While the pinmux_ops are ideally just a vtable for pin mux
calls, the "strict" setting belongs so intuitively with the
pin multiplexing that we should move it here anyway. Putting
it in the top pinctrl_desc makes no sense.
Cc: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Disallow simultaneous use of the the GPIO and peripheral mux
functions by setting a flag "strict" in struct pinctrl_desc.
The blackfin pinmux and gpio controller doesn't allow user to
set up a pin for both GPIO and peripheral function. So, add flag
strict in struct pinctrl_desc to check both gpio_owner and
mux_owner before approving the pin request.
v2-changes:
- if strict flag is set, check gpio_owner and mux_onwer in if and
else clause
v3-changes:
- add kerneldoc for this struct
- augment Documentation/pinctrl.txt
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Make the example code consistent wrt local function and struct definitions.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This API has changed in commit 6e5e959dde (pinctrl: API changes to support
multiple states per device).
Fixes: 6e5e959dde ('pinctrl: API changes to support multiple states per device')
Cc: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit 03e9f0cac5 (pinctrl: clean up after enable refactoring) updated the
documentation to remove mention of disable(), and rename enable() to set_mux().
One in-text mention was forgotten. Fix this.
Fixes: 03e9f0cac5 ('pinctrl: clean up after enable refactoring')
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
struct pinctrl_desc does not contain the maxpin member since commit 0d2006bbf0
(pinctrl: remove unnecessary max pin number).
Fixes: 0d2006bbf0 ('pinctrl: remove unnecessary max pin number')
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
commit 2243a87d90
"pinctrl: avoid duplicated calling enable_pinmux_setting for a pin"
removed the .disable callback from the struct pinmux_ops,
making the .enable() callback the only remaining callback.
However .enable() is a bad name as it seems to imply that a
muxing can also be disabled. Rename the callback to .set_mux()
and also take this opportunity to clean out any remaining
mentions of .disable() from the documentation.
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Acked-by: Fan Wu <fwu@marvell.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
I had been trying to learn a bit more about the pinctrl subsystem, and I
realized several typos and grammar issues while going through the documentation.
I have probably not caught all the possible issues, but this change is
addressing several places for improvement.
Signed-off-by: Laszlo Papp <lpapp@kde.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch adds a short description of how to use the newly added
pinctrl_get_group_pins function to the pinctrl documentation.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
__initdata should be placed between the variable name and equal
sign for the variable to be placed in the intended section. Fix
the examples.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This elaborates a bit on the pin control and pin muxing
logic vs GPIO arangements in the hardware.
Inspired by some drawings in a mail from Christian Ruppert.
Both arrangements are confirmed to exist in practice.
Cc: Rob Landley <rob@landley.net>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Pull trivial tree updates from Jiri Kosina:
"The usual stuff from trivial tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
treewide: relase -> release
Documentation/cgroups/memory.txt: fix stat file documentation
sysctl/net.txt: delete reference to obsolete 2.4.x kernel
spinlock_api_smp.h: fix preprocessor comments
treewide: Fix typo in printk
doc: device tree: clarify stuff in usage-model.txt.
open firmware: "/aliasas" -> "/aliases"
md: bcache: Fixed a typo with the word 'arithmetic'
irq/generic-chip: fix a few kernel-doc entries
frv: Convert use of typedef ctl_table to struct ctl_table
sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
doc: clk: Fix incorrect wording
Documentation/arm/IXP4xx fix a typo
Documentation/networking/ieee802154 fix a typo
Documentation/DocBook/media/v4l fix a typo
Documentation/video4linux/si476x.txt fix a typo
Documentation/virtual/kvm/api.txt fix a typo
Documentation/early-userspace/README fix a typo
Documentation/video4linux/soc-camera.txt fix a typo
lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
...
From the inception ot the pin config API there has been the
possibility to get a handle at a pin directly and configure
its electrical characteristics. For this reason we had:
int pin_config_get(const char *dev_name, const char *name,
unsigned long *config);
int pin_config_set(const char *dev_name, const char *name,
unsigned long config);
int pin_config_group_get(const char *dev_name,
const char *pin_group,
unsigned long *config);
int pin_config_group_set(const char *dev_name,
const char *pin_group,
unsigned long config);
After the introduction of the pin control states that will
control pins associated with devices, and its subsequent
introduction to the device core, as well as the
introduction of pin control hogs that can set up states on
boot and optionally also at sleep, this direct pin control
API is a thing of the past.
As could be expected, it has zero in-kernel users.
Let's delete this API and make our world simpler.
Reported-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This updates the GPIO range documentation with the API changes
for sparse/random/arbitrary pin-to-GPIO mappings.
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Recently as adoption of the pinctrl framework is reaching
niches where the pins are reconfigured during system sleep
and datasheets often talk about something called "GPIO mode",
some engineers become confused by this, thinking that since
it is named "GPIO (something something)" it must be modeled
in the kernel using <linux/gpio.h>.
To clarify things, let's put in this piece of documentation,
or just start off the discussion here.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Pankaj Dev <pankaj.dev@st.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
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>
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 switches the way that pins are reserved for multiplexing:
We used to do this when the map was parsed, at the creation of
the settings inside the pinctrl handle, in pinmux_map_to_setting().
However this does not work for us, because we want to use the
same set of pins with different devices at different times: the
current code assumes that the pin groups in a pinmux state will
only be used with one single device, albeit different groups can
be active at different times. For example if a single I2C driver
block is used to drive two different busses located on two
pin groups A and B, then the pins for all possible states of a
function are reserved when fetching the pinctrl handle: the
I2C bus can choose either set A or set B by a mux state at
runtime, but all pins in both group A and B (the superset) are
effectively reserved for that I2C function and mapped to the
device. Another device can never get in and use the pins in
group A, even if the device/function is using group B at the
moment.
Instead: let use reserve the pins when the state is activated
and drop them when the state is disabled, i.e. when we move to
another state. This way different devices/functions can use the
same pins at different times.
We know that this is an odd way of doing things, but we really
need to switch e.g. an SD-card slot to become a tracing output
sink at runtime: we plug in a special "tracing card" then mux
the pins that used to be an SD slot around to the tracing
unit and push out tracing data there instead of SD-card
traffic.
As a side effect pinmux_free_setting() is unused but the stubs
are kept for future additions of code.
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Loic Pallardy <loic.pallardy@st.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Jean Nicolas Graux <jean-nicolas.graux@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The semantics of the interactions between GPIO and pinctrl may be
unclear, e.g. which one do you request first? This amends the
documentation to make this clear.
Reported-by: Domenico Andreoli <cavokz@gmail.com>
Acked-by: Domenico Andreoli <domenico.andreoli@linux.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
These functions allow the driver core to automatically clean up any
allocations made by drivers, thus leading to simplified drivers.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Linus Walleij
Sonic Zhang
Baruch Siach
Laszlo Papp
Christian Ruppert
Axel Lin
Sachin Kamat
Linus Torvalds
James Hogan
Anatol Pomozov
Shiraz Hashim
Daniel Mack
Stephen Warren