This obvious bug was introduced by d755910b7 ("pinctrl: move subsystem
mutex to pinctrl_dev struct").
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.
Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().
For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
- pinctrl_get()/pinctrl_put()
- pinctrl_register_maps()
So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.
Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.
Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().
Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
is located inside pinctrl_select_state(). When parsing
the state->setting list, take the per-pin-controller driver
lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
in all functions which parse or modify pictrldev_list.
(Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
pinctrl/core.c in order to protect pinctrldev_list.
(Patrice).
- Sink mutex:es into some functions and remove some _locked
variants down to where the lists are actually accessed to
make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
and pinctrl_select_state() - no relevant mutex was taken
and it was unclear what this was protecting against. (Linus)
Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Instead of just enabling the settings that were disabled in the 1st
loop, it's simpler to recall pinctrl_select_state with the old state.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As Stephen Warren pointed out, pinctrl_free_setting() was called instead
of pinmux_disable_setting() on error.
In this error code, we want to call pinmux_disable_setting() where
pinmux_enable_setting() was called.
And when pinconf_apply_setting() was called, we can't do much to undo
the pin muxing (the closest thing I can think about for "unmuxing" a pin
is muxing it as GPIO input).
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As Stephen Warren suggested, checking first if the setting->node entry
is the first in the list or not is superfluous, as it is checked again
in the list_for_each_entry bellow.
So, remove it, the code will be simpler and lighter !
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In file included from drivers/pinctrl/core.c:30:0:
include/asm-generic/gpio.h: In function 'gpio_get_value_cansleep':
include/asm-generic/gpio.h:270:2: error: implicit declaration of
function '__gpio_get_value' [-Werror=implicit-function-declaration]
include/asm-generic/gpio.h: In function 'gpio_set_value_cansleep':
include/asm-generic/gpio.h:276:2: error: implicit declaration of
function '__gpio_set_value' [-Werror=implicit-function-declaration]
drivers/pinctrl/core.c: In function 'pinctrl_ready_for_gpio_range':
drivers/pinctrl/core.c:297:9: error: implicit declaration of function
'gpio_to_chip' [-Werror=implicit-function-declaration]
drivers/pinctrl/core.c:297:27: warning: initialization makes pointer
from integer without a cast [enabled by default]
drivers/pinctrl/core.c:304:45: error: dereferencing pointer to
incomplete type
drivers/pinctrl/core.c:305:26: error: dereferencing pointer to
incomplete type
drivers/pinctrl/core.c:305:39: error: dereferencing pointer to
incomplete type
cc1: some warnings being treated as errors
make[2]: *** [drivers/pinctrl/core.o] Error 1
make[1]: *** [drivers/pinctrl] Error 2
make[1]: *** Waiting for unfinished jobs....
It's caused by CONFIG_GPIOLIB isn't enabled for some platform. So
add the dependence on pinctrl_ready_for_gpio_range().
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
If a new state is applied, the groups configured in the old state but
not in the new state are disabled.
If something goes wrong and the new state can't be applied, we have to
re-enable those groups.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
If enabling a pin fails in pinctrl_select_state_locked(), all the
previous enabled pins have to be disabled to get back to the previous
state.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This prepares the implementation of pinctrl_select_state_locked() free code.
No functionnal change.
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
pinctrl_get_device_gpio_range() only checks whether a certain GPIO pin
is in gpio range. But maybe some GPIO pins don't have back-end pinctrl
interface, it means that these pins are always configured as GPIO
function. For example, gpio159 isn't related to back-end pinctrl device
in Hi3620 while other GPIO pins are related to back-end pinctrl device.
Append pinctrl_ready_for_gpio_range() that is used to check whether
pinctrl device with GPIO range is ready. This function will be called
after pinctrl_get_device_gpio_range() fails.
If pinctrl device with GPIO range is found, it means that pinctrl device
is already launched and a certain GPIO pin just don't have back-end pinctrl
interface. Then pinctrl_request_gpio() shouldn't return -EPROBE_DEFER in
this case.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
devres_release() can simplify the code, because devres_release()
will call the destructor for the resource as well as freeing
the devres data.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This update adds a debugfs interface to modify a pin configuration
for a given state in the pinctrl map. This allows to modify the
configuration for a non-active state, typically sleep state.
This configuration is not applied right away, but only when the state
will be entered.
This solution is mandated for us by HW validation: in order
to test and verify several pin configurations during sleep without
recompiling the software.
Signed-off-by: Laurent Meunier <laurent.meunier@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
'pinctrl_release' is used only in this file. Hence make it static.
Without this patch we get the following sparse error:
drivers/pinctrl/core.c:815:6: warning:
symbol 'pinctrl_release' was not declared. Should it be static?
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This makes the device core auto-grab the pinctrl handle and set
the "default" (PINCTRL_STATE_DEFAULT) state for every device
that is present in the device model right before probe. This will
account for the lion's share of embedded silicon devcies.
A modification of the semantics for pinctrl_get() is also done:
previously if the pinctrl handle for a certain device was already
taken, the pinctrl core would return an error. Now, since the
core may have already default-grabbed the handle and set its
state to "default", if the handle was already taken, this will
be disregarded and the located, previously instanitated handle
will be returned to the caller.
