mtd: merge mtdchar module with mtdcore

The MTD subsystem has historically tried to be as configurable as possible. The
side-effect of this is that its configuration menu is rather large, and we are
gradually shrinking it. For example, we recently merged partitions support with
the mtdcore.

This patch does the next step - it merges the mtdchar module to mtdcore. And in
this case this is not only about eliminating too fine-grained separation and
simplifying the configuration menu. This is also about eliminating seemingly
useless kernel module.

Indeed, mtdchar is a module that allows user-space making use of MTD devices
via /dev/mtd* character devices. If users do not enable it, they simply cannot
use MTD devices at all. They cannot read or write the flash contents. Is it a
sane and useful setup? I believe not. And everyone just enables mtdchar.

Having mtdchar separate is also a little bit harmful. People sometimes miss the
fact that they need to enable an additional configuration option to have
user-space MTD interfaces, and then they wonder why on earth the kernel does
not allow using the flash? They spend time asking around.

Thus, let's just get rid of this module and make it part of mtd core.

Note, mtdchar had additional configuration option to enable OTP interfaces,
which are present on some flashes. I removed that option as well - it saves a
really tiny amount space.

[dwmw2: Strictly speaking, you can mount file systems on MTD devices just
        fine without the mtdchar (or mtdblock) devices; you just can't do
        other manipulations directly on the underlying device. But still I
        agree that it makes sense to make this unconditional. And Yay! we
        get to kill off an instance of checking CONFIG_foo_MODULE, which is
        an abomination that should never happen.]

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 557bec599f4f6741255a3f6c16f6aff0c6d4585b..5fab4e6e83013c033c01d2465b4f25c756f39dce 100644 (file)
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -157,19 +157,6 @@ config MTD_BCM47XX_PARTS
 
 comment "User Modules And Translation Layers"
 
-config MTD_CHAR
-       tristate "Direct char device access to MTD devices"
-       help
-         This provides a character device for each MTD device present in
-         the system, allowing the user to read and write directly to the
-         memory chips, and also use ioctl() to obtain information about
-         the device, or to erase parts of it.
-
-config HAVE_MTD_OTP
-       bool
-       help
-         Enable access to OTP regions using MTD_CHAR.
-
 config MTD_BLKDEVS
        tristate "Common interface to block layer for MTD 'translation layers'"
        depends on BLOCK

diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 18a38e55b2f0fec9cc3eb7466cf51568862e7d70..4cfb31e6c966ad37d1384d59ccd12d572961ea93 100644 (file)
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -4,7 +4,7 @@
 
 # Core functionality.
 obj-$(CONFIG_MTD)              += mtd.o
-mtd-y                          := mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o
+mtd-y                          := mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o
 
 obj-$(CONFIG_MTD_OF_PARTS)     += ofpart.o
 obj-$(CONFIG_MTD_REDBOOT_PARTS) += redboot.o
@@ -15,7 +15,6 @@ obj-$(CONFIG_MTD_BCM63XX_PARTS)       += bcm63xxpart.o
 obj-$(CONFIG_MTD_BCM47XX_PARTS)        += bcm47xxpart.o
 
 # 'Users' - code which presents functionality to userspace.
-obj-$(CONFIG_MTD_CHAR)         += mtdchar.o
 obj-$(CONFIG_MTD_BLKDEVS)      += mtd_blkdevs.o
 obj-$(CONFIG_MTD_BLOCK)                += mtdblock.o
 obj-$(CONFIG_MTD_BLOCK_RO)     += mtdblock_ro.o

diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig
index c219e3d098d9d1572584fed1613aa52f627e9014..e4696b37f3deca35ccca51be33c8ff3181606c58 100644 (file)
--- a/drivers/mtd/chips/Kconfig
+++ b/drivers/mtd/chips/Kconfig
@@ -146,7 +146,6 @@ config MTD_CFI_I8
 config MTD_OTP
        bool "Protection Registers aka one-time programmable (OTP) bits"
        depends on MTD_CFI_ADV_OPTIONS
-       select HAVE_MTD_OTP
        default n
        help
          This enables support for reading, writing and locking so called

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index ec4a2cc3e9b57fb053a60f6747dae04a042115f5..2a4d55e4b3628b7437fb82d7d51a929c92cf79e2 100644 (file)
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -71,7 +71,6 @@ config MTD_DATAFLASH_WRITE_VERIFY
 config MTD_DATAFLASH_OTP
        bool "DataFlash OTP support (Security Register)"
        depends on MTD_DATAFLASH
-       select HAVE_MTD_OTP
        help
          Newer DataFlash chips (revisions C and D) support 128 bytes of
          one-time-programmable (OTP) data.  The first half may be written

