This was missed in the basic driver and is useful for debug, so add it.
Example regmap output before the patch:
|root@zed-tg:~# cat /sys/kernel/debug/regmap/44a60000.pwm/registers
|0: 00020100
And with it:
|root@zed-tg:~# cat /sys/kernel/debug/regmap/44a60000.pwm/registers
|00: 00020100
|04: 00000000
|08: 00000000
|0c: 601a3471
|10: 00000000
|14: 00000002
|18: 00000001
|1c: 00000000
|...
Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>
Link: https://lore.kernel.org/r/20240711125743.3956935-1-tgamblin@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
While driving a PWM via the sysfs API it's hard to determine the right
order of writes to the pseudo files "period" and "duty_cycle":
If you want to go from duty_cycle/period = 50/100 to 150/300 you have to
write period first (because 150/100 is invalid). If however you start at
400/500 the duty_cycle must be configured first. The rule that works is:
If you increase period write period first, otherwise write duty_cycle
first. A complication however is that it's usually sensible to configure
the polarity before both period and duty_cycle. This can only be done if
the current state's duty_cycle and period configuration isn't bogus
though. It is still worse (but I think only theoretic) if you have a PWM
that only supports inverted polarity and you start with period = 0 and
polarity = normal. Then you can change neither period (because polarity
= normal is refused) nor polarity (because there is still period = 0).
To simplify the corner cases for userspace, let invalid target states
pass if the current state is invalid already.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240628103519.105020-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
There are devm variants for clk_prepare_enable() and pwmchip_add(); and
clk_prepare_enable() can be done together with devm_clk_get(). This
allows to simplify the error paths in .probe() and drop .remove()
completely.
With the remove callback gone, the last user of platform_get_drvdata()
is gone and so the call to platform_set_drvdata() can be dropped, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20240628063524.92907-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
While the debugfs operations don't technically depend on an initialized
class, they loop over the idr that only can get entries when the class
is properly initialized.
This also fixes the ugly (but harmless) corner case that the debugfs
file stays around after the pwm class failed to initialize.
While at it, add an appropriate error message when class initialization
fails.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240626222529.2901200-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
There is no semantic change, but it is a nicer on the eyes of a reader,
because
TIM_CCR1 + 4 * ch
encodes internal register knowledge, while
TIM_CCRx(ch + 1)
keeps that information completely in the header defining the registers.
While I expected this to not result in any changes in the binary, gcc 13
(as provided by Debian in the gcc-13-arm-linux-gnueabihf 13.2.0-12cross1
package) compiles the new version with an allmodconfig to more compact
code:
$ source/scripts/bloat-o-meter drivers/pwm/pwm-stm32.o-pre drivers/pwm/pwm-stm32.o
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-488 (-488)
Function old new delta
stm32_pwm_get_state 968 936 -32
stm32_pwm_apply_locked 1920 1464 -456
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/d7ef7a6158df4ba6687233b0e00d37796b069fb3.1718791090.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Add a software PWM which toggles a GPIO from a high-resolution timer.
This will naturally not be as accurate or as efficient as a hardware
PWM, but it is useful in some cases. I have for example used it for
evaluating LED brightness handling (via leds-pwm) on a board where the
LED was just hooked up to a GPIO, and for a simple verification of the
timer frequency on another platform.
Since high-resolution timers are used, sleeping GPIO chips are not
supported and are rejected in the probe function.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Co-developed-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Co-developed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20240604-pwm-gpio-v7-2-6b67cf60db92@linaro.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
This function is not supposed to be used any more since commit
c748a6d77c ("pwm: Rename pwm_apply_state() to
pwm_apply_might_sleep()") that is included in v6.8-rc1. Two kernel
releases should be enough for everyone to adapt, so drop the old
function that was introduced as a compatibility stub for the transition.
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The cros-ec device tree binding only uses #pwm-cells = <1>, and so there
is no period provided in the device tree. Up to now this was handled by
hardcoding the period to the only supported value in the custom xlate
callback. Apart from that, the default xlate callback (i.e.
of_pwm_xlate_with_flags()) handles this just fine (and better, e.g. by
checking args->args_count >= 1 before accessing args->args[0]).
