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path: root/drivers/regulator/core.c
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2025-03-13regulator: check that dummy regulator has been probed before using itChristian Eggers
Due to asynchronous driver probing there is a chance that the dummy regulator hasn't already been probed when first accessing it. Cc: stable@vger.kernel.org Signed-off-by: Christian Eggers <ceggers@arri.de> Link: https://patch.msgid.link/20250313103051.32430-3-ceggers@arri.de Signed-off-by: Mark Brown <broonie@kernel.org>
2025-03-05regulator: core: Fix deadlock in create_regulator()Ludvig Pärsson
Currently, we are unnecessarily holding a regulator_ww_class_mutex lock when creating debugfs entries for a newly created regulator. This was brought up as a concern in the discussion in commit cba6cfdc7c3f ("regulator: core: Avoid lockdep reports when resolving supplies"). This causes the following lockdep splat after executing `ls /sys/kernel/debug` on my platform: ====================================================== WARNING: possible circular locking dependency detected 5.15.167-axis9-devel #1 Tainted: G O ------------------------------------------------------ ls/2146 is trying to acquire lock: ffffff803a562918 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x88 but task is already holding lock: ffffff80014497f8 (&sb->s_type->i_mutex_key#3){++++}-{3:3}, at: iterate_dir+0x50/0x1f4 which lock already depends on the new lock. [...] Chain exists of: &mm->mmap_lock --> regulator_ww_class_mutex --> &sb->s_type->i_mutex_key#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#3); lock(regulator_ww_class_mutex); lock(&sb->s_type->i_mutex_key#3); lock(&mm->mmap_lock); *** DEADLOCK *** This lock dependency still exists on the latest kernel and using a newer non-tainted kernel would still cause this problem. Fix by moving sysfs symlinking and creation of debugfs entries to after the release of the regulator lock. Fixes: cba6cfdc7c3f ("regulator: core: Avoid lockdep reports when resolving supplies") Fixes: eaa7995c529b ("regulator: core: avoid regulator_resolve_supply() race condition") Signed-off-by: Ludvig Pärsson <ludvig.parsson@axis.com> Link: https://patch.msgid.link/20250305-regulator_lockdep_fix-v1-1-ab938b12e790@axis.com Signed-off-by: Mark Brown <broonie@kernel.org>
2025-02-11regulator: core: let dt properties override driver init_dataJerome Brunet
This reverts commit cd7a38c40b231350a3cd0fd774f4e6bb68c4b411. When submitting the change above, it was thought that the origin of the init_data should be a clear choice, from the driver or from DT but not both. It turns out some devices, such as qcom-msm8974-lge-nexus5-hammerhead, relied on the old behaviour to override the init_data provided by the driver, making it some kind of default if none is provided by the platform. Using the init_data provided by the driver when it is present broke these devices so revert the change to fixup the situation and add a comment to make things a bit more clear Reported-by: Luca Weiss <luca@lucaweiss.eu> Closes: https://lore.kernel.org/lkml/5857103.DvuYhMxLoT@lucaweiss.eu Fixes: cd7a38c40b23 ("regulator: core: do not silently ignore provided init_data") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://patch.msgid.link/20250211-regulator-init-data-fixup-v1-1-5ce1c6cff990@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
2025-01-22regulator: core: Add missing newline characterAlexander Stein
dev_err_probe() error messages need newline character. Fixes: 6eabfc018e8d ("regulator: core: Allow specifying an initial load w/ the bulk API") Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Link: https://patch.msgid.link/20250122072019.1926093-1-alexander.stein@ew.tq-group.com Signed-off-by: Mark Brown <broonie@kernel.org>
2025-01-17regulator: Add support for power budgetKory Maincent
Introduce power budget management for the regulator device. Enable tracking of available power capacity by providing helpers to request and release power budget allocations. Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20250115-feature_regulator_pw_budget-v2-1-0a44b949e6bc@bootlin.com Signed-off-by: Mark Brown <broonie@kernel.org>
2025-01-09regulator: core: Resolve supply using of_node from regulator_configKory Maincent (Dent Project)
Previously, the regulator core resolved its supply only from the parent device or its children, ignoring the of_node specified in the regulator_config structure. This behavior causes issues in scenarios where multiple regulator devices are registered for components described as children of a controller, each with their own specific regulator supply. For instance, in a PSE controller with multiple PIs (Power Interfaces), each PI may have a distinct regulator supply. However, the regulator core would incorrectly use the PSE controller node or its first child to look up the regulator supply, rather than the node specified by the regulator_config->of_node for the PI. This update modifies the behavior to prioritize the of_node in regulator_config for resolving the supply. This ensures correct resolution of the power supply for each device. If no supply is found in the provided of_node, the core falls back to searching within the parent device as before. Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20250109-b4-feature_poe_arrange-v2-13-55ded947b510@bootlin.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-11-21regulator: core: Ignore unset max_uA constraints in current limit checkKory Maincent (Dent Project)
