[PATCH 3/4] Driver core: add "driver" default attribute

From: Dmitry Torokhov
Date: Tue Oct 12 2004 - 01:46:29 EST

#### AUTHOR dtor_core@xxxxxxxxxxxxx
#### COMMENT START
### Comments for ChangeSet
Driver core: add "driver" default device attribute that produces
name of the driver currently bound to the device and
allows execution of bus-specific actions for device
and driver via bus->rebind_helper()

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
### Comments for drivers/base/interface.c
Add "driver" default device attribute.
### Comments for include/linux/device.h
Add rebind_helper method to bus_type structure.
### Comments for drivers/input/serio/serio.c
Do not create "driver": attribute as driver core will create it for us;
install serio_rebind_driver as serio_bus's rebind_helper.
#### COMMENT END

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/10/11 00:39:53-05:00 dtor_core@xxxxxxxxxxxxx
# Driver core: add "driver" default device attribute that produces
# name of the driver currently bound to the device and
# allows execution of bus-specific actions for device
# and driver via bus->rebind_helper()
#
# Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
#
# include/linux/device.h
# 2004/10/11 00:39:34-05:00 dtor_core@xxxxxxxxxxxxx +2 -1
# Add rebind_helper method to bus_type structure.
#
# drivers/input/serio/serio.c
# 2004/10/11 00:39:34-05:00 dtor_core@xxxxxxxxxxxxx +31 -36
# Do not create "driver": attribute as driver core will create it for us;
# install serio_rebind_driver as serio_bus's rebind_helper.
#
# drivers/base/interface.c
# 2004/10/11 00:39:33-05:00 dtor_core@xxxxxxxxxxxxx +30 -1
# Add "driver" default device attribute.
#
diff -Nru a/drivers/base/interface.c b/drivers/base/interface.c
--- a/drivers/base/interface.c 2004-10-12 01:29:06 -05:00
+++ b/drivers/base/interface.c 2004-10-12 01:29:06 -05:00
@@ -42,10 +42,39 @@
return n;
}

-static DEVICE_ATTR(detach_state, 0644, detach_show, detach_store);
+/**
+ * driver - controls device and driver binding.
+ *
+ * Reading from the attribute gives name of driver that is bound to
+ * the device or "(none)". Result of writing to the attribute depends
+ * on the bus's rebind_helper implementation and can cause device to
+ * be disconnected or be rebound to a specific driver.
+ */
+
+static ssize_t driver_show(struct device * dev, char * buf)
+{
+ return sprintf(buf, "%s\n", dev->driver ? dev->driver->name : "(none)");
+}
+
+static ssize_t driver_store(struct device * dev, const char * buf, size_t count)
+{
+ int retval = -ENOSYS;
+
+ if (dev->bus->rebind_helper)
+ retval = dev->bus->rebind_helper(dev, buf, count);

+ if (retval < 0)
+ return retval;
+
+ return count;
+}
+
+
+static DEVICE_ATTR(detach_state, 0644, detach_show, detach_store);
+static DEVICE_ATTR(driver, 0644, driver_show, driver_store);

struct attribute * dev_default_attrs[] = {
&dev_attr_detach_state.attr,
+ &dev_attr_driver.attr,
NULL,
};
diff -Nru a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
--- a/drivers/input/serio/serio.c 2004-10-12 01:29:06 -05:00
+++ b/drivers/input/serio/serio.c 2004-10-12 01:29:06 -05:00
@@ -246,41 +246,6 @@
return sprintf(buf, "%s\n", serio->name);
}

-static ssize_t serio_show_driver(struct device *dev, char *buf)
-{
- return sprintf(buf, "%s\n", dev->driver ? dev->driver->name : "(none)");
-}
-
-static ssize_t serio_rebind_driver(struct device *dev, const char *buf, size_t count)
-{
- struct serio *serio = to_serio_port(dev);
- struct device_driver *drv;
- int retval;
-
- retval = down_interruptible(&serio_sem);
- if (retval)
- return retval;
-
- retval = count;
- if (!strncmp(buf, "none", count)) {
- serio_disconnect_port(serio);
- } else if (!strncmp(buf, "reconnect", count)) {
- serio_reconnect_port(serio);
- } else if (!strncmp(buf, "rescan", count)) {
- serio_disconnect_port(serio);
- serio_connect_port(serio, NULL);
- } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
- serio_disconnect_port(serio);
- serio_connect_port(serio, to_serio_driver(drv));
- put_driver(drv);
- } else {
- retval = -EINVAL;
- }
-
- up(&serio_sem);
-
- return retval;
-}

static ssize_t serio_show_bind_mode(struct device *dev, char *buf)
{
@@ -307,7 +272,6 @@

static struct device_attribute serio_device_attrs[] = {
__ATTR(description, S_IRUGO, serio_show_description, NULL),
- __ATTR(driver, S_IWUSR | S_IRUGO, serio_show_driver, serio_rebind_driver),
__ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
__ATTR_NULL
};
@@ -596,6 +560,36 @@
up(&serio_sem);
}

+static int serio_rebind_driver(struct device *dev, const char *buf, size_t count)
+{
+ struct serio *serio = to_serio_port(dev);
+ struct device_driver *drv;
+ int retval;
+
+ retval = down_interruptible(&serio_sem);
+ if (retval)
+ return retval;
+
+ if (!strncmp(buf, "none", count)) {
+ serio_disconnect_port(serio);
+ } else if (!strncmp(buf, "reconnect", count)) {
+ serio_reconnect_port(serio);
+ } else if (!strncmp(buf, "rescan", count)) {
+ serio_disconnect_port(serio);
+ serio_connect_port(serio, NULL);
+ } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
+ serio_disconnect_port(serio);
+ serio_connect_port(serio, to_serio_driver(drv));
+ put_driver(drv);
+ } else {
+ retval = -EINVAL;
+ }
+
+ up(&serio_sem);
+
+ return retval;
+}
+
static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
{
down(&serio->drv_sem);
@@ -660,6 +654,7 @@

serio_bus.dev_attrs = serio_device_attrs;
serio_bus.drv_attrs = serio_driver_attrs;
+ serio_bus.rebind_helper = serio_rebind_driver;
bus_register(&serio_bus);

return 0;
diff -Nru a/include/linux/device.h b/include/linux/device.h
--- a/include/linux/device.h 2004-10-12 01:29:06 -05:00
+++ b/include/linux/device.h 2004-10-12 01:29:06 -05:00
@@ -59,7 +59,8 @@
struct driver_attribute * drv_attrs;

int (*match)(struct device * dev, struct device_driver * drv);
- int (*hotplug) (struct device *dev, char **envp,
+ int (*rebind_helper)(struct device * dev, const char * buf, size_t count);
+ int (*hotplug) (struct device *dev, char **envp,
int num_envp, char *buffer, int buffer_size);
int (*suspend)(struct device * dev, u32 state);
int (*resume)(struct device * dev);
-
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