1 files changed, 92 insertions, 0 deletions

diff --git a/Documentation/scsi/hptiop.txt b/Documentation/scsi/hptiop.txt
new file mode 100644
index 000000000000..d28a31247d4c
--- /dev/null
+++ b/Documentation/scsi/hptiop.txt
@@ -0,0 +1,92 @@
+HIGHPOINT ROCKETRAID 3xxx RAID DRIVER (hptiop)
+
+Controller Register Map
+-------------------------
+
+The controller IOP is accessed via PCI BAR0.
+
+     BAR0 offset    Register
+            0x10    Inbound Message Register 0
+            0x14    Inbound Message Register 1
+            0x18    Outbound Message Register 0
+            0x1C    Outbound Message Register 1
+            0x20    Inbound Doorbell Register
+            0x24    Inbound Interrupt Status Register
+            0x28    Inbound Interrupt Mask Register
+            0x30    Outbound Interrupt Status Register
+            0x34    Outbound Interrupt Mask Register
+            0x40    Inbound Queue Port
+            0x44    Outbound Queue Port
+
+
+I/O Request Workflow
+----------------------
+
+All queued requests are handled via inbound/outbound queue port.
+A request packet can be allocated in either IOP or host memory.
+
+To send a request to the controller:
+
+    - Get a free request packet by reading the inbound queue port or
+      allocate a free request in host DMA coherent memory.
+
+      The value returned from the inbound queue port is an offset
+      relative to the IOP BAR0.
+
+      Requests allocated in host memory must be aligned on 32-bytes boundary.
+
+    - Fill the packet.
+
+    - Post the packet to IOP by writing it to inbound queue. For requests
+      allocated in IOP memory, write the offset to inbound queue port. For
+      requests allocated in host memory, write (0x80000000|(bus_addr>>5))
+      to the inbound queue port.
+
+    - The IOP process the request. When the request is completed, it
+      will be put into outbound queue. An outbound interrupt will be
+      generated.
+
+      For requests allocated in IOP memory, the request offset is posted to
+      outbound queue.
+
+      For requests allocated in host memory, (0x80000000|(bus_addr>>5))
+      is posted to the outbound queue. If IOP_REQUEST_FLAG_OUTPUT_CONTEXT
+      flag is set in the request, the low 32-bit context value will be
+      posted instead.
+
+    - The host read the outbound queue and complete the request.
+
+      For requests allocated in IOP memory, the host driver free the request
+      by writing it to the outbound queue.
+
+Non-queued requests (reset/flush etc) can be sent via inbound message
+register 0. An outbound message with the same value indicates the completion
+of an inbound message.
+
+
+User-level Interface
+---------------------
+
+The driver exposes following sysfs attributes:
+
+     NAME                 R/W    Description
+     driver-version        R     driver version string
+     firmware-version      R     firmware version string
+
+The driver registers char device "hptiop" to communicate with HighPoint RAID
+management software. Its ioctl routine acts as a general binary interface 
+between the IOP firmware and HighPoint RAID management software. New management
+functions can be implemented in application/firmware without modification
+in driver code.
+
+
+-----------------------------------------------------------------------------
+Copyright (C) 2006 HighPoint Technologies, Inc. All Rights Reserved.
+
+  This file is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  linux@highpoint-tech.com
+  http://www.highpoint-tech.com