* [PATCH v5 1/4] mtd: nand: omap: ecc.calculate: rename omap3_calculate_ecc_bch to omap_calculate_ecc_bch
2014-01-07 13:45 [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Pekon Gupta
@ 2014-01-07 13:45 ` Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 2/4] mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for BCHx_HW ecc-scheme Pekon Gupta
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Pekon Gupta @ 2014-01-07 13:45 UTC (permalink / raw)
To: Brian Norris; +Cc: Stefan Roese, linux-mtd, Pekon Gupta, Felipe Balbi
This patch renames omap3_calculate_ecc_bch -> omap_calculate_ecc_bch to
keep nomenclature independent of any device family.
Signed-off-by: Pekon Gupta <pekon@ti.com>
---
drivers/mtd/nand/omap2.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index c690721..bf9bf7e 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1211,15 +1211,15 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
#ifdef CONFIG_MTD_NAND_OMAP_BCH
/**
- * omap3_calculate_ecc_bch - Generate bytes of ECC bytes
+ * omap_calculate_ecc_bch - Generate bytes of ECC bytes
* @mtd: MTD device structure
* @dat: The pointer to data on which ecc is computed
* @ecc_code: The ecc_code buffer
*
* Support calculating of BCH4/8 ecc vectors for the page
*/
-static int omap3_calculate_ecc_bch(struct mtd_info *mtd, const u_char *dat,
- u_char *ecc_code)
+static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
+ const u_char *dat, u_char *ecc_code)
{
struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
mtd);
@@ -1858,7 +1858,7 @@ static int omap_nand_probe(struct platform_device *pdev)
nand_chip->ecc.strength = 4;
nand_chip->ecc.hwctl = omap3_enable_hwecc_bch;
nand_chip->ecc.correct = omap_elm_correct_data;
- nand_chip->ecc.calculate = omap3_calculate_ecc_bch;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
nand_chip->ecc.read_page = omap_read_page_bch;
nand_chip->ecc.write_page = omap_write_page_bch;
/* define ECC layout */
@@ -1929,7 +1929,7 @@ static int omap_nand_probe(struct platform_device *pdev)
nand_chip->ecc.strength = 8;
nand_chip->ecc.hwctl = omap3_enable_hwecc_bch;
nand_chip->ecc.correct = omap_elm_correct_data;
- nand_chip->ecc.calculate = omap3_calculate_ecc_bch;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
nand_chip->ecc.read_page = omap_read_page_bch;
nand_chip->ecc.write_page = omap_write_page_bch;
/* This ECC scheme requires ELM H/W block */
--
1.8.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v5 2/4] mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for BCHx_HW ecc-scheme
2014-01-07 13:45 [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 1/4] mtd: nand: omap: ecc.calculate: rename omap3_calculate_ecc_bch to omap_calculate_ecc_bch Pekon Gupta
@ 2014-01-07 13:45 ` Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 3/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch4 in omap_calculate_ecc_bch Pekon Gupta
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Pekon Gupta @ 2014-01-07 13:45 UTC (permalink / raw)
To: Brian Norris; +Cc: Stefan Roese, linux-mtd, Pekon Gupta, Felipe Balbi
OMAP NAND driver supports multiple flavours of BCH4 and BCH8 ECC algorithms.
+------+------------------------------------+---------------+---------------+
| Algo | ECC scheme |ECC calculation|Error detection|
+------+------------------------------------+---------------+---------------+
| |OMAP_ECC_BCH4_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W |
| BCH4 |OMAP_ECC_BCH4_CODE_HW |H/W (GPMC) |H/W (ELM) |
+------+------------------------------------+---------------+---------------+
| |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W |
| BCH8 |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) |
+------+------------------------------------+---------------+---------------+
As all implementations of H/W ecc-scheme use GPMC engine for ECC calculation,
Thus this patch:
(1) Replaces if..then..else with switch..case statements, so that code is
scalable for adding new ecc-schemes in future.
(2) Separates out ecc-scheme specific customizations into separate switch..case,
so that common code can be re-used between different flavours of ecc-scheme.