We should only consider max_uA constraints if they are explicitly defined. In cases where it is not set, we should assume the regulator has no current limit. Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20241121-feature_poe_port_prio-v3-2-83299fa6967c@bootlin.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-10-22regulator: init_data handling updateMark Brown
Merge series from Jerome Brunet <jbrunet@baylibre.com>: This patchset groups the regulator patches around the init_data topic discussed on pmbus write protect patchset [1] [1]: https://lore.kernel.org/r/20240920-pmbus-wp-v1-0-d679ef31c483@baylibre.com
2024-10-22regulator: core: Use fsleep() to get best sleep mechanismAnna-Maria Behnsen
_regulator_delay_helper() implements the recommondation of the outdated documentation which sleep mechanism should be used. There is already a function in place which does everything and also maps to reality called fsleep(). Use fsleep() directly. Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://patch.msgid.link/20241014-devel-anna-maria-b4-timers-flseep-v3-11-dc8b907cb62f@linutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
2024-10-22regulator: core: remove machine init callback from configJerome Brunet
The machine specific regulator_init() appears to be unused. It does not allow a lot of interaction with the regulator framework, since nothing from the framework is passed along (desc, config, etc ...) Machine specific init may also be done with the added init_cb() in the regulator description, so remove regulator_init(). Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://patch.msgid.link/20241008-regulator-ignored-data-v2-3-d1251e0ee507@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-10-22regulator: core: add callback to perform runtime initJerome Brunet
Provide an initialisation callback to handle runtime parameters. The idea is similar to the regulator_init() callback, but it provides regulator specific structures, instead of just the driver specific data. As an example, this allows the driver to amend the regulator constraints based on runtime parameters if necessary. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://patch.msgid.link/20241008-regulator-ignored-data-v2-2-d1251e0ee507@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-10-22regulator: core: do not silently ignore provided init_dataJerome Brunet
On DT platforms, if a regulator init_data is provided in config, it is silently ignored in favor of the DT parsing done by the framework, if of_match is set. of_match is an indication that init_data is expected to be set based on DT and the parsing should be done by the regulator framework. If the regulator provider passed init_data it must be because it is useful somehow, in such case of_match should be clear. If the driver expects the framework to initialize this data on its own, it should leave init_data clear. Warn if both init_data and of_match are set, then default to the provided init_data. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://patch.msgid.link/20241008-regulator-ignored-data-v2-1-d1251e0ee507@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-09-30regulator: Add of_regulator_get_optional() for pure DT regulator lookupChen-Yu Tsai
The to-be-introduced I2C component prober needs to enable regulator supplies (and toggle GPIO pins) for the various components it intends to probe. To support this, a new "pure DT lookup" method for getting regulator supplies is needed, since the device normally requesting the supply won't get created until after the component is probed to be available. Add a new of_regulator_get_optional() function for this. This mirrors the existing regulator_get_optional() function, but is OF-specific. The underlying code that supports the existing regulator_get*() functions has been reworked in previous patches to support this specific case. Also convert an existing usage of "dev && dev->of_node" to "dev_of_node(dev)". Link: https://lore.kernel.org/all/20231220203537.83479-2-jernej.skrabec@gmail.com/ [1] Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Link: https://patch.msgid.link/20240925093807.1026949-2-wenst@chromium.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2024-09-13regulator: Split up _regulator_get()Chen-Yu Tsai
_regulator_get() contains a lot of common code doing checks prior to the regulator lookup and housekeeping work after the lookup. Almost all the code could be shared with a OF-specific variant of _regulator_get(). Split out the common parts so that they can be reused. The OF-specific version of _regulator_get() will be added in a subsequent patch. No functional changes were made. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240911072751.365361-4-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-09-11regulator: core: fix the broken behavior of regulator_dev_lookup()Wei Fang