To simplify make use of of_pwm_xlate_with_flags(), drop the custom
callback and provide the default period in .probe() already.
Apart from simplifying the driver this also drops the last non-core user
of pwm_request_from_chip() and so makes further simplifications
possible.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20240607084416.897777-7-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Define all pwm core's symbols in the namespace "PWM". The necessary
module import statement is just added to the main header, this way every
file that knows about the public functions automatically has this
namespace available.
Thanks to Biju Das for pointing out a cut'n'paste failure in my initial
patch.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240607160012.1206874-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-imx1.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-imx27.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-intel-lgm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-mediatek.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-pxa.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-samsung.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-spear.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-visconti.o
Add the missing invocations of the MODULE_DESCRIPTION() macro.
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240610-md-drivers-pwm-v2-1-b337cfaa70ea@quicinc.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The hardware only supports a single period length for both PWM outputs. So
atmel_tcb_pwm_config() checks the configuration of the other output if it's
compatible with the currently requested setting. The register values are
then actually updated in atmel_tcb_pwm_enable(). To make this race free
the lock must be held during the whole process, so grab the lock in
.apply() instead of individually in atmel_tcb_pwm_disable() and
atmel_tcb_pwm_enable() which then also covers atmel_tcb_pwm_config().
To simplify handling, use the guard helper to let the compiler care for
unlocking. Otherwise unlocking would be more difficult as there is more
than one exit path in atmel_tcb_pwm_apply().
Fixes: 9421bade07 ("pwm: atmel: add Timer Counter Block PWM driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20240709101806.52394-3-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
When commit 89650a1e3b ("dt-bindings: pwm: Convert PWM bindings
to json-schema") converted the pwm provider section of the text binding
to dt-schema it also updated all references to pwm.txt in pwm provider
bindings to pwm.yaml.
Most pwm provider bindings had a reference to pwm.txt as it contains a
description of what the cells in #pwm-cells are, albeit in the consumer
section of the document. Only information in the provider section of the
document was moved to the yaml binding, and it contains no information
about the cell format, making all references to it for the cell format
unhelpful.
Fixes: 89650a1e3b ("dt-bindings: pwm: Convert PWM bindings to json-schema")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240517-patient-stingily-30611f73e792@spud
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
When the state changes from enabled to disabled, polarity, duty_cycle
and period are not configured in hardware and TIM_CCER_CCxE is just
cleared. However if the state changes from one disabled state to
another, all parameters are written to hardware because the early exit
from stm32_pwm_apply() is only taken if the pwm is currently enabled.
This yields surprises like: Applying
{ .period = 1, .duty_cycle = 0, .enabled = false }
succeeds if the pwm is initially on, but fails if it's already off
because 1 is a too small period.
Update the check for lazy disable to always exit early if the target
state is disabled, no matter what is currently configured.
Fixes: 7edf736920 ("pwm: Add driver for STM32 plaftorm")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240703110010.672654-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
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>
There are some registers that belong together and are numbered from 1 to
4. Introduce a macro definition for these that takes the channel number
as parameter and define the previously available constants using the new
ones.
This allows to simplify some users that up to now use constructs like
TIM_CCER_CC1NE << (ch * 4)
which is an ugly mix of using a predefined value and still knowing
internal details about it.
Note that there are several decrements by 1 involved. These are
necessary because software guys start counting at 0 while the hardware
designer started at 1 (and having TIM_CCER_CCxE(1) be TIM_CCER_CC2E
isn't a sane option). The compiler is expected to optimize these out
nicely.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/05df15f61dde81033407d3b4fcb67ee403ecc8db.1718791090.git.u.kleine-koenig@baylibre.com
Signed-off-by: Lee Jones <lee@kernel.org>
A small prescaler is beneficial, as this improves the resolution of the
duty_cycle configuration. However if the prescaler is too small, the
maximal possible period becomes considerably smaller than the requested
value.
