[PATCH 05/11] mtd: nand: remove AG-AND support

Artem Bityutskiy
2013-03-05T13:16:14Z

We have only one AG-AND driver and it was not touched since 2005. It looks
like AG-AND was not really make it to mass-production and can be considered
a dead technology.

Along with the AG-AND support, this patch removes the BBT_AUTO_REFRESH feature,
because the only user of this feature is AG-AND. And even though it is
implemented as a generic feature, I prefer to remove it because NAND flashes do
not really need it in this form.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
---
drivers/mtd/nand/nand_base.c | 80 ++----------------------------------------
drivers/mtd/nand/nand_bbt.c | 25 -------------
drivers/mtd/nand/nand_ids.c | 13 -------
include/linux/mtd/nand.h | 16 ---------
4 files changed, 2 insertions(+), 132 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4321415..925de01 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4,7 +4,6 @@
* Overview:
* This is the generic MTD driver for NAND flash devices. It should be
* capable of working with almost all NAND chips currently available.
- * Basic support for AG-AND chips is provided.
*
* Additional technical information is available on
* http://www.linux-mtd.infradead.org/doc/nand.html
@@ -22,8 +21,6 @@
* Enable cached programming for 2k page size chips
* Check, if mtd->ecctype should be set to MTD_ECC_HW
* if we have HW ECC support.
- * The AG-AND chips have nice features for speed improvement,
- * which are not supported yet. Read / program 4 pages in one go.
* BBT table is not serialized, has to be fixed
*
* This program is free software; you can redistribute it and/or modify
@@ -836,10 +833,7 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
*/
ndelay(100);

- if ((state == FL_ERASING) && (chip->options & NAND_IS_AND))
- chip->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
- else
- chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+ chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);

if (in_interrupt() || oops_in_progress)
panic_nand_wait(mtd, chip, timeo);
@@ -2465,24 +2459,6 @@ static void single_erase_cmd(struct mtd_info *mtd, int page)
}

/**
- * multi_erase_cmd - [GENERIC] AND specific block erase command function
- * @mtd: MTD device structure
- * @page: the page address of the block which will be erased
- *
- * AND multi block erase command function. Erase 4 consecutive blocks.
- */
-static void multi_erase_cmd(struct mtd_info *mtd, int page)
-{
- struct nand_chip *chip = mtd->priv;
- /* Send commands to erase a block */
- chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
- chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
- chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
- chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
- chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
-}
-
-/**
* nand_erase - [MTD Interface] erase block(s)
* @mtd: MTD device structure
* @instr: erase instruction
@@ -2494,7 +2470,6 @@ static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
return nand_erase_nand(mtd, instr, 0);
}

-#define BBT_PAGE_MASK 0xffffff3f
/**
* nand_erase_nand - [INTERN] erase block(s)
* @mtd: MTD device structure
@@ -2508,8 +2483,6 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
{
int page, status, pages_per_block, ret, chipnr;
struct nand_chip *chip = mtd->priv;
- loff_t rewrite_bbt[NAND_MAX_CHIPS] = {0};
- unsigned int bbt_masked_page = 0xffffffff;
loff_t len;

pr_debug("%s: start = 0x%012llx, len = %llu\n",
@@ -2540,15 +2513,6 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
goto erase_exit;
}

- /*
- * If BBT requires refresh, set the BBT page mask to see if the BBT
- * should be rewritten. Otherwise the mask is set to 0xffffffff which
- * can not be matched. This is also done when the bbt is actually
- * erased to avoid recursive updates.
- */
- if (chip->options & BBT_AUTO_REFRESH && !allowbbt)
- bbt_masked_page = chip->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
-
/* Loop through the pages */
len = instr->len;

@@ -2594,15 +2558,6 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
goto erase_exit;
}

- /*
- * If BBT requires refresh, set the BBT rewrite flag to the
- * page being erased.
- */
- if (bbt_masked_page != 0xffffffff &&
- (page & BBT_PAGE_MASK) == bbt_masked_page)
- rewrite_bbt[chipnr] =
- ((loff_t)page << chip->page_shift);
-
/* Increment page address and decrement length */
len -= (1 << chip->phys_erase_shift);
page += pages_per_block;
@@ -2612,15 +2567,6 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
chipnr++;
chip->select_chip(mtd, -1);
chip->select_chip(mtd, chipnr);
-
- /*
- * If BBT requires refresh and BBT-PERCHIP, set the BBT
- * page mask to see if this BBT should be rewritten.
- */
- if (bbt_masked_page != 0xffffffff &&
- (chip->bbt_td->options & NAND_BBT_PERCHIP))
- bbt_masked_page = chip->bbt_td->pages[chipnr] &
- BBT_PAGE_MASK;
}
}
instr->state = MTD_ERASE_DONE;
@@ -2637,23 +2583,6 @@ erase_exit:
if (!ret)
mtd_erase_callback(instr);