The behavior of regulator_dev_lookup() for non-DT way has been broken since the commit b8c325545714 ("regulator: Move OF-specific regulator lookup code to of_regulator.c"). Before the commit, of_get_regulator() was used to get the regulator, which returns NULL if the regulator is not found. So the regulator will be looked up through regulator_lookup_by_name() if no matching regulator is found in regulator_map_list. However, currently, of_regulator_dev_lookup() is used to instead of of_get_regulator(), but the variable 'r' is set to ERR_PTR(-ENODEV) instead of NULL if the regulator is not found. In this case, if no regulator is found in regulator_map_list, the variable 'r' is still ERR_PTR(-ENODEV), So regulator_dev_lookup() returns the value of 'r' directly instead of continuing to look up the regulator through regulator_lookup_by_name(). Fixes: b8c325545714 ("regulator: Move OF-specific regulator lookup code to of_regulator.c") Signed-off-by: Wei Fang <wei.fang@nxp.com> Link: https://patch.msgid.link/20240911120338.526384-1-wei.fang@nxp.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-09-04regulator: Move OF-specific regulator lookup code to of_regulator.cChen-Yu Tsai
There's still a bit of OF-specific code in the regulator device lookup function. Move those bits of code over to of_regulator.c, and create a new function of_regulator_dev_lookup() to encapsulate the code moved out of regulator_dev_lookup(). Also mark of_find_regulator_by_node() as static, since there are no other users in other compile units. There are no functional changes. A line alignment was also fixed. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Link: https://patch.msgid.link/20240904090016.2841572-4-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-29regulator: Unify "negative error number" terminology in commentsChen-Yu Tsai
Previous commits cleaning up kerneldoc used the term "negative error number" to refer to error condition return values. Update remaining instances of other terminology such as "error code" or "errno" as well so the whole regulator subsystem is unified. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240829085131.1361701-11-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-29regulator: core: Add missing kerneldoc "Return" sectionsChen-Yu Tsai
kernel-doc complains about missing "Return" section for many documented functions in the regulator core. Some with free-form return value descriptions have been fixed in the previous patch. The remaining are completely missing any mention of return values. Add "Return" sections to these kerneldoc blocks with basic descriptions. In a few cases where the functions don't call even more functions and the error numbers are known, those are documented in detail. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240829085131.1361701-5-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-29regulator: core: Fix incorrectly formatted kerneldoc "Return" sectionsChen-Yu Tsai
kernel-doc complains about missing "Return" section for many documented functions in the regulator core. Many of them actually have descriptions about the return values, just not in the format kernel-doc wants. Convert these to use the proper "Return:" section header. The existing descriptions have been reworded and moved around to fit the grammar and formatting. In a few cases where the functions don't call even more functions and the error numbers are known, those are documented in detail. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240829085131.1361701-4-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-29regulator: core: Fix regulator_is_supported_voltage() kerneldoc return valueChen-Yu Tsai
The kerneldoc for regulator_is_supported_voltage() states that the return value is a boolean. That is not correct, as it could return an error number if the check failed. Fix the description by expanding it to cover the valid return values and error conditions. The description is also converted to a proper "Return" section. Fixes: c5f3939b8fe0 ("regulator: core: Support fixed voltages in regulator_is_supported_voltage()") Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240829085131.1361701-3-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-29regulator: core: Fix short description for _regulator_check_status_enabled()Chen-Yu Tsai
kernel-doc complains that _regulator_check_status_enabled() is missing a short description. Since the current description is already quite short, just trim it a bit more and use it as the short description. Fixes: f7d7ad42a9dc ("regulator: Allow regulators to verify enabled during enable()") Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20240829085131.1361701-2-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-08-22regulator: Clarify error message for "id == NULL" in _regulator_get()Chen-Yu Tsai
The original error message simply said "get() with no identifier" without any context as to what was requested or what device the request was related to. The only thing the user or developer could do was grep for the message in the full source tree. Amend the error message to be more specific, and also use dev_* to associate the error message with a device. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Link: https://patch.msgid.link/20240822072047.3097740-2-wenst@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-06-26regulator: core: Add helper for allow HW access to enable/disable regulatorBiju Das
Add a helper function that allow regulator consumers to allow low-level HW access, in order to enable/disable regulator in atomic context. The use-case for RZ/G2L SoC is to enable VBUS selection register based on vbus detection that happens in interrupt context. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://patch.msgid.link/20240616105402.45211-4-biju.das.jz@bp.renesas.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-06-10regulator: core: Fix modpost error "regulator_get_regmap" undefinedBiju Das
