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mtd: nand: update the documentation to reflect framework changes

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The MTD device is now directly embedded in the nand_chip struct. Update the
mtdnand documentation to mention this aspect and fix the different
examples.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Boris BREZILLON 2015-12-10 09:00:30 +01:00 committed by Brian Norris
parent 960823a226
commit 3eb064e4b0
1 changed files with 15 additions and 16 deletions
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31
Documentation/DocBook/mtdnand.tmpl
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@ -162,12 +162,15 @@
<sect1 id="Basic_defines">
<title>Basic defines</title>
<para>
At least you have to provide a mtd structure and
a storage for the ioremap'ed chip address.
You can allocate the mtd structure using kmalloc
or you can allocate it statically.
In case of static allocation you have to allocate
a nand_chip structure too.
At least you have to provide a nand_chip structure
and a storage for the ioremap'ed chip address.
You can allocate the nand_chip structure using
kmalloc or you can allocate it statically.
The NAND chip structure embeds an mtd structure
which will be registered to the MTD subsystem.
You can extract a pointer to the mtd structure
from a nand_chip pointer using the nand_to_mtd()
helper.
</para>
<para>
Kmalloc based example
@ -180,7 +183,6 @@ static void __iomem *baseaddr;
Static example
</para>
<programlisting>
static struct mtd_info board_mtd;
static struct nand_chip board_chip;
static void __iomem *baseaddr;
</programlisting>
@ -274,13 +276,15 @@ static int __init board_init (void)
int err = 0;
/* Allocate memory for MTD device structure and private data */
board_mtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
if (!board_mtd) {
this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
if (!this) {
printk ("Unable to allocate NAND MTD device structure.\n");
err = -ENOMEM;
goto out;
}
board_mtd = nand_to_mtd(this);
/* map physical address */
baseaddr = ioremap(CHIP_PHYSICAL_ADDRESS, 1024);
if (!baseaddr) {
@ -289,11 +293,6 @@ static int __init board_init (void)
goto out_mtd;
}
/* Get pointer to private data */
this = (struct nand_chip *) ();
/* Link the private data with the MTD structure */
board_mtd->priv = this;
/* Set address of NAND IO lines */
this->IO_ADDR_R = baseaddr;
this->IO_ADDR_W = baseaddr;
@ -317,7 +316,7 @@ static int __init board_init (void)
out_ior:
iounmap(baseaddr);
out_mtd:
kfree (board_mtd);
kfree (this);
out:
return err;
}
@ -343,7 +342,7 @@ static void __exit board_cleanup (void)
iounmap(baseaddr);
/* Free the MTD device structure */
kfree (board_mtd);
kfree (mtd_to_nand(board_mtd));
}
module_exit(board_cleanup);
#endif