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path: root/drivers/gpio/gpiolib.c (follow)
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2016-07-04Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"Johan Hovold1-36/+16
This reverts commit 923b93e451db876d1479d3e4458fce14fec31d1c. Make sure consumers do not overwrite gpio flags for pins that have already been claimed. While adding support for gpio drivers to refuse a request using unsupported flags, the order of when the requested flag was checked and the new flags were applied was reversed to that consumers could overwrite flags for already requested gpios. This not only affects device-tree setups where two drivers could request the same gpio using conflicting configurations, but also allowed user space to clear gpio flags for already claimed pins simply by attempting to export them through the sysfs interface. By for example clearing the FLAG_ACTIVE_LOW flag this way, user space could effectively change the polarity of a signal. Reverting this change obviously prevents gpio drivers from doing sanity checks on the flags in their request callbacks. Fortunately only one recently added driver (gpio-tps65218 in v4.6) appears to do this, and a follow up patch could restore this functionality through a different interface. Cc: stable <stable@vger.kernel.org> # 4.4 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-17gpio: make library immune to error pointersLinus Walleij1-3/+11
Most functions that take a GPIO descriptor in need to check the descriptor for IS_ERR(). We do this mostly in the VALIDATE_DESC() macro except for the gpiod_to_irq() function which needs special handling. Cc: stable@vger.kernel.org Reported-by: Grygorii Strashko <grygorii.strashko@ti.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-17gpio: make sure gpiod_to_irq() returns negative on NULL descLinus Walleij1-1/+8
commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264 ("gpio: bail out silently on NULL descriptors") doesn't work for gpiod_to_irq(): drivers assume that NULL descriptors will give negative IRQ numbers in return. It has been pointed out that returning 0 is NO_IRQ and that drivers should be amended to treat this as an error, but that is for the longer term: now let us repair the semantics. Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Reported-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08gpiolib: Fix unaligned used of reference countersRicardo Ribalda Delgado1-2/+2
gpiolib relies on the reference counters to clean up the gpio_device structure. Although the number of get/put is properly aligned on gpiolib.c itself, it does not take into consideration how the referece counters are affected by other external functions such as cdev_add and device_add. Because of this, after the last call to put_device, the reference counter has a value of +3, therefore never calling gpiodevice_release. Due to the fact that some of the device has already been cleaned on gpiochip_remove, the library will end up OOPsing the kernel (e.g. a call to of_gpiochip_find_and_xlate). Cc: stable@vger.kernel.org Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08gpiolib: Fix NULL pointer deferenceRicardo Ribalda Delgado1-1/+1
Under some circumstances, a gpiochip might be half cleaned from the gpio_device list. This patch makes sure that the chip pointer is still valid, before calling the match function. [ 104.088296] BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 [ 104.089772] IP: [<ffffffff813d2045>] of_gpiochip_find_and_xlate+0x15/0x80 [ 104.128273] Call Trace: [ 104.129802] [<ffffffff813d2030>] ? of_parse_own_gpio+0x1f0/0x1f0 [ 104.131353] [<ffffffff813cd910>] gpiochip_find+0x60/0x90 [ 104.132868] [<ffffffff813d21ba>] of_get_named_gpiod_flags+0x9a/0x120 ... [ 104.141586] [<ffffffff8163d12b>] gpio_led_probe+0x11b/0x360 Cc: stable@vger.kernel.org Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: drop lock before reading GPIO directionLinus Walleij1-2/+2
When adding the gpiochip, the GPIO HW drivers' callback get_direction() could get called in atomic context. Some of the GPIO HW drivers may sleep when accessing the register. Move the lock before initializing the descriptors. Reported-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: bail out silently on NULL descriptorsLinus Walleij1-3/+8
In fdeb8e1547cb9dd39d5d7223b33f3565cf86c28e ("gpio: reflect base and ngpio into gpio_device") assumed that GPIO descriptors are either valid or error pointers, but gpiod_get_[index_]optional() actually return NULL descriptors and then all subsequent calls should just bail out. Cc: stable@vger.kernel.org Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Andrew Lunn <andrew@lunn.ch> Fixes: fdeb8e1547cb ("gpio: reflect base and ngpio into gpio_device") Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: handle compatible ioctl() pointersLinus Walleij1-2/+13
