summaryrefslogtreecommitdiff
path: root/drivers/base/pinctrl.c
AgeCommit message (Collapse)AuthorFilesLines
2017-12-07driver core: Remove redundant license textGreg Kroah-Hartman1-2/+0
Now that the SPDX tag is in all driver core files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13driver core: fix automatic pinctrl managementJohan Hovold1-0/+3
Commit ab78029ecc34 ("drivers/pinctrl: grab default handles from device core") added automatic pin-control management to driver core by looking up and setting any default pinctrl state found in device tree while a device is being probed. This obviously runs into problems as soon as device-tree nodes are reused for child devices which are later also probed as pins would already have been claimed by the ancestor device. For example if a USB host controller claims a pin, its root hub would consequently fail to probe when its device-tree node is set to the node of the controller: pinctrl-single 48002030.pinmux: pin PIN204 already requested by 48064800.ehci; cannot claim for usb1 pinctrl-single 48002030.pinmux: pin-204 (usb1) status -22 pinctrl-single 48002030.pinmux: could not request pin 204 (PIN204) from group usb_dbg_pins on device pinctrl-single usb usb1: Error applying setting, reverse things back usb: probe of usb1 failed with error -22 Fix this by checking the new of_node_reused flag and skipping automatic pinctrl configuration during probe if set. Note that the flag is checked in driver core rather than in pinctrl (e.g. in pinctrl_dt_to_map()) which would specifically have prevented intentional use of a parent's pinctrl properties by a child device (should such a need ever arise). Fixes: ab78029ecc34 ("drivers/pinctrl: grab default handles from device core") Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-14driver: base: pinctrl: return error from pinctrl_bind_pins()Deepak1-4/+8
strict pin controller returns -EINVAL in case of pin request which is already claimed by somebody else. Following is the sequence of calling pin_request() from pinctrl_bind_pins():- pinctrl_bind_pins()->pinctrl_select_state()->pinmux_enable_setting()-> pin_request() But pinctrl_bind_pins() only returns -EPROBE_DEFER which makes device driver probe successful even if the pin request is rejected by the pin controller subsystem. This commit modifies pinctrl_bind_pins() to return error if the pin is rejected by pin control subsystem. Signed-off-by: Deepak Das <deepak_das@mentor.com> [Rewrote to be cleaner] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-27drivers/pinctrl: Add the concept of an "init" stateDouglas Anderson1-2/+13
For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Caesar Wang <wxt@rock-chips.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-06-16drivers: pinctrl sleep and idle states in the coreLinus Walleij1-0/+19
If a device have sleep and idle states in addition to the default state, look up these in the core and stash them in the pinctrl state container. Add accessor functions for pinctrl consumers to put the pins into "default", "sleep" and "idle" states passing nothing but the struct device * affected. Solution suggested by Kevin Hilman, Mark Brown and Dmitry Torokhov in response to a patch series from Hebbar Gururaja. Cc: Hebbar Gururaja <gururaja.hebbar@ti.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-23drivers/pinctrl: grab default handles from device coreLinus Walleij1-0/+69
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>