path: root/Documentation/pinctrl.txt
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2014-09-04pinctrl: clean up after enable refactoringLinus Walleij1-12/+2
commit 2243a87d90b42eb38bc281957df3e57c712b5e56 "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>
2014-01-15pinctrl: Fix some typos and grammar issues in the documentationLaszlo Papp1-22/+21
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>
2013-10-16pinctrl: add documentation for pinctrl_get_group_pins()Christian Ruppert1-1/+6
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>
2013-08-23Documentation: pinctrl: Fix example code for pinctrl_registerAxel Lin1-1/+1
pinctrl_register() returns NULL on error, fix it. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-08-14Documentation: pinctrl: Fix example codeSachin Kamat1-4/+4
__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>
2013-07-22pinctrl: elaborate a bit on arrangements in docLinus Walleij1-6/+85
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>
2013-07-04Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 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 ...
2013-06-25pinctrl: rip out the direct pinconf APILinus Walleij1-9/+2
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>
2013-06-17pinctrl: update GPIO range docLinus Walleij1-3/+21
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>
2013-06-16Documentation/pinctrl.txt: fix typo "with with"James Hogan1-2/+2
Fix typo in "communicate directly with with the pinctrl subsystem". Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Linus Walleij <linus.walleij@linaro.org> Acked-by: Rob Landley <rob@landley.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-05-28doc: fix misspellings with 'codespell' toolAnatol Pomozov1-1/+1
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-18pinctrl: document the "GPIO mode" pitfallLinus Walleij1-0/+112
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>
2013-01-23drivers/pinctrl: grab default handles from device coreLinus Walleij1-3/+15
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>
2012-11-11gpiolib: provide provision to register pin rangesShiraz Hashim1-0/+3
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>
2012-11-11pinctrl: reserve pins when states are activatedLinus Walleij1-1/+3
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>
2012-09-17pinctrl: document semantics vs GPIOLinus Walleij1-2/+58
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>
2012-08-17Documentation/pinctrl.txt: Fix some misspelled macrosDaniel Mack1-3/+3
Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18pinctrl: implement devm_pinctrl_get()/put()Stephen Warren1-19/+29
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>
2012-04-18pinctrl: implement pinctrl deferred probingLinus Walleij1-0/+5
If drivers try to obtain pinctrl handles for a pin controller that has not yet registered to the subsystem, we need to be able to back out and retry with deferred probing. So let's return -EPROBE_DEFER whenever this location fails. Also downgrade the errors to info, maybe we will even set them to debug once the deferred probing is commonplace. Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18pinctrl: replace list_*() with get_*_count()Viresh Kumar1-22/+15
Most of the SoC drivers implement list_groups() and list_functions() routines for pinctrl and pinmux. These routines continue returning zero until the selector argument is greater than total count of available groups or functions. This patch replaces these list_*() routines with get_*_count() routines, which returns the number of available selection for SoC driver. pinctrl layer will use this value to check the range it can choose. This patch fixes all user drivers for this change. There are other routines in user drivers, which have checks to check validity of selector passed to them. It is also no more required and hence removed. Documentation updated as well. Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Viresh Kumar <viresh.kumar@st.com> [Folded in fix and fixed a minor merge artifact manually] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18pinctrl: mark const init data with __initconst instead of __initdataUwe Kleine-König1-1/+1
As long as there is no other non-const variable marked __initdata in the same compilation unit it doesn't hurt. If there were one however compilation would fail with error: $variablename causes a section type conflict because a section containing const variables is marked read only and so cannot contain non-const variables. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18Documentation: pinctrl: add missing spi0_0 grp in exampleViresh Kumar1-1/+1
Missed one group from the documentation when proofreading. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-05pinctrl: enhance mapping table to support pin config operationsStephen Warren1-12/+64
