PTR_ERR(conf->supply));
+		return PTR_ERR(conf->supply);
+	}
+	conf->supply_enabled = false;
+
+	conf->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(conf->reset_gpio)) {
+		dev_err(dev, "%s: error getting reset GPIO.", __func__);
+		return PTR_ERR(conf->reset_gpio);
+	}
+
+	return 0;
+}
+
+static int spi_hid_of_power_down(struct spihid_ops *ops)
+{
+	struct spi_hid_of_config *conf = container_of(ops,
+						      struct spi_hid_of_config,
+						      ops);
+	int error;
+
+	if (!conf->supply_enabled)
+		return 0;
+
+	error = regulator_disable(conf->supply);
+	if (error == 0)
+		conf->supply_enabled = false;
+
+	return error;
+}
+
+static int spi_hid_of_power_up(struct spihid_ops *ops)
+{
+	struct spi_hid_of_config *conf = container_of(ops,
+						      struct spi_hid_of_config,
+						      ops);
+	int error;
+
+	if (conf->supply_enabled)
+		return 0;
+
+	error = regulator_enable(conf->supply);
+
+	if (error == 0) {
+		conf->supply_enabled = true;
+		usleep_range(1000 * conf->post_power_on_delay_ms,
+			     1000 * (conf->post_power_on_delay_ms + 1));
+	}
+
+	return error;
+}
+
+static int spi_hid_of_assert_reset(struct spihid_ops *ops)
+{
+	struct spi_hid_of_config *conf = container_of(ops,
+						      struct spi_hid_of_config,
+						      ops);
+
+	gpiod_set_value(conf->reset_gpio, 1);
+	return 0;
+}
+
+static int spi_hid_of_deassert_reset(struct spihid_ops *ops)
+{
+	struct spi_hid_of_config *conf = container_of(ops,
+						      struct spi_hid_of_config,
+						      ops);
+
+	gpiod_set_value(conf->reset_gpio, 0);
+	return 0;
+}
+
+static void spi_hid_of_sleep_minimal_reset_delay(struct spihid_ops *ops)
+{
+	struct spi_hid_of_config *conf = container_of(ops,
+						      struct spi_hid_of_config,
+						      ops);
+	usleep_range(1000 * conf->minimal_reset_delay_ms,
+		     1000 * (conf->minimal_reset_delay_ms + 1));
+}
+
+static int spi_hid_of_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct spi_hid_of_config *config;
+	int error;
+
+	config = devm_kzalloc(dev, sizeof(struct spi_hid_of_config),
+			      GFP_KERNEL);
+	if (!config)
+		return -ENOMEM;
+
+	config->ops.power_up = spi_hid_of_power_up;
+	config->ops.power_down = spi_hid_of_power_down;
+	config->ops.assert_reset = spi_hid_of_assert_reset;
+	config->ops.deassert_reset = spi_hid_of_deassert_reset;
+	config->ops.sleep_minimal_reset_delay =
+		spi_hid_of_sleep_minimal_reset_delay;
+
+	error = spi_hid_of_populate_config(config, dev);
+	if (error) {
+		dev_err(dev, "%s: unable to populate config data.", __func__);
+		return error;
+	}
+
+	return spi_hid_core_probe(spi, &config->ops, &config->property_conf);
+}
+
+const struct of_device_id spi_hid_of_match[] = {
+	{ .compatible = "hid-over-spi" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, spi_hid_of_match);
+
+static const struct spi_device_id spi_hid_of_id_table[] = {
+	{ "hid", 0 },
+	{ "hid-over-spi", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, spi_hid_of_id_table);
+
+static struct spi_driver spi_hid_of_driver = {
+	.driver = {
+		.name	= "spi_hid_of",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(spi_hid_of_match),
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.dev_groups = spi_hid_groups,
+	},
+	.probe		= spi_hid_of_probe,
+	.remove		= spi_hid_core_remove,
+	.id_table	= spi_hid_of_id_table,
+};
+
+module_spi_driver(spi_hid_of_driver);
+
+MODULE_DESCRIPTION("HID over SPI OF transport driver");
+MODULE_AUTHOR("Dmitry Antipov <dmanti@microsoft.com>");
+MODULE_LICENSE("GPL");

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 07/12] HID: spi_hid: add ACPI support for SPI over HID
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Angela Czubak
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

From: Angela Czubak <acz@semihalf.com>

Detect SPI HID devices described in ACPI.

Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/Kconfig        |  15 +++
 drivers/hid/spi-hid/Makefile       |   1 +
 drivers/hid/spi-hid/spi-hid-acpi.c | 253 +++++++++++++++++++++++++++++++++++++
 drivers/hid/spi-hid/spi-hid-core.c |  27 +---
 drivers/hid/spi-hid/spi-hid.h      |  44 +++++++
 5 files changed, 316 insertions(+), 24 deletions(-)

diff --git a/drivers/hid/spi-hid/Kconfig b/drivers/hid/spi-hid/Kconfig
index 836fdefe8345..114b1e00da39 100644
--- a/drivers/hid/spi-hid/Kconfig
+++ b/drivers/hid/spi-hid/Kconfig
@@ -10,6 +10,21 @@ menuconfig SPI_HID
 
 if SPI_HID
 
+config SPI_HID_ACPI
+	tristate "HID over SPI transport layer ACPI driver"
+	depends on ACPI
+	select SPI_HID_CORE
+	help
+	  Say Y here if you use a keyboard, a touchpad, a touchscreen, or any
+	  other HID based devices which are connected to your computer via SPI.
+	  This driver supports ACPI-based systems.
+
+	  If unsure, say N.
+
+	  This support is also available as a module.  If so, the module
+	  will be called spi-hid-acpi. It will also build/depend on the
+	  module spi-hid.
+
 config SPI_HID_CORE
 	tristate
 endif
diff --git a/drivers/hid/spi-hid/Makefile b/drivers/hid/spi-hid/Makefile
index 92e24cddbfc2..753c7b7a7844 100644
--- a/drivers/hid/spi-hid/Makefile
+++ b/drivers/hid/spi-hid/Makefile
@@ -7,3 +7,4 @@
 
