On Thu, Mar 09, 2023 at 03:10:56PM +0800, Ye Xiang wrote: > +static int ljca_mng_get_version(struct ljca_stub *stub, char *buf) > +{ > + struct fw_version version = {}; > + unsigned int len = sizeof(version); > + int ret; > + > + ret = ljca_stub_write(stub, LJCA_MNG_GET_VERSION, NULL, 0, &version, &len, true, > + LJCA_USB_WRITE_ACK_TIMEOUT_MS); > + if (ret) > + return ret; > + > + if (len != sizeof(version)) { > + dev_err(&stub->intf->dev, "get version failed, len:%d\n", len); > + return -EINVAL; > + } > + > + return sysfs_emit(buf, "%d.%d.%d.%d\n", version.major, version.minor, > + le16_to_cpu(version.patch), le16_to_cpu(version.build)); > +} You have sysfs files, yet no Documentation/ABI/ entries? That's not allowed, you know this :( > +static ssize_t cmd_store(struct device *dev, struct device_attribute *attr, const char *buf, > + size_t count) > +{ > + struct usb_interface *intf = to_usb_interface(dev); > + struct ljca_dev *ljca_dev = usb_get_intfdata(intf); > + struct ljca_stub *mng_stub = ljca_stub_find(ljca_dev, LJCA_MNG_STUB); > + struct ljca_stub *diag_stub = ljca_stub_find(ljca_dev, LJCA_DIAG_STUB); > + > + if (sysfs_streq(buf, "dfu")) > + ljca_mng_set_dfu_mode(mng_stub); > + else if (sysfs_streq(buf, "debug")) > + ljca_diag_set_trace_level(diag_stub, 3); Sorry, but no, you can't do this in a sysfs file. > + > + return count; > +} > + > +static ssize_t cmd_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + return sysfs_emit(buf, "%s\n", "supported cmd: [dfu, debug]"); sysfs files do not show "help text". thanks, greg k-h