The pinctrl mapping table can now contain entries to: * Set the mux function of a pin group * Apply a set of pin config options to a pin or a group This allows pinctrl_select_state() to apply pin configs settings as well as mux settings. v3: Fix find_pinctrl() to iterate over the correct list. s/_MUX_CONFIGS_/_CONFIGS_/ in mapping table macros. Fix documentation to use correct mapping table macro. v2: Added numerous extra PIN_MAP_*() special-case macros. Fixed kerneldoc typo. Delete pinctrl_get_pin_id() and replace it with pin_get_from_name(). Various minor fixes. Updates due to rebase. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-05pinctrl: API changes to support multiple states per deviceStephen Warren1-41/+79
The API model is changed from: p = pinctrl_get(dev, "state1"); pinctrl_enable(p); ... pinctrl_disable(p); pinctrl_put(p); p = pinctrl_get(dev, "state2"); pinctrl_enable(p); ... pinctrl_disable(p); pinctrl_put(p); to this: p = pinctrl_get(dev); s1 = pinctrl_lookup_state(p, "state1"); s2 = pinctrl_lookup_state(p, "state2"); pinctrl_select_state(p, s1); ... pinctrl_select_state(p, s2); ... pinctrl_put(p); This allows devices to directly transition between states without disabling the pin controller programming and put()/get()ing the configuration data each time. This model will also better suit pinconf programming, which doesn't have a concept of "disable". The special-case hogging feature of pin controllers is re-written to use the regular APIs instead of special-case code. Hence, the pinmux-hogs debugfs file is removed; see the top-level pinctrl-handles files for equivalent data. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02pinctrl: assume map table entries can't have a NULL name fieldStephen Warren1-4/+3
pinctrl_register_mappings() already requires that every mapping table entry have a non-NULL name field. Logically, this makes sense too; drivers should always request a specific named state so they know what they're getting. Relying on getting the first mentioned state in the mapping table is error-prone, and a nasty special case to implement, given that a given the mapping table may define multiple states for a device. Remove a small part of the documentation that talked about optionally requesting a specific state; it's mandatory now. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02pinctrl: introduce PINCTRL_STATE_DEFAULT, define hogs as that stateStephen Warren1-4/+4
This provides a single centralized name for the default state. Update PIN_MAP_* macros to use this state name, instead of requiring the user to pass a state name in. With this change, hog entries in the mapping table are defined as those with state name PINCTRL_STATE_DEFAULT, i.e. all entries have the same name. This interacts badly with the nested iteration over mapping table entries in pinctrl_hog_maps() and pinctrl_hog_map() which would now attempt to claim each hog mapping table entry multiple times. Replacing the custom hog code with a simple pinctrl_get()/pinctrl_enable(). Update documentation and mapping tables to use this. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-29pinctrl: re-order struct pinctrl_mapStephen Warren1-12/+12
The lookup key in struct pinctrl_map is (.dev_name, .name). Re-order the struct definition to put the lookup key fields first, and the result values afterwards. To me at least, this slightly better reflects the lookup process. Update the documentation in a similar fashion. Note: PIN_MAP*() macros aren't updated; I plan to update this once later when enhancing the mapping table format to support pin config to reduce churn. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> [Rebased for cherry-picking] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-24pinctrl: disallow map table entries with NULL dev_name fieldStephen Warren1-10/+5
Hog entries are mapping table entries with .ctrl_dev_name == .dev_name. All other mapping table entries need .dev_name set so that they will match some pinctrl_get() call. All extant PIN_MAP*() macros set .dev_name. So, there is no reason to allow mapping table entries without .dev_name set. Update the code and documentation to disallow this. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-10pinctrl: changes hog mechanism to be self-referentialLinus Walleij1-4/+4
Instead of a specific boolean field to indicate if a map entry shall be hogged, treat self-reference as an indication of desired hogging. This drops one field off the map struct and has a nice Douglas R. Hofstadter-feel to it. Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-10pinctrl: move generic functions to the pinctrl_ namespaceLinus Walleij1-59/+59
Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-10pinctrl: break out a pinctrl consumer headerLinus Walleij1-1/+5
This breaks out a <linux/pinctrl/consumer.h> header to be used by all pinmux and pinconfig alike, so drivers needing services from pinctrl does not need to include different headers. This is similar to the approach taken by the regulator API. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-01pinctrl: delete raw device pointers in pinmux mapsLinus Walleij1-4/+1
