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2016-05-13Merge remote-tracking branches 'regulator/topic/can-change', ↵Mark Brown1-59/+83
'regulator/topic/constrain', 'regulator/topic/debugfs' and 'regulator/topic/doc' into regulator-next
2016-05-13Merge remote-tracking branch 'regulator/topic/supply' into regulator-nextMark Brown1-26/+41
2016-05-13Merge remote-tracking branch 'regulator/topic/core' into regulator-nextMark Brown1-3/+1
2016-05-13Merge remote-tracking branch 'regulator/topic/bypass' into regulator-nextMark Brown1-0/+14
2016-05-13Merge remote-tracking branches 'regulator/fix/constrain' and ↵Mark Brown1-11/+38
'regulator/fix/defer' into regulator-linus
2016-04-27regulator: core: Add early supply resolution for regulatorsJon Hunter1-11/+26
The call to set_machine_constraints() in regulator_register(), will attempt to get the voltage for the regulator. If a regulator is in bypass will fail to get the voltage (ie. it's bypass voltage) and hence register the regulator, because the supply for the regulator has not been resolved yet. To fix this, add a call to regulator_resolve_supply() before we call set_machine_constraints(). If the call to regulator_resolve_supply() fails, rather than returning an error at this point, allow the registration of the regulator to continue because for some regulators resolving the supply at this point may not be necessary and it will be resolved later as more regulators are added. Furthermore, if the supply is still not resolved for a bypassed regulator, this will be detected when we attempt to get the voltage for the regulator and an error will be propagated at this point. If a bypassed regulator does not have a supply when we attempt to get the voltage, rather than returing -EINVAL, return -EPROBE_DEFER instead to allow the registration of the regulator to be deferred and tried again later. Please note that regulator_resolve_supply() will call regulator_dev_lookup() which may acquire the regulator_list_mutex. To avoid any deadlocks we cannot hold the regulator_list_mutex when calling regulator_resolve_supply(). Therefore, rather than holding the lock around a large portion of the registration code, just hold the lock when aquiring any GPIOs and setting up supplies because these sections may add entries to the regulator_map_list and regulator_ena_gpio_list, respectively. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-27Merge branch 'topic/bypass' of ↵Mark Brown1-0/+14
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-supply
2016-04-25regulator: refactor valid_ops_mask checking codeWEN Pingbo1-59/+29
To make the code more compat and centralized, this patch add a unified function - regulator_ops_is_valid. So we can add some extra checking code easily later. Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-22regulator: core: Move registration of regulator deviceJon Hunter1-15/+9
The public functions to acquire a regulator, such as regulator_get(), internally look-up the regulator from the list of regulators that have been registered with the regulator device class. The registration of a new regulator with the regulator device class happens before the regulator has been completely setup. Therefore, it is possible that the regulator could be acquired before it has been setup successfully. To avoid this move the device registration of the regulator to the end of the regulator setup and update the error exit path accordingly. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-22Merge branch 'topic/sysfs-init' of ↵Mark Brown1-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-supply
2016-04-22regulator: core: Clear the supply pointer if enabling failsJon Hunter1-0/+1
During the resolution of a regulator's supply, we may attempt to enable the supply if the regulator itself is already enabled. If enabling the supply fails, then we will call _regulator_put() for the supply. However, the pointer to the supply has not been cleared for the regulator and this will cause a crash if we then unregister the regulator and attempt to call regulator_put() a second time for the supply. Fix this by clearing the supply pointer if enabling the supply after fails when resolving the supply for a regulator. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-22regulator: core: Don't terminate supply resolution earlyJon Hunter1-1/+6
The function regulator_register_resolve_supply() is called from the context of class_for_each_dev() (during the regulator registration) to resolve any supplies added. regulator_register_resolve_supply() will return an error if a regulator's supply cannot be resolved and this will terminate the loop in class_for_each_dev(). This means that we will not attempt to resolve any other supplies after one has failed. Hence, this may delay the resolution of other regulator supplies until the failing one itself can be resolved. Rather than terminating the loop early, don't return an error code and keep attempting to resolve any other supplies for regulators that have been registered. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-22regulator: core: Add debugfs to show constraint flagsRichard Fitzgerald1-0/+52
