[PATCH 4/6 v13] gpiolib: Fix default attributes for class
There is a race condition between creating a gpio or gpiochip device and adding
default attributes. This patch fixes this by defining the default attributes as
dev_attrs of the class. For this, it was necessary to create a separate
gpiochip_class besides gpio_class.
Signed-off-by: Roland Stigge
---
Documentation/ABI/testing/sysfs-gpio | 11
drivers/gpio/gpiolib.c | 78 ++-
2 files changed, 44 insertions(+), 45 deletions(-)
--- linux-2.6.orig/Documentation/ABI/testing/sysfs-gpio
+++ linux-2.6/Documentation/ABI/testing/sysfs-gpio
@@ -20,6 +20,17 @@ Description:
/value ... always readable, writes fail for input GPIOs
/direction ... r/w as: in, out (default low); write: high, low
/edge ... r/w as: none, falling, rising, both
+
+What: /sys/class/gpiochip/
+Date: October 2012
+KernelVersion: 3.7
+Contact: Roland Stigge
+Description:
+
+ Each gpiochip is represented by a separate device having the following
+ attributes:
+
+/sys/class/gpiochip
/gpiochipN ... for each gpiochip; #N is its first GPIO
/base ... (r/o) same as N
/label ... (r/o) descriptive, not necessarily unique
--- linux-2.6.orig/drivers/gpio/gpiolib.c
+++ linux-2.6/drivers/gpio/gpiolib.c
@@ -362,9 +362,6 @@ static ssize_t gpio_value_store(struct d
return status;
}
-static const DEVICE_ATTR(value, 0644,
- gpio_value_show, gpio_value_store);
-
static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
{
struct sysfs_dirent *value_sd = priv;
@@ -585,19 +582,6 @@ static ssize_t gpio_active_low_store(str
return status ? : size;
}
-static const DEVICE_ATTR(active_low, 0644,
- gpio_active_low_show, gpio_active_low_store);
-
-static const struct attribute *gpio_attrs[] = {
- _attr_value.attr,
- _attr_active_low.attr,
- NULL,
-};
-
-static const struct attribute_group gpio_attr_group = {
- .attrs = (struct attribute **) gpio_attrs,
-};
-
/*
* /sys/class/gpio/gpiochipN/
* /base ... matching gpio_chip.base (N)
@@ -612,7 +596,6 @@ static ssize_t chip_base_show(struct dev
return sprintf(buf, "%d\n", chip->base);
}
-static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
static ssize_t chip_label_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -621,7 +604,6 @@ static ssize_t chip_label_show(struct de
return sprintf(buf, "%s\n", chip->label ? : "");
}
-static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
static ssize_t chip_ngpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -630,18 +612,6 @@ static ssize_t chip_ngpio_show(struct de
return sprintf(buf, "%u\n", chip->ngpio);
}
-static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
-
-static const struct attribute *gpiochip_attrs[] = {
- _attr_base.attr,
- _attr_label.attr,
- _attr_ngpio.attr,
- NULL,
-};
-
-static const struct attribute_group gpiochip_attr_group = {
- .attrs = (struct attribute **) gpiochip_attrs,
-};
/*
* /sys/class/gpio/export ... write-only
@@ -720,11 +690,32 @@ static struct class_attribute gpio_class
__ATTR_NULL,
};
+static struct device_attribute gpio_attrs[] = {
+ __ATTR(active_low, 0644, gpio_active_low_show, gpio_active_low_store),
+ __ATTR(value, 0644, gpio_value_show, gpio_value_store),
+ __ATTR_NULL,
+};
+
static struct class gpio_class = {
.name = "gpio",
.owner =THIS_MODULE,
- .class_attrs = gpio_class_attrs,
+ .class_attrs = gpio_class_attrs,
+ .dev_attrs = gpio_attrs,
+};
+
+static struct device_attribute gpiochip_attrs[] = {
+ __ATTR(label, 0444, chip_label_show, NULL),
+ __ATTR(base, 0444, chip_base_show, NULL),
+ __ATTR(ngpio, 0444, chip_ngpio_show, NULL),
+ __ATTR_NULL,
+};
+
+static struct class gpiochip_class = {
+ .name = "gpiochip",
+ .owner =THIS_MODULE,
+
+ .dev_attrs =gpiochip_attrs,
};
@@ -791,10 +782,6 @@ int gpio_export(unsigned gpio, bool dire
goto fail_unlock;
}
- status = sysfs_create_group(>kobj, _attr_group);
- if (status)
- goto fail_unregister_device;
-
if (direction_may_change) {
status = device_create_file(dev, _attr_direction);
if (status)
@@ -962,25 +949,22 @@ EXPORT_SYMBOL_GPL(gpio_unexport);
static int gpiochip_export(struct gpio_chip *chip)
{
- int status;
+ int status = 0;
struct device *dev;
/* Many systems register gpio chips for SOC support very early,
* before driver model support is available. In those cases we
* export this later, in gpiolib_sysfs_init() ... here we just
-* verify that _some_ field
[PATCH 4/6 v13] gpiolib: Fix default attributes for class
There is a race condition between creating a gpio or gpiochip device and adding
default attributes. This patch fixes this by defining the default attributes as
dev_attrs of the class. For this, it was necessary to create a separate
gpiochip_class besides gpio_class.
