From: Jeff Mahoney <jeffm@suse.com>

This patch adds the hotplug routine for generating hotplug events when devices
are seen on the macio bus.  It uses the attributed created by the sysfs nodes
to generate the hotplug environment vars for userspace.

Since the characters allowed inside the 'compatible' field are NUL terminated,
they are exported as individual OF_COMPATIBLE_# variables, with
OF_COMPATIBLE_N maintaining a count of how many there are.

In order for hotplug to work with macio devices, patches to module-init-tools
and hotplug must be applied.  Those patches are available at:

 ftp://ftp.suse.com/pub/people/jeffm/linux/macio-hotplug/

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/macintosh/macio_asic.c |   73 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 73 insertions(+)

diff -puN drivers/macintosh/macio_asic.c~openfirmware-implement-hotplug-for-macio-devices drivers/macintosh/macio_asic.c
--- 25/drivers/macintosh/macio_asic.c~openfirmware-implement-hotplug-for-macio-devices	2005-06-28 22:42:50.000000000 -0700
+++ 25-akpm/drivers/macintosh/macio_asic.c	2005-06-28 22:42:50.000000000 -0700
@@ -128,9 +128,82 @@ static int macio_device_resume(struct de
 
 extern struct device_attribute macio_dev_attrs[];
 
+static int macio_hotplug (struct device *dev, char **envp, int num_envp,
+                          char *buffer, int buffer_size)
+{
+	struct macio_dev * macio_dev;
+	struct of_device * of;
+	char *scratch, *compat;
+	int i = 0;
+	int length = 0;
+	int cplen, seen = 0;
+
+	if (!dev)
+		return -ENODEV;
+
+	macio_dev = to_macio_device(dev);
+	if (!macio_dev)
+		return -ENODEV;
+
+	of = &macio_dev->ofdev;
+	scratch = buffer;
+
+	/* stuff we want to pass to /sbin/hotplug */
+	envp[i++] = scratch;
+	length += scnprintf(scratch, buffer_size - length, "OF_NAME=%s",
+				of->node->name);
+	if ((buffer_size - length <= 0) || (i >= num_envp))
+		return -ENOMEM;
+	++length;
+	scratch += length;
+
+	envp[i++] = scratch;
+	length += scnprintf(scratch, buffer_size - length, "OF_TYPE=%s",
+				of->node->type);
+	if ((buffer_size - length <= 0) || (i >= num_envp))
+		return -ENOMEM;
+	++length;
+	scratch += length;
+
+	/* Since the compatible field can contain pretty much anything
+	 * it's not really legal to split it out with commas. We split it
+	 * up using a number of environment variables instead. */
+
+	compat = (char *) get_property(of->node, "compatible", &cplen);
+	while (compat && cplen > 0) {
+		int l;
+		envp[i++] = scratch;
+		length += scnprintf(scratch, buffer_size - length,
+					"OF_COMPATIBLE_%d=%s", seen, compat);
+		if ((buffer_size - length <= 0) || (i >= num_envp))
+			return -ENOMEM;
+		length++;
+		scratch += length;
+		l = strlen (compat) + 1;
+		compat += l;
+		cplen -= l;
+		seen++;
+	}
+
+	envp[i++] = scratch;
+	length += scnprintf(scratch, buffer_size - length,
+				"OF_COMPATIBLE_N=%d", seen);
+	if ((buffer_size - length <= 0) || (i >= num_envp))
+		return -ENOMEM;
+	++length;
+	scratch += length;
+
+	envp[i] = NULL;
+
+	return 0;
+
+}
+extern struct device_attribute macio_dev_attrs[];
+
 struct bus_type macio_bus_type = {
        .name	= "macio",
        .match	= macio_bus_match,
+	.hotplug = macio_hotplug,
        .suspend	= macio_device_suspend,
        .resume	= macio_device_resume,
        .dev_attrs = macio_dev_attrs,
_