usb: gadget: udc: add a 'function' sysfs file

This file will print out the name of the currently running USB Gadget
Driver. It can be read even when there are no functions loaded.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Felipe Balbi 2017-06-07 14:07:01 +03:00
parent 06644aafb0
commit 104165686e
2 changed files with 21 additions and 0 deletions

View File

@ -91,3 +91,11 @@ Description:
'configured', and 'suspended'; however not all USB Device
Controllers support reporting all states.
Users:
What: /sys/class/udc/<udc>/function
Date: June 2017
KernelVersion: 4.13
Contact: Felipe Balbi <balbi@kernel.org>
Description:
Prints out name of currently running USB Gadget Driver.
Users:

View File

@ -1460,6 +1460,18 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(state);
static ssize_t function_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
struct usb_gadget_driver *drv = udc->driver;
if (!drv || !drv->function)
return 0;
return scnprintf(buf, PAGE_SIZE, "%s\n", drv->function);
}
static DEVICE_ATTR_RO(function);
#define USB_UDC_SPEED_ATTR(name, param) \
ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
@ -1495,6 +1507,7 @@ static struct attribute *usb_udc_attrs[] = {
&dev_attr_srp.attr,
&dev_attr_soft_connect.attr,
&dev_attr_state.attr,
&dev_attr_function.attr,
&dev_attr_current_speed.attr,
&dev_attr_maximum_speed.attr,