Fix the modpost error "regulator_get_regmap" undefined by adding export symbol. Fixes: 04eca28cde52 ("regulator: Add helpers for low-level register access") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406110117.mk5UR3VZ-lkp@intel.com Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://lore.kernel.org/r/20240610195532.175942-1-biju.das.jz@bp.renesas.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-05-14Merge tag 'regulator-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator Pull regulator updates from Mark Brown: "There's one API update here, a new API factoring out a common pattern for reference voltage supplies. These are supplies used as a reference by analogue circuits where the consumer requests and enables the supply, reads the voltage to calibrate the user and then never touches it again. This is factored out into a single operation which just returns the voltage and uses devm_ to manage the request and enable portion. Otherwise this has been a very quiet release, we've got some new device support, some small fixes, housekeeping and cleanup work but nothing substantial. There's also some non-regulator changes in here, a number of users for the new reference voltage API were merged along with it and some MFD changes were pulled in as dependencies for new driver work. Highlights: - Add a new API for single operation handling of reference voltages - Support for Allwinner AXP717 and D1, and NXP PCA9561A" * tag 'regulator-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (33 commits) regulator: sun20i: Add Allwinner D1 LDOs driver regulator: dt-bindings: Add Allwinner D1 system LDOs regulator: Mention regulator id in error message about dummy supplies staging: iio: impedance-analyzer: ad5933: Use devm_regulator_get_enable_read_voltage() iio: frequency: admv1013: Use devm_regulator_get_enable_read_voltage() iio: addac: ad74115: Use devm_regulator_get_enable_read_voltage() hwmon: (adc128d818) simplify final return in probe regulator: devres: fix devm_regulator_get_enable_read_voltage() return hwmon: (da9052) Use devm_regulator_get_enable_read_voltage() hwmon: (adc128d818) Use devm_regulator_get_enable_read_voltage() regulator: devres: add API for reference voltage supplies regulator: rtq2208: Fix LDO discharge register and add vsel setting regulator: dt-bindings: fixed-regulator: Add a preferred node name regulator: axp20x: add support for the AXP717 mfd: axp20x: Add support for AXP717 PMIC dt-bindings: mfd: x-powers,axp152: Document AXP717 regulator: axp20x: fix typo-ed identifier dt-bindings: regulator: qcom,usb-vbus-regulator: Add PM7250B compatible regulator: pca9450: add pca9451a support regulator: dt-bindings: pca9450: add pca9451a support ...
2024-05-09regulator: core: fix debugfs creation regressionJohan Hovold
regulator_get() may sometimes be called more than once for the same consumer device, something which before commit dbe954d8f163 ("regulator: core: Avoid debugfs: Directory ... already present! error") resulted in errors being logged. A couple of recent commits broke the handling of such cases so that attributes are now erroneously created in the debugfs root directory the second time a regulator is requested and the log is filled with errors like: debugfs: File 'uA_load' in directory '/' already present! debugfs: File 'min_uV' in directory '/' already present! debugfs: File 'max_uV' in directory '/' already present! debugfs: File 'constraint_flags' in directory '/' already present! on any further calls. Fixes: 2715bb11cfff ("regulator: core: Fix more error checking for debugfs_create_dir()") Fixes: 08880713ceec ("regulator: core: Streamline debugfs operations") Cc: stable@vger.kernel.org Cc: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20240509133304.8883-1-johan+linaro@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-05-07regulator: Mention regulator id in error message about dummy suppliesUwe Kleine-König
With the name that is currently looked up it is considerably easier to understand the issue and fix the warning. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20240507104703.2070117-2-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
2024-03-12regulator: core: Propagate the regulator state in case of exclusive getKory Maincent
Previously, performing an exclusive get on an already-enabled regulator resulted in inconsistent state initialization between child and parent regulators. While the child's counts were updated, its parent's counters remained unaffected. Consequently, attempting to disable an already-enabled exclusive regulator triggered unbalanced disables warnings from its parent regulator. This commit addresses the issue by propagating the enable state to the parent regulator using a regulator_enable call. This ensures consistent state management across the regulator hierarchy, preventing warnings! Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://msgid.link/r/20240312091638.1266167-1-kory.maincent@bootlin.com Signed-off-by: Mark Brown <broonie@kernel.org>
2024-03-05regulator: core: make regulator_class constantRicardo B. Marliere
Since commit 43a7206b0963 ("driver core: class: make class_register() take a const *"), the driver core allows for struct class to be in read-only memory, so move the regulator_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at boot time. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Link: https://msgid.link/r/20240305-class_cleanup-regulator-v1-1-4950345d6d8f@marliere.net Signed-off-by: Mark Brown <broonie@kernel.org>
2024-02-19regulator: core: Remove redundant assignment to variable possible_uVColin Ian King