Signed-off-by: Roland Stigge sti...@antcom.de
---
Documentation/ABI/testing/sysfs-gpio | 11
drivers/gpio/gpiolib.c | 78 ++-
2 files changed, 44 insertions(+), 45 deletions(-)
--- linux-2.6.orig/Documentation/ABI/testing/sysfs-gpio
+++ linux-2.6/Documentation/ABI/testing/sysfs-gpio
@@ -20,6 +20,17 @@ Description:
/value ... always readable, writes fail for input GPIOs
/direction ... r/w as: in, out (default low); write: high, low
/edge ... r/w as: none, falling, rising, both
+
+What: /sys/class/gpiochip/
+Date: October 2012
+KernelVersion: 3.7
+Contact: Roland Stigge sti...@antcom.de
+Description:
+
+ Each gpiochip is represented by a separate device having the following
+ attributes:
+
+/sys/class/gpiochip
/gpiochipN ... for each gpiochip; #N is its first GPIO
/base ... (r/o) same as N
/label ... (r/o) descriptive, not necessarily unique
--- linux-2.6.orig/drivers/gpio/gpiolib.c
+++ linux-2.6/drivers/gpio/gpiolib.c
@@ -362,9 +362,6 @@ static ssize_t gpio_value_store(struct d
return status;
}
-static const DEVICE_ATTR(value, 0644,
- gpio_value_show, gpio_value_store);
-
static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
{
struct sysfs_dirent *value_sd = priv;
@@ -585,19 +582,6 @@ static ssize_t gpio_active_low_store(str
return status ? : size;
}
-static const DEVICE_ATTR(active_low, 0644,
- gpio_active_low_show, gpio_active_low_store);
-
-static const struct attribute *gpio_attrs[] = {
- dev_attr_value.attr,
- dev_attr_active_low.attr,
- NULL,
-};
-
-static const struct attribute_group gpio_attr_group = {
- .attrs = (struct attribute **) gpio_attrs,
-};
-
/*
* /sys/class/gpio/gpiochipN/
* /base ... matching gpio_chip.base (N)
@@ -612,7 +596,6 @@ static ssize_t chip_base_show(struct dev
return sprintf(buf, %d\n, chip-base);
}
-static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
static ssize_t chip_label_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -621,7 +604,6 @@ static ssize_t chip_label_show(struct de
return sprintf(buf, %s\n, chip-label ? : );
}
-static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
static ssize_t chip_ngpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -630,18 +612,6 @@ static ssize_t chip_ngpio_show(struct de
return sprintf(buf, %u\n, chip-ngpio);
}
-static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
-
-static const struct attribute *gpiochip_attrs[] = {
- dev_attr_base.attr,
- dev_attr_label.attr,
- dev_attr_ngpio.attr,
- NULL,
-};
-
-static const struct attribute_group gpiochip_attr_group = {
- .attrs = (struct attribute **) gpiochip_attrs,
-};
/*
* /sys/class/gpio/export ... write-only
@@ -720,11 +690,32 @@ static struct class_attribute gpio_class
__ATTR_NULL,
};
+static struct device_attribute gpio_attrs[] = {
+ __ATTR(active_low, 0644, gpio_active_low_show, gpio_active_low_store),
+ __ATTR(value, 0644, gpio_value_show, gpio_value_store),
+ __ATTR_NULL,
+};
+
static struct class gpio_class = {
.name = gpio,
.owner =THIS_MODULE,
- .class_attrs = gpio_class_attrs,
+ .class_attrs = gpio_class_attrs,
+ .dev_attrs = gpio_attrs,
+};
+
+static struct device_attribute gpiochip_attrs[] = {
+ __ATTR(label, 0444, chip_label_show, NULL),
+ __ATTR(base, 0444, chip_base_show, NULL),
+ __ATTR(ngpio, 0444, chip_ngpio_show, NULL),
+ __ATTR_NULL,
+};
+
+static struct class gpiochip_class = {
+ .name = gpiochip,
+ .owner =THIS_MODULE,
+
+ .dev_attrs =gpiochip_attrs,
};
@@ -791,10 +782,6 @@ int gpio_export(unsigned gpio, bool dire
goto fail_unlock;
}
- status = sysfs_create_group(dev-kobj, gpio_attr_group);
- if (status)
- goto fail_unregister_device;
-
if (direction_may_change) {
status = device_create_file(dev, dev_attr_direction);
if (status)
@@ -962,25 +949,22 @@ EXPORT_SYMBOL_GPL(gpio_unexport);
static int gpiochip_export(struct gpio_chip *chip)
{
- int status;
+ int status = 0;
struct device *dev;
/* Many systems register gpio chips for SOC support very early,
* before driver model support is available. In those cases we
* export this later, in gpiolib_sysfs_init() ... here
