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

[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

drivers/mtd/mtd_blkdevs.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/mtd/mtdchar.c

+6 −41
Original line number Diff line number Diff line
@@ -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>");

drivers/mtd/mtdcore.c

+115 −0
Original line number Diff line number Diff line
@@ -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



/*====================================================================*/

drivers/mtd/mtdpart.c

+8 −1
Original line number Diff line number Diff line
@@ -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,

include/linux/mtd/mtd.h

+7 −0
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE