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authorJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2008-08-29 01:18:01 +0200
committerJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2008-08-29 12:25:02 +0200
commit55195773eacefb22dd483a3c560ea30a14263ce1 (patch)
tree295e541cb8f380792a0161c42f54ca9dce1a5c87 /drivers/net/phy/miiphybb.c
parente8314035996a9118ac5948df2ff8a2f2161ed67a (diff)
miiphybb: move to drivers/net/phy
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Diffstat (limited to 'drivers/net/phy/miiphybb.c')
-rw-r--r--drivers/net/phy/miiphybb.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/net/phy/miiphybb.c b/drivers/net/phy/miiphybb.c
new file mode 100644
index 0000000000..6446012f95
--- /dev/null
+++ b/drivers/net/phy/miiphybb.c
@@ -0,0 +1,235 @@
+/*
+ * (C) Copyright 2001
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * This provides a bit-banged interface to the ethernet MII management
+ * channel.
+ */
+
+#include <common.h>
+#include <ioports.h>
+#include <ppc_asm.tmpl>
+
+/*****************************************************************************
+ *
+ * Utility to send the preamble, address, and register (common to read
+ * and write).
+ */
+static void miiphy_pre (char read, unsigned char addr, unsigned char reg)
+{
+ int j; /* counter */
+#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM))
+ volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT);
+#endif
+
+ /*
+ * Send a 32 bit preamble ('1's) with an extra '1' bit for good measure.
+ * The IEEE spec says this is a PHY optional requirement. The AMD
+ * 79C874 requires one after power up and one after a MII communications
+ * error. This means that we are doing more preambles than we need,
+ * but it is safer and will be much more robust.
+ */
+
+ MDIO_ACTIVE;
+ MDIO (1);
+ for (j = 0; j < 32; j++) {
+ MDC (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ }
+
+ /* send the start bit (01) and the read opcode (10) or write (10) */
+ MDC (0);
+ MDIO (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ MDC (0);
+ MDIO (1);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ MDC (0);
+ MDIO (read);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ MDC (0);
+ MDIO (!read);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+
+ /* send the PHY address */
+ for (j = 0; j < 5; j++) {
+ MDC (0);
+ if ((addr & 0x10) == 0) {
+ MDIO (0);
+ } else {
+ MDIO (1);
+ }
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ addr <<= 1;
+ }
+
+ /* send the register address */
+ for (j = 0; j < 5; j++) {
+ MDC (0);
+ if ((reg & 0x10) == 0) {
+ MDIO (0);
+ } else {
+ MDIO (1);
+ }
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ reg <<= 1;
+ }
+}
+
+
+/*****************************************************************************
+ *
+ * Read a MII PHY register.
+ *
+ * Returns:
+ * 0 on success
+ */
+int bb_miiphy_read (char *devname, unsigned char addr,
+ unsigned char reg, unsigned short *value)
+{
+ short rdreg; /* register working value */
+ int j; /* counter */
+#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM))
+ volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT);
+#endif
+
+ miiphy_pre (1, addr, reg);
+
+ /* tri-state our MDIO I/O pin so we can read */
+ MDC (0);
+ MDIO_TRISTATE;
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+
+ /* check the turnaround bit: the PHY should be driving it to zero */
+ if (MDIO_READ != 0) {
+ /* puts ("PHY didn't drive TA low\n"); */
+ for (j = 0; j < 32; j++) {
+ MDC (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ }
+ return (-1);
+ }
+
+ MDC (0);
+ MIIDELAY;
+
+ /* read 16 bits of register data, MSB first */
+ rdreg = 0;
+ for (j = 0; j < 16; j++) {
+ MDC (1);
+ MIIDELAY;
+ rdreg <<= 1;
+ rdreg |= MDIO_READ;
+ MDC (0);
+ MIIDELAY;
+ }
+
+ MDC (1);
+ MIIDELAY;
+ MDC (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+
+ *value = rdreg;
+
+#ifdef DEBUG
+ printf ("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, *value);
+#endif
+
+ return 0;
+}
+
+
+/*****************************************************************************
+ *
+ * Write a MII PHY register.
+ *
+ * Returns:
+ * 0 on success
+ */
+int bb_miiphy_write (char *devname, unsigned char addr,
+ unsigned char reg, unsigned short value)
+{
+ int j; /* counter */
+#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM))
+ volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT);
+#endif
+
+ miiphy_pre (0, addr, reg);
+
+ /* send the turnaround (10) */
+ MDC (0);
+ MDIO (1);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ MDC (0);
+ MDIO (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+
+ /* write 16 bits of register data, MSB first */
+ for (j = 0; j < 16; j++) {
+ MDC (0);
+ if ((value & 0x00008000) == 0) {
+ MDIO (0);
+ } else {
+ MDIO (1);
+ }
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+ value <<= 1;
+ }
+
+ /*
+ * Tri-state the MDIO line.
+ */
+ MDIO_TRISTATE;
+ MDC (0);
+ MIIDELAY;
+ MDC (1);
+ MIIDELAY;
+
+ return 0;
+}