linux/drivers/gpio
Uwe Kleine-König fa38869b01 gpiolib: Don't support irq sharing for userspace
This concerns gpio edge detection for GPIO IRQs used from
userspace for GPIO event listeners.

Trying to work out the right event if it's not sure that the
examined gpio actually moved is impossible.

Consider two gpios "gpioA" and "gpioB" that share an interrupt.
gpioA's irq should trigger on any edge, gpioB's on a falling edge.
If now the common irq fires and both gpio lines are high, there
are several possibilities that could have happend:

 a) gpioA just had a low-to-high edge
 b) gpioB just had a high-to-low-to-high spike
 c) a combination of both a) and b)

While c) is unlikely (in most setups) a) and b) alone are bad
enough. Currently the code assumes case a) unconditionally and
doesn't report an event for gpioB. Note that even if there is no
irq sharing involved a spike for a gpio might not result in an
event if it's configured to trigger for a single edge only.

The only way to improve this is to drop support for interrupt
sharing. This way a spike results in an event for the right gpio
at least. Note that apart from dropping IRQF_SHARED this
effectively undoes commit df1e76f28f
("gpiolib: skip unwanted events, don't convert them to opposite edge").

This obviously breaks setups that rely on interrupt sharing,
but given that this cannot be reliable, this is probably an
acceptable trade-off.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[Assuming there are no users of interrupt sharing yet]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-13 10:58:38 +02:00
..
devres.c gpio: Export devm_gpiod_get_from_of_node() for consumers 2018-01-12 11:05:24 +01:00
gpio-74x164.c The is the bulk of GPIO changes for the v4.16 kernel cycle. 2018-01-31 12:25:27 -08:00
gpio-74xx-mmio.c gpio: 74xx-mmio: Use of_device_get_match_data() 2018-05-16 14:35:24 +02:00
gpio-104-dio-48e.c gpio: 104-dio-48e: make array 'ports' static, shrinks object size 2018-05-16 14:35:24 +02:00
gpio-104-idi-48.c gpio: make several const arrays static, shrinks object size 2018-05-16 14:35:24 +02:00
gpio-104-idio-16.c gpio: 104-idio-16: Implement get_multiple callback 2018-03-26 10:10:18 +02:00
gpio-adnp.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
gpio-adp5520.c drivers: gpio: Update MODULE AUTHOR email address 2018-08-29 13:30:25 +02:00
gpio-adp5588.c drivers: gpio: Update MODULE AUTHOR email address 2018-08-29 13:30:25 +02:00
gpio-altera-a10sr.c gpio: altera-a10sr: constify gpio_chip structure 2017-08-14 15:01:12 +02:00
gpio-altera.c gpio: altera: Include GPIO driver header 2018-01-13 22:18:34 +01:00
gpio-amd8111.c gpio: amd8111: Include proper header 2018-01-13 22:22:49 +01:00
gpio-amdpt.c
gpio-arizona.c gpio: arizona: Include proper header 2018-01-13 22:47:48 +01:00
gpio-aspeed.c gpio: aspeed: fix compile testing warning 2018-07-13 09:05:06 +02:00
gpio-ath79.c gpio: fix meaningless return expression 2018-07-29 23:34:54 +02:00
gpio-bcm-kona.c gpio-bcm-kona: use new req/relres and dis/enable_irq funcs 2018-09-10 08:57:36 +02:00
gpio-bd9571mwv.c gpio: Add ROHM BD9571MWV-M PMIC GPIO driver 2017-04-28 09:47:46 +02:00
gpio-brcmstb.c gpio: brcmstb: allow 0 width GPIO banks 2018-08-30 11:04:50 +02:00
gpio-bt8xx.c gpio: bt8xx: Include proper header 2018-01-13 22:56:52 +01:00
gpio-clps711x.c
gpio-crystalcove.c gpio: crystalcove: Include proper header 2018-01-14 01:48:48 +01:00
gpio-cs5535.c gpio: cs5535: Include proper header 2018-01-14 01:56:24 +01:00
gpio-da9052.c gpio: da905x: Include proper header 2018-01-14 02:00:10 +01:00
