From 223ecaf140b1dd1c1d2a1a1d96281efc5c906984 Mon Sep 17 00:00:00 2001 From: Michael Wu Date: Mon, 8 Jul 2019 13:23:08 +0800 Subject: [PATCH 1/3] gpiolib: fix incorrect IRQ requesting of an active-low lineevent When a pin is active-low, logical trigger edge should be inverted to match the same interrupt opportunity. For example, a button pushed triggers falling edge in ACTIVE_HIGH case; in ACTIVE_LOW case, the button pushed triggers rising edge. For user space the IRQ requesting doesn't need to do any modification except to configuring GPIOHANDLE_REQUEST_ACTIVE_LOW. For example, we want to catch the event when the button is pushed. The button on the original board drives level to be low when it is pushed, and drives level to be high when it is released. In user space we can do: req.handleflags = GPIOHANDLE_REQUEST_INPUT; req.eventflags = GPIOEVENT_REQUEST_FALLING_EDGE; while (1) { read(fd, &dat, sizeof(dat)); if (dat.id == GPIOEVENT_EVENT_FALLING_EDGE) printf("button pushed\n"); } Run the same logic on another board which the polarity of the button is inverted; it drives level to be high when pushed, and level to be low when released. For this inversion we add flag GPIOHANDLE_REQUEST_ACTIVE_LOW: req.handleflags = GPIOHANDLE_REQUEST_INPUT | GPIOHANDLE_REQUEST_ACTIVE_LOW; req.eventflags = GPIOEVENT_REQUEST_FALLING_EDGE; At the result, there are no any events caught when the button is pushed. By the way, button releasing will emit a "falling" event. The timing of "falling" catching is not expected. Cc: stable@vger.kernel.org Signed-off-by: Michael Wu Tested-by: Bartosz Golaszewski Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 3ee99d070608..bf05c29b53be 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -956,9 +956,11 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) } if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) - irqflags |= IRQF_TRIGGER_RISING; + irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) - irqflags |= IRQF_TRIGGER_FALLING; + irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; irqflags |= IRQF_ONESHOT; INIT_KFIFO(le->events); From ffe0bbabb0cffceceae07484fde1ec2a63b1537c Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 8 Jul 2019 10:23:43 +0200 Subject: [PATCH 2/3] gpio: don't WARN() on NULL descs if gpiolib is disabled If gpiolib is disabled, we use the inline stubs from gpio/consumer.h instead of regular definitions of GPIO API. The stubs for 'optional' variants of gpiod_get routines return NULL in this case as if the relevant GPIO wasn't found. This is correct so far. Calling other (non-gpio_get) stubs from this header triggers a warning because the GPIO descriptor couldn't have been requested. The warning however is unconditional (WARN_ON(1)) and is emitted even if the passed descriptor pointer is NULL. We don't want to force the users of 'optional' gpio_get to check the returned pointer before calling e.g. gpiod_set_value() so let's only WARN on non-NULL descriptors. Cc: stable@vger.kernel.org Reported-by: Claus H. Stovgaard Signed-off-by: Bartosz Golaszewski --- include/linux/gpio/consumer.h | 64 +++++++++++++++++------------------ 1 file changed, 32 insertions(+), 32 deletions(-) diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 9ddcf50a3c59..a7f08fb0f865 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -247,7 +247,7 @@ static inline void gpiod_put(struct gpio_desc *desc) might_sleep(); /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline void devm_gpiod_unhinge(struct device *dev, @@ -256,7 +256,7 @@ static inline void devm_gpiod_unhinge(struct device *dev, might_sleep(); /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline void gpiod_put_array(struct gpio_descs *descs) @@ -264,7 +264,7 @@ static inline void gpiod_put_array(struct gpio_descs *descs) might_sleep(); /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(descs); } static inline struct gpio_desc *__must_check @@ -317,7 +317,7 @@ static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) might_sleep(); /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline void devm_gpiod_put_array(struct device *dev, @@ -326,32 +326,32 @@ static inline void devm_gpiod_put_array(struct device *dev, might_sleep(); /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(descs); } static inline int gpiod_get_direction(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } static inline int gpiod_direction_input(struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } static inline int gpiod_direction_output(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } @@ -359,7 +359,7 @@ static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value) static inline int gpiod_get_value(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_get_array_value(unsigned int array_size, @@ -368,13 +368,13 @@ static inline int gpiod_get_array_value(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline void gpiod_set_value(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline int gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -382,13 +382,13 @@ static inline int gpiod_set_array_value(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline int gpiod_get_raw_value(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_get_raw_array_value(unsigned int array_size, @@ -397,13 +397,13 @@ static inline int gpiod_get_raw_array_value(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline int gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -411,14 +411,14 @@ static inline int gpiod_set_raw_array_value(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_get_array_value_cansleep(unsigned int array_size, @@ -427,13 +427,13 @@ static inline int gpiod_get_array_value_cansleep(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline int gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -441,13 +441,13 @@ static inline int gpiod_set_array_value_cansleep(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_get_raw_array_value_cansleep(unsigned int array_size, @@ -456,14 +456,14 @@ static inline int gpiod_get_raw_array_value_cansleep(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); } static inline int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -471,41 +471,41 @@ static inline int gpiod_set_raw_array_value_cansleep(unsigned int array_size, unsigned long *value_bitmap) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc_array); return 0; } static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } static inline int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -ENOSYS; } static inline int gpiod_is_active_low(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_cansleep(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return 0; } static inline int gpiod_to_irq(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -EINVAL; } @@ -513,7 +513,7 @@ static inline int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -EINVAL; } @@ -525,7 +525,7 @@ static inline struct gpio_desc *gpio_to_desc(unsigned gpio) static inline int desc_to_gpio(const struct gpio_desc *desc) { /* GPIO can never have been requested */ - WARN_ON(1); + WARN_ON(desc); return -EINVAL; } From d95da993383c78f7efd25957ba3af23af4b1c613 Mon Sep 17 00:00:00 2001 From: Chris Packham Date: Mon, 8 Jul 2019 08:35:58 +1200 Subject: [PATCH 3/3] gpiolib: Preserve desc->flags when setting state desc->flags may already have values set by of_gpiochip_add() so make sure that this isn't undone when setting the initial direction. Cc: stable@vger.kernel.org Fixes: 3edfb7bd76bd1cba ("gpiolib: Show correct direction from the beginning") Signed-off-by: Chris Packham Link: https://lore.kernel.org/r/20190707203558.10993-1-chris.packham@alliedtelesis.co.nz Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index bf05c29b53be..f497003f119c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1394,12 +1394,17 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, for (i = 0; i < chip->ngpio; i++) { struct gpio_desc *desc = &gdev->descs[i]; - if (chip->get_direction && gpiochip_line_is_valid(chip, i)) - desc->flags = !chip->get_direction(chip, i) ? - (1 << FLAG_IS_OUT) : 0; - else - desc->flags = !chip->direction_input ? - (1 << FLAG_IS_OUT) : 0; + if (chip->get_direction && gpiochip_line_is_valid(chip, i)) { + if (!chip->get_direction(chip, i)) + set_bit(FLAG_IS_OUT, &desc->flags); + else + clear_bit(FLAG_IS_OUT, &desc->flags); + } else { + if (!chip->direction_input) + set_bit(FLAG_IS_OUT, &desc->flags); + else + clear_bit(FLAG_IS_OUT, &desc->flags); + } } acpi_gpiochip_add(chip);