 obj-$(CONFIG_SPI_HID_CORE)	+= spi-hid.o
 spi-hid-objs 			= spi-hid-core.o
+obj-$(CONFIG_SPI_HID_ACPI)	+= spi-hid-acpi.o
diff --git a/drivers/hid/spi-hid/spi-hid-acpi.c b/drivers/hid/spi-hid/spi-hid-acpi.c
new file mode 100644
index 000000000000..612e74fe72f9
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-acpi.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID over SPI protocol, ACPI related code
+ *
+ * Copyright (c) 2021 Microsoft Corporation
+ * Copyright (c) 2026 Google LLC
+ *
+ * This code was forked out of the HID over SPI core code, which is partially
+ * based on "HID over I2C protocol implementation:
+ *
+ * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ * Copyright (c) 2012 Red Hat, Inc
+ *
+ * which in turn is partially based on "USB HID support for Linux":
+ *
+ * Copyright (c) 1999 Andreas Gal
+ * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ * Copyright (c) 2007-2008 Oliver Neukum
+ * Copyright (c) 2006-2010 Jiri Kosina
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/reset.h>
+#include <linux/uuid.h>
+
+#include "spi-hid.h"
+
+/* Config structure is filled with data from ACPI */
+struct spi_hid_acpi_config {
+	struct spihid_ops ops;
+
+	struct spi_hid_conf property_conf;
+	u32 post_power_on_delay_ms;
+	u32 minimal_reset_delay_ms;
+	struct acpi_device *adev;
+};
+
+/* HID SPI Device: 6e2ac436-0fcf41af-a265-b32a220dcfab */
+static guid_t spi_hid_guid =
+	GUID_INIT(0x6E2AC436, 0x0FCF, 0x41AF,
+		  0xA2, 0x65, 0xB3, 0x2A, 0x22, 0x0D, 0xCF, 0xAB);
+
+static int spi_hid_acpi_populate_config(struct spi_hid_acpi_config *conf,
+					struct acpi_device *adev)
+{
+	acpi_handle handle = acpi_device_handle(adev);
+	union acpi_object *obj;
+
+	conf->adev = adev;
+
+	/* Revision 3 for HID over SPI V1, see specification. */
+	obj = acpi_evaluate_dsm_typed(handle, &spi_hid_guid, 3, 1, NULL,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID input report header address failed");
+		return -ENODEV;
+	}
+	conf->property_conf.input_report_header_address = obj->integer.value;
+	ACPI_FREE(obj);
+
+	obj = acpi_evaluate_dsm_typed(handle, &spi_hid_guid, 3, 2, NULL,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID input report body address failed");
+		return -ENODEV;
+	}
+	conf->property_conf.input_report_body_address = obj->integer.value;
+	ACPI_FREE(obj);
+
+	obj = acpi_evaluate_dsm_typed(handle, &spi_hid_guid, 3, 3, NULL,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID output report header address failed");
+		return -ENODEV;
+	}
+	conf->property_conf.output_report_address = obj->integer.value;
+	ACPI_FREE(obj);
+
+	obj = acpi_evaluate_dsm_typed(handle, &spi_hid_guid, 3, 4, NULL,
+				      ACPI_TYPE_BUFFER);
+	if (!obj) {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID read opcode failed");
+		return -ENODEV;
+	}
+	if (obj->buffer.length == 1) {
+		conf->property_conf.read_opcode = obj->buffer.pointer[0];
+	} else {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID read opcode, too long buffer");
+		ACPI_FREE(obj);
+		return -ENODEV;
+	}
+	ACPI_FREE(obj);
+
+	obj = acpi_evaluate_dsm_typed(handle, &spi_hid_guid, 3, 5, NULL,
+				      ACPI_TYPE_BUFFER);
+	if (!obj) {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID write opcode failed");
+		return -ENODEV;
+	}
+	if (obj->buffer.length == 1) {
+		conf->property_conf.write_opcode = obj->buffer.pointer[0];
+	} else {
+		acpi_handle_err(handle,
+				"Error _DSM call to get HID write opcode, too long buffer");
+		ACPI_FREE(obj);
+		return -ENODEV;
+	}
+	ACPI_FREE(obj);
+
+	/* Value not provided in ACPI,*/
+	conf->post_power_on_delay_ms = 5;
+	conf->minimal_reset_delay_ms = 150;
+
+	if (!acpi_has_method(handle, "_RST")) {
+		acpi_handle_err(handle, "No reset method for acpi handle");
+		return -ENODEV;
+	}
+
+	/* FIXME: not reading hid-over-spi-flags, multi-SPI not supported */
+
+	return 0;
+}
+
+static int spi_hid_acpi_power_none(struct spihid_ops *ops)
+{
+	return 0;
+}
+
+static int spi_hid_acpi_power_down(struct spihid_ops *ops)
+{
+	struct spi_hid_acpi_config *conf = container_of(ops,
+							struct spi_hid_acpi_config,
+							ops);
+
+	return acpi_device_set_power(conf->adev, ACPI_STATE_D3);
+}
+
+static int spi_hid_acpi_power_up(struct spihid_ops *ops)
+{
+	struct spi_hid_acpi_config *conf = container_of(ops,
+							struct spi_hid_acpi_config,
+							ops);
+	int error;
+
+	error = acpi_device_set_power(conf->adev, ACPI_STATE_D0);
+	if (error) {
+		dev_err(&conf->adev->dev, "Error could not power up ACPI device: %d.", error);
+		return error;
+	}
+
+	if (conf->post_power_on_delay_ms)
+		msleep(conf->post_power_on_delay_ms);
+
+	return 0;
+}
+
+static int spi_hid_acpi_assert_reset(struct spihid_ops *ops)
+{
+	return 0;
+}
+
+static int spi_hid_acpi_deassert_reset(struct spihid_ops *ops)
+{
+	struct spi_hid_acpi_config *conf = container_of(ops,
+							struct spi_hid_acpi_config,
+							ops);
+
+	return device_reset(&conf->adev->dev);
+}
+
+static void spi_hid_acpi_sleep_minimal_reset_delay(struct spihid_ops *ops)
+{
+	struct spi_hid_acpi_config *conf = container_of(ops,
+							struct spi_hid_acpi_config,
+							ops);
+	usleep_range(1000 * conf->minimal_reset_delay_ms,
+		     1000 * (conf->minimal_reset_delay_ms + 1));
+}
+
+static int spi_hid_acpi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct acpi_device *adev;
+	struct spi_hid_acpi_config *config;
+	int error;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev) {
+		dev_err(dev, "Error could not get ACPI device.");
+		return -ENODEV;
+	}
+
+	config = devm_kzalloc(dev, sizeof(struct spi_hid_acpi_config),
+			      GFP_KERNEL);
+	if (!config)
+		return -ENOMEM;
+
+	if (acpi_device_power_manageable(adev)) {
+		config->ops.power_up = spi_hid_acpi_power_up;
+		config->ops.power_down = spi_hid_acpi_power_down;
+	} else {
+		config->ops.power_up = spi_hid_acpi_power_none;
+		config->ops.power_down = spi_hid_acpi_power_none;
+	}
+	config->ops.assert_reset = spi_hid_acpi_assert_reset;
+	config->ops.deassert_reset = spi_hid_acpi_deassert_reset;
+	config->ops.sleep_minimal_reset_delay =
+		spi_hid_acpi_sleep_minimal_reset_delay;
+
+	error = spi_hid_acpi_populate_config(config, adev);
+	if (error) {
+		dev_err(dev, "%s: unable to populate config data.", __func__);
+		return error;
+	}
+	return spi_hid_core_probe(spi, &config->ops, &config->property_conf);
+}
+
+static const struct acpi_device_id spi_hid_acpi_match[] = {
+	{ "ACPI0C51", 0 },
+	{ "PNP0C51", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, spi_hid_acpi_match);
+
+static struct spi_driver spi_hid_acpi_driver = {
+	.driver = {
+		.name	= "spi_hid_acpi",
+		.owner	= THIS_MODULE,
+		.acpi_match_table = ACPI_PTR(spi_hid_acpi_match),
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.dev_groups = spi_hid_groups,
+	},
+	.probe		= spi_hid_acpi_probe,
+	.remove		= spi_hid_core_remove,
+};
+
+module_spi_driver(spi_hid_acpi_driver);
+
+MODULE_DESCRIPTION("HID over SPI ACPI transport driver");
+MODULE_AUTHOR("Angela Czubak <aczubak@google.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index e3273846267e..02beb209a92d 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -43,6 +43,9 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
+#include "spi-hid.h"
+#include "spi-hid-core.h"
+
 /* Protocol constants */
 #define SPI_HID_READ_APPROVAL_CONSTANT		0xff
 #define SPI_HID_INPUT_HEADER_SYNC_BYTE		0x5a
@@ -105,30 +108,6 @@ struct spi_hid_output_report {
 	u8 *content;
 };
 
-/* struct spi_hid_conf - Conf provided to the core */
-struct spi_hid_conf {
-	u32 input_report_header_address;
-	u32 input_report_body_address;
-	u32 output_report_address;
-	u8 read_opcode;
-	u8 write_opcode;
-};
-
-/**
- * struct spihid_ops - Ops provided to the core
- * @power_up: do sequencing to power up the device
- * @power_down: do sequencing to power down the device
- * @assert_reset: do sequencing to assert the reset line
- * @deassert_reset: do sequencing to deassert the reset line
- */
-struct spihid_ops {
-	int (*power_up)(struct spihid_ops *ops);
-	int (*power_down)(struct spihid_ops *ops);
-	int (*assert_reset)(struct spihid_ops *ops);
-	int (*deassert_reset)(struct spihid_ops *ops);
-	void (*sleep_minimal_reset_delay)(struct spihid_ops *ops);
-};
-
 static struct hid_ll_driver spi_hid_ll_driver;
 
 static void spi_hid_populate_read_approvals(const struct spi_hid_conf *conf,
diff --git a/drivers/hid/spi-hid/spi-hid.h b/drivers/hid/spi-hid/spi-hid.h
new file mode 100644
index 000000000000..1fdd45262647
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ * Copyright (c) 2026 Google LLC
+ */
+
+#ifndef SPI_HID_H
+#define SPI_HID_H
+
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+
+/* struct spi_hid_conf - Conf provided to the core */
+struct spi_hid_conf {
+	u32 input_report_header_address;
+	u32 input_report_body_address;
+	u32 output_report_address;
+	u8 read_opcode;
+	u8 write_opcode;
+};
+
+/**
+ * struct spihid_ops - Ops provided to the core
+ * @power_up: do sequencing to power up the device
+ * @power_down: do sequencing to power down the device
+ * @assert_reset: do sequencing to assert the reset line
+ * @deassert_reset: do sequencing to deassert the reset line
+ */
+struct spihid_ops {
+	int (*power_up)(struct spihid_ops *ops);
+	int (*power_down)(struct spihid_ops *ops);
+	int (*assert_reset)(struct spihid_ops *ops);
+	int (*deassert_reset)(struct spihid_ops *ops);
+	void (*sleep_minimal_reset_delay)(struct spihid_ops *ops);
+};
+
+int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
+		       struct spi_hid_conf *conf);
+
+void spi_hid_core_remove(struct spi_device *spi);
+
+extern const struct attribute_group *spi_hid_groups[];
+
+#endif /* SPI_HID_H */

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 06/12] HID: spi_hid: add spi_hid traces
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Dmitry Antipov, Angela Czubak
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Add traces for purposed of debugging spi_hid driver.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-core.c |  71 -----------------
 drivers/hid/spi-hid/spi-hid-core.h |  83 ++++++++++++++++++++
 include/trace/events/spi_hid.h     | 156 +++++++++++++++++++++++++++++++++++++
 3 files changed, 239 insertions(+), 71 deletions(-)

diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 08865d42555f..e3273846267e 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -81,13 +81,6 @@
 #define SPI_HID_CREATE_DEVICE	4
 #define SPI_HID_ERROR	5
 
-/* Raw input buffer with data from the bus */
-struct spi_hid_input_buf {
-	u8 header[HIDSPI_INPUT_HEADER_SIZE];
-	u8 body[HIDSPI_INPUT_BODY_HEADER_SIZE];
-	u8 content[];
-};
-
 /* Processed data from input report header */
 struct spi_hid_input_header {
 	u8 version;
@@ -104,12 +97,6 @@ struct spi_hid_input_report {
 	u8 *content;
 };
 
-/* Raw output report buffer to be put on the bus */
-struct spi_hid_output_buf {
-	u8 header[SPI_HID_OUTPUT_HEADER_LEN];
-	u8 content[];
-};
-
 /* Data necessary to send an output report */
 struct spi_hid_output_report {
 	u8 report_type;
@@ -118,19 +105,6 @@ struct spi_hid_output_report {
 	u8 *content;
 };
 
-/* Processed data from a device descriptor */
-struct spi_hid_device_descriptor {
-	u16 hid_version;
-	u16 report_descriptor_length;
-	u16 max_input_length;
-	u16 max_output_length;
-	u16 max_fragment_length;
-	u16 vendor_id;
-	u16 product_id;
-	u16 version_id;
-	u8 no_output_report_ack;
-};
-
 /* struct spi_hid_conf - Conf provided to the core */
 struct spi_hid_conf {
 	u32 input_report_header_address;
@@ -155,51 +129,6 @@ struct spihid_ops {
 	void (*sleep_minimal_reset_delay)(struct spihid_ops *ops);
 };
 