If we're using the compatible ioctl() we need to handle the argument pointer in a special way or there will be trouble. Fixes: 3c702e9987e2 ("gpio: add a userspace chardev ABI for GPIOs") Reported-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30gpio: flush direction status in gpiochip_lock_as_irq()Linus Walleij1-4/+17
As irqchip and gpiochip functions are orthogonal, the IRQ set-up or something else can have changed the direction of the GPIO line from what the GPIO descriptor knows when we get into gpiochip_lock_as_irq(). Make sure to re-read the direction setting if we have the .get_direction() callback enabled for the chip. Else we get problems like this: iio iio:device2: interrupts on the rising edge gpio gpiochip2: (8012e080.gpio): gpiochip_lock_as_irq: tried to flag a GPIO set as output for IRQ gpio gpiochip2: (8012e080.gpio): unable to lock HW IRQ 0 for IRQ genirq: Failed to request resources for l3g4200d-trigger (irq 111) on irqchip nmk1-32-63 iio iio:device2: failed to request trigger IRQ. st-gyro-i2c: probe of 2-0068 failed with error -22 Fixes: 72d320006177 ("gpio: set up initial state from .get_direction()") Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-17Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds1-42/+91
Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for kernel cycle v4.7: Core infrastructural changes: - Support for natively single-ended GPIO driver stages. This means that if the hardware has registers to configure open drain or open source configuration, we use that rather than (as we did before) try to emulate it by switching the line to an input to get high impedance. This is also documented throughly in Documentation/gpio/driver.txt for those of you who did not understand one word of what I just wrote. - Start to do away with the unnecessarily complex and unitelligible ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another evolutional artifact from the time when the GPIO subsystem was unmaintained. Archs can now just select GPIOLIB and be done with it, cleanups to arches will trickle in for the next kernel. Some minor archs ACKed the changes immediately so these are included in this pull request. - Advancing the use of the data pointer inside the GPIO device for storing driver data by switching the PowerPC, Super-H Unicore and a few other subarches or subsystem drivers in ALSA SoC, Input, serial, SSB, staging etc to use it. - The initialization now reads the input/output state of the GPIO lines, so that each GPIO descriptor knows - if this callback is implemented - whether the line is input or output. This also reflects nicely in userspace "lsgpio". - It is now possible to name GPIO producer names, line names, from the device tree. (Platform data has been supported for a while). I bet we will get a similar mechanism for ACPI one of those days. This makes is possible to get sensible producer names for e.g. GPIO rails in "lsgpio" in userspace. New drivers: - New driver for the Loongson1. - The XLP driver now supports Broadcom Vulcan ARM64. - The IT87 driver now supports IT8620 and IT8628. - The PCA953X driver now supports Galileo Gen2. Driver improvements: - MCP23S08 was switched to use the gpiolib irqchip helpers and now also suppors level-triggered interrupts. - 74x164 and RCAR now supports the .set_multiple() callback - AMDPT was converted to use generic GPIO. - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994 support the new single ended callback for open drain and in some cases open source. - Implement the .get_direction() callback for a few more drivers like PL061, Xgene. Cleanups: - Paul Gortmaker combed through the drivers and de-modularized those who are not really modules. - Move the GPIO poweroff DT bindings to the power subdir where they belong. - Rename gpio-generic.c to gpio-mmio.c, which is much more to the point. That's what it is handling, nothing more, nothing less" * tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits) MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB gpio: zevio: make it explicitly non-modular gpio: timberdale: make it explicitly non-modular gpio: stmpe: make it explicitly non-modular gpio: sodaville: make it explicitly non-modular pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms gpio: dt-bindings: add wd,mbl-gpio bindings gpio: of: make it possible to name GPIO lines gpio: make gpiod_to_irq() return negative for NO_IRQ gpio: xgene: implement .get_direction() gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver gpio: tegra: Implement gpio_get_direction callback gpio: set up initial state from .get_direction() gpio: rename gpio-generic.c into gpio-mmio.c gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case gpio: dwapb: add gpio-signaled acpi event support gpio: dwapb: convert device node to fwnode gpio: dwapb: remove name from dwapb_port_property gpio/qoriq: select IRQ_DOMAIN ...