There are debugfs entries for voltage and current, but not for the constraint flags. It's useful for debugging to be able to see what these flags are so this patch adds a new debugfs file. We can't use debugfs_create_bool for this because the flags are bitfields, so as this needs a special read callback they have been collected into a single file that lists all the flags. Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-18regulator: core: remove lockdep assert from suspend_prepareTero Kristo1-2/+0
suspend_prepare can be called during regulator init time also, where the mutex is not locked yet. This causes a false lockdep warning. To avoid the problem, remove the lockdep assertion from the function causing the issue. An alternative would be to lock the mutex during init, but this would cause other problems (some APIs used during init will attempt to lock the mutex also, causing deadlock.) Signed-off-by: Tero Kristo <t-kristo@ti.com> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-13regulator: core: Fix locking of GPIO list on freeMark Brown1-1/+1
When we acquire a shareable enable GPIO on probe we do so with the regulator_list_mutex held. However when we release the GPIOs we do this immediately after dropping the mutex meaning that the list could become corrupted. Move the release into the locked region to avoid this. Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-13regulator: reorder initialization steps in regulator_register()Boris Brezillon1-10/+10
device_register() is calling ->get_voltage() as part of it's sysfs attribute initialization process, and this functions might need to know the regulator constraints to return a valid value. This is at least true for the pwm regulator driver (when operating in continuous mode) which needs to know the minimum and maximum voltage values to calculate the current voltage: min_uV + (((max_uV - min_uV) * dutycycle) / 100); Move device_register() after set_machine_constraints() to make sure those constraints are correctly initialized when ->get_voltage() is called. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reported-by: Stephen Barber <smbarber@chromium.org> Tested-by: Caesar Wang <wxt@rock-chips.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-04-12regulator: core: Use parent voltage from the supply when bypassedMark Brown1-0/+14
When a regulator is in bypass mode it is functioning as a switch returning the voltage set in the regulator will not give the voltage being output by the regulator as it's just passing through its supply. This means that when we are getting the voltage from a regulator we should check to see if it is in bypass mode and if it is we should report the voltage from the supply rather than that which is set on the regulator. Reported-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org> [treding@nvidia.com: return early for bypass mode] Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-30regulator: Fix deadlock during regulator registrationJon Hunter1-5/+5
Commit 5e3ca2b349b1 ("regulator: Try to resolve regulators supplies on registration") added a call to regulator_resolve_supply() within regulator_register() where the regulator_list_mutex is held. This causes a deadlock to occur on the Tegra114 Dalmore board when the palmas PMIC is registered because regulator_register_resolve_supply() calls regulator_dev_lookup() which may try to acquire the regulator_list_mutex again. Fix this by releasing the mutex before calling regulator_register_resolve_supply() and update the error exit path to ensure the mutex is released on an error. [Made commit message more legible -- broonie] Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-30regulator: core: Log when we bring constraints into rangeMark Brown1-0/+2
This aids in debugging problems triggered by the regulator core applying its constraints, we could potentially crash immediately after updating the voltage if the constraints are buggy. Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-28regulator: Try to resolve regulators supplies on registrationJavier Martinez Canillas1-0/+9
Commit 6261b06de565 ("regulator: Defer lookup of supply to regulator_get") moved the regulator supplies lookup logic from the regulators registration to the regulators get time. Unfortunately, that changed the behavior of the regulator core since now a parent supply with a child regulator marked as always-on, won't be enabled unless a client driver attempts to get the child regulator during boot. This patch tries to resolve the parent supply for the already registered regulators each time that a new regulator is registered. So the regulators that have child regulators marked as always on will be enabled regardless if a driver gets the child regulator or not. That was the behavior before the mentioned commit, since parent supplies were looked up at regulator registration time instead of during child get. Since regulator_resolve_supply() checks for rdev->supply, most of the times it will be a no-op. Errors aren't checked to keep the possible out of order dependencies which was the motivation for the mentioned commit. Also, the supply being available will be enforced on regulator get anyways in case the resolve fails on regulators registration. Fixes: 6261b06de565 ("regulator: Defer lookup of supply to regulator_get") Suggested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: <stable@vger.kernel.org> # 4.1+