gpio-da9055.c gpio: da905x: Include proper header 2018-01-14 02:00:10 +01:00
gpio-davinci.c gpio: davinci: Do not assume continuous IRQ numbering 2018-06-18 07:55:30 +02:00
gpio-dln2.c gpio: dln2: Include proper header 2018-03-19 01:50:07 +01:00
gpio-dwapb.c gpio: dwapb: Don't shadow error code of gpiochip_lock_as_irq() 2018-08-06 23:46:55 +02:00
gpio-eic-sprd.c gpio: eic: Add edge trigger emulation for EIC 2018-05-16 14:35:24 +02:00
gpio-em.c gpio: em: Don't shadow error code of gpiochip_lock_as_irq() 2018-08-06 23:46:55 +02:00
gpio-ep93xx.c gpio: ep93xx: fix test for end of loop 2018-09-10 08:48:24 +02:00
gpio-exar.c gpio: exar: Use correct property prefix and document bindings 2017-08-01 13:43:55 +02:00
gpio-f7188x.c gpio: f7188x: Add a missing break 2017-04-28 10:09:16 +02:00
gpio-ftgpio010.c gpio: ftgpio: Support debounce timer 2018-08-30 09:14:54 +02:00
gpio-ge.c gpio: ge: Fix build warning 2018-05-16 14:35:24 +02:00
gpio-gpio-mm.c gpio: make several const arrays static, shrinks object size 2018-05-16 14:35:24 +02:00
gpio-grgpio.c gpio: grgpio: Include the right header 2018-03-19 01:50:28 +01:00
gpio-hlwd.c gpio: Add GPIO driver for Nintendo Wii 2018-02-22 13:54:35 +01:00
gpio-htc-egpio.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
gpio-ich.c gpio: ich: Use BIT() macro 2018-03-19 01:50:29 +01:00
gpio-intel-mid.c gpio-intel-mid: Delete an error message 2018-02-22 15:29:05 +01:00
gpio-iop.c gpio: iop: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE 2017-12-02 22:42:21 +01:00
gpio-it87.c gpio: it87: Add support for IT8613 2018-08-10 23:19:17 +02:00
gpio-janz-ttl.c gpio: janz-ttl: Use BIT() macro 2018-03-19 01:50:30 +01:00
gpio-kempld.c gpio: kempld: Include the right header 2018-03-19 01:50:31 +01:00
gpio-ks8695.c gpio: ks8695: Include the right header 2018-03-19 01:50:31 +01:00
gpio-loongson1.c gpio: loongson1: fix bgpio usage 2017-10-25 11:25:38 +02:00
gpio-loongson.c gpio: loongson: Use BIT() macros 2018-05-16 14:35:24 +02:00
gpio-lp873x.c gpio: lp873x: Include the right header 2018-05-16 14:35:24 +02:00
gpio-lp3943.c gpio: lp3943: Include the right header 2018-05-16 14:35:24 +02:00
gpio-lp87565.c gpio: lp87565: Set proper output level and direction for direction_output 2017-07-31 15:26:57 +02:00
gpio-lpc18xx.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-lpc32xx.c gpio: lpc32xx: Include the right header 2018-05-16 14:35:24 +02:00
gpio-lynxpoint.c gpio: lynxpoint: Include the right header 2018-05-16 14:35:24 +02:00
gpio-madera.c gpio: madera: Support Cirrus Logic Madera class codecs 2018-06-05 11:15:30 +01:00
gpio-max730x.c gpio: max730x: Include the right header 2018-05-16 14:35:24 +02:00
gpio-max732x.c gpio: max732x: add error handling for i2c_new_dummy 2018-06-18 07:55:30 +02:00
gpio-max3191x.c gpio: Remove VLA from MAX3191X driver 2018-03-27 15:18:06 +02:00
gpio-max7300.c
gpio-max7301.c
gpio-max77620.c gpio: max77620: Make regmap_irq_chip const 2017-08-14 16:06:24 +02:00
gpio-mb86s7x.c gpio: mb86s70: Revert "Return error if requesting an already assigned gpio" 2017-10-31 13:13:34 +01:00
gpio-mc9s08dz60.c gpio: mc9s08dz60: Include the right header 2018-05-16 14:35:24 +02:00
gpio-mc33880.c gpio: mc33880: Include the right header 2018-05-16 14:35:24 +02:00
gpio-menz127.c gpio: Fix wrong rounding in gpio-menz127 2018-06-18 07:55:30 +02:00
gpio-merrifield.c gpio: merrifield: Delete an error message 2018-02-22 15:25:40 +01:00
gpio-ml-ioh.c gpio: ml-ioh: Fix buffer underwrite on probe error path 2018-07-29 23:13:09 +02:00
