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authorSylvie Barlow2018-04-20 14:58:40 +0200
committerMichael Brown2018-04-20 16:24:33 +0200
commitc239f0bff2496cefa5e9d3ef6b232f5d28a04d70 (patch)
treede517893ece5f9f5d42d5b309d694b7f2e25b652 /src
parent[mii] Add mii_find() (diff)
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[mii] Add bit-bashing interface
Signed-off-by: Sylvie Barlow <sylvie.c.barlow@gmail.com> Modified-by: Michael Brown <mcb30@ipxe.org> Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src')
-rw-r--r--src/drivers/bitbash/mii_bit.c162
-rw-r--r--src/include/ipxe/mii_bit.h55
2 files changed, 217 insertions, 0 deletions
diff --git a/src/drivers/bitbash/mii_bit.c b/src/drivers/bitbash/mii_bit.c
new file mode 100644
index 00000000..5f0ec04a
--- /dev/null
+++ b/src/drivers/bitbash/mii_bit.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2018 Sylvie Barlow <sylvie.c.barlow@gmail.com>.
+ *
+ * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <unistd.h>
+#include <ipxe/bitbash.h>
+#include <ipxe/mii_bit.h>
+
+/**
+ * Transfer bits over MII bit-bashing interface
+ *
+ * @v basher Bit basher
+ * @v mask Mask
+ * @v write Data to write
+ * @ret read Data read
+ */
+static uint32_t mii_bit_xfer ( struct bit_basher *basher,
+ uint32_t mask, uint32_t write ) {
+ uint32_t read = 0;
+ int bit;
+
+ for ( ; mask ; mask >>= 1 ) {
+
+ /* Delay */
+ udelay ( 1 );
+
+ /* Write bit to basher */
+ write_bit ( basher, MII_BIT_MDIO, ( write & mask ) );
+
+ /* Read bit from basher */
+ bit = read_bit ( basher, MII_BIT_MDIO );
+ read <<= 1;
+ read |= ( bit & 1 );
+
+ /* Set clock high */
+ write_bit ( basher, MII_BIT_MDC, 1 );
+
+ /* Delay */
+ udelay ( 1 );
+
+ /* Set clock low */
+ write_bit ( basher, MII_BIT_MDC, 0 );
+ }
+ return read;
+}
+
+/**
+ * Read or write via MII bit-bashing interface
+ *
+ * @v basher Bit basher
+ * @v phy PHY address
+ * @v reg Register address
+ * @v data Data to write
+ * @v cmd Command
+ * @ret data Data read
+ */
+static unsigned int mii_bit_rw ( struct bit_basher *basher,
+ unsigned int phy, unsigned int reg,
+ unsigned int data, unsigned int cmd ) {
+
+ /* Initiate drive for write */
+ write_bit ( basher, MII_BIT_DRIVE, 1 );
+
+ /* Write start */
+ mii_bit_xfer ( basher, MII_BIT_START_MASK, MII_BIT_START );
+
+ /* Write command */
+ mii_bit_xfer ( basher, MII_BIT_CMD_MASK, cmd );
+
+ /* Write PHY address */
+ mii_bit_xfer ( basher, MII_BIT_PHY_MASK, phy );
+
+ /* Write register address */
+ mii_bit_xfer ( basher, MII_BIT_REG_MASK, reg );
+
+ /* Switch drive to read if applicable */
+ write_bit ( basher, MII_BIT_DRIVE, ( cmd & MII_BIT_CMD_RW ) );
+
+ /* Allow space for turnaround */
+ mii_bit_xfer ( basher, MII_BIT_SWITCH_MASK, MII_BIT_SWITCH );
+
+ /* Read or write data */
+ data = mii_bit_xfer (basher, MII_BIT_DATA_MASK, data );
+
+ /* Initiate drive for read */
+ write_bit ( basher, MII_BIT_DRIVE, 0 );
+
+ return data;
+}
+
+/**
+ * Read from MII register
+ *
+ * @v mdio MII interface
+ * @v phy PHY address
+ * @v reg Register address
+ * @ret data Data read, or negative error
+ */
+static int mii_bit_read ( struct mii_interface *mdio, unsigned int phy,
+ unsigned int reg ) {
+ struct mii_bit_basher *miibit =
+ container_of ( mdio, struct mii_bit_basher, mdio );
+ struct bit_basher *basher = &miibit->basher;
+
+ return mii_bit_rw ( basher, phy, reg, 0, MII_BIT_CMD_READ );
+}
+
+/**
+ * Write to MII register
+ *
+ * @v mdio MII interface
+ * @v phy PHY address
+ * @v reg Register address
+ * @v data Data to write
+ * @ret rc Return status code
+ */
+static int mii_bit_write ( struct mii_interface *mdio, unsigned int phy,
+ unsigned int reg, unsigned int data ) {
+ struct mii_bit_basher *miibit =
+ container_of ( mdio, struct mii_bit_basher, mdio );
+ struct bit_basher *basher = &miibit->basher;
+
+ mii_bit_rw ( basher, phy, reg, data, MII_BIT_CMD_WRITE );
+ return 0;
+}
+
+/** MII bit basher operations */
+static struct mii_operations mii_bit_op = {
+ .read = mii_bit_read,
+ .write = mii_bit_write,
+};
+
+/**
+ * Initialise bit-bashing interface
+ *
+ * @v miibit MII bit basher
+ */
+void init_mii_bit_basher ( struct mii_bit_basher *miibit ) {
+ mdio_init ( &miibit->mdio, &mii_bit_op );
+};
diff --git a/src/include/ipxe/mii_bit.h b/src/include/ipxe/mii_bit.h
new file mode 100644
index 00000000..0f797e91
--- /dev/null
+++ b/src/include/ipxe/mii_bit.h
@@ -0,0 +1,55 @@
+#ifndef _IPXE_MII_BIT_H
+#define _IPXE_MII_BIT_H
+
+/** @file
+ *
+ * MII bit-bashing interface
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <ipxe/mii.h>
+#include <ipxe/bitbash.h>
+
+#define MII_BIT_START 0xffffffff /**< Start */
+#define MII_BIT_START_MASK 0x80000000 /**< Start mask */
+
+#define MII_BIT_CMD_MASK 0x00000008 /**< Command mask */
+#define MII_BIT_CMD_READ 0x00000006 /**< Command read */
+#define MII_BIT_CMD_WRITE 0x00000005 /**< Command write */
+#define MII_BIT_CMD_RW 0x00000001 /**< Command read or write */
+
+#define MII_BIT_PHY_MASK 0x00000010 /**< PHY mask */
+
+#define MII_BIT_REG_MASK 0x00000010 /**< Register mask */
+
+#define MII_BIT_SWITCH 0x00000002 /**< Switch */
+#define MII_BIT_SWITCH_MASK 0x00000002 /**< Switch mask */
+
+#define MII_BIT_DATA_MASK 0x00008000 /**< Data mask */
+
+/** A bit-bashing MII interface */
+struct mii_bit_basher {
+ /** MII interface */
+ struct mii_interface mdio;
+ /** Bit-bashing interface */
+ struct bit_basher basher;
+};
+
+/** Bit indices used for MII bit-bashing interface */
+enum {
+ /** MII clock */
+ MII_BIT_MDC = 0,
+ /** MII data */
+ MII_BIT_MDIO,
+ /** MII data direction */
+ MII_BIT_DRIVE,
+};
+
+/** Delay between MDC transitions */
+#define MII_BIT_UDELAY 1
+
+extern void init_mii_bit_basher ( struct mii_bit_basher *miibit );
+
+#endif /* _IPXE_MII_BIT_H */