By now there are drivers using shared reset controls and (de)assert
calls on platforms with self-deasserting reset lines and thus reset
drivers that do not implement .assert() and .deassert().
As long as the initial state of the reset line is deasserted, there
is no reason for a reset_control_assert call to return an error for
shared reset controls, or for a reset_control_deassert call to return
an error for either shared or exclusive reset controls: after a call
to reset_control_deassert the reset line is guaranteed to be deasserted,
and after a call to reset_control_assert it is valid for the reset
line to stay deasserted for shared reset controls.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Many devices may want to request a bunch of resets and control them. So
it's better to manage them as an array. Add APIs to _get() an array of
reset_control, reusing the _assert(), _deassert(), and _reset() APIs for
single reset controls. Since reset controls already may control multiple
reset lines with a single hardware bit, from the user perspective, reset
control arrays are not at all different from single reset controls.
Note that these APIs don't guarantee that the reset lines managed in the
array are handled in any particular order.
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
[p.zabel@pengutronix.de: changed API to hide reset control arrays behind
struct reset_control]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Rename the internal __reset_control_get/put functions to
__reset_control_get/put_internal and add an exported
__reset_control_get equivalent to __of_reset_control_get
that takes a struct device parameter.
This avoids the confusing call to __of_reset_control_get in
the non-DT case and fixes the devm_reset_control_get_optional
function to return NULL if RESET_CONTROLLER is enabled but
dev->of_node == NULL.
Fixes: bb475230b8 ("reset: make optional functions really optional")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Driver updates for ARM SoCs.
A handful of driver changes this time around. The larger changes are:
- Reset drivers for hi3660 and zx2967
- AHCI driver for Davinci, acked by Tejun and brought in here due to
platform dependencies
- Cleanups of atmel-ebi (External Bus Interface)
- Tweaks for Rockchip GRF (General Register File) usage (kitchensink misc
register range on the SoCs)
- PM domains changes for support of two new ZTE SoCs (zx296718 and zx2967)
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Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Arnd Bergmann:
"Driver updates for ARM SoCs.
A handful of driver changes this time around. The larger changes are:
- Reset drivers for hi3660 and zx2967
- AHCI driver for Davinci, acked by Tejun and brought in here due to
platform dependencies
- Cleanups of atmel-ebi (External Bus Interface)
- Tweaks for Rockchip GRF (General Register File) usage (kitchensink
misc register range on the SoCs)
- PM domains changes for support of two new ZTE SoCs (zx296718 and
zx2967)"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (53 commits)
soc: samsung: pmu: Add register defines for pad retention control
reset: make zx2967 explicitly non-modular
reset: core: fix reset_control_put
soc: samsung: pm_domains: Read domain name from the new label property
soc: samsung: pm_domains: Remove message about failed memory allocation
soc: samsung: pm_domains: Remove unused name field
soc: samsung: pm_domains: Use full names in subdomains registration log
sata: ahci-da850: un-hardcode the MPY bits
sata: ahci-da850: add a workaround for controller instability
sata: ahci: export ahci_do_hardreset() locally
sata: ahci-da850: implement a workaround for the softreset quirk
sata: ahci-da850: add device tree match table
sata: ahci-da850: get the sata clock using a connection id
soc: samsung: pmu: Remove duplicated define for ARM_L2_OPTION register
memory: atmel-ebi: Enable the SMC clock if specified
soc: samsung: pmu: Remove unused and duplicated defines
memory: atmel-ebi: Properly handle multiple reference to the same CS
memory: atmel-ebi: Fix the test to enable generic SMC logic
soc: samsung: pm_domains: Add new Exynos5433 compatible
soc: samsung: pmu: Add dummy support for Exynos5433 SoC
...
For a shared reset, when the reset is successful, the triggered_count is
incremented when trying to call the reset callback, so that another device
sharing the same reset line won't trigger it again. If the reset has not
been triggered successfully, the trigger_count should be decremented.
The code does the opposite, and decrements the trigger_count on success.
As a consequence, another device sharing the reset will be able to trigger
it again.
Fixed be removing negation in from of the error code of the reset function.
Fixes: 7da33a37b4 ("reset: allow using reset_control_reset with shared reset")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Commit "reset: make optional functions really optional" missed to
adjust one check in reset_control_put, causing a NULL pointer
access for optional resets.
Fixes: bb475230b8 "reset: make optional functions really optional"
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
The *_get_optional_* functions weren't really optional so this patch
makes them really optional.
These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.
Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Since the new parameter being added is going to be a bool this patch
changes the shared flag from int to bool to match the new parameter.
Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Some SoCs (for example Amlogic GXBB) implement a reset controller which
only supports a reset pulse (triggered via reset_control_reset). At the
same time multiple devices (in case of the Amlogic GXBB SoC both USB
PHYs) are sharing the same reset line.
This patch allows using reset_control_reset also for shared resets.
There are limitations though:
reset_control_reset can only be used if reset_control_assert was not
used yet.
reset_control_assert can only be used if reset_control_reset was not
used yet.
For shared resets the reset is only triggered once for the lifetime of
the reset_control instance (the reset can be triggered again if all
consumers of that specific reset_control are gone, as the reset
framework will free the reset_control instance in that case).
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Instead of potentially crashing, dump a backtrace and return -EINVAL if
rstc is NULL or an error code.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Add a device managed API for reset_controller_register().
This helps in reducing code in .remove callbacks and sometimes
dropping .remove callbacks entirely.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
In some SoCs some hw-blocks share a reset control. Add support for this
setup by adding new:
reset_control_get_shared()
devm_reset_control_get_shared()
devm_reset_control_get_shared_by_index()
methods to get a reset_control. Note that this patch omits adding of_
variants, if these are needed later they can be easily added.
This patch also changes the behavior of the existing exclusive
reset_control_get() variants, if these are now called more then once
for the same reset_control they will return -EBUSY. To catch existing
drivers triggering this error (there should not be any) a WARN_ON(1)
is added in this path.
When a reset_control is shared, the behavior of reset_control_assert /
deassert is changed, for shared reset_controls these will work like the
clock-enable/disable and regulator-on/off functions. They will keep a
deassert_count, and only (re-)assert the reset after reset_control_assert
has been called as many times as reset_control_deassert was called.
Calling reset_control_assert without first calling reset_control_deassert
is not allowed on a shared reset control. Calling reset_control_reset is
also not allowed on a shared reset control.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Now that struct reset_control no longer stores the device pointer for
the device calling reset_control_get we can share a single struct
reset_control when multiple calls to reset_control_get are made for
the same reset line (same id / index).
This is a preparation patch for adding support for shared reset lines.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
With both the regular, _by_index and _optional variants we already have
quite a few variants of [of_]reset_control_get[_foo], the upcoming
addition of shared reset lines support makes this worse.
This commit changes all the variants into wrappers around common core
functions. For completeness sake this commit also adds a new
devm_get_reset_control_by_index wrapper.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
The core currently doesn't check that the DT cell size matches what the
driver declares, which means that every xlate function needs to duplicate
that check.
Make sure that of_reset_control_get checks for this to avoid duplication
and errors.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
There is no need to initialize rstc, as it is unconditionally
assigned the return value of a kzalloc call before use.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Commit 0c5b2b915a ("reset: Mark function as static and remove unused
function in core.c") removed the only user of the device pointer in
struct reset_control. As it is now unused, remove it.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
ENOSYS is reserved to report invalid syscalls to userspace.
Consistently return ENOTSUPP to indicate that the driver doesn't support
the functionality or the reset framework is not enabled at all.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
When of_reset_control_get() is called without connection ID it returns
-ENOENT when the 'resets' property doesn't exists or is an empty entry.
However when a connection ID is given it returns -EINVAL when the 'resets'
property doesn't exists or the requested name can't be found. This is
because the error code returned by of_property_match_string() is just
passed down as an index to of_parse_phandle_with_args(), which then
returns -EINVAL.
To get a consistent return value with both code paths we must return
-ENOENT when of_property_match_string() fails.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Add of_reset_control_get_by_index() to allow the drivers to get reset
device without knowing its name.
Signed-off-by: Vince Hsu <vinceh@nvidia.com>
[jonathanh@nvidia.com: Updated stub function to return -ENOTSUPP instead
of -ENOSYS which should only be used for system calls.]
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the
reset controller API.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
In some cases, you might need to deassert from reset an hardware block that
doesn't associated to a struct device (CPUs, timers, etc.).
Add a small helper to retrieve the reset controller from the device tree
without the need to pass a struct device.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Mark function of_reset_simple_xlate() as static in core.c
because it is not used outside this file.
Also, remove functions devm_reset_control_put() and
devm_reset_control_match() because they are unused.
This eliminates the following warnings in core.c:
drivers/reset/core.c:46:5: warning: no previous prototype for ‘of_reset_simple_xlate’ [-Wmissing-prototypes]
drivers/reset/core.c:262:6: warning: no previous prototype for ‘devm_reset_control_put’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
If the requested reset controller is not yet available, have reset_control_get
and device_reset return -EPROBE_DEFER so the driver can decide to request
probe deferral.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
"rstc" is NULL here and we should use "rcdev" instead of "rstc->rcdev".
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Philipp Zabel