-/* Driver context */
-struct spi_hid {
-	struct spi_device	*spi;	/* spi device. */
-	struct hid_device	*hid;	/* pointer to corresponding HID dev. */
-
-	struct spi_transfer	input_transfer[2];	/* Transfer buffer for read and write. */
-	struct spi_message	input_message;	/* used to execute a sequence of spi transfers. */
-
-	struct spihid_ops	*ops;
-	struct spi_hid_conf	*conf;
-
-	struct spi_hid_device_descriptor desc;	/* HID device descriptor. */
-	struct spi_hid_output_buf *output;	/* Output buffer. */
-	struct spi_hid_input_buf *input;	/* Input buffer. */
-	struct spi_hid_input_buf *response;	/* Response buffer. */
-
-	u16 response_length;
-	u16 bufsize;
-
-	enum hidspi_power_state power_state;
-
-	u8 reset_attempts;	/* The number of reset attempts. */
-
-	unsigned long flags;	/* device flags. */
-
-	struct work_struct reset_work;
-
-	/* Control lock to make sure one output transaction at a time. */
-	struct mutex output_lock;
-	/* Power lock to make sure one power state change at a time. */
-	struct mutex power_lock;
-	struct completion output_done;
-
-	u8 read_approval_header[SPI_HID_READ_APPROVAL_LEN];
-	u8 read_approval_body[SPI_HID_READ_APPROVAL_LEN];
-
-	u32 report_descriptor_crc32;	/* HID report descriptor crc32 checksum. */
-
-	u32 regulator_error_count;
-	int regulator_last_error;
-	u32 bus_error_count;
-	int bus_last_error;
-	u32 dir_count;	/* device initiated reset count. */
-};
-
 static struct hid_ll_driver spi_hid_ll_driver;
 
 static void spi_hid_populate_read_approvals(const struct spi_hid_conf *conf,
diff --git a/drivers/hid/spi-hid/spi-hid-core.h b/drivers/hid/spi-hid/spi-hid-core.h
new file mode 100644
index 000000000000..2bfdfbe6d7fc
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-core.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ * Copyright (c) 2026 Google LLC
+ */
+
+#include <linux/hid-over-spi.h>
+#include <linux/spi/spi.h>
+
+/* Protocol message size constants */
+#define SPI_HID_READ_APPROVAL_LEN		5
+#define SPI_HID_OUTPUT_HEADER_LEN		8
+
+/* Raw input buffer with data from the bus */
+struct spi_hid_input_buf {
+	u8 header[HIDSPI_INPUT_HEADER_SIZE];
+	u8 body[HIDSPI_INPUT_BODY_HEADER_SIZE];
+	u8 content[];
+};
+
+/* Raw output report buffer to be put on the bus */
+struct spi_hid_output_buf {
+	u8 header[SPI_HID_OUTPUT_HEADER_LEN];
+	u8 content[];
+};
+
+/* Processed data from a device descriptor */
+struct spi_hid_device_descriptor {
+	u16 hid_version;
+	u16 report_descriptor_length;
+	u16 max_input_length;
+	u16 max_output_length;
+	u16 max_fragment_length;
+	u16 vendor_id;
+	u16 product_id;
+	u16 version_id;
+	u8 no_output_report_ack;
+};
+
+/* Driver context */
+struct spi_hid {
+	struct spi_device	*spi;	/* spi device. */
+	struct hid_device	*hid;	/* pointer to corresponding HID dev. */
+
+	struct spi_transfer	input_transfer[2];	/* Transfer buffer for read and write. */
+	struct spi_message	input_message;	/* used to execute a sequence of spi transfers. */
+
+	struct spihid_ops	*ops;
+	struct spi_hid_conf	*conf;
+
+	struct spi_hid_device_descriptor desc;	/* HID device descriptor. */
+	struct spi_hid_output_buf *output;	/* Output buffer. */
+	struct spi_hid_input_buf *input;	/* Input buffer. */
+	struct spi_hid_input_buf *response;	/* Response buffer. */
+
+	u16 response_length;
+	u16 bufsize;
+
+	enum hidspi_power_state power_state;
+
+	u8 reset_attempts;	/* The number of reset attempts. */
+
+	unsigned long flags;	/* device flags. */
+
+	struct work_struct reset_work;
+
+	/* Control lock to make sure one output transaction at a time. */
+	struct mutex output_lock;
+	/* Power lock to make sure one power state change at a time. */
+	struct mutex power_lock;
+	struct completion output_done;
+
+	u8 read_approval_header[SPI_HID_READ_APPROVAL_LEN];
+	u8 read_approval_body[SPI_HID_READ_APPROVAL_LEN];
+
+	u32 report_descriptor_crc32;	/* HID report descriptor crc32 checksum. */
+
+	u32 regulator_error_count;
+	int regulator_last_error;
+	u32 bus_error_count;
+	int bus_last_error;
+	u32 dir_count;		/* device initiated reset count. */
+};
diff --git a/include/trace/events/spi_hid.h b/include/trace/events/spi_hid.h
new file mode 100644
index 000000000000..e9a579b3806c
--- /dev/null
+++ b/include/trace/events/spi_hid.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM spi_hid
+
+#if !defined(_SPI_HID_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _SPI_HID_TRACE_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(spi_hid_transfer,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+		 const void *rx_buf, u16 rx_len, int ret),
+
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, ret)
+		__dynamic_array(u8, rx_buf, rx_len)
+		__dynamic_array(u8, tx_buf, tx_len)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->ret = ret;
+
+		memcpy(__get_dynamic_array(tx_buf), tx_buf, tx_len);
+		memcpy(__get_dynamic_array(rx_buf), rx_buf, rx_len);
+	),
+
+	TP_printk("spi%d.%d: len=%d tx=[%*phD] rx=[%*phD] --> %d",
+		  __entry->bus_num, __entry->chip_select,
+		  __get_dynamic_array_len(tx_buf) + __get_dynamic_array_len(rx_buf),
+		  __get_dynamic_array_len(tx_buf), __get_dynamic_array(tx_buf),
+		  __get_dynamic_array_len(rx_buf), __get_dynamic_array(rx_buf),
+		  __entry->ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_sync,
+	     TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+		      const void *rx_buf, u16 rx_len, int ret),
+	     TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret));
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_header_complete,
+	     TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+		      const void *rx_buf, u16 rx_len, int ret),
+	     TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret));
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_body_complete,
+	     TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+		      const void *rx_buf, u16 rx_len, int ret),
+	     TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret));
+
+DECLARE_EVENT_CLASS(spi_hid_irq,
+	TP_PROTO(struct spi_hid *shid, int irq),
+
+	TP_ARGS(shid, irq),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, irq)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->irq = irq;
+	),
+
+	TP_printk("spi%d.%d: IRQ %d",
+		  __entry->bus_num, __entry->chip_select, __entry->irq)
+);
+
+DEFINE_EVENT(spi_hid_irq, spi_hid_dev_irq,
+	     TP_PROTO(struct spi_hid *shid, int irq), TP_ARGS(shid, irq));
+
+DECLARE_EVENT_CLASS(spi_hid,
+	TP_PROTO(struct spi_hid *shid),
+
+	TP_ARGS(shid),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, power_state)
+		__field(u32, flags)
+
+		__field(int, vendor_id)
+		__field(int, product_id)
+		__field(int, max_input_length)
+		__field(int, max_output_length)
+		__field(u16, hid_version)
+		__field(u16, report_descriptor_length)
+		__field(u16, version_id)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->power_state = shid->power_state;
+		__entry->flags = shid->flags;
+
+		__entry->vendor_id = shid->desc.vendor_id;
+		__entry->product_id = shid->desc.product_id;
+		__entry->max_input_length = shid->desc.max_input_length;
+		__entry->max_output_length = shid->desc.max_output_length;
+		__entry->hid_version = shid->desc.hid_version;
+		__entry->report_descriptor_length =
+					shid->desc.report_descriptor_length;
+		__entry->version_id = shid->desc.version_id;
+	),
+
+	TP_printk("spi%d.%d: (%04x:%04x v%d) HID v%d.%d state p:%d len i:%d o:%d r:%d flags 0x%08x",
+		  __entry->bus_num, __entry->chip_select,
+		  __entry->vendor_id, __entry->product_id, __entry->version_id,
+		  __entry->hid_version >> 8, __entry->hid_version & 0xff,
+		  __entry->power_state,	__entry->max_input_length,
+		  __entry->max_output_length, __entry->report_descriptor_length,
+		  __entry->flags)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_header_transfer, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_process_input_report,
+	     TP_PROTO(struct spi_hid *shid), TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_input_report_handler,
+	     TP_PROTO(struct spi_hid *shid), TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_reset_response, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_create_device, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_refresh_device, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_response_handler, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+DEFINE_EVENT(spi_hid, spi_hid_error_handler, TP_PROTO(struct spi_hid *shid),
+	     TP_ARGS(shid));
+
+#endif /* _SPI_HID_TRACE_H */
+
+#include <trace/define_trace.h>

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 05/12] HID: spi-hid: add HID SPI protocol implementation
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Dmitry Antipov, Angela Czubak
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

This driver follows HID Over SPI Protocol Specification 1.0 available at
https://www.microsoft.com/en-us/download/details.aspx?id=103325. The
initial version of the driver does not support: 1) multi-fragment input
reports, 2) sending GET_INPUT and COMMAND output report types and
processing their respective acknowledge input reports, and 3) device
sleep power state.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-core.c | 562 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 557 insertions(+), 5 deletions(-)

diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 18b035324f06..08865d42555f 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -23,11 +23,16 @@
 #include <linux/completion.h>
 #include <linux/crc32.h>
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/hid.h>
 #include <linux/hid-over-spi.h>
+#include <linux/input.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
@@ -35,12 +40,22 @@
 #include <linux/string.h>
 #include <linux/sysfs.h>
 #include <linux/unaligned.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+/* Protocol constants */
+#define SPI_HID_READ_APPROVAL_CONSTANT		0xff
+#define SPI_HID_INPUT_HEADER_SYNC_BYTE		0x5a
+#define SPI_HID_INPUT_HEADER_VERSION		0x03
+#define SPI_HID_SUPPORTED_VERSION		0x0300
 
 #define SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST	0x00
 
-#define SPI_HID_RESP_TIMEOUT	1000
+#define SPI_HID_MAX_RESET_ATTEMPTS	3
+#define SPI_HID_RESP_TIMEOUT		1000
 
 /* Protocol message size constants */
+#define SPI_HID_READ_APPROVAL_LEN		5
 #define SPI_HID_OUTPUT_HEADER_LEN		8
 
