From 1f24b5a8ecbb2a3c7080f418974d40e3ffedb221 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Thu, 26 Mar 2009 00:42:41 -0700 Subject: [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 Signed-off-by: David Woodhouse --- drivers/mtd/mtdcore.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) (limited to 'drivers/mtd/mtdcore.c') 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 /*====================================================================*/ -- cgit v1.2.2