linux-stable.git/drivers/reset/core.c, branch v4.10.2

reset: fix shared reset triggered_count decrement on error

2017-02-17T07:11:47+00:00

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: 7da33a37b48f ("reset: allow using reset_control_reset with shared reset")

Signed-off-by: Jerome Brunet 
Acked-by: Martin Blumenstingl 
Signed-off-by: Philipp Zabel

reset: allow using reset_control_reset with shared reset

2016-11-14T08:58:28+00:00

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 
Signed-off-by: Philipp Zabel

reset: warn on invalid input to reset_control_reset/assert/deassert/status

2016-08-24T13:21:36+00:00

Instead of potentially crashing, dump a backtrace and return -EINVAL if
rstc is NULL or an error code.

Signed-off-by: Philipp Zabel

reset: add devm_reset_controller_register API

2016-05-30T07:37:47+00:00

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 
Acked-by: Laxman Dewangan 
Signed-off-by: Philipp Zabel

reset: Add support for shared reset controls

2016-03-30T13:42:05+00:00

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 
Signed-off-by: Philipp Zabel

reset: Share struct reset_control between reset_control_get calls

2016-03-30T13:42:03+00:00

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 
Signed-off-by: Philipp Zabel

reset: Make [of_]reset_control_get[_foo] functions wrappers

2016-03-30T13:42:01+00:00

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 
Signed-off-by: Philipp Zabel

reset: Move DT cell size check to the core

2016-01-25T09:58:44+00:00

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 
Signed-off-by: Philipp Zabel

reset: remove unnecessary local variable initialization from of_reset_control_get_by_index

2016-01-25T09:58:44+00:00

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

reset: remove unused device pointer from struct reset_control

2015-11-18T14:13:20+00:00

Commit 0c5b2b915a58 ("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