 /* flags */
@@ -49,6 +64,22 @@
  * requests. The FW becomes ready after sending the report descriptor.
  */
 #define SPI_HID_READY	0
+/*
+ * refresh_in_progress is set to true while the refresh_device worker
+ * thread is destroying and recreating the hidraw device. When this flag
+ * is set to true, the ll_close and ll_open functions will not cause
+ * power state changes.
+ */
+#define SPI_HID_REFRESH_IN_PROGRESS	1
+/*
+ * reset_pending indicates that the device is being reset. When this flag
+ * is set to true, garbage interrupts triggered during reset will be
+ * dropped and will not cause error handling.
+ */
+#define SPI_HID_RESET_PENDING	2
+#define SPI_HID_RESET_RESPONSE	3
+#define SPI_HID_CREATE_DEVICE	4
+#define SPI_HID_ERROR	5
 
 /* Raw input buffer with data from the bus */
 struct spi_hid_input_buf {
@@ -57,6 +88,22 @@ struct spi_hid_input_buf {
 	u8 content[];
 };
 
+/* Processed data from input report header */
+struct spi_hid_input_header {
+	u8 version;
+	u16 report_length;
+	u8 last_fragment_flag;
+	u8 sync_const;
+};
+
+/* Processed data from an input report */
+struct spi_hid_input_report {
+	u8 report_type;
+	u16 content_length;
+	u8 content_id;
+	u8 *content;
+};
+
 /* Raw output report buffer to be put on the bus */
 struct spi_hid_output_buf {
 	u8 header[SPI_HID_OUTPUT_HEADER_LEN];
@@ -113,6 +160,9 @@ struct spi_hid {
 	struct spi_device	*spi;	/* spi device. */
 	struct hid_device	*hid;	/* pointer to corresponding HID dev. */
 
+	struct spi_transfer	input_transfer[2];	/* Transfer buffer for read and write. */
+	struct spi_message	input_message;	/* used to execute a sequence of spi transfers. */
+
 	struct spihid_ops	*ops;
 	struct spi_hid_conf	*conf;
 
@@ -130,10 +180,17 @@ struct spi_hid {
 
 	unsigned long flags;	/* device flags. */
 
+	struct work_struct reset_work;
+
 	/* Control lock to make sure one output transaction at a time. */
 	struct mutex output_lock;
+	/* Power lock to make sure one power state change at a time. */
+	struct mutex power_lock;
 	struct completion output_done;
 
+	u8 read_approval_header[SPI_HID_READ_APPROVAL_LEN];
+	u8 read_approval_body[SPI_HID_READ_APPROVAL_LEN];
+
 	u32 report_descriptor_crc32;	/* HID report descriptor crc32 checksum. */
 
 	u32 regulator_error_count;
@@ -145,6 +202,66 @@ struct spi_hid {
 
 static struct hid_ll_driver spi_hid_ll_driver;
 
+static void spi_hid_populate_read_approvals(const struct spi_hid_conf *conf,
+					    u8 *header_buf, u8 *body_buf)
+{
+	header_buf[0] = conf->read_opcode;
+	put_unaligned_be24(conf->input_report_header_address, &header_buf[1]);
+	header_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT;
+
+	body_buf[0] = conf->read_opcode;
+	put_unaligned_be24(conf->input_report_body_address, &body_buf[1]);
+	body_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT;
+}
+
+static void spi_hid_parse_dev_desc(const struct hidspi_dev_descriptor *raw,
+				   struct spi_hid_device_descriptor *desc)
+{
+	desc->hid_version = le16_to_cpu(raw->bcd_ver);
+	desc->report_descriptor_length = le16_to_cpu(raw->rep_desc_len);
+	desc->max_input_length = le16_to_cpu(raw->max_input_len);
+	desc->max_output_length = le16_to_cpu(raw->max_output_len);
+
+	/* FIXME: multi-fragment not supported, field below not used */
+	desc->max_fragment_length = le16_to_cpu(raw->max_frag_len);
+
+	desc->vendor_id = le16_to_cpu(raw->vendor_id);
+	desc->product_id = le16_to_cpu(raw->product_id);
+	desc->version_id = le16_to_cpu(raw->version_id);
+	desc->no_output_report_ack = le16_to_cpu(raw->flags) & BIT(0);
+}
+
+static void spi_hid_populate_input_header(const u8 *buf,
+					  struct spi_hid_input_header *header)
+{
+	header->version            = buf[0] & 0xf;
+	header->report_length      = (get_unaligned_le16(&buf[1]) & 0x3fff) * 4;
+	header->last_fragment_flag = (buf[2] & 0x40) >> 6;
+	header->sync_const         = buf[3];
+}
+
+static void spi_hid_populate_input_body(const u8 *buf,
+					struct input_report_body_header *body)
+{
+	body->input_report_type = buf[0];
+	body->content_len = get_unaligned_le16(&buf[1]);
+	body->content_id = buf[3];
+}
+
+static void spi_hid_input_report_prepare(struct spi_hid_input_buf *buf,
+					 struct spi_hid_input_report *report)
+{
+	struct spi_hid_input_header header;
+	struct input_report_body_header body;
+
+	spi_hid_populate_input_header(buf->header, &header);
+	spi_hid_populate_input_body(buf->body, &body);
+	report->report_type = body.input_report_type;
+	report->content_length = body.content_len;
+	report->content_id = body.content_id;
+	report->content = buf->content;
+}
+
 static void spi_hid_populate_output_header(u8 *buf,
 					   const struct spi_hid_conf *conf,
 					   const struct spi_hid_output_report *report)
@@ -156,6 +273,33 @@ static void spi_hid_populate_output_header(u8 *buf,
 	buf[7] = report->content_id;
 }
 
+static int spi_hid_input_sync(struct spi_hid *shid, void *buf, u16 length,
+			      bool is_header)
+{
+	int error;
+
+	shid->input_transfer[0].tx_buf = is_header ?
+					 shid->read_approval_header :
+					 shid->read_approval_body;
+	shid->input_transfer[0].len = SPI_HID_READ_APPROVAL_LEN;
+
+	shid->input_transfer[1].rx_buf = buf;
+	shid->input_transfer[1].len = length;
+
+	spi_message_init_with_transfers(&shid->input_message,
+					shid->input_transfer, 2);
+
+	error = spi_sync(shid->spi, &shid->input_message);
+	if (error) {
+		dev_err(&shid->spi->dev, "Error starting sync transfer: %d.", error);
+		shid->bus_error_count++;
+		shid->bus_last_error = error;
+		return error;
+	}
+
+	return 0;
+}
+
 static int spi_hid_output(struct spi_hid *shid, const void *buf, u16 length)
 {
 	int error;
@@ -195,6 +339,50 @@ static void spi_hid_stop_hid(struct spi_hid *shid)
 		hid_destroy_device(hid);
 }
 
+static void spi_hid_error(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+	int error;
+
+	guard(mutex)(&shid->power_lock);
+	if (shid->power_state == HIDSPI_OFF)
+		return;
+
+	if (shid->reset_attempts++ >= SPI_HID_MAX_RESET_ATTEMPTS) {
+		dev_err(dev, "unresponsive device, aborting.");
+		spi_hid_stop_hid(shid);
+		shid->ops->assert_reset(shid->ops);
+		error = shid->ops->power_down(shid->ops);
+		if (error) {
+			dev_err(dev, "failed to disable regulator.");
+			shid->regulator_error_count++;
+			shid->regulator_last_error = error;
+		}
+		return;
+	}
+
+	clear_bit(SPI_HID_READY, &shid->flags);
+	set_bit(SPI_HID_RESET_PENDING, &shid->flags);
+
+	shid->ops->assert_reset(shid->ops);
+
+	shid->power_state = HIDSPI_OFF;
+
+	/*
+	 * We want to cancel pending reset work as the device is being reset
+	 * to recover from an error. cancel_work_sync will put us in a deadlock
+	 * because this function is scheduled in 'reset_work' and we should
+	 * avoid waiting for itself.
+	 */
+	cancel_work(&shid->reset_work);
+
+	shid->ops->sleep_minimal_reset_delay(shid->ops);
+
+	shid->power_state = HIDSPI_ON;
+
+	shid->ops->deassert_reset(shid->ops);
+}
+
 static int spi_hid_send_output_report(struct spi_hid *shid,
 				      struct spi_hid_output_report *report)
 {
@@ -249,6 +437,86 @@ static int spi_hid_sync_request(struct spi_hid *shid,
 	return 0;
 }
 
+/*
+ * Handle the reset response from the FW by sending a request for the device
+ * descriptor.
+ */
+static void spi_hid_reset_response(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = DEVICE_DESCRIPTOR,
+		.content_length = 0x0,
+		.content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST,
+		.content = NULL,
+	};
+	int error;
+
+	if (test_bit(SPI_HID_READY, &shid->flags)) {
+		dev_err(dev, "Spontaneous FW reset!");
+		clear_bit(SPI_HID_READY, &shid->flags);
+		shid->dir_count++;
+	}
+
+	if (shid->power_state == HIDSPI_OFF)
+		return;
+
+	error = spi_hid_sync_request(shid, &report);
+	if (error) {
+		dev_WARN_ONCE(dev, true,
+			      "Failed to send device descriptor request: %d.", error);
+		set_bit(SPI_HID_ERROR, &shid->flags);
+		schedule_work(&shid->reset_work);
+	}
+}
+
+static int spi_hid_input_report_handler(struct spi_hid *shid,
+					struct spi_hid_input_buf *buf)
+{
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_input_report r;
+	int error = 0;
+
+	if (!test_bit(SPI_HID_READY, &shid->flags) ||
+	    test_bit(SPI_HID_REFRESH_IN_PROGRESS, &shid->flags) || !shid->hid) {
+		dev_err(dev, "HID not ready");
+		return 0;
+	}
+
+	spi_hid_input_report_prepare(buf, &r);
+
+	error = hid_input_report(shid->hid, HID_INPUT_REPORT,
+				 r.content - 1, r.content_length + 1, 1);
+
+	if (error == -ENODEV || error == -EBUSY) {
+		dev_err(dev, "ignoring report --> %d.", error);
+		return 0;
+	} else if (error) {
+		dev_err(dev, "Bad input report: %d.", error);
+	}
+
+	return error;
+}
+
+static void spi_hid_response_handler(struct spi_hid *shid,
+				     struct input_report_body_header *body)
+{
+	shid->response_length = body->content_len;
+	/* completion_done returns 0 if there are waiters, otherwise 1 */
+	if (completion_done(&shid->output_done)) {
+		dev_err(&shid->spi->dev, "Unexpected response report.");
+	} else {
+		if (body->input_report_type == REPORT_DESCRIPTOR_RESPONSE ||
+		    body->input_report_type == GET_FEATURE_RESPONSE) {
+			memcpy(shid->response->body, shid->input->body,
+			       sizeof(shid->input->body));
+			memcpy(shid->response->content, shid->input->content,
+			       body->content_len);
+		}
+		complete(&shid->output_done);
+	}
+}
+
 /*
  * This function returns the length of the report descriptor, or a negative
  * error code if something went wrong.
@@ -268,6 +536,8 @@ static int spi_hid_report_descriptor_request(struct spi_hid *shid)
 	if (ret) {
 		dev_err(dev,
 			"Expected report descriptor not received: %d.", ret);
+		set_bit(SPI_HID_ERROR, &shid->flags);
+		schedule_work(&shid->reset_work);
 		return ret;
 	}
 