2016-05-02gpio: make gpiod_to_irq() return negative for NO_IRQLinus Walleij1-3/+12
If a translation returns zero, that means NO_IRQ, so we should return an error since the function is documented to return a negative code on error. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-30gpio: set up initial state from .get_direction()Linus Walleij1-7/+24
If the gpiochip supports the .get_direction() callback, then the initial state of the descriptor flags should be set up as output accordingly. Also put in comments explaining what is going on. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-26gpio: move gpiod_set_array_value_priv()Linus Walleij1-12/+12
This renames gpiod_set_array_value_priv() to gpiod_set_array_value_complex() and moves it to the gpiolib.h private header file so we can reuse it in the subsystem. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-14gpio: gpiolib: Print error number if gpio hog failedLaxman Dewangan1-5/+6
Print the error number of GPIO hog failed during its configurations. This helps in identifying the failure without instrumenting the code. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08gpiolib: Defer gpio device setup until after gpiolib initializationGuenter Roeck1-31/+67
Since commit ff2b13592299 ("gpio: make the gpiochip a real device"), attempts to add a gpio chip prior to gpiolib initialization cause the system to crash. This happens because gpio_bus_type has not been registered yet. Defer creating gpio devices until after gpiolib has been initialized to fix the problem. Cc: Greg Ungerer <gerg@uclinux.org> Cc: Alexandre Courbot <gnurou@gmail.com> Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08gpiolib: Do not use devm functions when registering gpio chipGuenter Roeck1-7/+12
It is possible that a gpio chip is registered before the gpiolib initialization code has run. This means we can not use devm_ functions to allocate memory at that time. Do it the old fashioned way. Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*Dmitry Torokhov1-4/+12
When firmware does not use _DSD properties that allow properly name GPIO resources, the kernel falls back on parsing _CRS resources, and will return entries described as GpioInt() as general purpose GPIOs even though they are meant to be used simply as interrupt sources for the device: Device (ETSA) { Name (_HID, "ELAN0001") ... Method(_CRS, 0x0, NotSerialized) { Name(BUF0,ResourceTemplate () { I2CSerialBus( 0x10, /* SlaveAddress */ ControllerInitiated, /* SlaveMode */ 400000, /* ConnectionSpeed */ AddressingMode7Bit, /* AddressingMode */ "\\_SB.I2C1", /* ResourceSource */ ) GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,, "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX } } ) Return (BUF0) } ... } This gives troubles with drivers such as Elan Touchscreen driver (elants_i2c) that uses devm_gpiod_get to look up "reset" GPIO line and decide whether the driver is responsible for powering up and resetting the device, or firmware is. In the above case the lookup succeeds, we map GPIO as output and later fail to request client->irq interrupt that is mapped to the same GPIO. Let's ignore resources described as GpioInt() while parsing _CRS when requesting output GPIOs (but allow them when requesting GPIOD_ASIS or GPIOD_IN as some drivers, such as i2c-hid, do request GPIO as input and then map it to interrupt with gpiod_to_irq). Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-05gpio: support native single-ended hardware driversLinus Walleij1-15/+37
Some GPIO controllers has a special hardware bit we can flip to support open drain / source. This means that on these hardwares we do not need to emulate OD/OS by setting the line to input instead of actively driving it high/low. Add an optional vtable callback to the driver set_single_ended() so that driver can implement this in hardware if they have it. We may need a pinctrl_gpio_set_config() call at some point to propagate this down to a backing pin control device on systems with split GPIO/pin control. Reported-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-16gpiolib: Fix comment referring to gpio_*() in gpiod_*()Geert Uytterhoeven1-2/+2
Fixes: 79a9becda8940deb ("gpiolib: export descriptor-based GPIO interface") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-08Merge branch 'devm-gpiochip-add-data' into develLinus Walleij1-0/+74
2016-03-07gpiolib: rewrite gpiodev_add_to_listBamvor Jian Zhang1-40/+25