- /*
- * If BBT requires refresh and erase was successful, rewrite any
- * selected bad block tables.
- */
- if (bbt_masked_page == 0xffffffff || ret)
- return ret;
-
- for (chipnr = 0; chipnr < chip->numchips; chipnr++) {
- if (!rewrite_bbt[chipnr])
- continue;
- /* Update the BBT for chip */
- pr_debug("%s: nand_update_bbt (%d:0x%0llx 0x%0x)\n",
- __func__, chipnr, rewrite_bbt[chipnr],
- chip->bbt_td->pages[chipnr]);
- nand_update_bbt(mtd, rewrite_bbt[chipnr]);
- }
-
/* Return more or less happy */
return ret;
}
@@ -3286,12 +3215,7 @@ ident_done:
}

chip->badblockbits = 8;
-
- /* Check for AND chips with 4 page planes */
- if (chip->options & NAND_4PAGE_ARRAY)
- chip->erase_cmd = multi_erase_cmd;
- else
- chip->erase_cmd = single_erase_cmd;
+ chip->erase_cmd = single_erase_cmd;

/* Do not replace user supplied command function! */
if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 916d6e9..2672643 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -1240,15 +1240,6 @@ int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
*/
static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

-static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
-
-static struct nand_bbt_descr agand_flashbased = {
- .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
- .offs = 0x20,
- .len = 6,
- .pattern = scan_agand_pattern
-};
-
/* Generic flash bbt descriptors */
static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
@@ -1333,22 +1324,6 @@ int nand_default_bbt(struct mtd_info *mtd)
{
struct nand_chip *this = mtd->priv;

- /*
- * Default for AG-AND. We must use a flash based bad block table as the
- * devices have factory marked _good_ blocks. Erasing those blocks
- * leads to loss of the good / bad information, so we _must_ store this
- * information in a good / bad table during startup.
- */
- if (this->options & NAND_IS_AND) {
- /* Use the default pattern descriptors */
- if (!this->bbt_td) {
- this->bbt_td = &bbt_main_descr;
- this->bbt_md = &bbt_mirror_descr;
- }
- this->bbt_options |= NAND_BBT_USE_FLASH;
- return nand_scan_bbt(mtd, &agand_flashbased);
- }
-
/* Is a flash based bad block table requested? */
if (this->bbt_options & NAND_BBT_USE_FLASH) {
/* Use the default pattern descriptors */
diff --git a/drivers/mtd/nand/nand_ids.c b/drivers/mtd/nand/nand_ids.c
index 44f9db3..7182d9b 100644
--- a/drivers/mtd/nand/nand_ids.c
+++ b/drivers/mtd/nand/nand_ids.c
@@ -136,19 +136,6 @@ struct nand_flash_dev nand_flash_ids[] = {
{"NAND 64GiB 1,8V 16-bit", 0x2E, 0, 65536, 0, LP_OPTIONS16},
{"NAND 64GiB 3,3V 16-bit", 0x4E, 0, 65536, 0, LP_OPTIONS16},

- /*
- * Renesas AND 1 Gigabit. Those chips do not support extended id and
- * have a strange page/block layout ! The chosen minimum erasesize is
- * 4 * 2 * 2048 = 16384 Byte, as those chips have an array of 4 page
- * planes 1 block = 2 pages, but due to plane arrangement the blocks
- * 0-3 consists of page 0 + 4,1 + 5, 2 + 6, 3 + 7 Anyway JFFS2 would
- * increase the eraseblock size so we chose a combined one which can be
- * erased in one go There are more speed improvements for reads and
- * writes possible, but not implemented now
- */
- {"AND 128MiB 3,3V 8-bit", 0x01, 2048, 128, 0x4000,
- NAND_IS_AND | NAND_4PAGE_ARRAY | BBT_AUTO_REFRESH},
-
{NULL,}
};

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 7ccb3c5..2aba049 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -171,22 +171,6 @@ typedef enum {
#define NAND_CACHEPRG 0x00000008
/* Chip has copy back function */
#define NAND_COPYBACK 0x00000010
-/*
- * AND Chip which has 4 banks and a confusing page / block
- * assignment. See Renesas datasheet for further information.
- */
-#define NAND_IS_AND 0x00000020
-/*
- * Chip has a array of 4 pages which can be read without
- * additional ready /busy waits.
- */
-#define NAND_4PAGE_ARRAY 0x00000040
-/*
- * Chip requires that BBT is periodically rewritten to prevent
- * bits from adjacent blocks from 'leaking' in altering data.
- * This happens with the Renesas AG-AND chips, possibly others.
- */
-#define BBT_AUTO_REFRESH 0x00000080
/* Chip does not allow subpage writes */
#define NAND_NO_SUBPAGE_WRITE 0x00000200

--
1.7.10.4