2016-03-27regulator: core: Ensure we are at least in bounds for our constraintsMark Brown1-7/+25
Currently we only attempt to set the voltage during constraints application if an exact voltage is specified. Extend this so that if the currently set voltage for the regulator is outside the bounds set in constraints we will move the voltage to the nearest constraint, raising to the minimum or lowering to the maximum as needed. This ensures that drivers can probe without the hardware being driven out of spec. Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-25regulator: core: Remove duplicate copy of active-discharge parsingVladimir Zapolskiy1-11/+0
Apparently due to a wrongly resolved merge conflict between two branches, which contained the same commit, the commit contents partially was added two times in a row. This change reverts the latter wrong inclusion of commit 909f7ee0b5f3 ("regulator: core: Add support for active-discharge configuration"). The first applied commit 670666b9e0af ("regulator: core: Add support for active-discharge configuration") is not touched. Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-21regulator: Remove unneded check for regulator supplyJavier Martinez Canillas1-1/+1
The regulator_resolve_supply() function checks if a supply has been associated with a regulator to avoid enabling it if that is not the case. But the supply was already looked up with regulator_resolve_supply() and set with set_supply() before the check and both return on error. So the fact that this statement has been reached means that neither of them failed and a supply must be associated with the regulator. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-13Merge remote-tracking branches 'regulator/topic/ltc3589', ↵Mark Brown1-0/+11
'regulator/topic/max77620', 'regulator/topic/max77686', 'regulator/topic/max77802' and 'regulator/topic/maxim' into regulator-next
2016-03-13Merge remote-tracking branches 'regulator/topic/discharge', ↵Mark Brown1-0/+11
'regulator/topic/fan53555', 'regulator/topic/gpio', 'regulator/topic/hi655x' and 'regulator/topic/lp872x' into regulator-next
2016-03-02regulator: core: Add support for active-discharge configurationLaxman Dewangan1-0/+11
Add support to enable/disable active discharge of regulator via machine constraints. This configuration is done when setting machine constraint during regulator register and if regulator driver implemented the callback ops. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-02regulator: core: Add support for active-discharge configurationLaxman Dewangan1-0/+11
Add support to enable/disable active discharge of regulator via machine constraints. This configuration is done when setting machine constraint during regulator register and if regulator driver implemented the callback ops. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-25regulator: core: fix crash in error path of regulator_registerKrzysztof Adamski1-4/+4
This problem was introduced by: commit daad134d6649 ("regulator: core: Request GPIO before creating sysfs entries") The error path was not updated correctly after moving GPIO registration code and in case regulator_ena_gpio_free failed, device_unregister() was called even though device_register() was not yet called. This problem breaks the boot at least on all Tegra 32-bit devices. It will also crash each device that specifices GPIO that is unavaiable at regulator_register call. Here's error log I've got when forced GPIO to be invalid: [ 1.116612] usb-otg-vbus-reg: Failed to request enable GPIO10: -22 [ 1.122794] Unable to handle kernel NULL pointer dereference at virtual address 00000044 [ 1.130894] pgd = c0004000 [ 1.133598] [00000044] *pgd=00000000 [ 1.137205] Internal error: Oops: 5 [#1] SMP ARM and here's backtrace from KDB: Exception stack(0xef11fbd0 to 0xef11fc18) fbc0: 00000000 c0738a14 00000000 00000000 fbe0: c0b2a0b0 00000000 00000000 c0738a14 c0b5fdf8 00000001 ef7f6074 ef11fc4c fc00: ef11fc50 ef11fc20 c02a8344 c02a7f1c 60000013 ffffffff [<c010cee0>] (__dabt_svc) from [<c02a7f1c>] (kernfs_find_ns+0x18/0xf8) [<c02a7f1c>] (kernfs_find_ns) from [<c02a8344>] (kernfs_find_and_get_ns+0x40/0x58) [<c02a8344>] (kernfs_find_and_get_ns) from [<c02ac4a4>] (sysfs_unmerge_group+0x28/0x68) [<c02ac4a4>] (sysfs_unmerge_group) from [<c044389c>] (dpm_sysfs_remove+0x30/0x5c) [<c044389c>] (dpm_sysfs_remove) from [<c0436ba8>] (device_del+0x48/0x1f4) [<c0436ba8>] (device_del) from [<c0436d84>] (device_unregister+0x30/0x6c) [<c0436d84>] (device_unregister) from [<c0403910>] (regulator_register+0x6d0/0xdac) [<c0403910>] (regulator_register) from [<c04052d4>] (devm_regulator_register+0x50/0x84) [<c04052d4>] (devm_regulator_register) from [<c0406298>] (reg_fixed_voltage_probe+0x25c/0x3c0) [<c0406298>] (reg_fixed_voltage_probe) from [<c043d21c>] (platform_drv_probe+0x60/0xb0) [<c043d21c>] (platform_drv_probe) from [<c043b078>] (driver_probe_device+0x24c/0x440) [<c043b078>] (driver_probe_device) from [<c043b5e8>] (__device_attach_driver+0xc0/0x120) [<c043b5e8>] (__device_attach_driver) from [<c043901c>] (bus_for_each_drv+0x6c/0x98) [<c043901c>] (bus_for_each_drv) from [<c043ad20>] (__device_attach+0xac/0x138) [<c043ad20>] (__device_attach) from [<c043b664>] (device_initial_probe+0x1c/0x20) [<c043b664>] (device_initial_probe) from [<c043a074>] (bus_probe_device+0x94/0x9c) [<c043a074>] (bus_probe_device) from [<c043a610>] (deferred_probe_work_func+0x80/0xcc) [<c043a610>] (deferred_probe_work_func) from [<c01381d0>] (process_one_work+0x158/0x454) [<c01381d0>] (process_one_work) from [<c013854c>] (worker_thread+0x38/0x510) [<c013854c>] (worker_thread) from [<c013e154>] (kthread+0xe8/0x104) [<c013e154>] (kthread) from [<c0108638>] (ret_from_fork+0x14/0x3c) Signed-off-by: Krzysztof Adamski <krzysztof.adamski@tieto.com> Reported-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-25Merge branch 'fix/core' of ↵Mark Brown1-17/+12