The original code of gpiodev_add_to_list is not very clear which lead to bugs or compiling warning, reference the following patches: Bugs: 1. Commit ef7c7553039b ("gpiolib: improve overlap check of range of gpio"). 2. Commit 96098df125c0 ("gpiolib: fix chip order in gpio list") Warning: 1. Commit e28ecca6eac4 ("gpio: fix warning about iterator"). of gpio"). There is a off-list discussion about how to improve it consequently. This commit try to follow this by rewriting the whole functions. Tested pass with my gpio mockup driver and test scripts[1]. [1] http://www.spinics.net/lists/linux-gpio/msg09598.html Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-25gpio: present the consumer of a line to userspaceLinus Walleij1-4/+4
I named the field representing the current user of GPIO line as "label" but this is too vague and ambiguous. Before anyone gets confused, rename it to "consumer" and indicate clearly in the documentation that this is a string set by the user of the line. Also clean up leftovers in the documentation. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-23gpio: Add devm_ apis for gpiochip_add_data and gpiochip_removeLaxman Dewangan1-0/+74
Add device managed APIs devm_gpiochip_add_data() and devm_gpiochip_remove() for the APIs gpiochip_add_data() and gpiochip_remove(). This helps in reducing code in error path and sometimes removal of .remove callback for driver unbind. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
2016-02-22gpio: fixup line flags for userspace ABILinus Walleij1-7/+9
This fixes the wrongly indicated lines in the userspace ABI: test for the right BITS, do not treat bit numbers as bitmasks. Reported-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-20gpiolib: fix crash when gpiochip removedBamvor Jian Zhang1-3/+2
Commit cb464a88e1ed ("gpio: make the gpiochip a real device") call gpiochip_sysfs_unregister after the gpiochip is empty. It lead to the following crash: [ 163.503994] Unable to handle kernel NULL pointer dereference at virtual address 0000007c [...] [ 163.525394] [<ffffffc0003719a0>] gpiochip_sysfs_unregister+0x44/0xa4 [ 163.525611] [<ffffffc00036f6a0>] gpiochip_remove+0x24/0x154 [ 163.525861] [<ffffffbffc00f0a4>] mockup_gpio_remove+0x38/0x64 [gpio_mockup] [ 163.526101] [<ffffffc00042b4b4>] platform_drv_remove+0x24/0x64 [ 163.526313] [<ffffffc000429cc8>] __device_release_driver+0x7c/0xfc [ 163.526525] [<ffffffc000429e54>] driver_detach+0xbc/0xc0 [ 163.526700] [<ffffffc000429014>] bus_remove_driver+0x58/0xac [ 163.526883] [<ffffffc00042a4cc>] driver_unregister+0x2c/0x4c [ 163.527067] [<ffffffc00042b5c0>] platform_driver_unregister+0x10/0x18 [ 163.527284] [<ffffffbffc00f340>] mock_device_exit+0x10/0x38 [gpio_mockup] [ 163.527593] [<ffffffc00011cefc>] SyS_delete_module+0x1b8/0x1fc [ 163.527799] [<ffffffc000085d8c>] __sys_trace_return+0x0/0x4 [ 163.528049] Code: 940d74b4 f9019abf aa1303e0 940d7439 (7940fac0) [ 163.536273] ---[ end trace 3d1329be504af609 ]--- This patch fix this by changing the code back. Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19gpio: add userspace ABI for GPIO line informationLinus Walleij1-2/+49
This adds a GPIO line ABI for getting name, label and a few select flags from the kernel. This hides the kernel internals and only tells userspace what it may need to know: the different in-kernel consumers are masked behind the flag "kernel" and that is all userspace needs to know. However electric characteristics like active low, open drain etc are reflected to userspace, as this is important information. We provide information on all lines on all chips, later on we will likely add a flag for the chardev consumer so we can filter and display only the lines userspace actually uses in e.g. lsgpio, but then we first need an ABI for userspace to grab and use (get/set/select direction) a GPIO line. Sample output from "lsgpio" on ux500: GPIO chip: gpiochip7, "8011e000.gpio", 32 GPIO lines line 0: unnamed unlabeled line 1: unnamed unlabeled (...) line 25: unnamed "SFH7741 Proximity Sensor" [kernel output open-drain] line 26: unnamed unlabeled (...) Tested-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19gpio: store reflect the label to userspaceLinus Walleij1-0/+13
The gpio_chip label is useful for userspace to understand what kind of GPIO chip it is dealing with. Let's store a copy of this label in the gpio_device, add it to the struct passed to userspace for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-18gpio: use kzalloc to allocate gpio_deviceJosh Cartwright1-1/+1