The variable possible_uV being assigned a value that is never read, the control flow via the following goto statement takes a path where the variable is not accessed. The assignment is redundant and can be removed. Cleans up clang scan build warning: drivers/regulator/core.c:3935:3: warning: Value stored to 'possible_uV' is never read [deadcode.DeadStores] Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://msgid.link/r/20240216134918.2108262-1-colin.i.king@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
2023-12-06regulator: event: Add regulator netlink event supportNaresh Solanki
This commit introduces netlink event support to the regulator subsystem. Changes: - Introduce event.c and regnl.h for netlink event handling. - Implement reg_generate_netlink_event to broadcast regulator events. - Update Makefile to include the new event.c file. Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> Link: https://lore.kernel.org/r/20231205105207.1262928-1-naresh.solanki@9elements.com Signed-off-by: Mark Brown <broonie@kernel.org>
2023-11-13regulator: add under-voltage support (part 2)Mark Brown
Merge series from Oleksij Rempel <o.rempel@pengutronix.de>: This series add under-voltage and emergency shutdown for system critical regulators
2023-11-13regulator: core: Only increment use_count when enable_count changesRui Zhang
The use_count of a regulator should only be incremented when the enable_count changes from 0 to 1. Similarly, the use_count should only be decremented when the enable_count changes from 1 to 0. In the previous implementation, use_count was sometimes decremented to 0 when some consumer called unbalanced disable, leading to unexpected disable even the regulator is enabled by other consumers. With this change, the use_count accurately reflects the number of users which the regulator is enabled. This should make things more robust in the case where a consumer does leak references. Signed-off-by: Rui Zhang <zr.zhang@vivo.com> Link: https://lore.kernel.org/r/20231103074231.8031-1-zr.zhang@vivo.com Signed-off-by: Mark Brown <broonie@kernel.org>
2023-11-13regulator: core: Add option to prevent disabling unused regulatorsJavier Martinez Canillas
This may be useful for debugging and develompent purposes, when there are drivers that depend on regulators to be enabled but do not request them. It is inspired from the clk_ignore_unused and pd_ignore_unused parameters, that are used to keep firmware-enabled clocks and power domains on even if these are not used by drivers. The parameter is not expected to be used in normal cases and should not be needed on a platform with proper driver support. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Brian Masney <bmasney@redhat.com> Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/20231107190926.1185326-1-javierm@redhat.com Signed-off-by: Mark Brown <broonie@kernel.org>
2023-11-13regulator: Implement uv_survival_time for handling under-voltage eventsOleksij Rempel
Add 'uv_survival_time' field to regulation_constraints for specifying survival time post critical under-voltage event. Update the regulator notifier call chain and Device Tree property parsing to use this new field, allowing a configurable timeout before emergency shutdown. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20231026144824.4065145-6-o.rempel@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
2023-11-13regulator: Introduce handling for system-critical under-voltage eventsOleksij Rempel
Handle under-voltage events for crucial regulators to maintain system stability and avoid issues during power drops. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20231026144824.4065145-3-o.rempel@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
2023-09-26regulator/core: Revert "fix kobject release warning and memory leak in ↵Michał Mirosław
regulator_register()" This reverts commit 5f4b204b6b8153923d5be8002c5f7082985d153f. Since rdev->dev now has a release() callback, the proper way of freeing the initialized device can be restored. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Link: https://lore.kernel.org/r/d7f469f3f7b1f0e1d52f9a7ede3f3c5703382090.1695077303.git.mirq-linux@rere.qmqm.pl Signed-off-by: Mark Brown <broonie@kernel.org>
2023-09-26regulator/core: regulator_register: set device->class earlierMichał Mirosław
When fixing a memory leak in commit d3c731564e09 ("regulator: plug of_node leak in regulator_register()'s error path") it moved the device_initialize() call earlier, but did not move the `dev->class` initialization. The bug was spotted and fixed by reverting part of the commit (in commit 5f4b204b6b81 "regulator: core: fix kobject release warning and memory leak in regulator_register()") but introducing a different bug: now early error paths use `kfree(dev)` instead of `put_device()` for an already initialized `struct device`. Move the missing assignments to just after `device_initialize()`. Fixes: d3c731564e09 ("regulator: plug of_node leak in regulator_register()'s error path") Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Link: https://lore.kernel.org/r/b5b19cb458c40c9d02f3d5a7bd1ba7d97ba17279.1695077303.git.mirq-linux@rere.qmqm.pl Signed-off-by: Mark Brown <broonie@kernel.org>
2023-05-25regulator: core: Streamline debugfs operationsGeert Uytterhoeven
