gpio: sysfs: clean up interrupt-interface implementation

Store the value sysfs entry in the gpiod data rather than in a global
table accessed through an index stored in the overloaded gpio-descriptor
flag field.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 0bc959f..bccba40 100644 (file)
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -12,11 +12,9 @@
 
 struct gpiod_data {
        struct gpio_desc *desc;
+       struct kernfs_node *value_kn;
 };
 
-static DEFINE_IDR(dirent_idr);
-
-
 /* lock protects against unexport_gpio() being called while
  * sysfs files are active.
  */
@@ -127,9 +125,10 @@ static DEVICE_ATTR_RW(value);
 
 static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
 {
-       struct kernfs_node      *value_sd = priv;
+       struct gpiod_data *data = priv;
+
+       sysfs_notify_dirent(data->value_kn);
 
-       sysfs_notify_dirent(value_sd);
        return IRQ_HANDLED;
 }
 
@@ -137,9 +136,8 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
 {
        struct gpiod_data       *data = dev_get_drvdata(dev);
        struct gpio_desc        *desc = data->desc;
-       struct kernfs_node      *value_sd;
        unsigned long           irq_flags;
-       int                     ret, irq, id;
+       int                     ret, irq;
 
        if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
                return 0;
@@ -148,17 +146,15 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
        if (irq < 0)
                return -EIO;
 
-       id = desc->flags >> ID_SHIFT;
-       value_sd = idr_find(&dirent_idr, id);
-       if (value_sd)
-               free_irq(irq, value_sd);
+       if (data->value_kn)
+               free_irq(irq, data);
 
        desc->flags &= ~GPIO_TRIGGER_MASK;
 
        if (!gpio_flags) {
                gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
                ret = 0;
-               goto free_id;
+               goto free_kn;
        }
 
        irq_flags = IRQF_SHARED;
@@ -169,25 +165,12 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
                irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
                        IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
 
-       if (!value_sd) {
-               value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
-               if (!value_sd) {
+       if (!data->value_kn) {
+               data->value_kn = sysfs_get_dirent(dev->kobj.sd, "value");
+               if (!data->value_kn) {
                        ret = -ENODEV;
                        goto err_out;
                }
-
-               ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
-               if (ret < 0)
-                       goto free_sd;
-               id = ret;
-
-               desc->flags &= GPIO_FLAGS_MASK;
-               desc->flags |= (unsigned long)id << ID_SHIFT;
-
-               if (desc->flags >> ID_SHIFT != id) {
-                       ret = -ERANGE;
-                       goto free_id;
-               }
        }
 
        /*
@@ -200,10 +183,10 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
         */
        ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
        if (ret < 0)
-               goto free_id;
+               goto free_kn;
 
        ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
-                               "gpiolib", value_sd);
+                               "gpiolib", data);
        if (ret < 0)
                goto err_unlock;
 
@@ -212,12 +195,11 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
 
 err_unlock:
        gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
-free_id:
-       idr_remove(&dirent_idr, id);
-       desc->flags &= GPIO_FLAGS_MASK;
-free_sd:
-       if (value_sd)
-               sysfs_put(value_sd);
+free_kn:
+       if (data->value_kn) {
+               sysfs_put(data->value_kn);
+               data->value_kn = NULL;
+       }
 err_out:
        return ret;
 }

diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index ea72f65..5c4f270 100644 (file)
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -92,9 +92,6 @@ struct gpio_desc {
 #define FLAG_SYSFS_DIR 10      /* show sysfs direction attribute */
 #define FLAG_IS_HOGGED 11      /* GPIO is hogged */
 
-#define ID_SHIFT       16      /* add new flags before this one */
-
-#define GPIO_FLAGS_MASK                ((1 << ID_SHIFT) - 1)
 #define GPIO_TRIGGER_MASK      (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
 
        const char              *label;