From: Dominik Brodowski <linux@dominikbrodowski.net>

Export information to /sbin/hotplug for PCMCIA devices: card_id, manf_id,
func_id, bus_id (like pcmcia1.0) and crc32-hashes of the prod_id strings.  

Why not the prod_id strings themselves?

a) They may contain all sorts of strange and difficult to handle characters, 
   like " ".

b) It's impossible to pass multiple strings to userspace.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 25-akpm/drivers/pcmcia/ds.c |   67 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 67 insertions(+)

diff -puN drivers/pcmcia/ds.c~pcmcia-hotplug-event-for-pcmcia-devices drivers/pcmcia/ds.c
--- 25/drivers/pcmcia/ds.c~pcmcia-hotplug-event-for-pcmcia-devices	Sun Mar  6 17:28:05 2005
+++ 25-akpm/drivers/pcmcia/ds.c	Sun Mar  6 17:28:05 2005
@@ -35,6 +35,7 @@
 #include <linux/delay.h>
 #include <linux/kref.h>
 #include <linux/workqueue.h>
+#include <linux/crc32.h>
 
 #include <asm/atomic.h>
 
@@ -601,6 +602,71 @@ static int pcmcia_bus_match(struct devic
 	return 0;
 }
 
+#ifdef CONFIG_HOTPLUG
+
+static int pcmcia_bus_hotplug(struct device *dev, char **envp, int num_envp,
+			      char *buffer, int buffer_size)
+{
+	struct pcmcia_device *p_dev;
+	int i, length = 0;
+	u32 hash[4] = { 0, 0, 0, 0};
+
+	if (!dev)
+		return -ENODEV;
+
+	p_dev = to_pcmcia_dev(dev);
+
+	/* calculate hashes */
+	for (i=0; i<4; i++) {
+		if (!p_dev->prod_id[i])
+			continue;
+		hash[i] = crc32(0, p_dev->prod_id[i], strlen(p_dev->prod_id[i]));
+	}
+
+	i = 0;
+
+	if (add_hotplug_env_var(envp, num_envp, &i,
+				buffer, buffer_size, &length,
+				"SOCKET_NO=%u",
+				p_dev->socket->sock))
+		return -ENOMEM;
+
+	if (add_hotplug_env_var(envp, num_envp, &i,
+				buffer, buffer_size, &length,
+				"DEVICE_NO=%02X",
+				p_dev->device_no))
+		return -ENOMEM;
+
+	if (add_hotplug_env_var(envp, num_envp, &i,
+				buffer, buffer_size, &length,
+				"MODNAME=pcmcia:m%04Xc%04Xf%02Xfn%02Xpfn%02X"
+				"pa%08Xpb%08Xpc%08Xpd%08X",
+				p_dev->has_manf_id ? p_dev->manf_id : 0,
+				p_dev->has_card_id ? p_dev->card_id : 0,
+				p_dev->has_func_id ? p_dev->func_id : 0,
+				p_dev->func,
+				p_dev->device_no,
+				hash[0],
+				hash[1],
+				hash[2],
+				hash[3]))
+		return -ENOMEM;
+
+	envp[i] = NULL;
+
+	return 0;
+}
+
+#else
+
+static int pcmcia_bus_hotplug(struct device *dev, char **envp, int num_envp,
+			      char *buffer, int buffer_size)
+{
+	return -ENODEV;
+}
+
+#endif
+
 /************************ per-device sysfs output ***************************/
 
 #define pcmcia_device_attr(field, test, format)				\
@@ -1573,6 +1639,7 @@ static struct class_interface pcmcia_bus
 
 struct bus_type pcmcia_bus_type = {
 	.name = "pcmcia",
+	.hotplug = pcmcia_bus_hotplug,
 	.match = pcmcia_bus_match,
 	.dev_attrs = pcmcia_dev_attrs,
 };
_