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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:40:14 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:40:14 -0700
commit038a5008b2f395c85e6e71d6ddf3c684e7c405b0 (patch)
tree4735eab577e97e5a22c3141e3f60071c8065585e /drivers/net/phy/mdio-bitbang.c
parentdd6d1844af33acb4edd0a40b1770d091a22c94be (diff)
parent266918303226cceac7eca38ced30f15f277bd89c (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits) [SKY2]: status polling loop (post merge) [NET]: Fix NAPI completion handling in some drivers. [TCP]: Limit processing lost_retrans loop to work-to-do cases [TCP]: Fix lost_retrans loop vs fastpath problems [TCP]: No need to re-count fackets_out/sacked_out at RTO [TCP]: Extract tcp_match_queue_to_sack from sacktag code [TCP]: Kill almost unused variable pcount from sacktag [TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L [TCP]: Add bytes_acked (ABC) clearing to FRTO too [IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2 [NETFILTER]: x_tables: add missing ip6t_modulename aliases [NETFILTER]: nf_conntrack_tcp: fix connection reopening [QETH]: fix qeth_main.c [NETLINK]: fib_frontend build fixes [IPv6]: Export userland ND options through netlink (RDNSS support) [9P]: build fix with !CONFIG_SYSCTL [NET]: Fix dev_put() and dev_hold() comments [NET]: make netlink user -> kernel interface synchronious [NET]: unify netlink kernel socket recognition [NET]: cleanup 3rd argument in netlink_sendskb ... Fix up conflicts manually in Documentation/feature-removal-schedule.txt and my new least favourite crap, the "mod_devicetable" support in the files include/linux/mod_devicetable.h and scripts/mod/file2alias.c. (The latter files seem to be explicitly _designed_ to get conflicts when different subsystems work with them - that have an absolutely horrid lack of subsystem separation!) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/net/phy/mdio-bitbang.c')
-rw-r--r--drivers/net/phy/mdio-bitbang.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio-bitbang.c b/drivers/net/phy/mdio-bitbang.c
new file mode 100644
index 00000000000..8cd243d92af
--- /dev/null
+++ b/drivers/net/phy/mdio-bitbang.c
@@ -0,0 +1,187 @@
+/*
+ * Bitbanged MDIO support.
+ *
+ * Author: Scott Wood <scottwood@freescale.com>
+ * Copyright (c) 2007 Freescale Semiconductor
+ *
+ * Based on CPM2 MDIO code which is:
+ *
+ * Copyright (c) 2003 Intracom S.A.
+ * by Pantelis Antoniou <panto@intracom.gr>
+ *
+ * 2005 (c) MontaVista Software, Inc.
+ * Vitaly Bordug <vbordug@ru.mvista.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/mdio-bitbang.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+
+#define MDIO_READ 1
+#define MDIO_WRITE 0
+
+#define MDIO_SETUP_TIME 10
+#define MDIO_HOLD_TIME 10
+
+/* Minimum MDC period is 400 ns, plus some margin for error. MDIO_DELAY
+ * is done twice per period.
+ */
+#define MDIO_DELAY 250
+
+/* The PHY may take up to 300 ns to produce data, plus some margin
+ * for error.
