/* write port value */ static ssize_t write_port(struct device *dev, struct device_attribute *attr, const char *buf, size_t count, int port_num, int write_id) { int value = -1; int result = 0; struct usb_interface *intf = to_usb_interface(dev); struct cypress *cyp = usb_get_intfdata(intf); dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num); /* validate input data */ if (sscanf(buf, "%d", &value) < 1) { result = -EINVAL; goto error; } if (value < 0 || value > 255) { result = -EINVAL; goto error; } result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id, (unsigned char)value); dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result); error: return result < 0 ? result : count; }
/* read port value */ static ssize_t read_port(struct device *dev, struct device_attribute *attr, char *buf, int port_num, int read_id) { int result = 0; struct usb_interface *intf = to_usb_interface(dev); struct cypress *cyp = usb_get_intfdata(intf); dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num); result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0); dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result); return sprintf(buf, "%d", cyp->port[port_num]); }