[patch/rfc 2.6.29 1/2] MTD: driver model updates

Kevin Cernekee
2009-04-03T20:00:56Z

Based on: http://lists.infradead.org/pipermail/linux-mtd/2009-March/025005.html

My only change from the previous posting
(http://lists.infradead.org/pipermail/linux-mtd/2009-April/025121.html)
was to remove the "mtd_" prefix on the device attributes.

David's 2/2 patch
(http://lists.infradead.org/pipermail/linux-mtd/2009-March/025011.html)
may still be used as-is.

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
---
drivers/mtd/mtd_blkdevs.c | 1 +
drivers/mtd/mtdchar.c | 47 ++----------
drivers/mtd/mtdcore.c | 184 +++++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/mtdpart.c | 9 ++-
include/linux/mtd/mtd.h | 7 ++
5 files changed, 206 insertions(+), 42 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 4109e0b..a49a9c8 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 f478f1f..763d3f0 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 65a7f37..89c1e5d 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 +36,160 @@ 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(type, S_IRUGO, mtd_type_show, NULL);
+
+static ssize_t mtd_flags_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
+
+}
+static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
+
+static ssize_t mtd_size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n",
+ (unsigned long long)mtd->size);
+
+}
+static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
+
+static ssize_t mtd_erasesize_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
+
+}
+static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
+
+static ssize_t mtd_writesize_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
+
+}
+static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
+
+static ssize_t mtd_oobsize_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
+
+}
+static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
+
+static ssize_t mtd_numeraseregions_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
+
+}
+static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
+ NULL);
+
+static ssize_t mtd_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_to_mtd(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
+
+}
+static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
+
+static struct attribute *mtd_attrs[] = {
+ &dev_attr_type.attr,
+ &dev_attr_flags.attr,
+ &dev_attr_size.attr,
+ &dev_attr_erasesize.attr,
+ &dev_attr_writesize.attr,
+ &dev_attr_oobsize.attr,
+ &dev_attr_numeraseregions.attr,
+ &dev_attr_name.attr,
+ 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 +198,7 @@ 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 +253,23 @@ 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 */
@@ -139,6 +314,8 @@ int del_mtd_device (struct mtd_info *mtd)
} else {
struct mtd_notifier *not;

+ device_unregister(&mtd->dev);
+
/* No need to get a refcount on the module containing
the notifier, since we hold the mtd_table_mutex */
list_for_each_entry(not, &mtd_notifiers, list)
@@ -413,6 +590,12 @@ done:

static int __init init_mtd(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);
+ }
if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
proc_mtd->read_proc = mtd_read_proc;
return 0;
@@ -422,6 +605,7 @@ static void __exit cleanup_mtd(void)
{
if (proc_mtd)
remove_proc_entry( "mtd", NULL);
+ class_destroy(mtd_class);
}

module_init(init_mtd);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 06d5b9d..02ce38f 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,
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 0c079fd..5675b63 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -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)
--
1.5.6.3