If CONFIG_DEBUG_FS is not set: regulator: Failed to create debugfs directory ... regulator-dummy: Failed to create debugfs directory As per the comments for debugfs_create_dir(), errors returned by this function should be expected, and ignored: * If debugfs is not enabled in the kernel, the value -%ENODEV will be * returned. * * NOTE: it's expected that most callers should _ignore_ the errors returned * by this function. Other debugfs functions handle the fact that the "dentry" * passed to them could be an error and they don't crash in that case. * Drivers should generally work fine even if debugfs fails to init anyway. Adhere to the debugfs spirit, and streamline all operations by: 1. Demoting the importance of the printed error messages to debug level, like is already done in create_regulator(), 2. Further ignoring any returned errors, as by design, all debugfs functions are no-ops when passed an error pointer. Fixes: 2bf1c45be3b8f3a3 ("regulator: Fix error checking for debugfs_create_dir") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/2f8bb6e113359ddfab7b59e4d4274bd4c06d6d0a.1685013051.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
2023-05-25regulator: core: Fix more error checking for debugfs_create_dir()Geert Uytterhoeven
In case of failure, debugfs_create_dir() does not return NULL, but an error pointer. Most incorrect error checks were fixed, but the one in create_regulator() was forgotten. Fix the remaining error check. Fixes: 2bf1c45be3b8f3a3 ("regulator: Fix error checking for debugfs_create_dir") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/ee980a108b5854dd8ce3630f8f673e784e057d17.1685013051.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
2023-05-16regulator: Fix error checking for debugfs_create_dirOsama Muhammad
This patch fixes the error checking in core.c in debugfs_create_dir. The correct way to check if an error occurred is 'IS_ERR' inline function. Signed-off-by: Osama Muhammad <osmtendev@gmail.com Suggested-by: Ivan Orlov <ivan.orlov0322@gmail.com Link: https://lore.kernel.org/r/20230515172938.13338-1-osmtendev@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org
2023-04-18regulator: core: Make regulator_lock_two() logic easier to followDouglas Anderson
The regulator_lock_two() function could be made clearer in the case of lock contention by having a local variable for each of the held and contended locks. Let's do that. At the same time, let's use the swap() function instead of open coding it. This change is expected to be a no-op and simply improves code clarity. Suggested-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/CAE-0n53Eb1BeDPmjBycXUaQAF4ppiAM6UDWje_jiB9GAmR8MMw@mail.gmail.com Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230413173359.1.I1ae92b25689bd6579952e6d458b79f5f8054a0c9@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2023-04-06regulator: core: Avoid lockdep reports when resolving suppliesDouglas Anderson
An automated bot told me that there was a potential lockdep problem with regulators. This was on the chromeos-5.15 kernel, but I see nothing that would be different downstream compared to upstream. The bot said: ============================================ WARNING: possible recursive locking detected 5.15.104-lockdep-17461-gc1e499ed6604 #1 Not tainted -------------------------------------------- kworker/u16:4/115 is trying to acquire lock: ffffff8083110170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: create_regulator+0x398/0x7ec but task is already holding lock: ffffff808378e170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: ww_mutex_trylock+0x3c/0x7b8 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(regulator_ww_class_mutex); lock(regulator_ww_class_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u16:4/115: #0: ffffff808006a948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x520/0x1348 #1: ffffffc00e0a7cc0 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x55c/0x1348 #2: ffffff80828a2260 (&dev->mutex){....}-{3:3}, at: __device_attach_async_helper+0xd0/0x2a4 #3: ffffff808378e170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: ww_mutex_trylock+0x3c/0x7b8 stack backtrace: CPU: 2 PID: 115 Comm: kworker/u16:4 Not tainted 5.15.104-lockdep-17461-gc1e499ed6604 #1 9292e52fa83c0e23762b2b3aa1bacf5787a4d5da Hardware name: Google Quackingstick (rev0+) (DT) Workqueue: events_unbound async_run_entry_fn Call trace: dump_backtrace+0x0/0x4ec show_stack+0x34/0x50 dump_stack_lvl+0xdc/0x11c dump_stack+0x1c/0x48 __lock_acquire+0x16d4/0x6c74 lock_acquire+0x208/0x750 __mutex_lock_common+0x11c/0x11f8 ww_mutex_lock+0xc0/0x440 create_regulator+0x398/0x7ec regulator_resolve_supply+0x654/0x7c4 regulator_register_resolve_supply+0x30/0x120 class_for_each_device+0x1b8/0x230 regulator_register+0x17a4/0x1f40 devm_regulator_register+0x60/0xd0 reg_fixed_voltage_probe+0x728/0xaec platform_probe+0x150/0x1c8 really_probe+0x274/0xa20 __driver_probe_device+0x1dc/0x3f4 driver_probe_device+0x78/0x1c0 __device_attach_driver+0x1ac/0x2c8 bus_for_each_drv+0x11c/0x190 __device_attach_async_helper+0x1e4/0x2a4 async_run_entry_fn+0xa0/0x3ac process_one_work+0x638/0x1348 worker_thread+0x4a8/0x9c4 kthread+0x2e4/0x3a0 ret_from_fork+0x10/0x20 The problem was first reported soon after we made many of the regulators probe asynchronously, though nothing I've seen implies that the problems couldn't have also happened even without that. I haven't personally been able to reproduce the lockdep issue, but the issue does look somewhat legitimate. Specifically, it looks like in regulator_resolve_supply() we are holding a "rdev" lock while calling set_supply() -> create_regulator() which