[MTD] driver model updates
Update driver model support in the MTD framework, so it fits
better into the current udev-based hotplug framework:
- Each mtd_info now has a device node. MTD drivers should set
the dev.parent field to point to the physical device, before
setting up partitions or otherwise declaring MTDs.
- Those device nodes always map to /sys/class/mtdX device nodes,
which no longer depend on MTD_CHARDEV.
- Those mtdX sysfs nodes have a "starter set" of attributes;
it's not yet sufficient to replace /proc/mtd.
- Enabling MTD_CHARDEV provides /sys/class/mtdXro/ nodes and the
/sys/class/mtd*/dev attributes (for udev, mdev, etc).
- Include a MODULE_ALIAS_CHARDEV_MAJOR macro. It'll work with
udev creating the /dev/mtd* nodes, not just a static rootfs.
So the sysfs structure is pretty much what you'd expect, except
that readonly chardev nodes are a bit quirky.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 65a7f37..a88f8bc 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -23,6 +23,9 @@
#include "mtdcore.h"
+
+static struct class *mtd_class;
+
/* These are exported solely for the purpose of mtd_blkdevs.c. You
should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex);
@@ -33,6 +36,82 @@
static LIST_HEAD(mtd_notifiers);
+
+#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
+#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
+#else
+#define MTD_DEVT(index) 0
+#endif
+
+/* REVISIT once MTD uses the driver model better, whoever allocates
+ * the mtd_info will probably want to use the release() hook...
+ */
+static void mtd_release(struct device *dev)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ /* remove /dev/mtdXro node if needed */
+ if (MTD_DEVT(mtd->index))
+ device_destroy(mtd_class, MTD_DEVT(mtd->index) + 1);
+}
+
+static ssize_t mtd_type_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+ char *type;
+
+ switch (mtd->type) {
+ case MTD_ABSENT:
+ type = "absent";
+ break;
+ case MTD_RAM:
+ type = "ram";
+ break;
+ case MTD_ROM:
+ type = "rom";
+ break;
+ case MTD_NORFLASH:
+ type = "nor";
+ break;
+ case MTD_NANDFLASH:
+ type = "nand";
+ break;
+ case MTD_DATAFLASH:
+ type = "dataflash";
+ break;
+ case MTD_UBIVOLUME:
+ type = "ubi";
+ break;
+ default:
+ type = "unknown";
+ }
+
+ return snprintf(buf, PAGE_SIZE, "%s\n", type);
+}
+static DEVICE_ATTR(mtd_type, S_IRUGO, mtd_type_show, NULL);
+
+static struct attribute *mtd_attrs[] = {
+ &dev_attr_mtd_type.attr,
+ /* FIXME provide a /proc/mtd superset */
+ NULL,
+};
+
+struct attribute_group mtd_group = {
+ .attrs = mtd_attrs,
+};
+
+struct attribute_group *mtd_groups[] = {
+ &mtd_group,
+ NULL,
+};
+
+static struct device_type mtd_devtype = {
+ .name = "mtd",
+ .groups = mtd_groups,
+ .release = mtd_release,
+};
+
/**
* add_mtd_device - register an MTD device
* @mtd: pointer to new MTD device info structure
@@ -41,6 +120,7 @@
* notify each currently active MTD 'user' of its arrival. Returns
* zero on success or 1 on failure, which currently will only happen
* if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
+ * or there's a sysfs error.
*/
int add_mtd_device(struct mtd_info *mtd)
@@ -95,6 +175,23 @@
mtd->name);
}
+ /* Caller should have set dev.parent to match the
+ * physical device.
+ */
+ mtd->dev.type = &mtd_devtype;
+ mtd->dev.class = mtd_class;
+ mtd->dev.devt = MTD_DEVT(i);
+ dev_set_name(&mtd->dev, "mtd%d", i);
+ if (device_register(&mtd->dev) != 0) {
+ mtd_table[i] = NULL;
+ break;
+ }
+
+ if (MTD_DEVT(i))
+ device_create(mtd_class, mtd->dev.parent,
+ MTD_DEVT(i) + 1,
+ NULL, "mtd%dro", i);
+
DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
/* No need to get a refcount on the module containing
the notifier, since we hold the mtd_table_mutex */
@@ -358,6 +455,24 @@
EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev);
+static int __init mtd_setup(void)
+{
+ mtd_class = class_create(THIS_MODULE, "mtd");
+
+ if (IS_ERR(mtd_class)) {
+ pr_err("Error creating mtd class.\n");
+ return PTR_ERR(mtd_class);
+ }
+ return 0;
+}
+core_initcall(mtd_setup);
+
+static void __exit mtd_teardown(void)
+{
+ class_destroy(mtd_class);
+}
+__exitcall(mtd_teardown);
+
#ifdef CONFIG_PROC_FS
/*====================================================================*/