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path: root/drivers/pinctrl/devicetree.c
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2016-06-18pinctrl: OF: Don't create a pinctrl handle if no pinctrl entries existJon Hunter1-1/+6
When pinctrl_get() is called for a device, it will return a valid handle even if the device itself has no pinctrl state entries defined in device-tree. This is caused by the function pinctrl_dt_to_map() which will return success even if the first pinctrl state, 'pinctrl-0', is not found in the device-tree node for a device. According to the pinctrl device-tree binding documentation, pinctrl states must be numbered starting from 0 and so 'pinctrl-0' should always be present if a device uses pinctrl and therefore, if 'pinctrl-0' is not present it seems valid that we should not return a valid pinctrl handle. Fix this by returning an error code if the property 'pinctrl-0' is not present for a device. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-16pinctrl: simplify of_pinctrl_get()Masahiro Yamada1-7/+1
This commit does not change the logic at all. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-06pinctrl: Don't just pretend to protect pinctrl_maps, do it for realDoug Anderson1-1/+1
Way back, when the world was a simpler place and there was no war, no evil, and no kernel bugs, there was just a single pinctrl lock. That was how the world was when (57291ce pinctrl: core device tree mapping table parsing support) was written. In that case, there were instances where the pinctrl mutex was already held when pinctrl_register_map() was called, hence a "locked" parameter was passed to the function to indicate that the mutex was already locked (so we shouldn't lock it again). A few years ago in (42fed7b pinctrl: move subsystem mutex to pinctrl_dev struct), we switched to a separate pinctrl_maps_mutex. ...but (oops) we forgot to re-think about the whole "locked" parameter for pinctrl_register_map(). Basically the "locked" parameter appears to still refer to whether the bigger pinctrl_dev mutex is locked, but we're using it to skip locks of our (now separate) pinctrl_maps_mutex. That's kind of a bad thing(TM). Probably nobody noticed because most of the calls to pinctrl_register_map happen at boot time and we've got synchronous device probing. ...and even cases where we're asynchronous don't end up actually hitting the race too often. ...but after banging my head against the wall for a bug that reproduced 1 out of 1000 reboots and lots of looking through kgdb, I finally noticed this. Anyway, we can now safely remove the "locked" parameter and go back to a war-free, evil-free, and kernel-bug-free world. Fixes: 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct") Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-24pinctrl: Quiet logging about missing DT nodes when not using DTMark Brown1-1/+3
On systems which were not booted using DT it is entirely unsurprising that device nodes don't have any DT information and this is going to happen for every single device in the system. Make pinctrl be less chatty about this situation by only logging in the case where we have DT. Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-26pinctrl: move subsystem mutex to pinctrl_dev structPatrice Chotard1-13/+2
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>
2013-03-07pinctrl: Declare operation structures as constLaurent Pinchart1-2/+2
The pinconf, pinctrl and pinmux operation structures hold function pointers that are never modified. Declare them as const. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-12pinctrl: do not defer device tree hogsLinus Walleij1-0/+5
commit af1024e0f7cde9023ddd0f3116db03911d5914c0 "pinctrl: skip deferral of hogs" Attempts to avoid probe deferral on hogged pins, but we forgot the device tree case. This patch fixes this. Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reported-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: separation of pin concernsLinus Walleij1-3/+1
The fact that of_gpiochip_add_pin_range() and gpiochip_add_pin_range() share too much code is fragile and will invariably mean that bugs need to be fixed in two places instead of one. So separate the concerns of gpiolib.c and gpiolib-of.c and have the latter call the former as back-end. This is necessary also when going forward with other device descriptions such as ACPI. This is done by: - Adding a return code to gpiochip_add_pin_range() so we can reliably check whether this succeeds. - Get rid of the custom of_pinctrl_add_gpio_range() from pinctrl. Instead create of_pinctrl_get() to just retrive the pin controller per se from an OF node. This composite function was just begging to be deleted, it was way to purpose-specific. - Use pinctrl_dev_get_name() to get the name of the retrieved pin controller and use that to call back into the generic gpiochip_add_pin_range(). Now the pin range is only allocated and tied to a pin controller from the core implementation in gpiolib.c. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11gpiolib: provide provision to register pin rangesShiraz Hashim1-0/+13
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>
2012-04-18pinctrl: implement pinctrl deferred probingLinus Walleij1-3/+3
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: core device tree mapping table parsing supportStephen Warren1-0/+249
During pinctrl_get(), if the client device has a device tree node, look for the common pinctrl properties there. If found, parse the referenced device tree nodes, with the help of the pinctrl drivers, and generate mapping table entries from them. During pinctrl_put(), free any results of device tree parsing. Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>