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-core
2016-02-22regulator: core: Request GPIO before creating sysfs entriesKrzysztof Adamski1-10/+10
regulator_attr_is_visible (which is a .is_visible callback of regulator_dev_group attribute_grpup) checks rdev->ena_pin to decide if "status" file should be present in sysfs. This field is set at the end of regulator_ena_gpio_request so it has to be called before device_register() otherwise this test will always fail, causing "status" file to not be visible. Since regulator_attr_is_visible also tests for is_enabled() op, this problem is only visible for regulators that does not define this callback, like regulator-fixed.c. Signed-off-by: Krzysztof Adamski <krzysztof.adamski@tieto.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-01-27regulator: core: Rely on regulator_dev_release to free constraintsCharles Keepax1-17/+12
As we now free the constraints in regulator_dev_release we will still call free on the constraints pointer even if we went down an error path in regulator_register, because it is only allocated after the device_register. As such we no longer need to free rdev->constraints on the error paths, so this patch removes said frees. Fixes: 29f5f4860a8e ("regulator: core: Move more deallocation into class unregister") Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-01-12Merge remote-tracking branches 'regulator/topic/lp8788', ↵Mark Brown1-2/+4
'regulator/topic/mt6311', 'regulator/topic/optional', 'regulator/topic/palmas' and 'regulator/topic/pv88060' into regulator-next
2016-01-12Merge remote-tracking branches 'regulator/topic/const', ↵Mark Brown1-1/+9
'regulator/topic/lm363x', 'regulator/topic/lockdep' and 'regulator/topic/lp872x' into regulator-next
2016-01-12Merge remote-tracking branch 'regulator/topic/core' into regulator-nextMark Brown1-9/+4
2016-01-07regulator: core: remove some dead codeDan Carpenter1-8/+3
Originally queue_delayed_work() used to negative error codes or 0 and 1 on success depending if the work was queued or not. It caused a lot of bugs where people treated all non-zero returns as failures so we changed it to return bool instead in d4283e937861 ('workqueue: make queueing functions return bool'). Now it never returns failure. Checking for negative values causes a static checker warning since it is impossible based on the bool type. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-01-05regulator: core: use dev_to_rdevGeliang Tang1-1/+1
Use dev_to_rdev() instead of open-coding it. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-02regulator: core: Fix nested locking of suppliesThierry Reding1-2/+9
Commit fa731ac7ea04 ("regulator: core: avoid unused variable warning") introduced a subtle change in how supplies are locked. Where previously code was always locking the regulator of the current iteration, the new implementation only locks the regulator if it has a supply. For any given power tree that means that the root will never get locked. On the other hand the regulator_unlock_supply() will still release all the locks, which in turn causes the lock debugging code to warn about a mutex being unlocked which wasn't locked. Cc: Mark Brown <broonie@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Fixes: Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning") Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-02regulator: core: Ensure we lock all regulatorsMark Brown1-1/+1
The latest workaround for the lockdep interface's not using the second argument of mutex_lock_nested() changed the loop missed locking the last regulator due to a thinko with the loop termination condition exiting one regulator too soon. Reported-by: Tyler Baker <tyler.baker@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-27regulator: core: fix regulator_lock_supply regressionArnd Bergmann1-1/+2
As noticed by Geert Uytterhoeven, my patch to avoid a harmless build warning in regulator_lock_supply() was total crap and introduced a real bug: > [ BUG: bad unlock balance detected! ] > kworker/u4:0/6 is trying to release lock (&rdev->mutex) at: > [<c0247b84>] regulator_set_voltage+0x38/0x50 we still lock the regulator supplies, but not the actual regulators, so we are missing a lock, and the unlock is unbalanced. This rectifies it by first locking the regulator device itself before using the same loop as before to lock its supplies. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 716fec9d1965 ("[SUBMITTED] regulator: core: avoid unused variable warning") Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-20regulator: core: avoid unused variable warningArnd Bergmann1-11/+3
