From 104165686ea388ddec6ec2834bf2c13873fbe91a Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Wed, 7 Jun 2017 14:07:01 +0300 Subject: 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 Signed-off-by: Felipe Balbi --- Documentation/ABI/stable/sysfs-class-udc | 8 ++++++++ drivers/usb/gadget/udc/core.c | 13 +++++++++++++ 2 files changed, 21 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-class-udc b/Documentation/ABI/stable/sysfs-class-udc index 85d3dac2e204..7370deb87f87 100644 --- a/Documentation/ABI/stable/sysfs-class-udc +++ b/Documentation/ABI/stable/sysfs-class-udc @@ -91,3 +91,11 @@ Description: 'configured', and 'suspended'; however not all USB Device Controllers support reporting all states. Users: + +What: /sys/class/udc//function +Date: June 2017 +KernelVersion: 4.13 +Contact: Felipe Balbi +Description: + Prints out name of currently running USB Gadget Driver. +Users: diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index eec388bccb25..08facbada30e 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -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, -- cgit v1.2.3