The use of kmalloc() to allocate the gpio_device leaves the contained struct device object in an unknown state. Calling dev_set_name() on a struct device of unknown state can trigger the free() of an invalid pointer, as seen in the following backtrace (collected by Tony Lindgren): kfree kobject_set_name_vargs dev_set_name gpiochip_add_data omap_gpio_probe platform_drv_probe ... Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Reported-by: Michael Welling <mwelling@ieee.org> Reported-by: Tony Lindgren <tony@atomide.com> Tested-by: Michael Welling <mwelling@ieee.org> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Josh Cartwright <joshc@ni.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16gpio: create an API to detect open drain/source on linesLinus Walleij1-0/+18
My left hand merges code to privatize the descriptor handling while my right hand merges drivers that poke around and disrespect with the same gpiolib internals. So let's expose the proper APIs for drivers to ask the gpiolib core if a line is marked as open drain or open source and get some order around things so this driver compiles again. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16gpio: move the subdriver data pointer into gpio_deviceLinus Walleij1-2/+15
We move to manage this pointer under gpiolib control rather than leave it in the subdevice's gpio_chip. We can not NULL it after gpiochip_remove so at to keep things tight. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16gpio: move the pin ranges into gpio_deviceLinus Walleij1-5/+5
Instead of keeping this reference to the pin ranges in the client driver-supplied gpio_chip, move it to the internal gpio_device as the drivers have no need to inspect this. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio: reference count the gpio device for each descLinus Walleij1-2/+6
Every time a descriptor is retrieved from the gpiolib, we issue module_get() to reference count the module supplying the GPIOs. We also need to call device_get() and device_put() as we also reference the backing gpio_device when doing this. Since the sysfs GPIO interface is using gpiod_get() this will also reference count the sysfs requests until all GPIOs are unexported. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio: reflect base and ngpio into gpio_deviceLinus Walleij1-122/+135
Some information about the GPIO chip need to stay around also after the gpio_chip has been removed and only the gpio_device persist. The base and ngpio are such things, for example we don't want a new chip arriving to overlap the number space of a dangling gpio_device, and the chardev may still query the device for the number of lines etc. Note that the code that assigns base and insert gpio_device into the global list no longer check for a missing gpio_chip: we respect the number space allocated by any other gpio_device. As a consequence of the gdev being referenced directly from the gpio_desc, we need to verify it differently from all in-kernel API calls that fall through to direct queries to the gpio_chip vtable: we first check that desc is !NULL, then that desc->gdev is !NULL, then, if desc->gdev->chip is NULL, we *BAIL OUT* without any error, so as to manage the case where operations are requested on a device that is gone. These checks were non-uniform and partly missing in the past: so to simplify: create the macros VALIDATE_DESC() that will return -EINVAL if the desc or desc->gdev is missing and just 0 if the chip is gone, and conversely VALIDATE_DESC_VOID() for the case where the function does not return an error. By using these macros, we get warning messages about missing gdev with reference to the right function in the kernel log. Despite the macro business this simplifies the code and make it more readable than if we copy/paste the same descriptor checking code into all code ABI call sites (IMHO). Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio/pinctrl: sunxi: stop poking around in private varsLinus Walleij1-0/+9
This kind of hacks disturbs the refactoring of the gpiolib. The descriptor table belongs to the gpiolib, if we want to know something about something in it, use or define the proper accessor functions. Let's add this gpiochip_lins_is_irq() to do what the sunxi driver is trying at so we can privatize the descriptors properly. Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio: move descriptors into gpio_deviceLinus Walleij1-31/+22