One situation where this goes wrong is the following: With a parent
clock rate of 208877930 Hz and max_arr = 0xffff = 65535, a request for
period = 941243 ns currently results in PSC = 1. The value for ARR is
then calculated to
ARR = 941243 * 208877930 / (1000000000 * 2) - 1 = 98301
This value is bigger than 65535 however and so doesn't fit into the
respective register field. In this particular case the PWM was
configured for a period of 313733.4806027616 ns (with ARR = 98301 &
0xffff). Even if ARR was configured to its maximal value, only period =
627495.6861167669 ns would be achievable.
Fix the calculation accordingly and adapt the comment to match the new
algorithm.
With the calculation fixed the above case results in PSC = 2 and so an
actual period of 941229.1667195285 ns.
Fixes: 8002fbeef1 ("pwm: stm32: Calculate prescaler with a division instead of a loop")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/b4d96b79917617434a540df45f20cb5de4142f88.1718979150.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
percpu.h depends on smp.h, but doesn't include it directly because of
circular header dependency issues; percpu.h is needed in a bunch of low
level headers.
This fixes a randconfig build error on mips:
include/linux/alloc_tag.h: In function '__alloc_tag_ref_set':
include/asm-generic/percpu.h:31:40: error: implicit declaration of function 'raw_smp_processor_id' [-Werror=implicit-function-declaration]
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 24e44cc22a ("mm: percpu: enable per-cpu allocation tagging")
Closes: https://lore.kernel.org/oe-kbuild-all/202405210052.DIrMXJNz-lkp@intel.com/
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf tool fix from Arnaldo Carvalho de Melo:
"Revert a patch causing a regression.
This made a simple 'perf record -e cycles:pp make -j199' stop working
on the Ampere ARM64 system Linus uses to test ARM64 kernels".
* tag 'perf-tools-fixes-for-v6.10-1-2024-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
Revert "perf parse-events: Prefer sysfs/JSON hardware events over legacy"
Pull smb client fixes from Steve French:
- two important netfs integration fixes - including for a data
corruption and also fixes for multiple xfstests
- reenable swap support over SMB3
* tag '6.10-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
cifs: Fix missing set of remote_i_size
cifs: Fix smb3_insert_range() to move the zero_point
cifs: update internal version number
smb3: reenable swapfiles over SMB3 mounts
Pull misc fixes from Andrew Morton:
"16 hotfixes, 11 of which are cc:stable.
A few nilfs2 fixes, the remainder are for MM: a couple of selftests
fixes, various singletons fixing various issues in various parts"
* tag 'mm-hotfixes-stable-2024-05-25-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/ksm: fix possible UAF of stable_node
mm/memory-failure: fix handling of dissolved but not taken off from buddy pages
mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again
nilfs2: fix potential hang in nilfs_detach_log_writer()
nilfs2: fix unexpected freezing of nilfs_segctor_sync()
nilfs2: fix use-after-free of timer for log writer thread
selftests/mm: fix build warnings on ppc64
arm64: patching: fix handling of execmem addresses
selftests/mm: compaction_test: fix bogus test success and reduce probability of OOM-killer invocation
selftests/mm: compaction_test: fix incorrect write of zero to nr_hugepages
selftests/mm: compaction_test: fix bogus test success on Aarch64
mailmap: update email address for Satya Priya
mm/huge_memory: don't unpoison huge_zero_folio
kasan, fortify: properly rename memintrinsics
lib: add version into /proc/allocinfo output
mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL
Pull irq fixes from Ingo Molnar:
- Fix x86 IRQ vector leak caused by a CPU offlining race
- Fix build failure in the riscv-imsic irqchip driver
caused by an API-change semantic conflict
- Fix use-after-free in irq_find_at_or_after()
* tag 'irq-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after()
genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline
irqchip/riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict
Pull x86 fixes from Ingo Molnar:
- Fix regressions of the new x86 CPU VFM (vendor/family/model)
enumeration/matching code
- Fix crash kernel detection on buggy firmware with
non-compliant ACPI MADT tables
- Address Kconfig warning
* tag 'x86-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Fix x86_match_cpu() to match just X86_VENDOR_INTEL
crypto: x86/aes-xts - switch to new Intel CPU model defines
x86/topology: Handle bogus ACPI tables correctly
x86/kconfig: Select ARCH_WANT_FRAME_POINTERS again when UNWINDER_FRAME_POINTER=y
