commit 23f9485510 upstream.
An IRQ handler can either be IRQF_NO_THREAD or acquire spinlock_t, as
CONFIG_PROVE_RAW_LOCK_NESTING warns:
=============================
[ BUG: Invalid wait context ]
6.18.0-rc1+git... #1
-----------------------------
some-user-space-process/1251 is trying to lock:
(&counter->events_list_lock){....}-{3:3}, at: counter_push_event [counter]
other info that might help us debug this:
context-{2:2}
no locks held by some-user-space-process/....
stack backtrace:
CPU: 0 UID: 0 PID: 1251 Comm: some-user-space-process 6.18.0-rc1+git... #1 PREEMPT
Call trace:
show_stack (C)
dump_stack_lvl
dump_stack
__lock_acquire
lock_acquire
_raw_spin_lock_irqsave
counter_push_event [counter]
interrupt_cnt_isr [interrupt_cnt]
__handle_irq_event_percpu
handle_irq_event
handle_simple_irq
handle_irq_desc
generic_handle_domain_irq
gpio_irq_handler
handle_irq_desc
generic_handle_domain_irq
gic_handle_irq
call_on_irq_stack
do_interrupt_handler
el0_interrupt
__el0_irq_handler_common
el0t_64_irq_handler
el0t_64_irq
... and Sebastian correctly points out. Remove IRQF_NO_THREAD as an
alternative to switching to raw_spinlock_t, because the latter would limit
all potential nested locks to raw_spinlock_t only.
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20251117151314.xwLAZrWY@linutronix.de/
Fixes: a55ebd47f2 ("counter: add IRQ or GPIO based counter")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20251118083603.778626-1-alexander.sverdlin@siemens.com
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9517d76dd1 upstream.
quad8_irq_handler() should return irqreturn_t enum values, but it
directly returns negative errno codes from regmap operations on error.
Return IRQ_NONE if the interrupt status cannot be read. If clearing the
interrupt fails, return IRQ_HANDLED to prevent the kernel from disabling
the IRQ line due to a spurious interrupt storm. Also, log these regmap
failures with dev_WARN_ONCE.
Fixes: 98ffe02529 ("counter: 104-quad-8: Migrate to the regmap API")
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20251215020114.1913-1-vulab@iscas.ac.cn
Cc: stable@vger.kernel.org
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7351312632 ]
Enable/disable seems to be racy on SMP, consider the following scenario:
CPU0 CPU1
interrupt_cnt_enable_write(true)
{
if (priv->enabled == enable)
return 0;
if (enable) {
priv->enabled = true;
interrupt_cnt_enable_write(false)
{
if (priv->enabled == enable)
return 0;
if (enable) {
priv->enabled = true;
enable_irq(priv->irq);
} else {
disable_irq(priv->irq)
priv->enabled = false;
}
enable_irq(priv->irq);
} else {
disable_irq(priv->irq);
priv->enabled = false;
}
The above would result in priv->enabled == false, but IRQ left enabled.
Protect both write (above race) and read (to propagate the value on SMP)
callbacks with a mutex.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Fixes: a55ebd47f2 ("counter: add IRQ or GPIO based counter")
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20250331163642.2382651-1-alexander.sverdlin@siemens.com
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8744dcd4fc upstream.
In case the stm32_lptim_set_enable_state() fails to update CMP and ARR,
a timeout error is raised, by regmap_read_poll_timeout. It may happen,
when the lptimer runs on a slow clock, and the clock is gated only
few times during the polling.
Badly, when this happen, STM32_LPTIM_ENABLE in CR register has been set.
So the 'enable' state in sysfs wrongly lies on the counter being
correctly enabled, due to CR is read as one in stm32_lptim_is_enabled().
To fix both issues:
- enable the clock before writing CMP, ARR and polling ISR bits. It will
avoid the possible timeout error.
- clear the ENABLE bit in CR and disable the clock in the error path.
