[RFC 1/2] export pcmcia info to hotplug

[Dominik Brodowski]

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 at dominikbrodowski.net>
---

 drivers/pcmcia/ds.c |   93 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 93 insertions(+)

Index: 2.6.11-rc3+/drivers/pcmcia/ds.c
===================================================================
--- 2.6.11-rc3+.orig/drivers/pcmcia/ds.c	2005-02-10 20:32:41.000000000 +0100
+++ 2.6.11-rc3+/drivers/pcmcia/ds.c	2005-02-10 20:54:56.000000000 +0100
@@ -35,6 +35,7 @@
 #include <linux/delay.h>
 #include <linux/kref.h>
 #include <linux/workqueue.h>
+#include <linux/crc32.h>
 
 #include <asm/atomic.h>
 
@@ -602,6 +603,97 @@
 	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;
+	char *scratch;
+	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]));
+	}
+
+	scratch = buffer;
+
+        /* stuff we want to pass to /sbin/hotplug */
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length,
+			     "PCMCIA_DEVICE=%01X",
+			     p_dev->device_no);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        scratch += length;
+
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length,
+			     "PCMCIA_DEVICE_FUNC=%01X",
+			     p_dev->func);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        scratch += length;
+
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length, "PCMCIA_FUNC_ID=%01X",
+                            p_dev->has_func_id ? p_dev->func_id : 0);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        scratch += length;
+
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length, "PCMCIA_ID=%04X:%04X",
+			     p_dev->has_manf_id ? p_dev->manf_id : 0,
+			     p_dev->has_card_id ? p_dev->card_id : 0);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        scratch += length;
+
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length,
+			     "PCMCIA_PRODUCT=%04X:%04X:%04X:%04X",
+			     hash[0], hash[1], hash[2], hash[3]);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                return -ENOMEM;
+        ++length;
+        scratch += length;
+
+        envp[i++] = scratch;
+        length += scnprintf (scratch, buffer_size - length,
+			     "PCMCIA_SLOT_NAME=%s",
+			     p_dev->dev.bus_id);
+        if ((buffer_size - length <= 0) || (i >= num_envp))
+                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)				\
@@ -1612,6 +1704,7 @@
 
 struct bus_type pcmcia_bus_type = {
 	.name = "pcmcia",
+	.hotplug = pcmcia_bus_hotplug,
 	.match = pcmcia_bus_match,
 	.dev_attrs = pcmcia_dev_attrs,
 };