- Import the common MII bitbang'ing code from NetBSD and convert drivers to

  take advantage of it instead of duplicating it. This reduces the size of
  the i386 GENERIC kernel by about 4k. The only potential in-tree user left
  unconverted is xe(4), which generally should be changed to use miibus(4)
  instead of implementing PHY handling on its own, as otherwise it makes not
  much sense to add a dependency on miibus(4)/mii_bitbang(4) to xe(4) just
  for the MII bitbang'ing code. The common MII bitbang'ing code also is
  useful in the embedded space for using GPIO pins to implement MII access.
- Based on lessons learnt with dc(4) (see r185750), add bus barriers to the
  MII bitbang read and write functions of the other drivers converted in
  order to ensure the intended ordering. Given that register access via an
  index register as well as register bank/window switching is subject to the
  same problem, also add bus barriers to the respective functions of smc(4),
  tl(4) and xl(4).
- Sprinkle some const.

Thanks to the following testers:
Andrew Bliznak (nge(4)), nwhitehorn@ (bm(4)), yongari@ (sis(4) and ste(4))
Thanks to Hans-Joerg Sirtl for supplying hardware to test stge(4).

Reviewed by:	yongari (subset of drivers)
Obtained from:	NetBSD (partially)

1 files changed, 54 insertions, 0 deletions

diff --git a/sys/dev/mii/mii_bitbang.h b/sys/dev/mii/mii_bitbang.h
new file mode 100644
index 0000000..2bc7427
--- /dev/null
+++ b/sys/dev/mii/mii_bitbang.h
@@ -0,0 +1,54 @@
+/*	$NetBSD: mii_bitbang.h,v 1.6 2009/05/12 14:31:27 cegger Exp $	*/
+
+/*-
+ * Copyright (c) 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
+ * NASA Ames Research Center.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#define	MII_BIT_MDO		0	/* data out (host->PHY) */
+#define	MII_BIT_MDI		1	/* data in (PHY->host) */
+#define	MII_BIT_MDC		2	/* clock */
+#define	MII_BIT_DIR_HOST_PHY	3	/* set direction: host->PHY */
+#define	MII_BIT_DIR_PHY_HOST	4	/* set direction: PHY->host */
+#define	MII_NBITS		5
+
+struct mii_bitbang_ops {
+	uint32_t	(*mbo_read)(device_t);
+	void		(*mbo_write)(device_t, uint32_t);
+	uint32_t	mbo_bits[MII_NBITS];
+};
+
+typedef	const struct mii_bitbang_ops *mii_bitbang_ops_t;
+
+int	mii_bitbang_readreg(device_t dev, mii_bitbang_ops_t ops,
+	    int phy, int reg);
+void	mii_bitbang_sync(device_t dev, mii_bitbang_ops_t ops);
+void	mii_bitbang_writereg(device_t dev, mii_bitbang_ops_t ops,
+	    int phy, int reg, int val);