The second argument of the mutex_lock_nested() helper is only evaluated if CONFIG_DEBUG_LOCK_ALLOC is set. Otherwise we get this build warning for the new regulator_lock_supply function: drivers/regulator/core.c: In function 'regulator_lock_supply': drivers/regulator/core.c:142:6: warning: unused variable 'i' [-Wunused-variable] To avoid the warning, this restructures the code to make it both simpler and to move the 'i++' outside of the mutex_lock_nested call, where it is now always used and the variable is not flagged as unused. We had some discussion about changing mutex_lock_nested to an inline function, which would make the code do the right thing here, but in the end decided against it, in order to guarantee that mutex_lock_nested() does not introduced overhead without CONFIG_DEBUG_LOCK_ALLOC. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9f01cd4a915 ("regulator: core: introduce function to lock regulators and its supplies") Link: http://permalink.gmane.org/gmane.linux.kernel/2068900 Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-17regulator: Make bulk API support optional suppliesBjorn Andersson1-2/+4
Make it possible to use the bulk API with optional supplies, by allowing the consumer to marking supplies as optional in the regulator_bulk_data. Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-04Merge remote-tracking branches 'regulator/topic/supply', ↵Mark Brown1-70/+179
'regulator/topic/tps6105x' and 'regulator/topic/tps65023' into regulator-next
2015-11-04Merge remote-tracking branch 'regulator/topic/list' into regulator-nextMark Brown1-91/+164
2015-11-04Merge remote-tracking branch 'regulator/topic/core' into regulator-nextMark Brown1-4/+4
2015-11-04regulator: Use regulator_lock_supply() for get_voltage() tooMark Brown1-3/+3
Since we need to read voltages of parents as part of setting supply voltages we need to be able to do get_voltage() internally without taking locks so reorganize the locking to take locks on the full tree on entry rather than as we recurse when called externally. Reported-by: John Stultz <john.stultz@linaro.org> Tested-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-22regulator: core: Propagate voltage changes to supply regulatorsSascha Hauer1-2/+52
Until now changing the voltage of a regulator only ever effected the regulator itself, but never its supplies. It's a common pattern though to put LDO regulators behind switching regulators. The switching regulators efficiently drop the input voltage but have a high ripple on their output. The output is then cleaned up by the LDOs. For higher energy efficiency the voltage drop at the LDOs should be minimized. For this scenario we need to propagate the voltage change to the supply regulators. Another scenario where voltage propagation is desired is a regulator which only consists of a switch and thus cannot regulate voltages itself. In this case we can pass setting voltages to the supply. This patch adds support for voltage propagation. We do voltage propagation when the current regulator has a minimum dropout voltage specified or if the current regulator lacks a get_voltage operation (indicating it's a switch and not a regulator). Changing the supply voltage must be done carefully. When we are increasing the current regulators output we must first increase the supply voltage and then the regulator itself. When we are decreasing the current regulators voltage we must decrease the supply voltage after changing the current regulators voltage. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-20regulator: core: Factor out regulator_map_voltageSascha Hauer1-17/+18
_regulator_call_set_voltage has code to translate a minimum/maximum voltage pair into a selector. This code is useful for others aswell, so create a regulator_map_voltage function. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-16regulator: core: create unlocked version of regulator_set_voltageSascha Hauer1-23/+34
The unlocked version will be needed when we start propagating voltage changes to the supply regulators. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-01regulator: core: create unlocked version of regulator_list_voltageSascha Hauer1-27/+35
The unlocked version will be needed when we start propagating voltage changes to the supply regulators. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-01regulator: core: introduce function to lock regulators and its suppliesSascha Hauer1-0/+39
Each regulator_dev is locked with its own mutex. This is fine as long as only one regulator_dev is locked, but makes lockdep unhappy when we have to walk up the supply chain like it can happen in regulator_get_voltage: regulator_get_voltage -> mutex_lock(&regulator->rdev->mutex) -> _regulator_get_voltage(regulator->rdev) -> regulator_get_voltage(rdev->supply) -> mutex_lock(&regulator->rdev->mutex); This causes lockdep to issue a possible deadlock warning. There are at least two ways to work around this: - We can always lock the whole supply chain using the functions introduced with this patch. - We could store the current voltage in struct regulator_rdev so that we do not have to walk up the supply chain for the _regulator_get_voltage case. Anyway, regulator_lock_supply/regulator_unlock_supply will be needed once we allow regulator_set_voltage to optimize the supply voltages. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>