Fixes: d8958824cf ("iio: counter: Add support for STM32 LPTimer")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20250224170657.3368236-1-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull char / misc and other driver updates from Greg KH:
"Here is the "big" set of char/misc and other driver subsystem changes
for 6.11-rc1. Nothing major in here, just loads of new drivers and
updates. Included in here are:
- IIO api updates and new drivers added
- wait_interruptable_timeout() api cleanups for some drivers
- MODULE_DESCRIPTION() additions for loads of drivers
- parport out-of-bounds fix
- interconnect driver updates and additions
- mhi driver updates and additions
- w1 driver fixes
- binder speedups and fixes
- eeprom driver updates
- coresight driver updates
- counter driver update
- new misc driver additions
- other minor api updates
All of these, EXCEPT for the final Kconfig build fix for 32bit
systems, have been in linux-next for a while with no reported issues.
The Kconfig fixup went in 29 hours ago, so might have missed the
latest linux-next, but was acked by everyone involved"
* tag 'char-misc-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (330 commits)
misc: Kconfig: exclude mrvl-cn10k-dpi compilation for 32-bit systems
misc: delete Makefile.rej
binder: fix hang of unregistered readers
misc: Kconfig: add a new dependency for MARVELL_CN10K_DPI
virtio: add missing MODULE_DESCRIPTION() macro
agp: uninorth: add missing MODULE_DESCRIPTION() macro
spmi: add missing MODULE_DESCRIPTION() macros
dev/parport: fix the array out-of-bounds risk
samples: configfs: add missing MODULE_DESCRIPTION() macro
misc: mrvl-cn10k-dpi: add Octeon CN10K DPI administrative driver
misc: keba: Fix missing AUXILIARY_BUS dependency
slimbus: Fix struct and documentation alignment in stream.c
MAINTAINERS: CC dri-devel list on Qualcomm FastRPC patches
misc: fastrpc: use coherent pool for untranslated Compute Banks
misc: fastrpc: support complete DMA pool access to the DSP
misc: fastrpc: add missing MODULE_DESCRIPTION() macro
misc: fastrpc: Add missing dev_err newlines
misc: fastrpc: Use memdup_user()
nvmem: core: Implement force_ro sysfs attribute
nvmem: Use sysfs_emit() for type attribute
...
Pull pwm updates from Uwe Kleine-König:
"This contains the usual mix of fixes, cleanups, two new drivers and
several dt binding updates. The fixes are for minor issues that are
already old (4.11-rc1 and 3.9-rc1) and were found by code review and
not during usage, so I didn't sent them for earlier inclusion.
The changes to include/linux/mfd/stm32-timers.h and
drivers/counter/stm32-timer-cnt.c are part of an immutable branch that
will also be included in the mfd and counter pulls. It changes some
register definitions and affects the pwm-stm32 driver.
Thanks go to Andy Shevchenko, AngeloGioacchino Del Regno, Conor
Dooley, David Lechner, Dhruva Gole, Drew Fustini, Frank Li, Jeff
Johnson, Junyi Zhao, Kelvin Zhang, Krzysztof Kozlowski, Lee Jones,
Linus Walleij, Linus Walleij, Michael Hennerich, Nicola Di Lieto,
Nicolas Ferre, Nuno Sa, Paul Cercueil, Raag Jadav, Rob Herring, Sean
Anderson, Sean Young, Shenwei Wang, Stefan Wahren, Trevor Gamblin,
Tzung-Bi Shih, Vincent Whitchurch and William Breathitt Gray for their
contributions to this pull request; they authored changes, spend time
reviewing changes and coordinated the above mentioned immutable
branch"
* tag 'pwm/for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: (38 commits)
pwm: axi-pwmgen: add .max_register to regmap
dt-bindings: pwm: at91: Add sama7d65 compatible string
pwm: atmel-tcb: Make private data variable naming consistent
pwm: atmel-tcb: Simplify checking the companion output
pwm: Allow pwm state transitions from an invalid state
pwm: xilinx: Simplify using devm_ functions
pwm: Use guards for pwm_lookup_lock instead of explicity mutex_lock + mutex_unlock
pwm: Use guards for export->lock instead of explicity mutex_lock + mutex_unlock
pwm: Use guards for pwm_lock instead of explicity mutex_lock + mutex_unlock
pwm: Register debugfs operations after the pwm class
pwm: imx-tpm: Enable pinctrl setting for sleep state
pwm: lpss: drop redundant runtime PM handles
pwm: lpss: use devm_pm_runtime_enable() helper
pwm-stm32: Make use of parametrised register definitions
dt-bindings: pwm: imx: remove interrupt property from required
pwm: meson: Add support for Amlogic S4 PWM
pwm: Add GPIO PWM driver
dt-bindings: pwm: Add pwm-gpio
pwm: Drop pwm_apply_state()
bus: ts-nbus: Use pwm_apply_might_sleep()
...
