Staging: add Driver for Altera PCI Express Chaining DMA reference design

Altera PCI Express Chaining DMA driver

A reference driver that exercises the Chaining DMA logic reference
design generated along the Altera FPGA PCI Express soft or hard core,
only if instantiated using the MegaWizard, not the SOPC builder, of
Quartus 8.1.

This driver can be used to test the logic instantiation and PCI
Express layers and acts as a starting point for driving custom logic
connected to the PCI Express End Point Chaining DMA engines.

Signed-off-by: Leon Woestenberg <leon@sidebranch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -79,5 +79,7 @@ source "drivers/staging/asus_oled/Kconfig"
 
 source "drivers/staging/panel/Kconfig"
 
+source "drivers/staging/altpciechdma/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

@@ -22,3 +22,4 @@ obj-$(CONFIG_BENET)		+= benet/
 obj-$(CONFIG_COMEDI)		+= comedi/
 obj-$(CONFIG_ASUS_OLED)		+= asus_oled/
 obj-$(CONFIG_PANEL)		+= panel/
+obj-$(CONFIG_ALTERA_PCIE_CHDMA)	+= altpciechdma/

drivers/staging/altpciechdma/Kconfig

@@ -0,0 +1,10 @@
+config ALTERA_PCIE_CHDMA
+	tristate "Altera PCI Express Chaining DMA driver"
+	depends on PCI
+	default N
+	---help---
+	  A reference driver that exercises the Chaining DMA logic reference
+	  design generated along the Altera FPGA PCI Express soft or hard core,
+	  only if instantiated using the MegaWizard, not the SOPC builder, of
+	  Quartus 8.1.
+

drivers/staging/altpciechdma/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_ALTERA_PCIE_CHDMA)	+= altpciechdma.o
+

drivers/staging/altpciechdma/TODO

@@ -0,0 +1,15 @@
+DONE:
+    - functionality similar to logic testbench
+
+TODO:
+	- checkpatch.pl cleanups.
+	- keep state of DMA engines.
+	- keep data structure that keeps state of each transfer.
+	- interrupt handler should iterate over outstanding descriptor tables.
+	- complete userspace cdev to read/write using the DMA engines.
+	- split off the DMA support functions in a module, re-usable by custom
+	  drivers.
+
+Please coordinate work with, and send patches to
+Leon Woestenberg <leon@sidebranch.com>
+