gpio-mm-lantiq.c gpio: mm-lantiq: Include the right header 2018-05-16 14:35:24 +02:00
gpio-mmio.c gpio: mmio: Fix up inverted direction registers 2018-08-10 23:19:17 +02:00
gpio-mockup.c gpio: mockup: use the SPDX identifier and remove license boilerplate 2018-05-16 14:35:24 +02:00
gpio-mpc8xxx.c gpio: mpc8xxx: Do not reverse bits using bgpio 2017-10-25 11:25:40 +02:00
gpio-mpc5200.c
gpio-msic.c gpio: msic: Include the right header 2018-05-16 14:35:24 +02:00
gpio-mt7621.c gpio: mt7621: Edit to preferred syntax 2018-07-09 13:51:57 +02:00
gpio-mvebu.c gpio: mvebu: Use the proper APIs 2018-05-16 14:35:24 +02:00
gpio-mxc.c gpio: mxc: add power management support 2018-07-29 22:23:17 +02:00
gpio-mxs.c gpio: mxs: Get rid of external API call 2018-09-04 08:22:47 +02:00
gpio-octeon.c gpio: octeon: Include the right header 2018-05-24 14:22:04 +02:00
gpio-omap.c gpio: omap: Add get/set_multiple() callbacks 2018-08-06 23:46:55 +02:00
gpio-palmas.c gpio: palmas: Include the right header 2018-05-24 14:25:13 +02:00
gpio-pca953x.c gpio: pca953x: suppress interrupts warning when not applicable 2018-07-02 16:00:49 +02:00
gpio-pcf857x.c gpio: pcf857x: Include the right header 2018-05-24 17:09:41 +02:00
gpio-pch.c gpio: pch: Include the right header 2018-05-24 17:09:41 +02:00
gpio-pci-idio-16.c gpio: pci-idio-16: Fix port memory offset for get_multiple callback 2018-04-27 00:55:16 +02:00
gpio-pcie-idio-24.c gpio: pcie-idio-24: Fix off-by-one error in get_multiple loop 2018-04-30 10:48:08 +02:00
gpio-pisosr.c gpio-pisosr: add support for get_multiple 2018-07-29 21:55:33 +02:00
gpio-pl061.c gpio: pl061: Include the right header 2018-05-24 17:09:41 +02:00
gpio-pmic-eic-sprd.c gpio: pmic_eic: Add edge trigger emulation for PMIC EIC 2018-05-16 14:35:24 +02:00
gpio-pxa.c gpio: pxa: handle corner case of unprobed device 2018-08-29 13:56:46 +02:00
gpio-raspberrypi-exp.c gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service 2018-02-22 13:49:59 +01:00
gpio-rc5t583.c gpio: rc5t583: Include the right header 2018-07-02 16:00:49 +02:00
gpio-rcar.c gpio: rcar: Add GPIO hole support 2018-08-29 10:46:41 +02:00
gpio-rdc321x.c gpio: rdc321x: Include the right header 2018-07-02 16:00:49 +02:00
gpio-reg.c gpio: gpio-reg: fix build 2017-12-22 15:24:31 +01:00
gpio-sa1100.c gpio: sa1100: Include the right header 2018-07-02 16:00:49 +02:00
gpio-sch311x.c gpio: sch311x: Replace unsigned char with u8 2018-07-02 16:00:49 +02:00
gpio-sch.c gpio: sch: Implement .get_direction() 2018-07-02 16:00:49 +02:00
gpio-sodaville.c gpio: sodaville: use resource management for irqs 2017-03-15 11:16:36 +01:00
gpio-spear-spics.c gpio: spear-spics: Include the right header 2018-07-02 16:00:49 +02:00
gpio-sprd.c gpio: Add GPIO driver for Spreadtrum SC9860 platform 2018-03-02 11:00:43 +01:00
gpio-sta2x11.c gpio: sta2x11: Inline regs macro 2018-07-02 16:00:49 +02:00
gpio-stmpe.c gpio: stmpe: Include the right header 2018-07-02 16:00:49 +02:00
gpio-stp-xway.c gpio: stp-xway: Include the right header 2018-07-02 16:00:49 +02:00
gpio-syscon.c gpio: syscon: rockchip: add GRF GPIO support for rk3328 2018-08-06 23:46:55 +02:00
gpio-tb10x.c gpio: tb10x: Use GENERIC_GPIO 2018-08-29 08:53:37 +02:00
gpio-tc3589x.c gpio: Move irqdomain into struct gpio_irq_chip 2017-11-08 14:06:21 +01:00
gpio-tegra186.c gpio: tegra186: Add support for Tegra194 2018-07-02 16:01:02 +02:00
gpio-tegra.c This is the bulk of GPIO changes for the v4.19 kernel cycle: 2018-08-15 21:35:38 -07:00
gpio-thunderx.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