+ */
+#define MDIO_READ_DELAY 350
+
+/* MDIO must already be configured as output. */
+static void mdiobb_send_bit(struct mdiobb_ctrl *ctrl, int val)
+{
+ const struct mdiobb_ops *ops = ctrl->ops;
+
+ ops->set_mdio_data(ctrl, val);
+ ndelay(MDIO_DELAY);
+ ops->set_mdc(ctrl, 1);
+ ndelay(MDIO_DELAY);
+ ops->set_mdc(ctrl, 0);
+}
+
+/* MDIO must already be configured as input. */
+static int mdiobb_get_bit(struct mdiobb_ctrl *ctrl)
+{
+ const struct mdiobb_ops *ops = ctrl->ops;
+
+ ndelay(MDIO_DELAY);
+ ops->set_mdc(ctrl, 1);
+ ndelay(MDIO_READ_DELAY);
+ ops->set_mdc(ctrl, 0);
+
+ return ops->get_mdio_data(ctrl);
+}
+
+/* MDIO must already be configured as output. */
+static void mdiobb_send_num(struct mdiobb_ctrl *ctrl, u16 val, int bits)
+{
+ int i;
+
+ for (i = bits - 1; i >= 0; i--)
+ mdiobb_send_bit(ctrl, (val >> i) & 1);
+}
+
+/* MDIO must already be configured as input. */
+static u16 mdiobb_get_num(struct mdiobb_ctrl *ctrl, int bits)
+{
+ int i;
+ u16 ret = 0;
+
+ for (i = bits - 1; i >= 0; i--) {
+ ret <<= 1;
+ ret |= mdiobb_get_bit(ctrl);
+ }
+
+ return ret;
+}
+
+/* Utility to send the preamble, address, and
+ * register (common to read and write).
+ */
+static void mdiobb_cmd(struct mdiobb_ctrl *ctrl, int read, u8 phy, u8 reg)
+{
+ const struct mdiobb_ops *ops = ctrl->ops;
+ int i;
+
+ ops->set_mdio_dir(ctrl, 1);
+
+ /*
+ * 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.
+ */
+
+ for (i = 0; i < 32; i++)
+ mdiobb_send_bit(ctrl, 1);
+
+ /* send the start bit (01) and the read opcode (10) or write (10) */
+ mdiobb_send_bit(ctrl, 0);
+ mdiobb_send_bit(ctrl, 1);
+ mdiobb_send_bit(ctrl, read);
+ mdiobb_send_bit(ctrl, !read);
+
+ mdiobb_send_num(ctrl, phy, 5);
+ mdiobb_send_num(ctrl, reg, 5);
+}
+
+
+static int mdiobb_read(struct mii_bus *bus, int phy, int reg)
+{
+ struct mdiobb_ctrl *ctrl = bus->priv;
+ int ret, i;
+
+ mdiobb_cmd(ctrl, MDIO_READ, phy, reg);
+ ctrl->ops->set_mdio_dir(ctrl, 0);
+
+ /* check the turnaround bit: the PHY should be driving it to zero */
+ if (mdiobb_get_bit(ctrl) != 0) {
+ /* PHY didn't drive TA low -- flush any bits it
+ * may be trying to send.
+ */
+ for (i = 0; i < 32; i++)
+ mdiobb_get_bit(ctrl);
+
+ return 0xffff;
+ }
+
+ ret = mdiobb_get_num(ctrl, 16);
+ mdiobb_get_bit(ctrl);
+ return ret;
+}
+
+static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val)
+{
+ struct mdiobb_ctrl *ctrl = bus->priv;
+
+ mdiobb_cmd(ctrl, MDIO_WRITE, phy, reg);
+
+ /* send the turnaround (10) */
+ mdiobb_send_bit(ctrl, 1);
+ mdiobb_send_bit(ctrl, 0);
+
+ mdiobb_send_num(ctrl, val, 16);
+
+ ctrl->ops->set_mdio_dir(ctrl, 0);
+ mdiobb_get_bit(ctrl);
+ return 0;
+}
+
+struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl)
+{
+ struct mii_bus *bus;
+
+ bus = kzalloc(sizeof(struct mii_bus), GFP_KERNEL);
+ if (!bus)
+ return NULL;
+
+ __module_get(ctrl->ops->owner);
+
+ bus->read = mdiobb_read;
+ bus->write = mdiobb_write;
+ bus->priv = ctrl;
+
+ return bus;
+}
+
+void free_mdio_bitbang(struct mii_bus *bus)
+{
+ struct mdiobb_ctrl *ctrl = bus->priv;
+
+ module_put(ctrl->ops->owner);
+ kfree(bus);
+}