[PATCH] mipsnet: Virtual ethernet driver for MIPSsim.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 drivers/net/Kconfig   |    8 +
 drivers/net/Makefile  |    1
 drivers/net/mipsnet.c |  371 ++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/net/mipsnet.h |  127 +++++++++++++++++
 4 files changed, 507 insertions(+)
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/mipsnet.h

@@ -0,0 +1,127 @@
+//
+// <COPYRIGHT CLASS="1B" YEAR="2005">
+// Unpublished work (c) MIPS Technologies, Inc.  All rights reserved.
+// Unpublished rights reserved under the copyright laws of the U.S.A. and
+//  other countries.
+//
+// PROPRIETARY / SECRET CONFIDENTIAL INFORMATION OF MIPS TECHNOLOGIES, INC.
+// FOR INTERNAL USE ONLY.
+//
+// Under no circumstances (contract or otherwise) may this information be
+// disclosed to, or copied, modified or used by anyone other than employees
+// or contractors of MIPS Technologies having a need to know.
+// </COPYRIGHT>
+//
+//++
+// File: MIPS_Net.h
+//
+// Description:
+//   The definition of the emulated MIPSNET device's interface.
+//
+// Notes: This include file needs to work from a Linux device drivers.
+//
+//--
+//
+
+#ifndef __MIPSNET_H
+#define __MIPSNET_H
+
+/*
+ *  Id of this Net device, as seen by the core.
+ */
+#define MIPS_NET_DEV_ID ((uint64_t)           \
+	                     ((uint64_t)'M'<< 0)| \
+	                     ((uint64_t)'I'<< 8)| \
+	                     ((uint64_t)'P'<<16)| \
+	                     ((uint64_t)'S'<<24)| \
+	                     ((uint64_t)'N'<<32)| \
+	                     ((uint64_t)'E'<<40)| \
+	                     ((uint64_t)'T'<<48)| \
+	                     ((uint64_t)'0'<<56))
+
+/*
+ * Net status/control block as seen by sw in the core.
+ * (Why not use bit fields? can't be bothered with cross-platform struct
+ *  packing.)
+ */
+typedef struct _net_control_block {
+	/// dev info for probing
+	///  reads as MIPSNET%d where %d is some form of version
+	uint64_t devId;		/*0x00 */
+
+	/*
+	 * read only busy flag.
+	 * Set and cleared by the Net Device to indicate that an rx or a tx
+	 * is in progress.
+	 */
+	uint32_t busy;		/*0x08 */
+
+	/*
+	 * Set by the Net Device.
+	 * The device will set it once data has been received.
+	 * The value is the number of bytes that should be read from
+	 * rxDataBuffer.  The value will decrease till 0 until all the data
+	 * from rxDataBuffer has been read.
+	 */
+	uint32_t rxDataCount;	/*0x0c */
+#define MIPSNET_MAX_RXTX_DATACOUNT (1<<16)
+
+	/*
+	 * Settable from the MIPS core, cleared by the Net Device.
+	 * The core should set the number of bytes it wants to send,
+	 *   then it should write those bytes of data to txDataBuffer.
+	 * The device will clear txDataCount has been processed (not necessarily sent).
+	 */
+	uint32_t txDataCount;	/*0x10 */
+
+	/*
+	 * Interrupt control
+	 *
+	 * Used to clear the interrupted generated by this dev.
+	 * Write a 1 to clear the interrupt. (except bit31).
+	 *
+	 * Bit0 is set if it was a tx-done interrupt.
+	 * Bit1 is set when new rx-data is available.
+	 *      Until this bit is cleared there will be no other RXs.
+	 *
+	 * Bit31 is used for testing, it clears after a read.
+	 *    Writing 1 to this bit will cause an interrupt to be generated.
+	 *    To clear the test interrupt, write 0 to this register.
+	 */
+	uint32_t interruptControl;	/*0x14 */
+#define MIPSNET_INTCTL_TXDONE     ((uint32_t)(1<< 0))
+#define MIPSNET_INTCTL_RXDONE     ((uint32_t)(1<< 1))
+#define MIPSNET_INTCTL_TESTBIT    ((uint32_t)(1<<31))
+#define MIPSNET_INTCTL_ALLSOURCES (MIPSNET_INTCTL_TXDONE|MIPSNET_INTCTL_RXDONE|MIPSNET_INTCTL_TESTBIT)
+
+	/*
+	 * Readonly core-specific interrupt info for the device to signal the core.
+	 * The meaning of the contents of this field might change.
+	 */
+	/*###\todo: the whole memIntf interrupt scheme is messy: the device should have
+	 *  no control what so ever of what VPE/register set is being used.
+	 *  The MemIntf should only expose interrupt lines, and something in the
+	 *  config should be responsible for the line<->core/vpe bindings.
+	 */
+	uint32_t interruptInfo;	/*0x18 */
+
+	/*
+	 *  This is where the received data is read out.
+	 *  There is more data to read until rxDataReady is 0.
+	 *  Only 1 byte at this regs offset is used.
+	 */
+	uint32_t rxDataBuffer;	/*0x1c */
+
+	/*
+	 * This is where the data to transmit is written.
+	 * Data should be written for the amount specified in the txDataCount register.
+	 *  Only 1 byte at this regs offset is used.
+	 */
+	uint32_t txDataBuffer;	/*0x20 */
+} MIPS_T_NetControl;
+
+#define MIPSNET_IO_EXTENT 0x40	/* being generous */
+
+#define field_offset(field) ((int)&((MIPS_T_NetControl*)(0))->field)
+
+#endif /* __MIPSNET_H */