Extend regulator notification support
This series extends the regulator notification and error flag support.
Initial discussion on the topic can be found here:
https://lore.kernel.org/lkml/6046836e22b8252983f08d5621c35ececb97820d.camel@fi.rohmeurope.com/
In a nutshell - the series adds:
1. WARNING level events/error flags. (Patch 3)
Current regulator 'ERROR' event notifications for over/under
voltage, over current and over temperature are used to indicate
condition where monitored entity is so badly "off" that it actually
indicates a hardware error which can not be recovered. The most
typical hanling for that is believed to be a (graceful)
system-shutdown. Here we add set of 'WARNING' level flags to allow
sending notifications to consumers before things are 'that badly off'
so that consumer drivers can implement recovery-actions.
2. Device-tree properties for specifying limit values. (Patches 1, 5)
Add limits for above mentioned 'ERROR' and 'WARNING' levels (which
send notifications to consumers) and also for a 'PROTECTION' level
(which will be used to immediately shut-down the regulator(s) W/O
informing consumer drivers. Typically implemented by hardware).
Property parsing is implemented in regulator core which then calls
callback operations for limit setting from the IC drivers. A
warning is emitted if protection is requested by device tree but the
underlying IC does not support configuring requested protection.
3. Helpers which can be registered by IC. (Patch 4)
Target is to avoid implementing IRQ handling and IRQ storm protection
in each IC driver. (Many of the ICs implementin these IRQs do not allow
masking or acking the IRQ but keep the IRQ asserted for the whole
duration of problem keeping the processor in IRQ handling loop).
4. Emergency poweroff function (refactored out of the thermal_core to
kernel/reboot.c) which is called if IC fires error IRQs but IC reading
fails and given retry-count is exceeded. (Patches 2, 4)
Please note that the mutex in the emergency shutdown was replaced by a
simple atomic in order to allow call from any context.
The helper was attempted to be done so it could be used to implement
roughly same logic as is used in qcom-labibb regulator. This means
amongst other things a safety shut-down if IC registers are not readable.
Using these shut-down retry counters are optional. The idea is that the
helper could be also used by simpler ICs which do not provide status
register(s) which can be used to check if error is still active.
ICs which do not have such status register can simply omit the 'renable'
callback (and retry-counts etc) - and helper assumes the situation is Ok
and re-enables IRQ after given time period. If problem persists the
handler is ran again and another notification is sent - but at least the
delay allows processor to avoid IRQ loop.
Patch 7 takes this notification support in use at BD9576MUF.
Patch 8 is related to MFD change which is not really related to the RFC
here. It was added to this series in order to avoid potential conflicts.
Patch 9 adds a maintainers entry.
Changelog v10-RESEND:
- rebased on v5.13-rc4
Changelog v10:
- rebased on v5.13-rc2
- Move rdev_*() print macros to the internal.h and use rdev_dbg()
from irq_helpers.c
- Export rdev_get_name() and move it from coupler.h to driver.h for
others to use. (It was already in coupler.h but not exported -
usage was limited and coupler.h does not sound like optimal place
as rdev_name is not only used by coupled regulators)
- Send all regulator notifications from irq_helpers.c at one OR'd
event for the sake of simplicity. For BD9576 this does not matter
as it has own IRQ for each event case. Header defining events says
they may be OR'd.
- Change WARN() at protection shutdown to pr_emerg as suggested by
Petr.
Changelog v9:
- rebases on v5.13-rc1
- Update thermal documentation
- Fix regulator notification event number
Changelog v8:
- split shutdown API adding and thermal core taking it in use to
own patches.
- replace the spinlock with atomic when ensuring the emergency
shutdown is only called once.
Changelog v7:
general:
- rebased on v5.12-rc7
- new patch for refactoring the hw-failure reboot logic out of
thermal_core.c for others to use.
notification helpers:
- fix regulator error_flags query
- grammar/typos
- do not BUG() but attempt to shut-down the system
- use BITS_PER_TYPE()
Changelog v6:
Add MAINTAINERS entry
Changes to IRQ notifiers
- move devm functions to drivers/regulator/devres.c
- drop irq validity check
- use devm_add_action_or_reset()
- fix styling issues
- fix kerneldocs
Changelog v5:
- Fix the badly formatted pr_emerg() call.
Changelog v4:
- rebased on v5.12-rc6
- dropped RFC
- fix external FET DT-binding.
- improve prints for cases when expecting HW failure.
- styling and typos
Changelog v3:
Regulator core:
- Fix dangling pointer access at regulator_irq_helper()
stpmic1_regulator:
- fix function prototype (compile error)
bd9576-regulator:
- Update over current limits to what was given in new data-sheet
(REV00K)
- Allow over-current monitoring without external FET. Set limits to
values given in data-sheet (REV00K).