These two defines have the same purpose and this change doesn't
introduce any differences in drivers/counter/stm32-timer-cnt.o.
The only difference between the two is that
TIM_DIER_CC_IE(1) == TIM_DIER_CC2IE
while
TIM_DIER_CCxIE(1) == TIM_DIER_CC1IE
. That makes it necessary to have an explicit "+ 1" in the user code,
but IMHO this is a good thing as this is the code locatation that
"knows" that for software channel 1 you have to use TIM_DIER_CC2IE
(because software guys start counting at 0, while the relevant hardware
designer started at 1).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Acked-by: William Breathitt Gray <wbg@kernel.org>
Link: https://lore.kernel.org/r/126bd153a03f39e42645573eecf44ffab5354fc7.1718791090.git.u.kleine-koenig@baylibre.com
Signed-off-by: Lee Jones <lee@kernel.org>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: David Lechner <david@lechnology.com>
Link: https://lore.kernel.org/r/bf78595f6a49be0b6bb403b466c13177d72c02b7.1710057753.git.u.kleine-koenig@pengutronix.de
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/f70902b2aabecaa9295c28629cd7a8a0e6eb06d0.1710057753.git.u.kleine-koenig@pengutronix.de
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Add support for capture events. Captured counter value for each channel
can be retrieved through CCRx register.
STM32 timers can have up to 4 capture channels (on input channel 1 to
channel 4), hence need to check the number of channels before reading
the capture data.
The capture configuration is hard-coded to capture signals on both edges
(non-inverted). Interrupts are used to report events independently for
each channel.
Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-11-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Add support overflow events. Also add the related validation and
configuration routine. Register and enable interrupts to push events.
STM32 Timers can have either 1 global interrupt, or 4 dedicated interrupt
lines. Request only the necessary interrupt, e.g. either global interrupt
that can report all event types, or update interrupt only for overflow
event.
Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-10-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
This is a precursor patch to support capture channels on all possible
channels and stm32 timer types. Original driver was intended to be used
only as quadrature encoder and simple counter on internal clock.
So, add a check on encoder capability, so the driver may be probed for
timer instances without encoder feature. This way, all timers may be used
as simple counter on internal clock, starting from here.
Encoder capability is retrieved by using the timer index (originally in
stm32-timer-trigger driver and dt-bindings). The need to keep backward
compatibility with existing device tree lead to parse aside trigger node.
Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-7-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Introduce the internal clock signal, used to count when in simple rising
function. Also add the "frequency" extension to the clock signal.
With this patch, signal action reports a consistent state when "increase"
function is used, and the counting frequency:
$ echo increase > function
$ grep -H "" signal*_action
signal0_action:none
signal1_action:none
signal2_action:rising edge
$ echo 1 > enable
$ cat count
25425
$ cat count
44439
$ cat ../signal2/frequency
208877930
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-5-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Drop the Quadrature convention in the signal name. On stm32-timer:
- Quadrature A signal corresponds to timer input ch1, hence "Channel 1"
- Quadrature B signal corresponds to timer input ch2, hence "Channel 2".
So name these signals after their channel. I suspect it referred to the
(unique) quadrature counter support earlier, but the physical input
really is CH1/CH2. This will be easier to support other counter modes.
Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-2-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
William writes:
First set of Counter fixes for 6.6
The counter_get_ext() function would incorrectly refer to the first
element of the extensions array to handle component array extensions
when they are located at a different index; a fix is provided to index
to the correct element in the array for this case. A fix for the
microchip-tcb-capture is provided as well to correct an inverted
internal GCLK logic for clock selection.
* tag 'counter-fixes-for-6.6a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: microchip-tcb-capture: Fix the use of internal GCLK logic
counter: chrdev: fix getting array extensions
Pull NFD updates from Lee Jones:
"New Drivers:
- Add support for the Cirrus Logic CS42L43 Audio CODEC
Fix-ups:
- Make use of specific printk() format tags for various optimisations
- Kconfig / module modifications / tweaking
- Simplify obtaining resources (memory, device data) using unified
API helpers
- Bunch of Device Tree additions, conversions and adaptions
- Convert a bunch of Regmap configurations to use the Maple Tree
cache
- Ensure correct includes are present and remove some that are not
required
- Remove superfluous code
- Reduce amount of cycles spent in critical sections
- Omit the use of redundant casts and if relevant replace with better
ones
- Swap out raw_spin_{un}lock_irq{save,restore}() for
spin_{un}lock_irq{save,restore}()
Bug Fixes:
- Repair theoretical deadlock situation
- Fix some link-time dependencies
- Use more appropriate datatype when casting"
* tag 'mfd-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (70 commits)
mfd: mc13xxx: Simplify device data fetching in probe()
mfd: rz-mtu3: Replace raw_spin_lock->spin_lock()
mfd: rz-mtu3: Reduce critical sections
mfd: mxs-lradc: Fix Wvoid-pointer-to-enum-cast warning
mfd: wm31x: Fix Wvoid-pointer-to-enum-cast warning
mfd: wm8994: Fix Wvoid-pointer-to-enum-cast warning
mfd: tc3589: Fix Wvoid-pointer-to-enum-cast warning
mfd: lp87565: Fix Wvoid-pointer-to-enum-cast warning
mfd: hi6421-pmic: Fix Wvoid-pointer-to-enum-cast warning
mfd: max77541: Fix Wvoid-pointer-to-enum-cast warning
mfd: max14577: Fix Wvoid-pointer-to-enum-cast warning
mfd: stmpe: Fix Wvoid-pointer-to-enum-cast warning
mfd: rn5t618: Remove redundant of_match_ptr()
mfd: lochnagar-i2c: Remove redundant of_match_ptr()
mfd: stpmic1: Remove redundant of_match_ptr()
mfd: act8945a: Remove redundant of_match_ptr()
mfd: rsmu_spi: Remove redundant of_match_ptr()
mfd: altera-a10sr: Remove redundant of_match_ptr()
mfd: rsmu_i2c: Remove redundant of_match_ptr()
mfd: tc3589x: Remove redundant of_match_ptr()
...
When trying to watch a component array extension, and the array isn't the
first extended element, it fails as the type comparison is always done on
the 1st element. Fix it by indexing the 'ext' array.
Example on a dummy struct counter_comp:
static struct counter_comp dummy[] = {
COUNTER_COMP_DIRECTION(..),
...,
COUNTER_COMP_ARRAY_CAPTURE(...),
};
static struct counter_count dummy_cnt = {
...
.ext = dummy,
.num_ext = ARRAY_SIZE(dummy),
}
Currently, counter_get_ext() returns -EINVAL when trying to add a watch
event on one of the capture array element in such example.
