usbatm: create sysfs link "device" from atm class device to usb interface
There is currently no path from the ATM device in /sys to the USB device's
interface that the driver is using; this patch creates a "device" symlink. It
is then possible to get to the cxacru ADSL statistics
(http://lkml.org/lkml/2007/2/23/328):
/sys/class/atm/cxacru0/device $ ls *_rate *_margin *_attenuation
downstream_attenuation downstream_snr_margin upstream_rate
downstream_rate upstream_attenuation upstream_snr_margin
If this link is not appropriate I'd have to create device files in
/sys/class/atm/cxacru0 instead - which seems less appropriate since the ADSL
statistics are for the USB device not ATM (which is running over the ADSL).
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: Duncan Sands <duncan.sands@math.u-psud.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index d3e2c5f..746d30ff 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -968,6 +968,14 @@
/* temp init ATM device, set to 128kbit */
atm_dev->link_rate = 128 * 1000 / 424;
+ ret = sysfs_create_link(&atm_dev->class_dev.kobj,
+ &instance->usb_intf->dev.kobj, "device");
+ if (ret) {
+ atm_err(instance, "%s: sysfs_create_link failed: %d\n",
+ __func__, ret);
+ goto fail_sysfs;
+ }
+
if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
goto fail;
@@ -986,6 +994,8 @@
return 0;
fail:
+ sysfs_remove_link(&atm_dev->class_dev.kobj, "device");
+ fail_sysfs:
instance->atm_dev = NULL;
atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
return ret;
@@ -1318,8 +1328,10 @@
kfree(instance->cell_buf);
/* ATM finalize */
- if (instance->atm_dev)
+ if (instance->atm_dev) {
+ sysfs_remove_link(&instance->atm_dev->class_dev.kobj, "device");
atm_dev_deregister(instance->atm_dev);
+ }
usbatm_put_instance(instance); /* taken in usbatm_usb_probe */
}