Changelog v2:
Generic:
- rebase on v5.12-rc2 + BD9576 series
- Split devm variant of delayed wq to own series
Regulator framework:
- Provide non devm variant of IRQ notification helpers
- shorten dt-property names as suggested by Rob
- unconditionally call map_event in IRQ handling and require it to be
populated
BD9576 regulators:
- change the FET resistance property to micro-ohms
- fix voltage computation in OC limit setting
Add 'warning' level events and error flags to regulator core.
Current regulator core notifications are used to inform consumers
about errors where HW is misbehaving in such way it is assumed to
be broken/unrecoverable.
There are PMICs which are designed for system(s) that may have use
for regulator indications sent before HW is damaged so that some
board/consumer specific recovery-event can be performed while
continuing most of the normal operations.
Add new WARNING level events and notifications to be used for
that purpose.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/9b54aa5589ae4b5945d53d114bac3fae55fa4818.1622628333.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The MT6359 is a regulator found on boards based on MediaTek MT6779 and
probably other SoCs. It is a so called pmic and connects as a slave to
SoC using SPI, wrapped inside the pmic-wrapper.
Signed-off-by: Wen Su <wen.su@mediatek.com>
Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@mediatek.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Some NVIDIA Tegra devices use a CPU soft-reset method for the reboot and
in this case we need to restore the coupled voltages to the state that is
suitable for hardware during boot. Add new regulator_sync_voltage_rdev()
helper which is needed by regulator drivers in order to sync voltage of
a coupled regulators.
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The jiffies-based off_on_delay implementation has a couple of problems
that cause it to sometimes not actually delay for the required time:
(1) If, for example, the off_on_delay time is equivalent to one jiffy,
and the ->last_off_jiffy is set just before a new jiffy starts,
then _regulator_do_enable() does not wait at all since it checks
using time_before().
(2) When jiffies overflows, the value of "remaining" becomes higher
than "max_delay" and the code simply proceeds without waiting.
Fix these problems by changing it to use ktime_t instead.
[Note that since jiffies doesn't start at zero but at INITIAL_JIFFIES
("-5 minutes"), (2) above also led to the code not delaying if
the first regulator_enable() is called when the ->last_off_jiffy is not
initialised, such as for regulators with ->constraints->boot_on set.
It's not clear to me if this was intended or not, but I've preserved
this behaviour explicitly with the check for a non-zero ->last_off.]
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20210423114524.26414-1-vincent.whitchurch@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>
By default the PCA9450 doesn't handle the assertion of the WDOG_B
signal, but this is required to guarantee that things like software
resets triggered by the watchdog work reliably.
As we don't want to rely on the bootloader to enable this, we tell
the PMIC to issue a cold reset in case the WDOG_B signal is
asserted (WDOG_B_CFG = 10), just as the NXP U-Boot code does.
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Link: https://lore.kernel.org/r/20210211105534.38972-3-frieder.schrempf@kontron.de
Signed-off-by: Mark Brown <broonie@kernel.org>
The struct ab8500_regulator_platform_data was a leftover
since the days before we probed all regulators from the
device tree. The ab8500-ext regulator was the only used,
defining platform data and register intialization that
was never used for anything, a copy of a boardfile no
longer in use.
Delete the ab8500_regulator_platform_data and make the
ab8500-ext regulator reference the regulator init data
in the local file directly. We are 100% device tree
these days.
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201205004057.1712753-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
During regulators registration, if .of_match and .regulators_node are
defined as non-null strings in struct regulator_desc the core searches the
DT subtree rooted at .regulators_node trying to match, at first, .of_match
against the 'regulator-compatible' property and, then, falling back to use
the name of the node itself to determine a good match.
Property 'regulator-compatible', though, is now deprecated and falling back
to match against the node name, works fine only as long as the involved
nodes are named in an unique way across the searched subtree; if that's not
the case, like when using <common-name>@<unit> style naming for properties
indexed via 'reg' property (as advised by the standard), the above matching
mechanism based on the simple common name will lead to multiple matches and
the only viable alternative would be to properly define the now deprecated
'regulator-compatible' as the node full name, i.e. <common-name>@<unit>.
In order to address this case without using such deprecated binding, define
a new boolean flag .of_match_full_name in struct regulator_desc to force
the core to match against the node full-name instead of the plain name.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20201119191051.46363-4-cristian.marussi@arm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Silence documentation build warning by correcting kernel-doc comments.
./include/linux/regulator/machine.h:196: warning: Function parameter or member 'max_uV_step' not described in 'regulation_constraints'
./include/linux/regulator/driver.h:206: warning: Function parameter or member 'resume' not described in 'regulator_ops'
Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Link: https://lore.kernel.org/r/20200715191438.29312-1-colton.w.lewis@protonmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
