Commit 1f24b5a8 authored by David Brownell's avatar David Brownell Committed by David Woodhouse

[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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 9d63287a
......@@ -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);
......
......@@ -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>");
......
......@@ -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
/*====================================================================*/
......
......@@ -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,
......
......@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/uio.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/mtd/compatmac.h>
#include <mtd/mtd-abi.h>
......@@ -237,6 +238,7 @@ struct mtd_info {
void *priv;
struct module *owner;
struct device dev;
int usecount;
/* If the driver is something smart, like UBI, it may need to maintain
......@@ -247,6 +249,11 @@ struct mtd_info {
void (*put_device) (struct mtd_info *mtd);
};
static inline struct mtd_info *dev_to_mtd(struct device *dev)
{
return dev ? container_of(dev, struct mtd_info, dev) : NULL;
}
static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
{
if (mtd->erasesize_shift)
......
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