From cef1717b7ff9ad7de747aedb5d222936913570fd Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 4 May 2015 17:10:48 +0200 Subject: [PATCH] gpio: sysfs: move irq trigger flags to class-device data Move irq trigger flags, which as sysfs-interface specific, to the class device data. This avoids accessing the gpio-descriptor flags field using non-atomic operations without any locking, and allows for a more clear separation of the sysfs interface from gpiolib core. Signed-off-by: Johan Hovold Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-sysfs.c | 47 ++++++++++++++++++------------------ drivers/gpio/gpiolib.h | 4 --- 2 files changed, 24 insertions(+), 27 deletions(-) diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 9047b2d556a0..b57ed8e55ab5 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -10,12 +10,18 @@ #include "gpiolib.h" +#define GPIO_IRQF_TRIGGER_FALLING BIT(0) +#define GPIO_IRQF_TRIGGER_RISING BIT(1) +#define GPIO_IRQF_TRIGGER_BOTH (GPIO_IRQF_TRIGGER_FALLING | \ + GPIO_IRQF_TRIGGER_RISING) + struct gpiod_data { struct gpio_desc *desc; struct mutex mutex; struct kernfs_node *value_kn; int irq; + unsigned char irq_flags; bool direction_can_change; }; @@ -143,7 +149,7 @@ static irqreturn_t gpio_sysfs_irq(int irq, void *priv) } /* Caller holds gpiod-data mutex. */ -static int gpio_sysfs_request_irq(struct device *dev, unsigned long gpio_flags) +static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags) { struct gpiod_data *data = dev_get_drvdata(dev); struct gpio_desc *desc = data->desc; @@ -159,10 +165,10 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned long gpio_flags) return -ENODEV; irq_flags = IRQF_SHARED; - if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) + if (flags & GPIO_IRQF_TRIGGER_FALLING) irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; - if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) + if (flags & GPIO_IRQF_TRIGGER_RISING) irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; @@ -183,7 +189,7 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned long gpio_flags) if (ret < 0) goto err_unlock; - desc->flags |= gpio_flags; + data->irq_flags = flags; return 0; @@ -204,7 +210,7 @@ static void gpio_sysfs_free_irq(struct device *dev) struct gpiod_data *data = dev_get_drvdata(dev); struct gpio_desc *desc = data->desc; - desc->flags &= ~GPIO_TRIGGER_MASK; + data->irq_flags = 0; free_irq(data->irq, data); gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc)); sysfs_put(data->value_kn); @@ -212,28 +218,25 @@ static void gpio_sysfs_free_irq(struct device *dev) static const struct { const char *name; - unsigned long flags; + unsigned char flags; } trigger_types[] = { { "none", 0 }, - { "falling", BIT(FLAG_TRIG_FALL) }, - { "rising", BIT(FLAG_TRIG_RISE) }, - { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, + { "falling", GPIO_IRQF_TRIGGER_FALLING }, + { "rising", GPIO_IRQF_TRIGGER_RISING }, + { "both", GPIO_IRQF_TRIGGER_BOTH }, }; static ssize_t edge_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gpiod_data *data = dev_get_drvdata(dev); - struct gpio_desc *desc = data->desc; - unsigned long mask; ssize_t status = 0; int i; mutex_lock(&data->mutex); for (i = 0; i < ARRAY_SIZE(trigger_types); i++) { - mask = desc->flags & GPIO_TRIGGER_MASK; - if (mask == trigger_types[i].flags) { + if (data->irq_flags == trigger_types[i].flags) { status = sprintf(buf, "%s\n", trigger_types[i].name); break; } @@ -248,8 +251,7 @@ static ssize_t edge_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct gpiod_data *data = dev_get_drvdata(dev); - struct gpio_desc *desc = data->desc; - unsigned long flags; + unsigned char flags; ssize_t status = size; int i; @@ -265,12 +267,12 @@ static ssize_t edge_store(struct device *dev, mutex_lock(&data->mutex); - if ((desc->flags & GPIO_TRIGGER_MASK) == flags) { + if (flags == data->irq_flags) { status = size; goto out_unlock; } - if (desc->flags & GPIO_TRIGGER_MASK) + if (data->irq_flags) gpio_sysfs_free_irq(dev); if (flags) { @@ -292,6 +294,7 @@ static int gpio_sysfs_set_active_low(struct device *dev, int value) struct gpiod_data *data = dev_get_drvdata(dev); struct gpio_desc *desc = data->desc; int status = 0; + unsigned int flags = data->irq_flags; if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) return 0; @@ -302,12 +305,10 @@ static int gpio_sysfs_set_active_low(struct device *dev, int value) clear_bit(FLAG_ACTIVE_LOW, &desc->flags); /* reconfigure poll(2) support if enabled on one edge only */ - if (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ - !!test_bit(FLAG_TRIG_FALL, &desc->flags)) { - unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; - + if (flags == GPIO_IRQF_TRIGGER_FALLING || + flags == GPIO_IRQF_TRIGGER_RISING) { gpio_sysfs_free_irq(dev); - status = gpio_sysfs_request_irq(dev, trigger_flags); + status = gpio_sysfs_request_irq(dev, flags); } return status; @@ -700,7 +701,7 @@ void gpiod_unexport(struct gpio_desc *desc) /* * Release irq after deregistration to prevent race with edge_store. */ - if (desc->flags & GPIO_TRIGGER_MASK) + if (data->irq_flags) gpio_sysfs_free_irq(dev); mutex_unlock(&sysfs_lock); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 479041f8d381..bf343004b008 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -83,16 +83,12 @@ struct gpio_desc { #define FLAG_IS_OUT 1 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ -#define FLAG_TRIG_FALL 4 /* trigger on falling edge */ -#define FLAG_TRIG_RISE 5 /* trigger on rising edge */ #define FLAG_ACTIVE_LOW 6 /* value has active low */ #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ -#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) - const char *label; }; -- 2.20.1