@@ -322,6 +592,205 @@ static int spi_hid_create_device(struct spi_hid *shid)
 	return 0;
 }
 
+static void spi_hid_refresh_device(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+	u32 new_crc32 = 0;
+	int error = 0;
+
+	error = spi_hid_report_descriptor_request(shid);
+	if (error < 0) {
+		dev_err(dev,
+			"%s: failed report descriptor request: %d",
+			__func__, error);
+		return;
+	}
+	new_crc32 = crc32_le(0, (unsigned char const *)shid->response->content,
+			     (size_t)error);
+
+	/* Same report descriptor, so no need to create a new hid device. */
+	if (new_crc32 == shid->report_descriptor_crc32) {
+		set_bit(SPI_HID_READY, &shid->flags);
+		return;
+	}
+
+	shid->report_descriptor_crc32 = new_crc32;
+
+	set_bit(SPI_HID_REFRESH_IN_PROGRESS, &shid->flags);
+
+	spi_hid_stop_hid(shid);
+
+	error = spi_hid_create_device(shid);
+	if (error) {
+		dev_err(dev, "%s: Failed to create hid device: %d.", __func__, error);
+		return;
+	}
+
+	clear_bit(SPI_HID_REFRESH_IN_PROGRESS, &shid->flags);
+}
+
+static void spi_hid_reset_work(struct work_struct *work)
+{
+	struct spi_hid *shid =
+		container_of(work, struct spi_hid, reset_work);
+	struct device *dev = &shid->spi->dev;
+	int error = 0;
+
+	if (test_and_clear_bit(SPI_HID_RESET_RESPONSE, &shid->flags)) {
+		spi_hid_reset_response(shid);
+		return;
+	}
+
+	if (test_and_clear_bit(SPI_HID_CREATE_DEVICE, &shid->flags)) {
+		guard(mutex)(&shid->power_lock);
+		if (shid->power_state == HIDSPI_OFF) {
+			dev_err(dev, "%s: Powered off, returning", __func__);
+			return;
+		}
+
+		if (!shid->hid) {
+			error = spi_hid_create_device(shid);
+			if (error) {
+				dev_err(dev, "%s: Failed to create hid device: %d.",
+					__func__, error);
+				return;
+			}
+		} else {
+			spi_hid_refresh_device(shid);
+		}
+
+		return;
+	}
+
+	if (test_and_clear_bit(SPI_HID_ERROR, &shid->flags)) {
+		spi_hid_error(shid);
+		return;
+	}
+}
+
+static int spi_hid_process_input_report(struct spi_hid *shid,
+					struct spi_hid_input_buf *buf)
+{
+	struct spi_hid_input_header header;
+	struct input_report_body_header body;
+	struct device *dev = &shid->spi->dev;
+	struct hidspi_dev_descriptor *raw;
+
+	spi_hid_populate_input_header(buf->header, &header);
+	spi_hid_populate_input_body(buf->body, &body);
+
+	if (body.content_len > header.report_length) {
+		dev_err(dev, "Bad body length %d > %d.", body.content_len,
+			header.report_length);
+		return -EPROTO;
+	}
+
+	switch (body.input_report_type) {
+	case DATA:
+		return spi_hid_input_report_handler(shid, buf);
+	case RESET_RESPONSE:
+		clear_bit(SPI_HID_RESET_PENDING, &shid->flags);
+		set_bit(SPI_HID_RESET_RESPONSE, &shid->flags);
+		schedule_work(&shid->reset_work);
+		break;
+	case DEVICE_DESCRIPTOR_RESPONSE:
+		/* Mark the completion done to avoid timeout */
+		spi_hid_response_handler(shid, &body);
+
+		/* Reset attempts at every device descriptor fetch */
+		shid->reset_attempts = 0;
+		raw = (struct hidspi_dev_descriptor *)buf->content;
+
+		/* Validate device descriptor length before parsing */
+		if (body.content_len != HIDSPI_DEVICE_DESCRIPTOR_SIZE) {
+			dev_err(dev, "Invalid content length %d, expected %lu.",
+				body.content_len,
+				HIDSPI_DEVICE_DESCRIPTOR_SIZE);
+			return -EPROTO;
+		}
+
+		if (le16_to_cpu(raw->dev_desc_len) !=
+		    HIDSPI_DEVICE_DESCRIPTOR_SIZE) {
+			dev_err(dev,
+				"Invalid wDeviceDescLength %d, expected %lu.",
+				raw->dev_desc_len,
+				HIDSPI_DEVICE_DESCRIPTOR_SIZE);
+			return -EPROTO;
+		}
+
+		spi_hid_parse_dev_desc(raw, &shid->desc);
+
+		if (shid->desc.hid_version != SPI_HID_SUPPORTED_VERSION) {
+			dev_err(dev,
+				"Unsupported device descriptor version %4x.",
+				shid->desc.hid_version);
+			return -EPROTONOSUPPORT;
+		}
+
+		set_bit(SPI_HID_CREATE_DEVICE, &shid->flags);
+		schedule_work(&shid->reset_work);
+
+		break;
+	case OUTPUT_REPORT_RESPONSE:
+		if (shid->desc.no_output_report_ack) {
+			dev_err(dev, "Unexpected output report response.");
+			break;
+		}
+		fallthrough;
+	case GET_FEATURE_RESPONSE:
+	case SET_FEATURE_RESPONSE:
+	case REPORT_DESCRIPTOR_RESPONSE:
+		spi_hid_response_handler(shid, &body);
+		break;
+	/*
+	 * FIXME: sending GET_INPUT and COMMAND reports not supported, thus
+	 * throw away responses to those, they should never come.
+	 */
+	case GET_INPUT_REPORT_RESPONSE:
+	case COMMAND_RESPONSE:
+		dev_err(dev, "Not a supported report type: 0x%x.",
+			body.input_report_type);
+		break;
+	default:
+		dev_err(dev, "Unknown input report: 0x%x.", body.input_report_type);
+		return -EPROTO;
+	}
+
+	return 0;
+}
+
+static int spi_hid_bus_validate_header(struct spi_hid *shid,
+				       struct spi_hid_input_header *header)
+{
+	struct device *dev = &shid->spi->dev;
+
+	if (header->version != SPI_HID_INPUT_HEADER_VERSION) {
+		dev_err(dev, "Unknown input report version (v 0x%x).",
+			header->version);
+		return -EINVAL;
+	}
+
+	if (shid->desc.max_input_length != 0 &&
+	    header->report_length > shid->desc.max_input_length) {
+		dev_err(dev, "Input report body size %u > max expected of %u.",
+			header->report_length, shid->desc.max_input_length);
+		return -EMSGSIZE;
+	}
+
+	if (header->last_fragment_flag != 1) {
+		dev_err(dev, "Multi-fragment reports not supported.");
+		return -EOPNOTSUPP;
+	}
+
+	if (header->sync_const != SPI_HID_INPUT_HEADER_SYNC_BYTE) {
+		dev_err(dev, "Invalid input report sync constant (0x%x).",
+			header->sync_const);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int spi_hid_get_request(struct spi_hid *shid, u8 content_id)
 {
 	struct device *dev = &shid->spi->dev;
@@ -338,6 +807,8 @@ static int spi_hid_get_request(struct spi_hid *shid, u8 content_id)
 		dev_err(dev,
 			"Expected get request response not received! Error %d.",
 			error);
+		set_bit(SPI_HID_ERROR, &shid->flags);
+		schedule_work(&shid->reset_work);
 		return error;
 	}
 
@@ -357,9 +828,81 @@ static int spi_hid_set_request(struct spi_hid *shid, u8 *arg_buf, u16 arg_len,
 	return spi_hid_sync_request(shid, &report);
 }
 
-/* This is a placeholder. Will be implemented in the next patch. */
 static irqreturn_t spi_hid_dev_irq(int irq, void *_shid)
 {
+	struct spi_hid *shid = _shid;
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_input_header header;
+	int error = 0;
+
+	error = spi_hid_input_sync(shid, shid->input->header,
+				   sizeof(shid->input->header), true);
+	if (error) {
+		dev_err(dev, "Failed to transfer header: %d.", error);
+		goto err;
+	}
+
+	if (shid->power_state == HIDSPI_OFF) {
+		dev_warn(dev, "Device is off after header was received.");
+		goto out;
+	}
+
+	if (shid->input_message.status < 0) {
+		dev_warn(dev, "Error reading header: %d.",
+			 shid->input_message.status);
+		shid->bus_error_count++;
+		shid->bus_last_error = shid->input_message.status;
+		goto err;
+	}
+
+	spi_hid_populate_input_header(shid->input->header, &header);
+
+	error = spi_hid_bus_validate_header(shid, &header);
+	if (error) {
+		if (!test_bit(SPI_HID_RESET_PENDING, &shid->flags)) {
+			dev_err(dev, "Failed to validate header: %d.", error);
+			print_hex_dump(KERN_ERR, "spi_hid: header buffer: ",
+				       DUMP_PREFIX_NONE, 16, 1, shid->input->header,
+				       sizeof(shid->input->header), false);
+			shid->bus_error_count++;
+			shid->bus_last_error = error;
+			goto err;
+		}
+		goto out;
+	}
+
+	error = spi_hid_input_sync(shid, shid->input->body, header.report_length,
+				   false);
+	if (error) {
+		dev_err(dev, "Failed to transfer body: %d.", error);
+		goto err;
+	}
+
+	if (shid->power_state == HIDSPI_OFF) {
+		dev_warn(dev, "Device is off after body was received.");
+		goto out;
+	}
+
+	if (shid->input_message.status < 0) {
+		dev_warn(dev, "Error reading body: %d.",
+			 shid->input_message.status);
+		shid->bus_error_count++;
+		shid->bus_last_error = shid->input_message.status;
+		goto err;
+	}
+
+	error = spi_hid_process_input_report(shid, shid->input);
+	if (error) {
+		dev_err(dev, "Failed to process input report: %d.", error);
+		goto err;
+	}
+
+out:
+	return IRQ_HANDLED;
+
+err:
+	set_bit(SPI_HID_ERROR, &shid->flags);
+	schedule_work(&shid->reset_work);
 	return IRQ_HANDLED;
 }
 