We need gpio_device to hold the descriptors so that they can be lifecycled with the struct gpio_device held from userspace. Move the descriptor array into gpio_device. Also rename it from "desc" (singularis) to "descs" (pluralis) to reflect the fact that it is an array. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio: move sysfs mock device to the gpio_deviceLinus Walleij1-2/+2
Since gpio_device is the struct that survives if the backing gpio_chip is removed, move the sysfs mock device to this state container so it becomes part of the dangling state of the GPIO device on removal. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-11gpio: remember to finally free gpio_deviceLinus Walleij1-0/+1
When the device core reference count for the device goes to 0 and it calls .release() we free resources and so can also finally free up the GPIO state container, struct gpio_device. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09gpio: add a userspace chardev ABI for GPIOsLinus Walleij1-1/+124
A new chardev that is to be used for userspace GPIO access is added in this patch. It is intended to gradually replace the horribly broken sysfs ABI. Using a chardev has many upsides: - All operations are per-gpiochip, which is the actual device underlying the GPIOs, making us tie in to the kernel device model properly. - Hotpluggable GPIO controllers can come and go, as this kind of problem has been know to userspace for character devices since ages, and if a gpiochip handle is held in userspace we know we will break something, whereas the sysfs is stateless. - The one-value-per-file rule of sysfs is really hard to maintain when you want to twist more than one knob at a time, for example have in-kernel APIs to switch several GPIO lines at the same time, and this will be possible to do with a single ioctl() from userspace, saving a lot of context switching. We also need to add a new bus type for GPIO. This is necessary for example for userspace coldplug, where sysfs is traversed to find the boot-time device nodes and create the character devices in /dev. This new chardev ABI is *non* *optional* and can be counted on to be present in the future, emphasizing the preference of this ABI. The ABI only implements one single ioctl() to get the name and number of GPIO lines of a chip. Even this is debatable: see it as a minimal example for review. This ABI shall be ruthlessly reviewed and etched in stone. The old /sys/class/gpio is still optional to compile in, but will be deprecated. Unique device IDs are created using IDR, which is overkill and insanely scalable, but also well tested. Cc: Johan Hovold <johan@kernel.org> Cc: Michael Welling <mwelling@ieee.org> Cc: Markus Pargmann <mpa@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09gpio: refer to gpio device in prints and debugfsLinus Walleij1-3/+3
We use the new struct device inside gpio_chip to related debug prints and warnings, and we also add it to the debugfs dump. Cc: Johan Hovold <johan@kernel.org> Cc: Michael Welling <mwelling@ieee.org> Cc: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-09gpio: make the gpiochip a real deviceLinus Walleij1-68/+164
GPIO chips have been around for years, but were never real devices, instead they were piggy-backing on a parent device (such as a platform_device or amba_device) but this was always optional. GPIO chips could also exist without any device at all, with its struct device *parent (ex *dev) pointer being set to null. When sysfs was in use, a mock device would be created, with the optional parent assigned, or just floating orphaned with NULL as parent. If sysfs is active, it will use this device as parent. We now create a gpio_device struct containing a real struct device and move the subsystem over to using that. The list of struct gpio_chip:s is augmented to hold struct gpio_device:s and we find gpio_chips:s by first looking up the struct gpio_device. The struct gpio_device is designed to stay around even if the gpio_chip is removed, so as to satisfy users in userspace that need a backing data structure to hold the state of the session initiated with e.g. a character device even if there is no physical chip anymore. From this point on, gpiochips are devices. Cc: Johan Hovold <johan@kernel.org> Cc: Michael Welling <mwelling@ieee.org> Cc: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-17Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds1-42/+68