This way all code in drivers explicitly requesting their pinctrl
handlers will still be functional, and drivers that want to
explicitly retrieve and switch their handles can still do that.
But if the desired functionality is just boilerplate of this
type in the probe() function:
struct pinctrl *p;
p = devm_pinctrl_get_select_default(&dev);
if (IS_ERR(p)) {
if (PTR_ERR(p) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_warn(&dev, "no pinctrl handle\n");
}
The discussion began with the addition of such boilerplate
to the omap4 keypad driver:
http://marc.info/?l=linux-input&m=135091157719300&w=2
A previous approach using notifiers was discussed:
http://marc.info/?l=linux-kernel&m=135263661110528&w=2
This failed because it could not handle deferred probes.
This patch alone does not solve the entire dilemma faced:
whether code should be distributed into the drivers or
if it should be centralized to e.g. a PM domain. But it
solves the immediate issue of the addition of boilerplate
to a lot of drivers that just want to grab the default
state. As mentioned, they can later explicitly retrieve
the handle and set different states, and this could as
well be done by e.g. PM domains as it is only related
to a certain struct device * pointer.
ChangeLog v4->v5 (Stephen):
- Simplified the devicecore grab code.
- Deleted a piece of documentation recommending that pins
be mapped to a device rather than hogged.
ChangeLog v3->v4 (Linus):
- Drop overzealous NULL checks.
- Move kref initialization to pinctrl_create().
- Seeking Tested-by from Stephen Warren so we do not disturb
the Tegra platform.
- Seeking ACK on this from Greg (and others who like it) so I
can merge it through the pinctrl subsystem.
ChangeLog v2->v3 (Linus):
- Abstain from using IS_ERR_OR_NULL() in the driver core,
Russell recently sent a patch to remove it. Handle the
NULL case explicitly even though it's a bogus case.
- Make sure we handle probe deferral correctly in the device
core file. devm_kfree() the container on error so we don't
waste memory for devices without pinctrl handles.
- Introduce reference counting into the pinctrl core using
<linux/kref.h> so that we don't release pinctrl handles
that have been obtained for two or more places.
ChangeLog v1->v2 (Linus):
- Only store a pointer in the device struct, and only allocate
this if it's really used by the device.
Cc: Felipe Balbi <balbi@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Mitch Bradley <wmb@firmworks.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Rickard Andersson <rickard.andersson@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to
correctly handle deferred probe. Removed admonition from docs not to use
pinctrl hogs for devices]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add new function to get devname from pinctrl_dev. pinctrl_dev_get_name()
can only get pinctrl description name. If we want to use gpio driver to
find pinctrl device node, we need to fetch the pinctrl device name.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This fix allows handling sleep mode for hogged
pins in pinctrl. It provides functions to set pins
to sleep/default configurations according to their
current state.
Signed-off-by: Julien Delacou <julien.delacou@stericsson.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Up until now, as hogs were always taken at the end of the
pin control device registration, it didn't cause any problem.
But when starting to hog pins from the device core it will
cause deferral of the pin controller device itself since the
default pin fetch is done *before* the device probes, so
let's fix this annoyance (which is also aesthetically ugly).
Also take some care to make sure that if any one map entry
results in a deferral rather than a failure, then that
deferral will take precedence.
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds a function to the pinctrl core to retrieve the GPIO
range associated with a certain pin for a certain controller.
This is needed when a pinctrl driver want to look up the
corresponding struct gpio_chip for a certain pin. As the
GPIO drivers can now create these ranges themselves, the
pinctrl driver no longer knows about all its associated GPIO
chips.
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This makes the pinctrl_find_and_add_gpio_range() return
-EPROBE_DEFER if the range hosting pin controller cannot be
located. We may assume that the common case for why adding a
range fails is that the targe pin controller device has not
probed yet.
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Rename the function find_pinctrl_and_add_gpio_range()
to pinctrl_find_and_add_gpio_range() so as to be consistent
with the rest of the functions.
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
pinctrl subsystem needs gpio chip base to prepare set of gpio
pin ranges, which a given pinctrl driver can handle. This is
important to handle pinctrl gpio request calls in order to
program a given pin properly for gpio operation.
As gpio base is allocated dynamically during gpiochip
registration, presently there exists no clean way to pass this
information to the pinctrl subsystem.
After few discussions from [1], it was concluded that may be
gpio controller reporting the pin range it supports, is a
better way than pinctrl subsystem directly registering it.
[1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
[Edited documentation a bit]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This reverts earlier commit which removed
pinctrl_remove_gpio_range(), because at that time there
weren't any more users of that routine. It was removed as the
removal of ranges was done in unregister of pinctrl.
But as we are now registering stuff from gpiolib, we may
remove and insert a gpio module multiple times. So, we
need this routine again.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Daniel Mack
Patrice Chotard
Richard Genoud
Haojian Zhuang
Jingoo Han
Laurent Meunier
Sachin Kamat
Linus Walleij
Julien Delacou
Shiraz Hashim
Viresh Kumar