grabs the lock of a _different_ "rdev" (the one for our supply). This is not necessarily safe from a lockdep perspective since there is no documented ordering between these two locks. In reality, we should always be locking a regulator before the supplying regulator, so I don't expect there to be any real deadlocks in practice. However, the regulator framework in general doesn't express this to lockdep. Let's fix the issue by simply grabbing the two locks involved in the same way we grab multiple locks elsewhere in the regulator framework: using the "wound/wait" mechanisms. Fixes: eaa7995c529b ("regulator: core: avoid regulator_resolve_supply() race condition") Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230329143317.RFC.v2.2.I30d8e1ca10cfbe5403884cdd192253a2e063eb9e@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2023-04-06regulator: core: Consistently set mutex_owner when using ww_mutex_lock_slow()Douglas Anderson
When a codepath locks a rdev using ww_mutex_lock_slow() directly then that codepath is responsible for incrementing the "ref_cnt" and also setting the "mutex_owner" to "current". The regulator core consistently got that right for "ref_cnt" but didn't always get it right for "mutex_owner". Let's fix this. It's unlikely that this truly matters because the "mutex_owner" is only needed if we're going to do subsequent locking of the same rdev. However, even though it's not truly needed it seems less surprising if we consistently set "mutex_owner" properly. Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230329143317.RFC.v2.1.I4e9d433ea26360c06dd1381d091c82bb1a4ce843@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2023-03-14regulator: core: Shorten off-on-delay-us for always-on/boot-on by time since ↵Douglas Anderson
booted This is very close to a straight revert of commit 218320fec294 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators"). We've identified that patch as causing a boot speed regression on sc7180-trogdor boards. While boot speed certainly isn't more important than making sure that power sequencing is correct, looking closely at the original change it doesn't seem to have been fully justified. It mentions "cycling issues" without describing exactly what the issues were. That means it's possible that the cycling issues were really a problem that should be fixed in a different way. Let's take a careful look at how we should handle regulators that have an off-on-delay and that are boot-on or always-on. Linux currently doesn't have any way to identify whether a GPIO regulator was already on when the kernel booted. That means that when the kernel boots we probe a regulator, see that it wants boot-on / always-on we, and then turn the regulator on. We could be in one of two cases when we do this: a) The regulator might have been left on by the bootloader and we're ensuring that it stays on. b) The regulator might have been left off by the bootloader and we're just now turning it on. For case a) we definitely don't need any sort of delay. For case b) we _might_ need some delay in case the bootloader turned the regulator off _right_ before booting the kernel. To get the proper delay for case b) then we can just assume a `last_off` of 0, which is what it gets initialized to by default. As per above, we can't tell whether we're in case a) or case b) so we'll assume the longer delay (case b). This basically puts the code to how it was before commit 218320fec294 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators"). However, we add one important change: we make sure that the delay is actually honored if `last_off` is 0. Though the original "cycling issues" cited were vague, I'm hopeful that this important extra change will be enough to fix the issues that the initial commit mentioned. With this fix, I've confined that on a sc7180-trogdor board the delay at boot goes down from 500 ms to ~250 ms. That's not as good as the 0 ms that we had prior to commit 218320fec294 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators"), but it's probably safer because we don't know if the bootloader turned the regulator off right before booting. One note is that it's possible that we could be in a state that's not a) or b) if there are other issues in the kernel. The only one I can think of is related to pinctrl. If the pinctrl driver being used on a board isn't careful about avoiding glitches when setting up a pin then it's possible that setting up a pin could cause the regulator to "turn off" briefly immediately before the regulator probes. If this is indeed causing problems then the pinctrl driver should be fixed, perhaps in a similar way to what was done in commit d21f4b7ffc22 ("pinctrl: qcom: Avoid glitching lines when we first mux to output") Fixes: 218320fec294 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators") Cc: Christian Kohlschütter <christian@kohlschutter.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230313111806.1.I2eaad872be0932a805c239a7c7a102233fb0b03b@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2023-02-23regulator: core: Use ktime_get_boottime() to determine how long a regulator ↵Matthias Kaehlcke
