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authorDavid Brownell <dbrownell@users.sourceforge.net>2009-03-26 10:42:41 +0300
committerDavid Woodhouse <David.Woodhouse@intel.com>2009-04-04 17:29:07 +0400
commit1f24b5a8ecbb2a3c7080f418974d40e3ffedb221 (patch)
tree07dfc44f62dac78bdf4a8cdb4d91d60f73c04ff4 /drivers/mtd
parent9d63287a461c269edb39941744f4ff22223cf349 (diff)
downloadlinux-1f24b5a8ecbb2a3c7080f418974d40e3ffedb221.tar.xz
[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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/mtd_blkdevs.c1
-rw-r--r--drivers/mtd/mtdchar.c47
-rw-r--r--drivers/mtd/mtdcore.c115
-rw-r--r--drivers/mtd/mtdpart.c9
4 files changed, 130 insertions, 42 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 4109e0bb94f5..a49a9c8f2cb1 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -286,6 +286,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
gd->private_data = new;
new->blkcore_priv = gd;
gd->queue = tr->blkcore_priv->rq;
+ gd->driverfs_dev = new->mtd->dev.parent;
if (new->readonly)
set_disk_ro(gd, 1);
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index f478f1fc3949..763d3f0a1f42 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -20,33 +20,6 @@
#include <asm/uaccess.h>
-static struct class *mtd_class;
-
-static void mtd_notify_add(struct mtd_info* mtd)
-{
- if (!mtd)
- return;
-
- device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
- NULL, "mtd%d", mtd->index);
-
- device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
- NULL, "mtd%dro", mtd->index);
-}
-
-static void mtd_notify_remove(struct mtd_info* mtd)
-{
- if (!mtd)
- return;
-
- device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
- device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
-}
-
-static struct mtd_notifier notifier = {
- .add = mtd_notify_add,
- .remove = mtd_notify_remove,
-};
/*
* Data structure to hold the pointer to the mtd device as well
@@ -854,34 +827,26 @@ static const struct file_operations mtd_fops = {
static int __init init_mtdchar(void)
{
- if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
+ int status;
+
+ status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
+ if (status < 0) {
printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
MTD_CHAR_MAJOR);
- return -EAGAIN;
- }
-
- mtd_class = class_create(THIS_MODULE, "mtd");
-
- if (IS_ERR(mtd_class)) {
- printk(KERN_ERR "Error creating mtd class.\n");
- unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
- return PTR_ERR(mtd_class);
}
- register_mtd_user(&notifier);
- return 0;
+ return status;
}
static void __exit cleanup_mtdchar(void)
{
- unregister_mtd_user(&notifier);
- class_destroy(mtd_class);
unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
}
module_init(init_mtdchar);
module_exit(cleanup_mtdchar);
+MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 65a7f3703881..a88f8bc9a534 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 @@ EXPORT_SYMBOL_GPL(mtd_table);
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 @@ static LIST_HEAD(mtd_notifiers);
* 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 @@ int add_mtd_device(struct mtd_info *mtd)
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(register_mtd_user);
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
/*====================================================================*/
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 06d5b9d8853a..02ce38fb1fc3 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -356,6 +356,11 @@ static struct mtd_part *add_one_partition(struct mtd_info *master,
slave->mtd.owner = master->owner;
slave->mtd.backing_dev_info = master->backing_dev_info;
+ /* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
+ * to have the same data be in two different partitions.
+ */
+ slave->mtd.dev.parent = master->dev.parent;
+
slave->mtd.read = part_read;
slave->mtd.write = part_write;
@@ -508,7 +513,9 @@ out_register:
* This function, given a master MTD object and a partition table, creates
* and registers slave MTD objects which are bound to the master according to
* the partition definitions.
- * (Q: should we register the master MTD object as well?)
+ *
+ * We don't register the master, or expect the caller to have done so,
+ * for reasons of data integrity.
*/
int add_mtd_partitions(struct mtd_info *master,