Add an attribute 'wakeup' to the GPIO sysfs interface which allows
marking/unmarking a GPIO as wake IRQ.
The file 'wakeup' is created in each exported GPIOs directory, if an IRQ
is associated with that GPIO and the irqchip implements set_wake().
Writing 'enabled' to that file will enable wake for that GPIO, while
writing 'disabled' will disable wake.
Reading that file will return either 'disabled' or 'enabled' depening on
the currently set flag for the GPIO's IRQ.
Signed-off-by: Soren Brinkmann <soren.brinkm...@xilinx.com>
Reviewed-by: Alexandre Courbot <acour...@nvidia.com>
---
v2:
- fix error path to unlock mutex before return
---
drivers/gpio/gpiolib-sysfs.c | 77 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 71 insertions(+), 6 deletions(-)
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 5f2150b619a7..7588b6d5ba94 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -286,6 +286,58 @@ found:
static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
+static ssize_t gpio_wakeup_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t status;
+ const struct gpio_desc *desc = dev_get_drvdata(dev);
+ int irq = gpiod_to_irq(desc);
+ struct irq_desc *irq_desc = irq_to_desc(irq);
+
+ mutex_lock(&sysfs_lock);
+
+ if (irqd_is_wakeup_set(&irq_desc->irq_data))
+ status = sprintf(buf, "enabled\n");
+ else
+ status = sprintf(buf, "disabled\n");
+
+ mutex_unlock(&sysfs_lock);
+
+ return status;
+}
+
+static ssize_t gpio_wakeup_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ int ret;
+ unsigned int on;
+ struct gpio_desc *desc = dev_get_drvdata(dev);
+ int irq = gpiod_to_irq(desc);
+
+ mutex_lock(&sysfs_lock);
+
+ if (sysfs_streq("enabled", buf)) {
+ on = true;
+ } else if (sysfs_streq("disabled", buf)) {
+ on = false;
+ } else {
+ mutex_unlock(&sysfs_lock);
+ return -EINVAL;
+ }
+
+ ret = irq_set_irq_wake(irq, on);
+
+ mutex_unlock(&sysfs_lock);
+
+ if (ret)
+ pr_warn("%s: failed to %s wake\n", __func__,
+ on ? "enable" : "disable");
+
+ return size;
+}
+
+static DEVICE_ATTR(wakeup, 0644, gpio_wakeup_show, gpio_wakeup_store);
+
static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
int value)
{
@@ -526,7 +578,7 @@ static struct class gpio_class = {
int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
{
unsigned long flags;
- int status;
+ int status, irq;
const char *ioname = NULL;
struct device *dev;
int offset;
@@ -582,11 +634,24 @@ int gpiod_export(struct gpio_desc *desc, bool
direction_may_change)
goto fail_unregister_device;
}
- if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
- !test_bit(FLAG_IS_OUT, &desc->flags))) {
- status = device_create_file(dev, &dev_attr_edge);
- if (status)
- goto fail_unregister_device;
+ irq = gpiod_to_irq(desc);
+ if (irq >= 0) {
+ struct irq_desc *irq_desc = irq_to_desc(irq);
+ struct irq_chip *irqchip = irq_desc_get_chip(irq_desc);
+
+ if (direction_may_change ||
+ !test_bit(FLAG_IS_OUT, &desc->flags)) {
+ status = device_create_file(dev, &dev_attr_edge);
+ if (status)
+ goto fail_unregister_device;
+ }
+
+ if (irqchip->flags & IRQCHIP_SKIP_SET_WAKE ||
+ irqchip->irq_set_wake) {
+ status = device_create_file(dev, &dev_attr_wakeup);
+ if (status)
+ goto fail_unregister_device;
+ }
}
set_bit(FLAG_EXPORT, &desc->flags);
--
2.1.2.1.g5e69ed6
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