@@ -661,11 +1204,22 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	shid->power_state = HIDSPI_ON;
 	shid->ops = ops;
 	shid->conf = conf;
+	set_bit(SPI_HID_RESET_PENDING, &shid->flags);
 
 	spi_set_drvdata(spi, shid);
 
+	/* Using now populated conf let's pre-calculate the read approvals */
+	spi_hid_populate_read_approvals(shid->conf, shid->read_approval_header,
+					shid->read_approval_body);
+
+	mutex_init(&shid->output_lock);
+	mutex_init(&shid->power_lock);
+	init_completion(&shid->output_done);
+
+	INIT_WORK(&shid->reset_work, spi_hid_reset_work);
+
 	/*
-	 * we need to allocate the buffer without knowing the maximum
+	 * We need to allocate the buffer without knowing the maximum
 	 * size of the reports. Let's use SZ_2K, then we do the
 	 * real computation later.
 	 */
@@ -705,8 +1259,6 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	dev_dbg(dev, "%s: d3 -> %s.", __func__,
 		spi_hid_power_mode_string(shid->power_state));
 
-	spi_hid_create_device(shid);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(spi_hid_core_probe);

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 04/12] HID: spi-hid: add spi-hid driver HID layer
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Dmitry Antipov, Angela Czubak
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

Add HID low level driver callbacks to register SPI as a HID driver, and
an external touch device as a HID device.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/spi-hid/spi-hid-core.c | 519 +++++++++++++++++++++++++++++++++++++
 1 file changed, 519 insertions(+)

diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
index 5431c60efd50..18b035324f06 100644
--- a/drivers/hid/spi-hid/spi-hid-core.c
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -20,13 +20,69 @@
  *  Copyright (c) 2006-2010 Jiri Kosina
  */
 
+#include <linux/completion.h>
+#include <linux/crc32.h>
 #include <linux/device.h>
+#include <linux/err.h>
 #include <linux/hid.h>
 #include <linux/hid-over-spi.h>
 #include <linux/interrupt.h>
+#include <linux/jiffies.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/unaligned.h>
+
+#define SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST	0x00
+
+#define SPI_HID_RESP_TIMEOUT	1000
+
+/* Protocol message size constants */
+#define SPI_HID_OUTPUT_HEADER_LEN		8
+
+/* flags */
+/*
+ * ready flag indicates that the FW is ready to accept commands and
+ * requests. The FW becomes ready after sending the report descriptor.
+ */
+#define SPI_HID_READY	0
+
+/* Raw input buffer with data from the bus */
+struct spi_hid_input_buf {
+	u8 header[HIDSPI_INPUT_HEADER_SIZE];
+	u8 body[HIDSPI_INPUT_BODY_HEADER_SIZE];
+	u8 content[];
+};
+
+/* Raw output report buffer to be put on the bus */
+struct spi_hid_output_buf {
+	u8 header[SPI_HID_OUTPUT_HEADER_LEN];
+	u8 content[];
+};
+
+/* Data necessary to send an output report */
+struct spi_hid_output_report {
+	u8 report_type;
+	u16 content_length;
+	u8 content_id;
+	u8 *content;
+};
+
+/* Processed data from a device descriptor */
+struct spi_hid_device_descriptor {
+	u16 hid_version;
+	u16 report_descriptor_length;
+	u16 max_input_length;
+	u16 max_output_length;
+	u16 max_fragment_length;
+	u16 vendor_id;
+	u16 product_id;
+	u16 version_id;
+	u8 no_output_report_ack;
+};
 
 /* struct spi_hid_conf - Conf provided to the core */
 struct spi_hid_conf {
@@ -60,8 +116,26 @@ struct spi_hid {
 	struct spihid_ops	*ops;
 	struct spi_hid_conf	*conf;
 
+	struct spi_hid_device_descriptor desc;	/* HID device descriptor. */
+	struct spi_hid_output_buf *output;	/* Output buffer. */
+	struct spi_hid_input_buf *input;	/* Input buffer. */
+	struct spi_hid_input_buf *response;	/* Response buffer. */
+
+	u16 response_length;
+	u16 bufsize;
+
 	enum hidspi_power_state power_state;
 
+	u8 reset_attempts;	/* The number of reset attempts. */
+
+	unsigned long flags;	/* device flags. */
+
+	/* Control lock to make sure one output transaction at a time. */
+	struct mutex output_lock;
+	struct completion output_done;
+
+	u32 report_descriptor_crc32;	/* HID report descriptor crc32 checksum. */
+
 	u32 regulator_error_count;
 	int regulator_last_error;
 	u32 bus_error_count;
@@ -69,6 +143,33 @@ struct spi_hid {
 	u32 dir_count;	/* device initiated reset count. */
 };
 
+static struct hid_ll_driver spi_hid_ll_driver;
+
+static void spi_hid_populate_output_header(u8 *buf,
+					   const struct spi_hid_conf *conf,
+					   const struct spi_hid_output_report *report)
+{
+	buf[0] = conf->write_opcode;
+	put_unaligned_be24(conf->output_report_address, &buf[1]);
+	buf[4] = report->report_type;
+	put_unaligned_le16(report->content_length, &buf[5]);
+	buf[7] = report->content_id;
+}
+
+static int spi_hid_output(struct spi_hid *shid, const void *buf, u16 length)
+{
+	int error;
+
+	error = spi_write(shid->spi, buf, length);
+
+	if (error) {
+		shid->bus_error_count++;
+		shid->bus_last_error = error;
+	}
+
+	return error;
+}
+
 static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state)
 {
 	switch (power_state) {
@@ -83,11 +184,416 @@ static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state
 	}
 }
 
+static void spi_hid_stop_hid(struct spi_hid *shid)
+{
+	struct hid_device *hid = shid->hid;
+
+	shid->hid = NULL;
+	clear_bit(SPI_HID_READY, &shid->flags);
+
+	if (hid)
+		hid_destroy_device(hid);
+}
+
+static int spi_hid_send_output_report(struct spi_hid *shid,
+				      struct spi_hid_output_report *report)
+{
+	struct spi_hid_output_buf *buf = shid->output;
+	struct device *dev = &shid->spi->dev;
+	u16 report_length;
+	u16 padded_length;
+	u8 padding;
+	int error;
+
+	guard(mutex)(&shid->output_lock);
+	if (report->content_length > shid->desc.max_output_length) {
+		dev_err(dev, "Output report too big, content_length 0x%x.",
+			report->content_length);
+		return -E2BIG;
+	}
+
+	spi_hid_populate_output_header(buf->header, shid->conf, report);
+
+	if (report->content_length)
+		memcpy(&buf->content, report->content, report->content_length);
+
+	report_length = sizeof(buf->header) + report->content_length;
+	padded_length = round_up(report_length,	4);
+	padding = padded_length - report_length;
+	memset(&buf->content[report->content_length], 0, padding);
+
+	error = spi_hid_output(shid, buf, padded_length);
+	if (error)
+		dev_err(dev, "Failed output transfer: %d.", error);
+
+	return error;
+}
+
+static int spi_hid_sync_request(struct spi_hid *shid,
+				struct spi_hid_output_report *report)
+{
+	struct device *dev = &shid->spi->dev;
+	int error;
+
+	error = spi_hid_send_output_report(shid, report);
+	if (error)
+		return error;
+
+	error = wait_for_completion_interruptible_timeout(&shid->output_done,
+							  msecs_to_jiffies(SPI_HID_RESP_TIMEOUT));
+	if (error == 0) {
+		dev_err(dev, "Response timed out.");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/*
+ * This function returns the length of the report descriptor, or a negative
+ * error code if something went wrong.
+ */
+static int spi_hid_report_descriptor_request(struct spi_hid *shid)
+{
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = REPORT_DESCRIPTOR,
+		.content_length = 0,
+		.content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST,
+		.content = NULL,
+	};
+	int ret;
+
+	ret =  spi_hid_sync_request(shid, &report);
+	if (ret) {
+		dev_err(dev,
+			"Expected report descriptor not received: %d.", ret);
+		return ret;
+	}
+
+	ret = shid->response_length;
+	if (ret != shid->desc.report_descriptor_length) {
+		ret = min_t(unsigned int, ret, shid->desc.report_descriptor_length);
+		dev_err(dev, "Received report descriptor length doesn't match device descriptor field, using min of the two: %d.",
+			ret);
+	}
+
+	return ret;
+}
+
+static int spi_hid_create_device(struct spi_hid *shid)
+{
+	struct hid_device *hid;
+	struct device *dev = &shid->spi->dev;
+	int error;
+
+	hid = hid_allocate_device();
+	error = PTR_ERR_OR_ZERO(hid);
+	if (error) {
+		dev_err(dev, "Failed to allocate hid device: %d.", error);
+		return error;
+	}
+
+	hid->driver_data = shid->spi;
+	hid->ll_driver = &spi_hid_ll_driver;
+	hid->dev.parent = &shid->spi->dev;
+	hid->bus = BUS_SPI;
+	hid->version = shid->desc.hid_version;
+	hid->vendor = shid->desc.vendor_id;
+	hid->product = shid->desc.product_id;
+
+	snprintf(hid->name, sizeof(hid->name), "spi %04X:%04X",
+		 hid->vendor, hid->product);
+	strscpy(hid->phys, dev_name(&shid->spi->dev), sizeof(hid->phys));
+
+	shid->hid = hid;
+
+	error = hid_add_device(hid);
+	if (error) {
+		dev_err(dev, "Failed to add hid device: %d.", error);
+		/*
+		 * We likely got here because report descriptor request timed
+		 * out. Let's disconnect and destroy the hid_device structure.
+		 */
+		spi_hid_stop_hid(shid);
+		return error;
+	}
+
+	return 0;
+}
+
+static int spi_hid_get_request(struct spi_hid *shid, u8 content_id)
+{
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = GET_FEATURE,
+		.content_length = 0,
+		.content_id = content_id,
+		.content = NULL,
+	};
+	int error;
+
+	error = spi_hid_sync_request(shid, &report);
+	if (error) {
+		dev_err(dev,
+			"Expected get request response not received! Error %d.",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int spi_hid_set_request(struct spi_hid *shid, u8 *arg_buf, u16 arg_len,
+			       u8 content_id)
+{
+	struct spi_hid_output_report report = {
+		.report_type = SET_FEATURE,
+		.content_length = arg_len,
+		.content_id = content_id,
+		.content = arg_buf,
+	};
+
+	return spi_hid_sync_request(shid, &report);
+}
+
+/* This is a placeholder. Will be implemented in the next patch. */
 static irqreturn_t spi_hid_dev_irq(int irq, void *_shid)
 {
 	return IRQ_HANDLED;
 }
 
