ide-generic: add ide_generic class and attribute for adding new interfaces

* Add ide_generic_sysfs_init() helper registering 'ide_generic' class
  (together with ide_generic_class_release() ->class_release method)
  and use it in ide_generic_init().

* Add "add" class attribute to 'ide_generic' class for adding new interfaces
  (it is intended to be a replacement for obsoleted "idex=base[,ctl[,irq]]"
  kernel parameters).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 77 insertions, 1 deletions

diff --git a/drivers/ide/ide-generic.c b/drivers/ide/ide-generic.c
index c1d8d71f8791..387574fe4b2b 100644
--- a/drivers/ide/ide-generic.c
+++ b/drivers/ide/ide-generic.c
@@ -1,17 +1,89 @@
 /*
  * generic/default IDE host driver
  *
- * Copyright (C) 2004 Bartlomiej Zolnierkiewicz
+ * Copyright (C) 2004, 2008 Bartlomiej Zolnierkiewicz
  * This code was split off from ide.c.  See it for original copyrights.
  *
  * May be copied or modified under the terms of the GNU General Public License.
  */
 
+/*
+ * For special cases new interfaces may be added using sysfs, i.e.
+ *
+ *      echo -n "0x168:0x36e:10" > /sys/class/ide_generic/add
+ *
+ * will add an interface using I/O ports 0x168-0x16f/0x36e and IRQ 10.
+ */
+
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/ide.h>
 
+#define DRV_NAME        "ide_generic"
+
+static ssize_t store_add(struct class *cls, const char *buf, size_t n)
+{
+        ide_hwif_t *hwif;
+        unsigned int base, ctl;
+        int irq;
+        hw_regs_t hw;
+        u8 idx[] = { 0xff, 0xff, 0xff, 0xff };
+
+        if (sscanf(buf, "%x:%x:%d", &base, &ctl, &irq) != 3)
+                return -EINVAL;
+
+        hwif = ide_find_port(base);
+        if (hwif == NULL)
+                return -ENOENT;
+
+        memset(&hw, 0, sizeof(hw));
+        ide_std_init_ports(&hw, base, ctl);
+        hw.irq = irq;
+        hw.chipset = ide_generic;
+
+        ide_init_port_hw(hwif, &hw);
+
+        idx[0] = hwif->index;
+
+        ide_device_add(idx, NULL);
+
+        return n;
+};
+
+static struct class_attribute ide_generic_class_attrs[] = {
+        __ATTR(add, S_IWUSR, NULL, store_add),
+        __ATTR_NULL
+};
+
+static void ide_generic_class_release(struct class *cls)
+{
+        kfree(cls);
+}
+
+static int __init ide_generic_sysfs_init(void)
+{
+        struct class *cls;
+        int rc;
+
+        cls = kzalloc(sizeof(*cls), GFP_KERNEL);
+        if (!cls)
+                return -ENOMEM;
+
+        cls->name = DRV_NAME;
+        cls->owner = THIS_MODULE;
+        cls->class_release = ide_generic_class_release;
+        cls->class_attrs = ide_generic_class_attrs;
+
+        rc = class_register(cls);
+        if (rc) {
+                kfree(cls);
+                return rc;
+        }
+
+        return 0;
+}
+
 static int __init ide_generic_init(void)
 {
         u8 idx[MAX_HWIFS];
@@ -30,6 +102,10 @@ static int __init ide_generic_init(void)
 
         ide_device_add_all(idx, NULL);
 
+        if (ide_generic_sysfs_init())
+                printk(KERN_ERR DRV_NAME ": failed to create ide_generic "
+                                         "class\n");
+
         return 0;
 }