After discussion with Mark Brown in an unrelated thread about ADC lookups, it came to my knowledge that the ability to pass a struct device * in the regulator consumers is just a historical artifact, and not really recommended. Since there are no in-kernel users of these pointers, we just kill them right now, before someone starts to use them. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-26pinctrl: fix some pinmux typosTony Lindgren1-1/+1
Fix some pinmux typos so implementing pinmux drivers is a bit easier. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-24Documentation/pinctrl: fix a few syntax errors in code examplesUwe Kleine-König1-8/+7
Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: some typo fixesDong Aisheng1-5/+5
Minor copyedits. Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: pass name instead of device to pin_config_*Stephen Warren1-1/+1
Obtaining a "struct pinctrl_dev *" is difficult for code not directly related to the pinctrl subsystem. However, the device name of the pinctrl device is fairly well known. So, modify pin_config_*() to take the device name instead of the "struct pinctrl_dev *". Signed-off-by: Stephen Warren <swarren@nvidia.com> [rebased on top of refactoring code] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: don't create a device for each pin controllerStephen Warren1-13/+13
Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: add a pin config interfaceLinus Walleij1-6/+90
This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: make a copy of pinmux mapLinus Walleij1-2/+2
This makes a deep copy of the pinmux function map instead of keeping the copy supplied from the platform around. This makes it possible to tag the platforms map with __initdata as is also done as part of this patch. Rationale: a certain target platform (PXA) has numerous pinmux maps, many of which will be lying around unused after boot in a multi-platform binary. Instead, deep-copy the one we're going to use and tag them all __initdata so they go away after boot. ChangeLog v1->v2: - Fixup the deep copy, missed a few items on the struct, plus mark bool member non-const since we're making runtime copies if this stuff now. ChangeLog v2->v3: - Make a shallow copy (just copy the array of map structs) as Arnd noticed, string constants never get discarded by the kernel anyway, so these pointers may be safely copied over. Reviewed-by: Arnd Bergmann <arnd.bergmann@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: GPIO direction support for muxingLinus Walleij1-8/+24
When requesting a single GPIO pin to be muxed in, some controllers will need to poke a different value into the control register depending on whether the pin will be used for GPIO output or GPIO input. So create pinmux counterparts to gpio_direction_[input|output] in the pinctrl framework. ChangeLog v1->v2: - This also amends the documentation to make it clear the this function and associated machinery is *ONLY* intended as a backend to gpiolib machinery, not for everyone and his dog to start playing around with pins. ChangeLog v2->v3: - Don't pass an argument to the common request function, instead provide pinmux_* counterparts to the gpio_direction_[input|output] calls, simpler and anyone can understand it. ChangeLog v3->v4: - Fix numerous spelling mistakes and dangling text in documentation. Add Ack and Rewewed-by. Cc: Igor Grinberg <grinberg@compulab.co.il> Acked-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thomas Abraham <thomas.abraham@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: add a pin_base for sparse gpio-rangesChanho Park1-25/+23
This patch enables mapping a base offset of gpio ranges with a pin offset even if does'nt matched. A base of pinctrl_gpio_range means a base offset of gpio. However, we cannot convert gpio to pin number for sparse gpio ranges just only using a gpio base offset. We can convert a gpio to real pin number(even if not matched) using a new pin_base which means a base pin offset of requested gpio range. Now, the pin control subsystem passes the pin base offset to the pinmux driver. For example, let's assume below two gpio ranges in the system. static struct pinctrl_gpio_range gpio_range_a = { .name = "chip a", .id = 0, .base = 32, .pin_base = 32, .npins = 16, .gc = &chip_a; }; static struct pinctrl_gpio_range gpio_range_b = { .name = "chip b", .id = 0, .base = 48, .pin_base = 64, .npins = 8, .gc = &chip_b; }; We can calucalate a exact pin ranges even if doesn't matched with gpio ranges. chip a: gpio-range : [32 .. 47] pin-range : [32 .. 47] chip b: gpio-range : [48 .. 55] pin-range : [64 .. 71] Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03pinctrl: documentation updateLinus Walleij1-26/+26
Update the docs removing an obsolete __refdata tag and document the mysterious return value of pin_free(). And fixes up some various confusions in the pinctrl documentation. Reported-by: Rajendra Nayak <rnayak@ti.com> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: Thomas Abraham <thomas.abraham@linaro.org> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-13drivers: create a pin control subsystemLinus Walleij1-0/+950
This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

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