+static int spi_hid_alloc_buffers(struct spi_hid *shid, size_t report_size)
+{
+	struct device *dev = &shid->spi->dev;
+	int inbufsize = sizeof(shid->input->header) + sizeof(shid->input->body) + report_size;
+	int outbufsize = sizeof(shid->output->header) + report_size;
+
+	// devm_krealloc with __GFP_ZERO ensures the new memory is initialized
+	shid->output = devm_krealloc(dev, shid->output, outbufsize, GFP_KERNEL | __GFP_ZERO);
+	shid->input = devm_krealloc(dev, shid->input, inbufsize, GFP_KERNEL | __GFP_ZERO);
+	shid->response = devm_krealloc(dev, shid->response, inbufsize, GFP_KERNEL | __GFP_ZERO);
+
+	if (!shid->output || !shid->input || !shid->response)
+		return -ENOMEM;
+
+	shid->bufsize = report_size;
+
+	return 0;
+}
+
+static int spi_hid_get_report_length(struct hid_report *report)
+{
+	return ((report->size - 1) >> 3) + 1 +
+		report->device->report_enum[report->type].numbered + 2;
+}
+
+/*
+ * Traverse the supplied list of reports and find the longest
+ */
+static void spi_hid_find_max_report(struct hid_device *hid, u32 type,
+				    u16 *max)
+{
+	struct hid_report *report;
+	u16 size;
+
+	/*
+	 * We should not rely on wMaxInputLength, as some devices may set it to
+	 * a wrong length.
+	 */
+	list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
+		size = spi_hid_get_report_length(report);
+		if (*max < size)
+			*max = size;
+	}
+}
+
+/* hid_ll_driver interface functions */
+
+static int spi_hid_ll_start(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	int error = 0;
+	u16 bufsize = 0;
+
+	spi_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
+	spi_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
+	spi_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
+
+	if (bufsize < HID_MIN_BUFFER_SIZE) {
+		dev_err(&spi->dev,
+			"HID_MIN_BUFFER_SIZE > max_input_length (%d).",
+			bufsize);
+		return -EINVAL;
+	}
+
+	if (bufsize > shid->bufsize) {
+		guard(disable_irq)(&shid->spi->irq);
+
+		error = spi_hid_alloc_buffers(shid, bufsize);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+static void spi_hid_ll_stop(struct hid_device *hid)
+{
+	hid->claimed = 0;
+}
+
+static int spi_hid_ll_open(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+
+	set_bit(SPI_HID_READY, &shid->flags);
+	return 0;
+}
+
+static void spi_hid_ll_close(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+
+	clear_bit(SPI_HID_READY, &shid->flags);
+	shid->reset_attempts = 0;
+}
+
+static int spi_hid_ll_power(struct hid_device *hid, int level)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	int error = 0;
+
+	guard(mutex)(&shid->output_lock);
+	if (!shid->hid)
+		error = -ENODEV;
+
+	return error;
+}
+
+static int spi_hid_ll_parse(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int error, len;
+
+	len = spi_hid_report_descriptor_request(shid);
+	if (len < 0) {
+		dev_err(dev, "Report descriptor request failed, %d.", len);
+		return len;
+	}
+
+	/*
+	 * FIXME: below call returning 0 doesn't mean that the report descriptor
+	 * is good. We might be caching a crc32 of a corrupted r. d. or who
+	 * knows what the FW sent. Need to have a feedback loop about r. d.
+	 * being ok and only then cache it.
+	 */
+	error = hid_parse_report(hid, (u8 *)shid->response->content, len);
+	if (error) {
+		dev_err(dev, "failed parsing report: %d.", error);
+		return error;
+	}
+	shid->report_descriptor_crc32 = crc32_le(0,
+						 (unsigned char const *)shid->response->content,
+						 len);
+
+	return 0;
+}
+
+static int spi_hid_ll_raw_request(struct hid_device *hid,
+				  unsigned char reportnum, __u8 *buf,
+				  size_t len, unsigned char rtype, int reqtype)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int ret;
+
+	switch (reqtype) {
+	case HID_REQ_SET_REPORT:
+		if (buf[0] != reportnum) {
+			dev_err(dev, "report id mismatch.");
+			return -EINVAL;
+		}
+
+		ret = spi_hid_set_request(shid, &buf[1], len - 1,
+					  reportnum);
+		if (ret) {
+			dev_err(dev, "failed to set report.");
+			return ret;
+		}
+
+		ret = len;
+		break;
+	case HID_REQ_GET_REPORT:
+		ret = spi_hid_get_request(shid, reportnum);
+		if (ret) {
+			dev_err(dev, "failed to get report.");
+			return ret;
+		}
+
+		ret = min_t(size_t, len,
+			    (shid->response->body[1] | (shid->response->body[2] << 8)) + 1);
+		buf[0] = shid->response->body[3];
+		memcpy(&buf[1], &shid->response->content, ret);
+		break;
+	default:
+		dev_err(dev, "invalid request type.");
+		return -EIO;
+	}
+
+	return ret;
+}
+
+static int spi_hid_ll_output_report(struct hid_device *hid, __u8 *buf,
+				    size_t len)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = OUTPUT_REPORT,
+		.content_length = len - 1,
+		.content_id = buf[0],
+		.content = &buf[1],
+	};
+	int error;
+
+	if (!test_bit(SPI_HID_READY, &shid->flags)) {
+		dev_err(dev, "%s called in unready state", __func__);
+		return -ENODEV;
+	}
+
+	if (shid->desc.no_output_report_ack)
+		error = spi_hid_send_output_report(shid, &report);
+	else
+		error = spi_hid_sync_request(shid, &report);
+
+	if (error) {
+		dev_err(dev, "failed to send output report.");
+		return error;
+	}
+
+	return len;
+}
+
+static struct hid_ll_driver spi_hid_ll_driver = {
+	.start = spi_hid_ll_start,
+	.stop = spi_hid_ll_stop,
+	.open = spi_hid_ll_open,
+	.close = spi_hid_ll_close,
+	.power = spi_hid_ll_power,
+	.parse = spi_hid_ll_parse,
+	.output_report = spi_hid_ll_output_report,
+	.raw_request = spi_hid_ll_raw_request,
+};
+
 static ssize_t bus_error_count_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
@@ -158,6 +664,15 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 
 	spi_set_drvdata(spi, shid);
 
+	/*
+	 * we need to allocate the buffer without knowing the maximum
+	 * size of the reports. Let's use SZ_2K, then we do the
+	 * real computation later.
+	 */
+	error = spi_hid_alloc_buffers(shid, SZ_2K);
+	if (error)
+		return error;
+
 	/*
 	 * At the end of probe we initialize the device:
 	 *   0) assert reset, bias the interrupt line
@@ -190,6 +705,8 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
 	dev_dbg(dev, "%s: d3 -> %s.", __func__,
 		spi_hid_power_mode_string(shid->power_state));
 
+	spi_hid_create_device(shid);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(spi_hid_core_probe);
@@ -200,6 +717,8 @@ void spi_hid_core_remove(struct spi_device *spi)
 	struct device *dev = &spi->dev;
 	int error;
 
+	spi_hid_stop_hid(shid);
+
 	shid->ops->assert_reset(shid->ops);
 	error = shid->ops->power_down(shid->ops);
 	if (error)

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 03/12] HID: spi-hid: add transport driver skeleton for HID over SPI bus
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Angela Czubak, Dmitry Antipov
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

From: Angela Czubak <acz@semihalf.com>

Create spi-hid folder and add Kconfig and Makefile for spi-hid driver.
Add basic device structure, definitions, and probe/remove functions.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/Kconfig                |   2 +
 drivers/hid/Makefile               |   2 +
 drivers/hid/spi-hid/Kconfig        |  15 +++
 drivers/hid/spi-hid/Makefile       |   9 ++
 drivers/hid/spi-hid/spi-hid-core.c | 212 +++++++++++++++++++++++++++++++++++++
 5 files changed, 240 insertions(+)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 920a64b66b25..c6ae23bfb75d 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -1434,6 +1434,8 @@ source "drivers/hid/bpf/Kconfig"
 
 source "drivers/hid/i2c-hid/Kconfig"
 