Pull GPIO updates from Linus Walleij: "Here is the bulk of GPIO changes for v4.5. Notably there are big refactorings mostly by myself, aimed at getting the gpio_chip into a shape that makes me believe I can proceed to preserve state for a proper userspace ABI (character device) that has already been proposed once, but resulted in the feedback that I need to go back and restructure stuff. So I've been restructuring stuff. On the way I ran into brokenness (return code from the get_value() callback) and had to fix it. Also, refactored generic GPIO to be simpler. Some of that is still waiting to trickle down from the subsystems all over the kernel that provide random gpio_chips, I've touched every single GPIO driver in the kernel now, oh man I didn't know I was responsible for so much... Apart from that we're churning along as usual. I took some effort to test and retest so it should merge nicely and we shook out a couple of bugs in -next. Infrastructural changes: - In struct gpio_chip, rename the .dev node to .parent to better reflect the fact that this is not the GPIO struct device abstraction. We will add that soon so this would be totallt confusing. - It was noted that the driver .get_value() callbacks was sometimes reporting negative -ERR values to the gpiolib core, expecting them to be propagated to consumer gpiod_get_value() and gpio_get_value() calls. This was not happening, so as there was a mess of drivers returning negative errors and some returning "anything else than zero" to indicate that a line was active. As some would have bit 31 set to indicate "line active" it clashed with negative error codes. This is fixed by the largeish series clamping values in all drivers with !!value to [0,1] and then augmenting the code to propagate error codes to consumers. (Includes some ACKed patches in other subsystems.) - Add a void *data pointer to struct gpio_chip. The container_of() design pattern is indeed very nice, but we want to reform the struct gpio_chip to be a non-volative, stateless business, and keep states internal to the gpiolib to be able to hold on to the state when adding a proper userspace ABI (character device) further down the road. To achieve this, drivers need a handle at the internal state that is not dependent on their struct gpio_chip() so we add gpiochip_add_data() and gpiochip_get_data() following the pattern of many other subsystems. All the "use gpiochip data pointer" patches transforms drivers to this scheme. - The Generic GPIO chip header has been merged into the general <linux/gpio/driver.h> header, and the custom header for that removed. Instead of having a separate mm_gpio_chip struct for these generic drivers, merge that into struct gpio_chip, simplifying the code and removing the need for separate and confusing includes. Misc improvements: - Stabilize the way GPIOs are looked up from the ACPI legacy specification. - Incremental driver features for PXA, PCA953X, Lantiq (patches from the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48 New drivers: - Add a GPIO chip to the ALSA SoC AC97 driver. - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir, but the branch is merged here too to account for infrastructural changes). - The sx150x driver now supports the sx1502" * tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits) gpio: generic: make bgpio_pdata always visible gpiolib: fix chip order in gpio list gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs() gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs() gpio: brcmstb: Allow building driver for BMIPS_GENERIC gpio: brcmstb: Set endian flags for big-endian MIPS gpio: moxart: fix build regression gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs() leds: pca9532: use gpiochip data pointer leds: tca6507: use gpiochip data pointer hid: cp2112: use gpiochip data pointer bcma: gpio: use gpiochip data pointer avr32: gpio: use gpiochip data pointer video: fbdev: via: use gpiochip data pointer gpio: pch: Optimize pch_gpio_get() Revert "pinctrl: lantiq: Implement gpio_chip.to_irq" pinctrl: nsp-gpio: use gpiochip data pointer pinctrl: vt8500-wmt: use gpiochip data pointer pinctrl: exynos5440: use gpiochip data pointer pinctrl: at91-pio4: use gpiochip data pointer ...
