mtd: nand: add 'oob_required' argument to NAND {read,write}_page interfaces

New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).

This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.

Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.

Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.

[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Acked-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Brian Norris
2012-05-02 10:14:55 -07:00
committed by David Woodhouse
parent b4f7aa84d6
commit 1fbb938dff
15 changed files with 90 additions and 72 deletions

View File

@@ -692,6 +692,7 @@ static void fsmc_write_buf_dma(struct mtd_info *mtd, const uint8_t *buf,
* @mtd: mtd info structure
* @chip: nand chip info structure
* @buf: buffer to store read data
* @oob_required: caller expects OOB data read to chip->oob_poi
* @page: page number to read
*
* This routine is needed for fsmc version 8 as reading from NAND chip has to be
@@ -701,7 +702,7 @@ static void fsmc_write_buf_dma(struct mtd_info *mtd, const uint8_t *buf,
* max of 8 bits)
*/
static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
uint8_t *buf, int page)
uint8_t *buf, int oob_required, int page)
{
struct fsmc_nand_data *host = container_of(mtd,
struct fsmc_nand_data, mtd);