USB: Added driver for a Delcom USB 7-segment LED Display

Added basic support for a Delcom USB 7-segment LED Display

Signed-off by: Harrison Metzger <harrisonmetz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/usb/misc_usbsevseg.txt

@@ -0,0 +1,46 @@
+USB 7-Segment Numeric Display
+Manufactured by Delcom Engineering
+
+Device Information
+------------------
+USB VENDOR_ID	0x0fc5
+USB PRODUCT_ID	0x1227
+Both the 6 character and 8 character displays have PRODUCT_ID,
+and according to Delcom Engineering no queryable information
+can be obtained from the device to tell them apart.
+
+Device Modes
+------------
+By default, the driver assumes the display is only 6 characters
+The mode for 6 characters is:
+	MSB 0x06; LSB 0x3f
+For the 8 character display:
+	MSB 0x08; LSB 0xff
+The device can accept "text" either in raw, hex, or ascii textmode.
+raw controls each segment manually,
+hex expects a value between 0-15 per character,
+ascii expects a value between '0'-'9' and 'A'-'F'.
+The default is ascii.
+
+Device Operation
+----------------
+1.	Turn on the device:
+	echo 1 > /sys/bus/usb/.../powered
+2.	Set the device's mode:
+	echo $mode_msb > /sys/bus/usb/.../mode_msb
+	echo $mode_lsb > /sys/bus/usb/.../mode_lsb
+3.	Set the textmode:
+	echo $textmode > /sys/bus/usb/.../textmode
+4.	set the text (for example):
+	echo "123ABC" > /sys/bus/usb/.../text (ascii)
+	echo "A1B2" > /sys/bus/usb/.../text (ascii)
+	echo -ne "\x01\x02\x03" > /sys/bus/usb/.../text (hex)
+5.	Set the decimal places.
+	The device has either 6 or 8 decimal points.
+	to set the nth decimal place calculate 10 ** n
+	and echo it in to /sys/bus/usb/.../decimals
+	To set multiple decimals points sum up each power.
+	For example, to set the 0th and 3rd decimal place
+	echo 1001 > /sys/bus/usb/.../decimals
+
+