staging: fpgaboot: Xilinx FPGA firmware download driver

This driver downloads Xilinx FPGA firmware using gpio pins.
It loads Xilinx FPGA bitstream format firmware image and
program the Xilinx FPGA using SelectMAP (parallel) mode.

Signed-off-by: Insop Song <insop.song@gainspeed.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/staging/gs_fpgaboot/README b/drivers/staging/gs_fpgaboot/README
new file mode 100644
index 000000000000..cfa8624304e5
--- /dev/null
+++ b/drivers/staging/gs_fpgaboot/README
@@ -0,0 +1,71 @@
+==============================================================================
+Linux Driver Source for Xilinx FPGA firmware download
+==============================================================================
+
+
+TABLE OF CONTENTS.
+
+1.  SUMMARY
+2.  BACKGROUND
+3.  DESIGN
+4.  HOW TO USE
+5.  REFERENCE
+
+1. SUMMARY
+
+	- Download Xilinx FPGA firmware
+	- This module downloads Xilinx FPGA firmware using gpio pins.
+
+2. BACKGROUND
+
+	An FPGA (Field Programmable Gate Array) is a programmable hardware that is
+	used in various applications. Hardware design needs to programmed through
+	a dedicated device or CPU assisted way (serial or parallel).
+	This driver provides a way to download FPGA firmware.
+
+3. DESIGN
+
+	- load Xilinx FPGA bitstream format[1] firmware image file using 
+	  kernel firmware framework, request_firmware()
+	- program the Xilinx FPGA using SelectMAP (parallel) mode [2]
+	- FPGA prgram is done by gpio based bit-banging, as an example
+	- platform independent file: gs_fpgaboot.c
+	- platform dependent file: io.c
+	
+
+4. HOW TO USE
+
+	$ insmod gs_fpga.ko file="xlinx_fpga_top_bitstream.bit"
+	$ rmmod gs_fpga
+
+5. USE CASE (from a mailing list discussion with Greg)
+
+	a. As a FPGA development support tool,
+	During FPGA firmware development, you need to download a new FPGA
+	image frequently.
+	You would do that with a dedicated JTAG, which usually a limited
+	resource in the lab.
+	However, if you use my driver, you don't have to have a dedicated JTAG.
+	This is a real gain :)
+
+	b. For the FPGA that runs without config after the download, which
+	doesn't talk to any of Linux interfaces (such as PCIE).
+
+	We download FPGA firmware from user triggered or some other way, and that's it.
+	Since that FPGA runs on its own, it doesn't require a linux driver
+	after the download.
+
+	c. For the FPGA that requires config after the download, which talk to
+	any of linux interfaces (such as PCIE)
+
+	Then, this type of FPGA config can be put into device tree and have a
+	separate driver (pcie or others), then THAT driver calls my driver to
+	download FPGA firmware during the Linux boot, the take over the device
+	through the interface.
+
+6. REFERENCE
+
+	1. Xilinx APP NOTE XAPP583:
+	  http://www.xilinx.com/support/documentation/application_notes/xapp583-fpga-configuration.pdf
+	2. bitstream file info:
+	  http://home.earthlink.net/~davesullins/software/bitinfo.html