Fixes: d2011be1e2 ("counter: Introduce the COUNTER_COMP_ARRAY component type")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20230829134029.2402868-2-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
The new set of drivers for RZ/G2L MTU3a tries to enable compile-testing the
individual client drivers even when the MFD portion is disabled but gets it
wrong, causing a link failure when the core is in a loadable module but the
other drivers are built-in:
x86_64-linux-ld: drivers/pwm/pwm-rz-mtu3.o: in function `rz_mtu3_pwm_apply':
pwm-rz-mtu3.c:(.text+0x4bf): undefined reference to `rz_mtu3_8bit_ch_write'
x86_64-linux-ld: pwm-rz-mtu3.c:(.text+0x509): undefined reference to `rz_mtu3_disable'
arm-linux-gnueabi-ld: drivers/counter/rz-mtu3-cnt.o: in function `rz_mtu3_cascade_counts_enable_get':
rz-mtu3-cnt.c:(.text+0xbec): undefined reference to `rz_mtu3_shared_reg_read'
It seems better not to add the extra complexity here but instead just use
a normal hard dependency, so remove the #else portion in the header along
with the "|| COMPILE_TEST". This could also be fixed by having slightly more
elaborate Kconfig dependencies or using the cursed 'IS_REACHABLE()' helper,
but in practice it's already possible to compile-test all these drivers
by enabling the mtd portion.
Fixes: 254d3a7274 ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
Fixes: 0be8907359 ("counter: Add Renesas RZ/G2L MTU3a counter driver")
Fixes: 654c293e16 ("mfd: Add Renesas RZ/G2L MTU3a core driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230719090430.1925182-1-arnd@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174357.4053541-1-robh@kernel.org/
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
William writes:
First set of Counter fixes for 6.5
In commit d428487471 ("counter: i8254: Introduce the Intel 8254
interface library module"), the misplacement of the I8254 Kconfig entry
results in the "Counter support" submenu items disappearing in
menuconfig. A fix is provided to reposition the I8254 Kconfig entry to
restore the intended submenu behavior.
* tag 'counter-fixes-for-6.5a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: Fix menuconfig "Counter support" submenu entries disappearance
William writes:
First set of Counter updates for the 6.5 cycle
Biggest changes in this set include the introduction of a new Intel 8254
interface library module and the refactoring of the existing 104-quad-8
modules to migrate it to the regmap API. Some other minor cleanups
touching tools/counter and stm32-timer-cnt are also present.
Changes
* 104-quad-8
- Remove reference in Kconfig to 25-bit counter value
- Utilize bitfield access macros
- Refactor to buffer states for CMR, IOR, and IDR
- Utilize helper functions to handle PR, FLAG and PSC
- Migrate to the regmap API
* i8254
- Introduce the Intel 8254 interface library module
* stm32-timer-cnt
- Reset TIM_TISEL to its default value in probe
* tools/counter
- Add .gitignore
- Remove lingering 'include' directories on make clean
* tag 'counter-updates-for-6.5a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: i8254: Introduce the Intel 8254 interface library module
counter: 104-quad-8: Migrate to the regmap API
counter: 104-quad-8: Utilize helper functions to handle PR, FLAG and PSC
counter: 104-quad-8: Refactor to buffer states for CMR, IOR, and IDR
counter: 104-quad-8: Utilize bitfield access macros
tools/counter: Makefile: Remove lingering 'include' directories on make clean
tools/counter: Add .gitignore
counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe
counter: 104-quad-8: Remove reference in Kconfig to 25-bit counter value
Exposes consumer library functions providing support for interfaces
compatible with the venerable Intel 8254 Programmable Interval Timer
(PIT).
The Intel 8254 PIT first appeared in the early 1980s and was used
initially in IBM PC compatibles. The popularity of the original Intel
825x family of chips led to many subsequent variants and clones of the
interface in various chips and integrated circuits. Although still
popular, interfaces compatible with the Intel 8254 PIT are nowdays
typically found embedded in larger VLSI processing chips and FPGA
components rather than as discrete ICs.
A CONFIG_I8254 Kconfig option is introduced by this patch. Modules
wanting access to these i8254 library functions should select this
Kconfig option, and import the I8254 symbol namespace.
Link: https://lore.kernel.org/r/f6fe32c2db9525d816ab1a01f45abad56c081652.1681665189.git.william.gray@linaro.org/
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver. With regmap we get boundary checks, read-write
permissions, operation synchronization locks, and more for free. Most
important of all, rather than rolling our own we utilize implementations
that are known to work and gain from any future improvements and fixes
that come.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/1f1f7920d2be94aedb6fdf49f429fe6137c8cb24.1681753140.git.william.gray@linaro.org/
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