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index c7292528c7bb8348968c3190ffa47623622fb30b..e0e59bf9b915a83c1b30cc09be8e3d61c365699e 100644 (file)
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -38,6 +38,8 @@
 
 #include <asm/uaccess.h>
 
+#include "mtdcore.h"
+
 static DEFINE_MUTEX(mtd_mutex);
 
 /*
@@ -365,7 +367,6 @@ static void mtdchar_erase_callback (struct erase_info *instr)
        wake_up((wait_queue_head_t *)instr->priv);
 }
 
-#ifdef CONFIG_HAVE_MTD_OTP
 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 {
        struct mtd_info *mtd = mfi->mtd;
@@ -395,9 +396,6 @@ static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 
        return 0;
 }
-#else
-# define otp_select_filemode(f,m)      -EOPNOTSUPP
-#endif
 
 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
        uint64_t start, uint32_t length, void __user *ptr,
@@ -890,7 +888,6 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
                break;
        }
 
-#ifdef CONFIG_HAVE_MTD_OTP
        case OTPSELECT:
        {
                int mode;
@@ -946,7 +943,6 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
                ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
                break;
        }
-#endif
 
        /* This ioctl is being deprecated - it truncates the ECC layout */
        case ECCGETLAYOUT:
@@ -1242,7 +1238,7 @@ static struct file_system_type mtd_inodefs_type = {
 };
 MODULE_ALIAS_FS("mtd_inodefs");
 
-static int __init init_mtdchar(void)
+int __init init_mtdchar(void)
 {
        int ret;
 
@@ -1268,18 +1264,10 @@ err_unregister_chdev:
        return ret;
 }
 
-static void __exit cleanup_mtdchar(void)
+void __exit cleanup_mtdchar(void)
 {
        unregister_filesystem(&mtd_inodefs_type);
        __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "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>");
-MODULE_DESCRIPTION("Direct character-device access to MTD devices");
 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 91c2efd22e1f04e1dfb4b4d948869bf3a648d74f..71877ff77cbff90d186f0e9f4f788ef30e70384b 100644 (file)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -41,6 +41,7 @@
 #include <linux/mtd/partitions.h>
 
 #include "mtdcore.h"
+
 /*
  * backing device capabilities for non-mappable devices (such as NAND flash)
  * - permits private mappings, copies are taken of the data
@@ -96,11 +97,7 @@ EXPORT_SYMBOL_GPL(__mtd_next_device);
 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...
@@ -1185,8 +1182,15 @@ static int __init init_mtd(void)
 
        proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
 
+       ret = init_mtdchar();
+       if (ret)
+               goto out_procfs;
+
        return 0;
 
+out_procfs:
+       if (proc_mtd)
+               remove_proc_entry("mtd", NULL);
 err_bdi3:
        bdi_destroy(&mtd_bdi_ro_mappable);
 err_bdi2:
@@ -1200,6 +1204,7 @@ err_reg:
 
 static void __exit cleanup_mtd(void)
 {
+       cleanup_mtdchar();
        if (proc_mtd)
                remove_proc_entry("mtd", NULL);
        class_unregister(&mtd_class);

diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index 9b10fed1ae2c5504bf85b2a58e9b7fe9d97b0404..7b0353399a10642f44ca4d15994942066693e9b2 100644 (file)
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -1,6 +1,6 @@
 /*
- * These are exported solely for the purpose of mtd_blkdevs.c. You
- * should not use them for _anything_ else.
+ * These are exported solely for the purpose of mtd_blkdevs.c and mtdchar.c.
+ * You should not use them for _anything_ else.
  */
 
 extern struct mutex mtd_table_mutex;
@@ -14,6 +14,9 @@ int parse_mtd_partitions(struct mtd_info *master, const char * const *types,
                         struct mtd_partition **pparts,
                         struct mtd_part_parser_data *data);
 
+int __init init_mtdchar(void);
+void __exit cleanup_mtdchar(void);
+
 #define mtd_for_each_device(mtd)                       \
        for ((mtd) = __mtd_next_device(0);              \
             (mtd) != NULL;                             \

diff --git a/drivers/mtd/onenand/Kconfig b/drivers/mtd/onenand/Kconfig
index 91467bb036341fe52f84a5db00c7664365d0abb9..eac7bb28360d2c97f463a95d3411d6fbc5580a0e 100644 (file)
--- a/drivers/mtd/onenand/Kconfig
+++ b/drivers/mtd/onenand/Kconfig
@@ -40,7 +40,6 @@ config MTD_ONENAND_SAMSUNG
 
 config MTD_ONENAND_OTP
        bool "OneNAND OTP Support"
-       select HAVE_MTD_OTP
        help
          One Block of the NAND Flash Array memory is reserved as
          a One-Time Programmable Block memory area.