Signed-off-by: Pekon Gupta <pekon@ti.com>
---
drivers/mtd/nand/omap2.c | 69 +++++++++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 33 deletions(-)
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index bf9bf7e..dabea92 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1219,33 +1219,26 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
* Support calculating of BCH4/8 ecc vectors for the page
*/
static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
- const u_char *dat, u_char *ecc_code)
+ const u_char *dat, u_char *ecc_calc)
{
struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
mtd);
+ int eccbytes = info->nand.ecc.bytes;
+ enum omap_ecc ecc_opt = info->ecc_opt;
+ struct gpmc_nand_regs *gpmc_regs = &info->reg;
+ u8 *ecc_code;
unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4;
- int i, eccbchtsel;
+ int i;
nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
- /*
- * find BCH scheme used
- * 0 -> BCH4
- * 1 -> BCH8
- */
- eccbchtsel = ((readl(info->reg.gpmc_ecc_config) >> 12) & 0x3);
-
for (i = 0; i < nsectors; i++) {
-
- /* Read hw-computed remainder */
- bch_val1 = readl(info->reg.gpmc_bch_result0[i]);
- bch_val2 = readl(info->reg.gpmc_bch_result1[i]);
- if (eccbchtsel) {
- bch_val3 = readl(info->reg.gpmc_bch_result2[i]);
- bch_val4 = readl(info->reg.gpmc_bch_result3[i]);
- }
-
- if (eccbchtsel) {
- /* BCH8 ecc scheme */
+ ecc_code = ecc_calc;
+ switch (ecc_opt) {
+ case OMAP_ECC_BCH8_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
+ bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
+ bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
*ecc_code++ = (bch_val4 & 0xFF);
*ecc_code++ = ((bch_val3 >> 24) & 0xFF);
*ecc_code++ = ((bch_val3 >> 16) & 0xFF);
@@ -1259,14 +1252,10 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
*ecc_code++ = ((bch_val1 >> 16) & 0xFF);
*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
*ecc_code++ = (bch_val1 & 0xFF);
- /*
- * Setting 14th byte to zero to handle
- * erased page & maintain compatibility
- * with RBL
- */
- *ecc_code++ = 0x0;
- } else {
- /* BCH4 ecc scheme */
+ break;
+ case OMAP_ECC_BCH4_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
*ecc_code++ = ((bch_val2 >> 12) & 0xFF);
*ecc_code++ = ((bch_val2 >> 4) & 0xFF);
*ecc_code++ = ((bch_val2 & 0xF) << 4) |
@@ -1275,12 +1264,26 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
*ecc_code++ = ((bch_val1 >> 12) & 0xFF);
*ecc_code++ = ((bch_val1 >> 4) & 0xFF);
*ecc_code++ = ((bch_val1 & 0xF) << 4);
- /*
- * Setting 8th byte to zero to handle
- * erased page
- */
- *ecc_code++ = 0x0;
+ break;
+ default:
+ return -EINVAL;
}
+
+ /* ECC scheme specific syndrome customizations */
+ switch (ecc_opt) {
+ case OMAP_ECC_BCH4_CODE_HW:
+ /* Set 8th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ case OMAP_ECC_BCH8_CODE_HW:
+ /* Set 14th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ecc_calc += eccbytes;
}
return 0;
--
1.8.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v5 3/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch4 in omap_calculate_ecc_bch
2014-01-07 13:45 [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 1/4] mtd: nand: omap: ecc.calculate: rename omap3_calculate_ecc_bch to omap_calculate_ecc_bch Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 2/4] mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for BCHx_HW ecc-scheme Pekon Gupta
@ 2014-01-07 13:45 ` Pekon Gupta
2014-01-07 13:45 ` [PATCH v5 4/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch8 " Pekon Gupta
2014-01-08 8:08 ` [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Stefan Roese
4 siblings, 0 replies; 6+ messages in thread
From: Pekon Gupta @ 2014-01-07 13:45 UTC (permalink / raw)
To: Brian Norris; +Cc: Stefan Roese, linux-mtd, Pekon Gupta, Felipe Balbi
chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by
processing the data passed during Read/Write accesses.
All H/W ECC schemes use GPMC controller for ECC syndrome calculation,but each
ecc-scheme implements its own calback to config, process and fetch ECC syndrome.