+source "drivers/hid/spi-hid/Kconfig"
+
 source "drivers/hid/intel-ish-hid/Kconfig"
 
 source "drivers/hid/amd-sfh-hid/Kconfig"
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 361a7daedeb8..6b43e789b39a 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -169,6 +169,8 @@ obj-$(CONFIG_USB_KBD)		+= usbhid/
 
 obj-$(CONFIG_I2C_HID_CORE)	+= i2c-hid/
 
+obj-$(CONFIG_SPI_HID_CORE)	+= spi-hid/
+
 obj-$(CONFIG_INTEL_ISH_HID)	+= intel-ish-hid/
 
 obj-$(CONFIG_AMD_SFH_HID)       += amd-sfh-hid/
diff --git a/drivers/hid/spi-hid/Kconfig b/drivers/hid/spi-hid/Kconfig
new file mode 100644
index 000000000000..836fdefe8345
--- /dev/null
+++ b/drivers/hid/spi-hid/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (c) 2021 Microsoft Corporation
+#
+
+menuconfig SPI_HID
+	tristate "SPI HID support"
+	default y
+	depends on SPI
+
+if SPI_HID
+
+config SPI_HID_CORE
+	tristate
+endif
diff --git a/drivers/hid/spi-hid/Makefile b/drivers/hid/spi-hid/Makefile
new file mode 100644
index 000000000000..92e24cddbfc2
--- /dev/null
+++ b/drivers/hid/spi-hid/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the SPI HID input drivers
+#
+# Copyright (c) 2021 Microsoft Corporation
+#
+
+obj-$(CONFIG_SPI_HID_CORE)	+= spi-hid.o
+spi-hid-objs 			= spi-hid-core.o
diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
new file mode 100644
index 000000000000..5431c60efd50
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID over SPI protocol implementation
+ *
+ * Copyright (c) 2021 Microsoft Corporation
+ * Copyright (c) 2026 Google LLC
+ *
+ * This code is partly based on "HID over I2C protocol implementation:
+ *
+ *  Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ *  Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ *  Copyright (c) 2012 Red Hat, Inc
+ *
+ *  which in turn is partly based on "USB HID support for Linux":
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2007-2008 Oliver Neukum
+ *  Copyright (c) 2006-2010 Jiri Kosina
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/hid-over-spi.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+/* struct spi_hid_conf - Conf provided to the core */
+struct spi_hid_conf {
+	u32 input_report_header_address;
+	u32 input_report_body_address;
+	u32 output_report_address;
+	u8 read_opcode;
+	u8 write_opcode;
+};
+
+/**
+ * struct spihid_ops - Ops provided to the core
+ * @power_up: do sequencing to power up the device
+ * @power_down: do sequencing to power down the device
+ * @assert_reset: do sequencing to assert the reset line
+ * @deassert_reset: do sequencing to deassert the reset line
+ */
+struct spihid_ops {
+	int (*power_up)(struct spihid_ops *ops);
+	int (*power_down)(struct spihid_ops *ops);
+	int (*assert_reset)(struct spihid_ops *ops);
+	int (*deassert_reset)(struct spihid_ops *ops);
+	void (*sleep_minimal_reset_delay)(struct spihid_ops *ops);
+};
+
+/* Driver context */
+struct spi_hid {
+	struct spi_device	*spi;	/* spi device. */
+	struct hid_device	*hid;	/* pointer to corresponding HID dev. */
+
+	struct spihid_ops	*ops;
+	struct spi_hid_conf	*conf;
+
+	enum hidspi_power_state power_state;
+
+	u32 regulator_error_count;
+	int regulator_last_error;
+	u32 bus_error_count;
+	int bus_last_error;
+	u32 dir_count;	/* device initiated reset count. */
+};
+
+static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state)
+{
+	switch (power_state) {
+	case HIDSPI_ON:
+		return "d0";
+	case HIDSPI_SLEEP:
+		return "d2";
+	case HIDSPI_OFF:
+		return "d3";
+	default:
+		return "unknown";
+	}
+}
+
+static irqreturn_t spi_hid_dev_irq(int irq, void *_shid)
+{
+	return IRQ_HANDLED;
+}
+
+static ssize_t bus_error_count_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d (%d)\n",
+			  shid->bus_error_count, shid->bus_last_error);
+}
+static DEVICE_ATTR_RO(bus_error_count);
+
+static ssize_t regulator_error_count_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d (%d)\n",
+			  shid->regulator_error_count,
+			  shid->regulator_last_error);
+}
+static DEVICE_ATTR_RO(regulator_error_count);
+
+static ssize_t device_initiated_reset_count_show(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", shid->dir_count);
+}
+static DEVICE_ATTR_RO(device_initiated_reset_count);
+
+static struct attribute *spi_hid_attrs[] = {
+	&dev_attr_bus_error_count.attr,
+	&dev_attr_regulator_error_count.attr,
+	&dev_attr_device_initiated_reset_count.attr,
+	NULL	/* Terminator */
+};
+
+static const struct attribute_group spi_hid_group = {
+	.attrs = spi_hid_attrs,
+};
+
+const struct attribute_group *spi_hid_groups[] = {
+	&spi_hid_group,
+	NULL
+};
+EXPORT_SYMBOL_GPL(spi_hid_groups);
+
+int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops,
+		       struct spi_hid_conf *conf)
+{
+	struct device *dev = &spi->dev;
+	struct spi_hid *shid;
+	int error;
+
+	if (spi->irq <= 0)
+		return dev_err_probe(dev, spi->irq ?: -EINVAL, "Missing IRQ\n");
+
+	shid = devm_kzalloc(dev, sizeof(*shid), GFP_KERNEL);
+	if (!shid)
+		return -ENOMEM;
+
+	shid->spi = spi;
+	shid->power_state = HIDSPI_ON;
+	shid->ops = ops;
+	shid->conf = conf;
+
+	spi_set_drvdata(spi, shid);
+
+	/*
+	 * At the end of probe we initialize the device:
+	 *   0) assert reset, bias the interrupt line
+	 *   1) sleep minimal reset delay
+	 *   2) request IRQ
+	 *   3) power up the device
+	 *   4) deassert reset (high)
+	 * After this we expect an IRQ with a reset response.
+	 */
+
+	shid->ops->assert_reset(shid->ops);
+
+	shid->ops->sleep_minimal_reset_delay(shid->ops);
+
+	error = devm_request_threaded_irq(dev, spi->irq, NULL, spi_hid_dev_irq,
+					  IRQF_ONESHOT, dev_name(&spi->dev), shid);
+	if (error) {
+		dev_err(dev, "%s: unable to request threaded IRQ.", __func__);
+		return error;
+	}
+
+	error = shid->ops->power_up(shid->ops);
+	if (error) {
+		dev_err(dev, "%s: could not power up.", __func__);
+		return error;
+	}
+
+	shid->ops->deassert_reset(shid->ops);
+
+	dev_dbg(dev, "%s: d3 -> %s.", __func__,
+		spi_hid_power_mode_string(shid->power_state));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_hid_core_probe);
+
+void spi_hid_core_remove(struct spi_device *spi)
+{
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int error;
+
+	shid->ops->assert_reset(shid->ops);
+	error = shid->ops->power_down(shid->ops);
+	if (error)
+		dev_err(dev, "failed to disable regulator.");
+}
+EXPORT_SYMBOL_GPL(spi_hid_core_remove);
+
+MODULE_DESCRIPTION("HID over SPI transport driver");
+MODULE_AUTHOR("Dmitry Antipov <dmanti@microsoft.com>");
+MODULE_LICENSE("GPL");

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 02/12] HID: Add BUS_SPI support and define HID_SPI_DEVICE macro
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Jarrett Schultz, Dmitry Antipov
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

From: Jarrett Schultz <jaschultz@microsoft.com>

If connecting a hid_device with bus field indicating BUS_SPI print out
"SPI" in the debug print.

Macro sets the bus field to BUS_SPI and uses arguments to set vendor
product fields.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 drivers/hid/hid-core.c | 3 +++
 include/linux/hid.h    | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a5b3a8ca2fcb..813c9c743ccd 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2316,6 +2316,9 @@ int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
 	case BUS_I2C:
 		bus = "I2C";
 		break;
+	case BUS_SPI:
+		bus = "SPI";
+		break;
 	case BUS_SDW:
 		bus = "SOUNDWIRE";
 		break;
diff --git a/include/linux/hid.h b/include/linux/hid.h
index dce862cafbbd..957f322a0ebd 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -786,6 +786,8 @@ struct hid_descriptor {
 	.bus = BUS_BLUETOOTH, .vendor = (ven), .product = (prod)
 #define HID_I2C_DEVICE(ven, prod)				\
 	.bus = BUS_I2C, .vendor = (ven), .product = (prod)
+#define HID_SPI_DEVICE(ven, prod)				\
+	.bus = BUS_SPI, .vendor = (ven), .product = (prod)
 
 #define HID_REPORT_ID(rep) \
 	.report_type = (rep)

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related

* [PATCH 01/12] Documentation: Correction in HID output_report callback description.
From: Jingyuan Liang @ 2026-03-03  6:12 UTC (permalink / raw)
  To: Jiri Kosina, Benjamin Tissoires, Jonathan Corbet, Mark Brown,
	Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
	Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: linux-input, linux-doc, linux-kernel, linux-spi,
	linux-trace-kernel, devicetree, hbarnor, Jingyuan Liang,
	Jarrett Schultz, Dmitry Antipov
In-Reply-To: <20260303-send-upstream-v1-0-1515ba218f3d@chromium.org>

From: Jarrett Schultz <jaschultz@microsoft.com>

Originally output_report callback was described as must-be asynchronous,
but that is not the case in some implementations, namely i2c-hid.
Correct the documentation to say that it may be asynchronous.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 Documentation/hid/hid-transport.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/hid/hid-transport.rst b/Documentation/hid/hid-transport.rst
index 6f1692da296c..2008cf432af1 100644
--- a/Documentation/hid/hid-transport.rst
+++ b/Documentation/hid/hid-transport.rst
@@ -327,8 +327,8 @@ The available HID callbacks are:
 
    Send raw output report via intr channel. Used by some HID device drivers
    which require high throughput for outgoing requests on the intr channel. This
-   must not cause SET_REPORT calls! This must be implemented as asynchronous
-   output report on the intr channel!
+   must not cause SET_REPORT calls! This call might be asynchronous, so the
+   caller should not expect an immediate response!
 
    ::
 

-- 
2.53.0.473.g4a7958ca14-goog


^ permalink raw reply related


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