This provides seperate
tty_device_initialize_attr()
and
tty_device_add_attr()
similar to device_initialize() and device_add().
Similiarly tty_port_initialize_device_attr() is added to match
tty_port_register_device_attr().
It will allow a client to separate initalization and adding of the
device.
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
drivers/tty/tty_io.c | 102 +++++++++++++++++++++++++++++++++---------------
drivers/tty/tty_port.c | 24 +++++++++++
include/linux/tty.h | 9 ++++
3 files changed, 104 insertions(+), 31 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index ccb99b772965..83ca25b9c2da 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3205,8 +3205,29 @@ static void tty_device_create_release(struct device *dev)
kfree(dev);
}
+int tty_device_add(struct tty_driver *driver, struct device *dev)
+{
+ int retval;
+ bool cdev = false;
+ int index = dev->devt - MKDEV(driver->major,
+ driver->minor_start);
+
+ if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+ retval = tty_cdev_add(driver, dev->devt, index, 1);
+ if (retval)
+ return retval;
+ cdev = true;
+ }
+ retval = device_add(dev);
+ if (retval == 0)
+ return 0;
+ if (cdev)
+ cdev_del(&driver->cdevs[index]);
+ return retval;
+}
+EXPORT_SYMBOL(tty_device_add);
/**
- * tty_register_device_attr - register a tty device
+ * tty_device_initialize_attr - initialize a tty device, but don't 'add'
* @driver: the tty driver that describes the tty device
* @index: the index in the tty driver for this tty device
* @device: a struct device that is associated with this tty device.
@@ -3218,23 +3239,19 @@ static void tty_device_create_release(struct device *dev)
* Returns a pointer to the struct device for this tty device
* (or ERR_PTR(-EFOO) on error).
*
- * This call is required to be made to register an individual tty device
- * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
- * that bit is not set, this function should not be called by a tty
- * driver.
+ * tty_device_add() must be called after this call returns successfully
+ * before the device will be full registered and available.
*
* Locking: ??
*/
-struct device *tty_register_device_attr(struct tty_driver *driver,
- unsigned index, struct device *device,
- void *drvdata,
- const struct attribute_group **attr_grp)
+struct device *tty_device_initialize_attr(struct tty_driver *driver,
+ unsigned index, struct device *device,
+ void *drvdata,
+ const struct attribute_group **attr_grp)
{
char name[64];
dev_t devt = MKDEV(driver->major, driver->minor_start) + index;
struct device *dev = NULL;
- int retval = -ENODEV;
- bool cdev = false;
if (index >= driver->num) {
printk(KERN_ERR "Attempt to register invalid tty line number "
@@ -3247,19 +3264,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver,
else
tty_line_name(driver, index, name);
- if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
- retval = tty_cdev_add(driver, devt, index, 1);
- if (retval)
- goto error;
- cdev = true;
- }
-
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
- if (!dev) {
- retval = -ENOMEM;
- goto error;
- }
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+ device_initialize(dev);
dev->devt = devt;
dev->class = tty_class;
dev->parent = device;
@@ -3268,17 +3277,48 @@ struct device *tty_register_device_attr(struct tty_driver *driver,
dev->groups = attr_grp;
dev_set_drvdata(dev, drvdata);
- retval = device_register(dev);
- if (retval)
- goto error;
-
return dev;
+}
+EXPORT_SYMBOL_GPL(tty_device_initialize_attr);
-error:
- put_device(dev);
- if (cdev)
- cdev_del(&driver->cdevs[index]);
- return ERR_PTR(retval);
+/**
+ * tty_register_device_attr - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ * This field is optional, if there is no known struct device
+ * for this tty device it can be set to NULL safely.
+ * @drvdata: Driver data to be set to device.
+ * @attr_grp: Attribute group to be set on device.
+ *
+ * Returns a pointer to the struct device for this tty device
+ * (or ERR_PTR(-EFOO) on error).
+ *
+ * This call is required to be made to register an individual tty device
+ * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
+ * that bit is not set, this function should not be called by a tty
+ * driver.
+ *
+ * Locking: ??
+ */
+struct device *tty_register_device_attr(struct tty_driver *driver,
+ unsigned index, struct device *device,
+ void *drvdata,
+ const struct attribute_group **attr_grp)
+{
+ struct device *dev;
+ int ret;
+
+ dev = tty_device_initialize_attr(driver, index, device,
+ drvdata, attr_grp);
+ if (IS_ERR(dev))
+ return dev;
+ ret = tty_device_add(driver, dev);
+ if (ret) {
+ put_device(dev);
+ return ERR_PTR(ret);
+ }
+ return dev;
}
EXPORT_SYMBOL_GPL(tty_register_device_attr);
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 40b31835f80b..f4145c0f1f45 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -97,6 +97,30 @@ struct device *tty_port_register_device_attr(struct tty_port *port,
}
EXPORT_SYMBOL_GPL(tty_port_register_device_attr);
+/**
+ * tty_port_initialize_device_attr - initialize tty device
+ * @port: tty_port of the device
+ * @driver: tty_driver for this device
+ * @index: index of the tty
+ * @device: parent if exists, otherwise NULL
+ * @drvdata: Driver data to be set to device.
+ * @attr_grp: Attribute group to be set on device.
+ *
+ * It is the same as tty_initialize_device_attr except the provided @port is
+ * linked to a concrete tty specified by @index. Use this or tty_port_install
+ * (or both). Call tty_port_link_device as a last resort.
+ */
+struct device *tty_port_initialize_device_attr(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device, void *drvdata,
+ const struct attribute_group **attr_grp)
+{
+ tty_port_link_device(port, driver, index);
+ return tty_device_initialize_attr(driver, index, device, drvdata,
+ attr_grp);
+}
+EXPORT_SYMBOL_GPL(tty_port_initialize_device_attr);
+
int tty_port_alloc_xmit_buf(struct tty_port *port)
{
/* We may sleep in get_zeroed_page() */
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 04d5f1213700..1b371ba9ed09 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -436,6 +436,11 @@ extern struct device *tty_register_device_attr(struct tty_driver *driver,
unsigned index, struct device *device,
void *drvdata,
const struct attribute_group **attr_grp);
+extern struct device *tty_device_initialize_attr(struct tty_driver *driver,
+ unsigned index, struct device *device,
+ void *drvdata,
+ const struct attribute_group **attr_grp);
+extern int tty_device_add(struct tty_driver *driver, struct device *dev);
extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
int buflen);
@@ -534,6 +539,10 @@ extern struct device *tty_port_register_device_attr(struct tty_port *port,
struct tty_driver *driver, unsigned index,
struct device *device, void *drvdata,
const struct attribute_group **attr_grp);
+extern struct device *tty_port_initialize_device_attr(struct tty_port *port,
+ struct tty_driver *driver, unsigned index,
+ struct device *device, void *drvdata,
+ const struct attribute_group **attr_grp);
extern int tty_port_alloc_xmit_buf(struct tty_port *port);
extern void tty_port_free_xmit_buf(struct tty_port *port);
extern void tty_port_destroy(struct tty_port *port);
--
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