gpio-timberdale.c gpio: timberdale: Include the right header 2018-08-10 23:04:27 +02:00
gpio-tpic2810.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-tps6586x.c gpio: tps65xxx: Use SPDX license tag 2018-09-04 08:22:47 +02:00
gpio-tps65086.c gpio: tps65xxx: Use SPDX license tag 2018-09-04 08:22:47 +02:00
gpio-tps65218.c pinctrl / gpio: Introduce .set_config() callback for GPIO chips 2017-01-26 15:27:37 +01:00
gpio-tps65910.c gpio: tps65xxx: Use SPDX license tag 2018-09-04 08:22:47 +02:00
gpio-tps65912.c gpio: tps65xxx: Use SPDX license tag 2018-09-04 08:22:47 +02:00
gpio-tps68470.c gpio: tps68470: Update to SPDX license identifier 2018-02-23 15:26:42 +01:00
gpio-ts4800.c gpio: ts4800: Fix module autoload 2016-10-21 14:55:07 +02:00
gpio-ts4900.c gpio: ts4900: Use of_device_get_match_data() 2018-05-16 14:35:24 +02:00
gpio-ts5500.c gpio: ts5500: Delete platform data handling 2018-09-04 08:22:47 +02:00
gpio-twl4030.c gpio: twl4030: Implement .get_direction() 2018-09-10 08:48:51 +02:00
gpio-twl6040.c gpio: twl6040: Implement .get_direction() 2018-09-10 08:49:22 +02:00
gpio-ucb1400.c
gpio-uniphier.c This is the bulk of GPIO changes for the v4.19 kernel cycle: 2018-08-15 21:35:38 -07:00
gpio-vf610.c gpio: vf610: Cut down on boilerplate 2018-09-12 14:48:40 +02:00
gpio-viperboard.c
gpio-vr41xx.c gpio: vr41xx: Bail out on gpiochip_lock_as_irq() error 2018-08-06 23:46:55 +02:00
gpio-vx855.c pinctrl / gpio: Introduce .set_config() callback for GPIO chips 2017-01-26 15:27:37 +01:00
gpio-wcove.c gpio: Move irqdomain into struct gpio_irq_chip 2017-11-08 14:06:21 +01:00
gpio-winbond.c gpio: winbond: Add driver 2018-01-09 14:51:00 +01:00
gpio-wm831x.c gpio-wm831x: Use seq_putc() in wm831x_gpio_dbg_show() 2018-02-12 09:36:06 +01:00
gpio-wm8350.c gpio: constify gpio_chip structures 2016-09-13 10:35:56 +02:00
gpio-wm8994.c pinctrl / gpio: Introduce .set_config() callback for GPIO chips 2017-01-26 15:27:37 +01:00
gpio-ws16c48.c gpio: ws16c48: Implement get_multiple callback 2018-03-26 10:28:19 +02:00
gpio-xgene-sb.c gpio: xgene-sb: Don't shadow error code of gpiochip_lock_as_irq() 2018-08-06 23:46:55 +02:00
gpio-xgene.c gpio: xgene: mark PM functions as __maybe_unused 2017-03-06 14:35:22 +01:00
gpio-xilinx.c gpio: xilinx: Use the right include 2018-08-10 23:19:17 +02:00
gpio-xlp.c gpio: xlp: Use of_device_get_match_data() 2018-05-16 14:35:24 +02:00
gpio-xra1403.c gpio: xra1403: Switch to a fixed upper bound for registers 2018-04-27 01:06:21 +02:00
gpio-xtensa.c
gpio-zevio.c gpio: zevio: Include the right header 2018-09-04 08:22:47 +02:00
gpio-zx.c gpio: Move irqdomain into struct gpio_irq_chip 2017-11-08 14:06:21 +01:00
gpio-zynq.c gpio: zynq: Setup chip->base based on alias ID 2018-05-23 11:43:03 +02:00
gpiolib-acpi.c ACPI updates for 4.19-rc1 2018-08-14 13:39:52 -07:00
gpiolib-devprop.c gpio: fix "gpio-line-names" property retrieval 2017-12-22 15:24:31 +01:00
gpiolib-legacy.c Revert "gpiolib: Split GPIO flags parsing and GPIO configuration" 2016-07-04 16:51:29 +02:00
gpiolib-of.c gpio: of: Handle SPI chipselect legacy bindings 2018-09-11 13:54:41 +02:00
gpiolib-sysfs.c gpio: sysfs: avoid using kstrtol() in 'value' attribute write 2017-12-20 10:34:58 +01:00
gpiolib.c gpiolib: Don't support irq sharing for userspace 2018-09-13 10:58:38 +02:00
gpiolib.h gpiolib: add flag to indicate if the irq is disabled 2018-09-10 08:56:11 +02:00
Kconfig Merge branch 'ib-ingenic' of ../linux-pinctrl into devel 2018-08-29 14:10:57 +02:00
Makefile gpio: ingenic: Remove driver 2018-08-29 13:38:20 +02:00