Add USB host ethernet adapter support

This adds support for using USB Ethernet dongles in host mode. This is just
the framework - drivers will come later. A new config option called
CONFIG_USB_HOST_ETHER can be defined in board config files to switch this
on.

The was originally written by NVIDIA and was cleaned up for release by the
Chromium authors.

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 188 insertions, 0 deletions

diff --git a/drivers/usb/eth/Makefile b/drivers/usb/eth/Makefile
new file mode 100644
index 0000000..a0f5676
--- /dev/null
+++ b/drivers/usb/eth/Makefile
@@ -0,0 +1,45 @@
+#
+# Copyright (c) 2011 The Chromium OS Authors.
+# 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
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	:= $(obj)libusb_eth.a
+
+# new USB host ethernet layer dependencies
+COBJS-$(CONFIG_USB_HOST_ETHER) += usb_ether.o
+
+COBJS	:= $(COBJS-y)
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/drivers/usb/eth/usb_ether.c b/drivers/usb/eth/usb_ether.c
new file mode 100644
index 0000000..c2342ed
--- /dev/null
+++ b/drivers/usb/eth/usb_ether.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * 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
+ */
+
+#include <common.h>
+#include <usb.h>
+
+#include "usb_ether.h"
+
+typedef void (*usb_eth_before_probe)(void);
+typedef int (*usb_eth_probe)(struct usb_device *dev, unsigned int ifnum,
+			struct ueth_data *ss);
+typedef int (*usb_eth_get_info)(struct usb_device *dev, struct ueth_data *ss,
+			struct eth_device *dev_desc);
+
+struct usb_eth_prob_dev {
+	usb_eth_before_probe	before_probe; /* optional */
+	usb_eth_probe			probe;
+	usb_eth_get_info		get_info;
+};
+
+/* driver functions go here, each bracketed by #ifdef CONFIG_USB_ETHER_xxx */
+static const struct usb_eth_prob_dev prob_dev[] = {
+	{ },		/* END */
+};
+
+static int usb_max_eth_dev; /* number of highest available usb eth device */
+static struct ueth_data usb_eth[USB_MAX_ETH_DEV];
+
+/*******************************************************************************
+ * tell if current ethernet device is a usb dongle
+ */
+int is_eth_dev_on_usb_host(void)
+{
+	int i;
+	struct eth_device *dev = eth_get_dev();
+
+	if (dev) {
+		for (i = 0; i < usb_max_eth_dev; i++)
+			if (&usb_eth[i].eth_dev == dev)
+				return 1;
+	}
+	return 0;
+}
+
+/*
+ * Given a USB device, ask each driver if it can support it, and attach it
+ * to the first driver that says 'yes'
+ */
+static void probe_valid_drivers(struct usb_device *dev)
+{
+	int j;
+
+	for (j = 0; prob_dev[j].probe && prob_dev[j].get_info; j++) {
+		if (!prob_dev[j].probe(dev, 0, &usb_eth[usb_max_eth_dev]))
+			continue;
+		/*
+		 * ok, it is a supported eth device. Get info and fill it in
+		 */
+		if (prob_dev[j].get_info(dev,
+			&usb_eth[usb_max_eth_dev],
+			&usb_eth[usb_max_eth_dev].eth_dev)) {
+			/* found proper driver */
+			/* register with networking stack */
+			usb_max_eth_dev++;
+
+			/*
+			 * usb_max_eth_dev must be incremented prior to this
+			 * call since eth_current_changed (internally called)
+			 * relies on it
+			 */
+			eth_register(&usb_eth[usb_max_eth_dev - 1].eth_dev);
+			break;
+			}
+		}
+	}
+
+/*******************************************************************************
+ * scan the usb and reports device info
+ * to the user if mode = 1
+ * returns current device or -1 if no
+ */
+int usb_host_eth_scan(int mode)
+{
+	int i, old_async;
+	struct usb_device *dev;
+
+
+	if (mode == 1)
+		printf("       scanning bus for ethernet devices... ");
+
+	old_async = usb_disable_asynch(1); /* asynch transfer not allowed */
+
+	for (i = 0; i < USB_MAX_ETH_DEV; i++)
+		memset(&usb_eth[i], 0, sizeof(usb_eth[i]));
+
+	for (i = 0; prob_dev[i].probe; i++) {
+		if (prob_dev[i].before_probe)
+			prob_dev[i].before_probe();
+	}
+
+	usb_max_eth_dev = 0;
+	for (i = 0; i < USB_MAX_DEVICE; i++) {
+		dev = usb_get_dev_index(i); /* get device */
+		debug("i=%d\n", i);
+		if (dev == NULL)
+			break; /* no more devices avaiable */
+
+		/* find valid usb_ether driver for this device, if any */
+		probe_valid_drivers(dev);
+
+		/* check limit */
+		if (usb_max_eth_dev == USB_MAX_ETH_DEV) {
+			printf("max USB Ethernet Device reached: %d stopping\n",
+				usb_max_eth_dev);
+			break;
+		}
+	} /* for */
+
+	usb_disable_asynch(old_async); /* restore asynch value */
+	printf("%d Ethernet Device(s) found\n", usb_max_eth_dev);
+	if (usb_max_eth_dev > 0)
+		return 0;
+	return -1;
+}
+