2016-01-13Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/inputLinus Torvalds1-0/+3
Pull input updates from Dmitry Torokhov: - new driver for eGalaxTouch serial touchscreen - new driver for TS-4800 touchscreen - an update for Goodix touchscreen driver - PS/2 mouse module was reworked to limit number of protocols we try on pass-through ports to speed up their detection time - wacom_w8001 touchscreen driver now reports pen and touch via separate instances of input devices - other driver changes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (42 commits) Input: elantech - mark protocols v2 and v3 as semi-mt Input: wacom_w8001 - drop use of ABS_MT_TOOL_TYPE Input: gpio-keys - fix check for disabling unsupported keys Input: omap-keypad - remove dead check Input: ti_am335x_tsc - fix HWPEN interrupt handling Input: omap-keypad - set tasklet data earlier Input: rohm_bu21023 - fix handling of retrying firmware update Input: ALPS - report v3 pinnacle trackstick device only if is present Input: ALPS - detect trackstick presence for v7 protocol Input: pcap_ts - use to_delayed_work Input: bma150 - constify bma150_cfg structure Input: i8042 - add Fujitsu Lifebook U745 to the nomux list Input: egalax_ts_serial - fix potential NULL dereference on error Input: uinput - sanity check on ff_effects_max and EV_FF Input: uinput - rework ABS validation Input: uinput - add new UINPUT_DEV_SETUP and UI_ABS_SETUP ioctl Input: goodix - use "inverted_[xy]" flags instead of "rotated_screen" Input: goodix - add axis swapping and axis inversion support Input: goodix - use goodix_i2c_write_u8 instead of i2c_master_send Input: goodix - add power management support ...
2016-01-13gpiolib: fix chip order in gpio listJulien Grossholtz1-2/+4
In some situations the gpio_list order is not correct. As a consequence gpiochip_find_base returns the same base number twice. This happens when a first ship is added with manual base number, then other ships are added using automatic base number. To prevent this behaviour, this patch add the new chip after the last element of the gpio list. Signed-off-by: Julien Grossholtz <julien.grossholtz@savoirfairelinux.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-05gpio: fix misleading commentLinus Walleij1-1/+1
We are not relying on container_of() now that we have gpiochip_get_data(). Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-05gpio: add a data pointer to gpio_chipLinus Walleij1-4/+6
This adds a void * pointer to gpio_chip so that driver can assign and retrieve some states. This is done to get rid of container_of() calls for gpio_chips embedded inside state containers, so we can remove the need to have the gpio_chip or later (planned) struct gpio_device be dynamically allocated at registration time, so that its struct device can be properly reference counted and not bound to its parent device (e.g. a platform_device) but instead live on after unregistration if it is opened by e.g. a char device or sysfs. The data is added with the new function gpiochip_add_data() and for compatibility we add static inline wrapper function gpiochip_add() that will call gpiochip_add_data() with NULL as argument. The latter will be removed once we have exorcised gpiochip_add() from the kernel. gpiochip_get_data() is added as a static inline accessor for drivers to quickly get their data out. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-01ACPI / gpio: Add irq_type when a GPIO is used as an interruptChristophe RICARD1-2/+2
When a GPIO is used as an interrupt in ACPI, the irq_type was not available for device driver. Make available polarity and triggering information in acpi_find_gpio by renaming acpi_gpio_info field active_low to polarity and adding triggering field (edge/level). For sanity, in gpiolib.c replace info.active_low by "info.polarity == GPIO_ACTIVE_LOW". Set the irq_type if necessary in acpi_dev_gpio_irq_get. Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-27gpio: fix warning about iteratorSudip Mukherjee1-8/+12
We were getting build warning about "iterator" being used uninitialized. Use iterator properly to fix the build warning and in the process remove the variable "pos" which is not required now. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-26Revert "gpio: revert get() to non-errorprogating behaviour"Linus Walleij1-7/+1
This reverts commit 45ad7db90b42555c8107f18ec6d6a1e9bce34860. We have fixed all the drivers that were returning ambious values not clamped to [0,1] or an error code, so return the error propagating behaviour of the API. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-21Merge tag 'v4.4-rc6' into develLinus Walleij1-2/+8
Linux 4.4-rc6
2015-12-17gpio: revert get() to non-errorprogating behaviourLinus Walleij1-1/+7
commit e20538b82f1f ("gpio: Propagate errors from chip->get()") started to propagate errors from the .get() functions since we can get errors from the infrastructure of e.g. slowbus GPIO expanders. However it turns out a bunch of drivers relied on the core to clamp the value, so we need to revert to the old behaviour and go over all drivers and fix them to conform to the expectations of the core before we go back to propagating the error code. Cc: stable@vger.kernel.org # 4.3+ Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com> Cc: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Fixes: e20538b82f1f ("gpio: Propagate errors from chip->get()") Reported-by: Michael Trimarchi <michael@amarulasolutions.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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