[MTD] nandsim: enhance nandsim to allow arbitrary NAND size

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=a5ac8aeb29000fcab8d91848273a6616fcd039ee
Commit:     a5ac8aeb29000fcab8d91848273a6616fcd039ee
Parent:     57aa6b545f6f772dd317ccd29bdada999b16a13d
Author:     Adrian Hunter <ext-adrian.hunter at nokia.com>
AuthorDate: Mon Mar 19 12:49:11 2007 +0200
Committer:  David Woodhouse <dwmw2 at infradead.org>
CommitDate: Tue Apr 17 13:55:55 2007 -0400

    [MTD] nandsim: enhance nandsim to allow arbitrary NAND size
    
    A new module parameter has been added called 'overridesize',
    which overrides the size that would be determined by the
    ID bytes. 'overridesize' is specified in erase blocks and
    as the exponent of a power of two e.g. 5 means a size of
    32 erase blocks.
    
    Signed-off-by: Adrian Hunter <ext-adrian.hunter at nokia.com>
    Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
 drivers/mtd/nand/nandsim.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 1a44ef6..205df0f 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -100,6 +100,7 @@ static char *weakpages = NULL;
 static unsigned int bitflips = 0;
 static char *gravepages = NULL;
 static unsigned int rptwear = 0;
+static unsigned int overridesize = 0;
 
 module_param(first_id_byte,  uint, 0400);
 module_param(second_id_byte, uint, 0400);
@@ -121,8 +122,9 @@ module_param(weakpages,      charp, 0400);
 module_param(bitflips,       uint, 0400);
 module_param(gravepages,     charp, 0400);
 module_param(rptwear,        uint, 0400);
+module_param(overridesize,   uint, 0400);
 
-MODULE_PARM_DESC(first_id_byte,  "The fist byte returned by NAND Flash 'read ID' command (manufaturer ID)");
+MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID)");
 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command");
 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
@@ -149,6 +151,9 @@ MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (default
 				 " separated by commas e.g. 1401:2 means page 1401"
 				 " can be read only twice before failing");
 MODULE_PARM_DESC(rptwear,        "Number of erases inbetween reporting wear, if not zero");
+MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
+				 "The size is specified in erase blocks and as the exponent of a power of two"
+				 " e.g. 5 means a size of 32 erase blocks");
 
 /* The largest possible page size */
 #define NS_LARGEST_PAGE_SIZE	2048
@@ -1959,6 +1964,8 @@ static int __init ns_init_module(void)
 	chip->verify_buf = ns_nand_verify_buf;
 	chip->read_word  = ns_nand_read_word;
 	chip->ecc.mode   = NAND_ECC_SOFT;
+	/* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
+	/* and 'badblocks' parameters to work */
 	chip->options   |= NAND_SKIP_BBTSCAN;
 
 	/*
@@ -1999,6 +2006,18 @@ static int __init ns_init_module(void)
 		goto error;
 	}
 
+	if (overridesize) {
+		u_int32_t new_size = nsmtd->erasesize << overridesize;
+		if (new_size >> overridesize != nsmtd->erasesize) {
+			NS_ERR("overridesize is too big\n");
+			goto err_exit;
+		}
+		/* N.B. This relies on nand_scan not doing anything with the size before we change it */
+		nsmtd->size = new_size;
+		chip->chipsize = new_size;
+		chip->chip_shift = ffs(new_size) - 1;
+	}
+
 	if ((retval = setup_wear_reporting(nsmtd)) != 0)
 		goto err_exit;