From e9bdf7e655b9ee81ee912fae1d59df48ce7311b6 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 27 May 2020 16:07:58 +0200 Subject: gpio: fix locking open drain IRQ lines We provided the right semantics on open drain lines being by definition output but incidentally the irq set up function would only allow IRQs on lines that were "not output". Fix the semantics to allow output open drain lines to be used for IRQs. Reported-by: Hans Verkuil Signed-off-by: Linus Walleij Signed-off-by: Hans Verkuil Tested-by: Hans Verkuil Cc: Russell King Cc: stable@vger.kernel.org # v5.3+ Link: https://lore.kernel.org/r/20200527140758.162280-1-linus.walleij@linaro.org Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/gpio') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index b4b5792fe2ff..c14f0784274a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4220,7 +4220,9 @@ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset) } } - if (test_bit(FLAG_IS_OUT, &desc->flags)) { + /* 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)) { chip_err(gc, "%s: tried to flag a GPIO set as output for IRQ\n", __func__); @@ -4283,7 +4285,12 @@ void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset) if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) { - WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags)); + /* + * We must not be output when using IRQ UNLESS we are + * open drain. + */ + WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) && + !test_bit(FLAG_OPEN_DRAIN, &desc->flags)); set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } } -- cgit v1.2.3