Extend regulator notification support This is an RFC series for getting feedback on extending the regulator notification and error flag support. Initial discussion on the topic can be found here: https://lore.kernel.org/lkml/6046836e22b8252983f08d5621c35ececb97820d.camel@xxxxxxxxxxxxxxxxx/ This series is built on top of the: commit 7aa382cfe714 ("regulator: mt6315: Add support for MT6315 regulator") regulator tree for-5.12 branch + The BD9576MUF support patch series v8 which is not yet in-tree Here: https://lore.kernel.org/lkml/cover.1613031055.git.matti.vaittinen@xxxxxxxxxxxxxxxxx/ In a nutshell - the RFC adds: 1. WARNING level events/error flags. (Patch 2) 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, 4) 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 3) 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). 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 6 takes this notification support in use at BD9576MUF. -- Matti Vaittinen (7): dt_bindings: Add protection limit properties regulator: add warning flags regulator: IRQ based event/error notification helpers regulator: add property parsing and callbacks to set protection limits dt-bindings: regulator: bd9576 add FET ON-resistance for OCW regulator: bd9576: Support error reporting regulator: bd9576: Fix the driver name in id table .../bindings/regulator/regulator.yaml | 82 ++ .../regulator/rohm,bd9576-regulator.yaml | 5 + drivers/regulator/Makefile | 2 +- drivers/regulator/bd9576-regulator.c | 1030 ++++++++++++++--- drivers/regulator/core.c | 146 ++- drivers/regulator/irq_helpers.c | 396 +++++++ drivers/regulator/of_regulator.c | 58 + drivers/regulator/qcom-labibb-regulator.c | 10 +- drivers/regulator/stpmic1_regulator.c | 17 +- include/linux/regulator/consumer.h | 14 + include/linux/regulator/driver.h | 170 ++- include/linux/regulator/machine.h | 26 + 12 files changed, 1816 insertions(+), 140 deletions(-) create mode 100644 drivers/regulator/irq_helpers.c -- 2.25.4 -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]
