Go to file
Matthias Schiffer 01aa7b7a3d gpio: tqmx86: introduce shadow register for GPIO output value
[ Upstream commit 9d6a811b52 ]

The TQMx86 GPIO controller uses the same register address for input and
output data. Reading the register will always return current inputs
rather than the previously set outputs (regardless of the current
direction setting). Therefore, using a RMW pattern does not make sense
when setting output values. Instead, the previously set output register
value needs to be stored as a shadow register.

As there is no reliable way to get the current output values from the
hardware, also initialize all channels to 0, to ensure that stored and
actual output values match. This should usually not have any effect in
practise, as the TQMx86 UEFI sets all outputs to 0 during boot.

Also prepare for extension of the driver to more than 8 GPIOs by using
DECLARE_BITMAP.

Fixes: b868db94a6 ("gpio: tqmx86: Add GPIO from for this IO controller")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/d0555933becd45fa92a85675d26e4d59343ddc01.1717063994.git.matthias.schiffer@ew.tq-group.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21 14:38:29 +02:00
arch powerpc/uaccess: Fix build errors seen with GCC 13/14 2024-06-21 14:38:26 +02:00
block blk-cgroup: Properly propagate the iostat update up the hierarchy 2024-06-12 11:12:46 +02:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: ecrdsa - Fix module auto-load on add_key 2024-06-16 13:47:39 +02:00
Documentation mm: fix race between __split_huge_pmd_locked() and GUP-fast 2024-06-16 13:47:40 +02:00
drivers gpio: tqmx86: introduce shadow register for GPIO output value 2024-06-21 14:38:29 +02:00
fs NFS: add barriers when testing for NFS_FSDATA_BLOCKED 2024-06-21 14:38:29 +02:00
include cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read() 2024-06-21 14:38:27 +02:00
init smp: Provide 'setup_max_cpus' definition on UP too 2024-06-16 13:47:49 +02:00
io_uring io_uring: check for non-NULL file pointer in io_file_can_poll() 2024-06-21 14:38:23 +02:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel bpf: fix multi-uprobe PID filtering logic 2024-06-21 14:38:22 +02:00
lib lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure 2024-06-12 11:12:08 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/memory-failure: fix handling of dissolved but not taken off from buddy pages 2024-06-21 14:38:21 +02:00
net SUNRPC: return proper error from gss_wrap_req_priv 2024-06-21 14:38:28 +02:00
rust rust: kernel: require Send for Module implementations 2024-05-17 12:01:56 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts kconfig: fix comparison to constant symbols, 'm', 'n' 2024-06-12 11:12:58 +02:00
security landlock: Fix d_parent walk 2024-06-21 14:38:24 +02:00
sound ALSA: seq: Fix incorrect UMP type for system messages 2024-06-16 13:47:48 +02:00
tools selftests/tracing: Fix event filter test to retry up to 10 times 2024-06-21 14:38:29 +02:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:28:18 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS pwm: Rename pwm_apply_state() to pwm_apply_might_sleep() 2024-06-12 11:12:24 +02:00
Makefile Linux 6.6.34 2024-06-16 13:47:49 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.