[PATCH] 2.5.31 driverfs: patch for your consideration

[Adam Belay]

Here's the patch as we discussed.

diff -ur --new-file a/drivers/base/interface.c b/drivers/base/interface.c
--- a/drivers/base/interface.c    Wed Aug 14 17:09:28 2002
+++ b/drivers/base/interface.c    Fri Aug 16 22:03:18 2002
@@ -88,8 +88,20 @@
 static DEVICE_ATTR(power,"power",S_IWUSR | S_IRUGO,
            device_read_power,device_write_power);
 
+
+static ssize_t device_read_driver(struct device * dev, char * buf, 
size_t count, loff_t off)
+{
+    if (dev->driver)
+        return off ? 0 : sprintf(buf,"%s\n",dev->driver->name);
+    else
+        return 0;
+}
+
+static DEVICE_ATTR(driver,"driver",S_IRUGO,device_read_driver,NULL);
+
 struct device_attribute * device_default_files[] = {
     &dev_attr_name,
     &dev_attr_power,
+    &dev_attr_driver,
     NULL,
 };

Also if You're interested here's the write support for "driver".

diff -ur --new-file a/drivers/base/base.h b/drivers/base/base.h
--- a/drivers/base/base.h    Fri Aug 16 12:20:18 2002
+++ b/drivers/base/base.h    Fri Aug 16 22:17:26 2002
@@ -26,3 +26,5 @@
 
 extern int driver_attach(struct device_driver * drv);
 extern void driver_detach(struct device_driver * drv);
+extern int do_driver_detach(struct device * dev, struct device_driver * 
drv);
+extern int do_driver_attach(struct device * dev, void * data);
diff -ur --new-file a/drivers/base/core.c b/drivers/base/core.c
--- a/drivers/base/core.c    Wed Aug 14 17:09:28 2002
+++ b/drivers/base/core.c    Fri Aug 16 22:16:30 2002
@@ -98,7 +98,7 @@
 
 static void device_detach(struct device * dev)
 {
-    struct device_driver * drv;
+    struct device_driver * drv;
 
     if (dev->driver) {
         lock_device(dev);
@@ -117,7 +117,7 @@
     }
 }
 
-static int do_driver_attach(struct device * dev, void * data)
+int do_driver_attach(struct device * dev, void * data)
 {
     struct device_driver * drv = (struct device_driver *)data;
     int error = 0;
@@ -134,7 +134,7 @@
     return bus_for_each_dev(drv->bus,drv,do_driver_attach);
 }
 
-static int do_driver_detach(struct device * dev, struct device_driver * 
drv)
+int do_driver_detach(struct device * dev, struct device_driver * drv)
 {
     lock_device(dev);
     if (dev->driver == drv) {
diff -ur --new-file a/drivers/base/interface.c b/drivers/base/interface.c
--- a/drivers/base/interface.c    Fri Aug 16 22:06:41 2002
+++ b/drivers/base/interface.c    Fri Aug 16 22:15:29 2002
@@ -8,6 +8,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/stat.h>
+#include "base.h"
 
 static ssize_t device_read_name(struct device * dev, char * buf, size_t 
count, loff_t off)
 {
@@ -97,7 +98,44 @@
         return 0;
 }
 
-static DEVICE_ATTR(driver,"driver",S_IRUGO,device_read_driver,NULL);
+struct device_driver * find_driver_by_name(struct bus_type * bus, char 
* name)
+{
+    struct list_head * pos;
+    struct device_driver * drv;
+    list_for_each (pos, &bus->drivers)
+    {
+        drv = list_entry(pos, struct device_driver, bus_list);
+        if (!strncmp(drv->name,name,strlen(name) - 1))
+            return drv;
+
+    }
+    return NULL;
+
+}
+
+static ssize_t device_write_driver(struct device * dev, char * buf, 
size_t count, loff_t off)
+{
+    struct device_driver * drv = NULL;
+    int error = 0;
+    if (off)
+        return 0;
+    if (!dev->bus)
+        return count;
+    if (!dev->driver)
+    {
+        drv = find_driver_by_name(dev->bus, buf);
+        if (drv)
+            error = do_driver_attach(dev,drv);
+
+    } else if (!strnicmp(buf,"remove",6))
+    {
+        error = do_driver_detach(dev, dev->driver);
+    }
+    return error < 0 ? error : count;
+}
+
+static DEVICE_ATTR(driver,"driver",S_IWUSR | S_IRUGO,
+           device_read_driver,device_write_driver);
 
 struct device_attribute * device_default_files[] = {
     &dev_attr_name,

I look forward to hearing from you.

Thanks,
Adam

PS:   Would you be interested in a patch that would port the pnpbios 
driver to the driver model?