From dd537b547de5461ae7fc2064e5037404bcb12f9c Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 24 Apr 2018 14:42:27 +0100 Subject: [PATCH] gpiolib: Don't prevent IRQ usage of output GPIOs Upstream Linux deems using output GPIOs to generate IRQs as a bogus use case, even though the BCM2835 GPIO controller is capable of doing so. A number of users would like to make use of this facility, so disable the checks. See: https://github.com/raspberrypi/linux/issues/2527 Signed-off-by: Phil Elwell --- drivers/gpio/gpiolib.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -52,6 +52,8 @@ #define extra_checks 0 #endif +#define dont_test_bit(b,d) (0) + /* Device and char device-related information */ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; @@ -2408,8 +2410,8 @@ int gpiod_direction_output(struct gpio_d value = !!value; /* GPIOs used for enabled IRQs shall not be set as output */ - if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) && - test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) { + if (dont_test_bit(FLAG_USED_AS_IRQ, &desc->flags) && + dont_test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) { gpiod_err(desc, "%s: tried to set a GPIO tied to an IRQ as output\n", __func__); @@ -3226,8 +3228,8 @@ int gpiochip_lock_as_irq(struct gpio_chi } /* To be valid for IRQ the line needs to be input or open drain */ - if (test_bit(FLAG_IS_OUT, &desc->flags) && - !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { + if (dont_test_bit(FLAG_IS_OUT, &desc->flags) && + !dont_test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { chip_err(gc, "%s: tried to flag a GPIO set as output for IRQ\n", __func__);