was off For regulators with 'off-on-delay-us' the regulator framework currently uses ktime_get() to determine how long the regulator has been off before re-enabling it (after a delay if needed). A problem with using ktime_get() is that it doesn't account for the time the system is suspended. As a result a regulator with a longer 'off-on-delay' (e.g. 500ms) that was switched off during suspend might still incurr in a delay on resume before it is re-enabled, even though the regulator might have been off for hours. ktime_get_boottime() accounts for suspend time, use it instead of ktime_get(). Fixes: a8ce7bd89689 ("regulator: core: Fix off_on_delay handling") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20230223003301.v2.1.I9719661b8eb0a73b8c416f9c26cf5bd8c0563f99@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2022-12-23Merge tag 'regulator-fix-v6.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator Pull regulator fixes from Mark Brown: "Two core fixes here, one for a long standing race which some Qualcomm systems have started triggering with their UFS driver and another fixing a problem with supply lookup introduced by the fixes for devm related use after free issues that were introduced in this merge window" * tag 'regulator-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: regulator: core: fix deadlock on regulator enable regulator: core: Fix resolve supply lookup issue
2022-12-15regulator: core: fix deadlock on regulator enableJohan Hovold
When updating the operating mode as part of regulator enable, the caller has already locked the regulator tree and drms_uA_update() must not try to do the same in order not to trigger a deadlock. The lock inversion is reported by lockdep as: ====================================================== WARNING: possible circular locking dependency detected 6.1.0-next-20221215 #142 Not tainted ------------------------------------------------------ udevd/154 is trying to acquire lock: ffffc11f123d7e50 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x280 but task is already holding lock: ffff80000e4c36e8 (regulator_ww_class_acquire){+.+.}-{0:0}, at: regulator_enable+0x34/0x80 which lock already depends on the new lock. ... Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(regulator_ww_class_acquire); lock(regulator_list_mutex); lock(regulator_ww_class_acquire); lock(regulator_list_mutex); *** DEADLOCK *** just before probe of a Qualcomm UFS controller (occasionally) deadlocks when enabling one of its regulators. Fixes: 9243a195be7a ("regulator: core: Change voltage setting path") Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Cc: stable@vger.kernel.org # 5.0 Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20221215104646.19818-1-johan+linaro@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
2022-12-14regulator: core: Fix resolve supply lookup issueChiYuan Huang
From Marek's log, the previous change modify the parent of rdev. https://lore.kernel.org/all/58b92e75-f373-dae7-7031-8abd465bb874@samsung.com/ In 'regulator_resolve_supply', it uses the parent DT node of rdev as the DT-lookup starting node. But the parent DT node may not exist. This will cause the NULL supply issue. This patch modify the parent of rdev back to the device that provides from 'regulator_config' in 'regulator_register'. Fixes: 8f3cbcd6b440 ("regulator: core: Use different devices for resource allocation and DT lookup") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: ChiYuan Huang <cy_huang@richtek.com> Link: https://lore.kernel.org/r/1670981831-12583-1-git-send-email-u0084500@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-12-13Merge tag 'regulator-v6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator Pull regulator updates from Mark Brown: "Quite a quiet release for regulator, the diffstat is dominated by the I2C migration to probe_new() and the newly added MT6357 driver. We've just one framework addition and the rest is all new device support, fixes and cleanups. The framework addition is an API for requesting all regulators defined in DT, this isn't great practice but has reasonable applications when there is generic code handling devices on buses where the bus specification doesn't include power. The immediate application is MDIO but I believe there's others, it's another API that'll need an eye keeping on it for undesirable usage. Summary: - An API for requesting all regulators defined in DT - Conversion of lots of drivers to the I2C probe_new() API - Support for Mediatek MT6357, Qualcomm PM8550, PMR735a and Richtek RT6190" * tag 'regulator-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (56 commits) regulator: core: Use different devices for resource allocation and DT lookup dt-bindings: Add missing 'unevaluatedProperties' to regulator nodes regulator: qcom-labibb: Fix missing of_node_put() in qcom_labibb_regulator_probe() regulator: add mt6357 regulator regulator: dt-bindings: Add binding schema for mt6357 regulators regulator: core: fix resource leak in regulator_register() regulator: core: fix module refcount leak in set_supply() regulator: core: fix use_count leakage when handling boot-on regulator: rk808: Use dev_err_probe regulator: rk808: reduce 'struct rk808' usage regulator: Drop obsolete dependencies on COMPILE_TEST regulator: pv88080-regulator: Convert to i2c's .probe_new() regulator: pfuze100-regulator: Convert to i2c's .probe_new() regulator: isl6271a-regulator: Convert to i2c's .probe_new() regulator: fan53555: Convert to i2c's .probe_new() regulator: act8865-regulator: Convert to i2c's .probe_new() regulator: qcom-rpmh: Add support for PM8550 regulators regulator: dt-bindings: qcom,rpmh: Add compatible for PM8550 regulator: tps65023-regulator: Convert to i2c's .probe_new() regulator: tps62360-regulator: Convert to i2c's .probe_new() ...