This patch merges omap3_calculate_ecc_bch4() into omap_calculate_ecc_bch()
to re-use common code between BCH4_HW and BCH4_HW_DETECTION_SW
+---------------------+-------------------------------------------------------+
|ecc-scheme | implementations for nand_chip->calculate() |
+---------------------+-------------------------------------------------------+
|HAM1_ECC | omap_calculate_ecc() |
+---------------------+-------------------------------------------------------+
|BCH4_HW_DETECTION_SW | omap3_calculate_ecc_bch4() -> omap_calculate_ecc_bch()|
|BCH4_HW | omap_calculate_ecc_bch() |
|BCH8_HW_DETECTION_SW | omap3_calculate_ecc_bch8() |
|BCH8_HW | omap_calculate_ecc_bch() |
+---------------------+-------------------------------------------------------+
Signed-off-by: Pekon Gupta <pekon@ti.com>
---
drivers/mtd/nand/omap2.c | 51 ++++++++++--------------------------------------
1 file changed, 10 insertions(+), 41 deletions(-)
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index dabea92..26db491 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -141,6 +141,7 @@ static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
0xac, 0x6b, 0xff, 0x99, 0x7b};
static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
#endif
+static u8 bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
/* oob info generated runtime depending on ecc algorithm and layout selected */
static struct nand_ecclayout omap_oobinfo;
@@ -1124,45 +1125,6 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
#ifdef CONFIG_MTD_NAND_ECC_BCH
/**
- * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes
- * @mtd: MTD device structure
- * @dat: The pointer to data on which ecc is computed
- * @ecc_code: The ecc_code buffer
- */
-static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat,
- u_char *ecc_code)
-{
- struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
- mtd);
- unsigned long nsectors, val1, val2;
- int i;
-
- nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
-
- for (i = 0; i < nsectors; i++) {
-
- /* Read hw-computed remainder */
- val1 = readl(info->reg.gpmc_bch_result0[i]);
- val2 = readl(info->reg.gpmc_bch_result1[i]);
-
- /*
- * Add constant polynomial to remainder, in order to get an ecc
- * sequence of 0xFFs for a buffer filled with 0xFFs; and
- * left-justify the resulting polynomial.
- */
- *ecc_code++ = 0x28 ^ ((val2 >> 12) & 0xFF);
- *ecc_code++ = 0x13 ^ ((val2 >> 4) & 0xFF);
- *ecc_code++ = 0xcc ^ (((val2 & 0xF) << 4)|((val1 >> 28) & 0xF));
- *ecc_code++ = 0x39 ^ ((val1 >> 20) & 0xFF);
- *ecc_code++ = 0x96 ^ ((val1 >> 12) & 0xFF);
- *ecc_code++ = 0xac ^ ((val1 >> 4) & 0xFF);
- *ecc_code++ = 0x7f ^ ((val1 & 0xF) << 4);
- }
-
- return 0;
-}
-
-/**
* omap3_calculate_ecc_bch8 - Generate 13 bytes of ECC bytes
* @mtd: MTD device structure
* @dat: The pointer to data on which ecc is computed
@@ -1209,7 +1171,6 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
}
#endif /* CONFIG_MTD_NAND_ECC_BCH */
-#ifdef CONFIG_MTD_NAND_OMAP_BCH
/**
* omap_calculate_ecc_bch - Generate bytes of ECC bytes
* @mtd: MTD device structure
@@ -1253,6 +1214,7 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
*ecc_code++ = ((bch_val1 >> 8) & 0xFF);
*ecc_code++ = (bch_val1 & 0xFF);
break;
+ case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
case OMAP_ECC_BCH4_CODE_HW:
bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
@@ -1271,6 +1233,12 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
/* ECC scheme specific syndrome customizations */
switch (ecc_opt) {
+ case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
+ /* Add constant polynomial to remainder, so that
+ * ECC of blank pages results in 0x0 on reading back */
+ for (i = 0; i < eccbytes; i++)
+ ecc_calc[i] ^= bch4_polynomial[i];
+ break;
case OMAP_ECC_BCH4_CODE_HW:
/* Set 8th ECC byte as 0x0 for ROM compatibility */
ecc_calc[eccbytes - 1] = 0x0;
@@ -1289,6 +1257,7 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
return 0;
}
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
/**
* omap_elm_correct_data - corrects page data area in case error reported
* @mtd: MTD device structure
@@ -1823,7 +1792,7 @@ static int omap_nand_probe(struct platform_device *pdev)
nand_chip->ecc.strength = 4;
nand_chip->ecc.hwctl = omap3_enable_hwecc_bch;
nand_chip->ecc.correct = nand_bch_correct_data;
- nand_chip->ecc.calculate = omap3_calculate_ecc_bch4;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
/* define ECC layout */
ecclayout->eccbytes = nand_chip->ecc.bytes *
(mtd->writesize /
--
1.8.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v5 4/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch8 in omap_calculate_ecc_bch
2014-01-07 13:45 [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Pekon Gupta
` (2 preceding siblings ...)
2014-01-07 13:45 ` [PATCH v5 3/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch4 in omap_calculate_ecc_bch Pekon Gupta
@ 2014-01-07 13:45 ` Pekon Gupta
2014-01-08 8:08 ` [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Stefan Roese
4 siblings, 0 replies; 6+ messages in thread
From: Pekon Gupta @ 2014-01-07 13:45 UTC (permalink / raw)
To: Brian Norris; +Cc: Stefan Roese, linux-mtd, Pekon Gupta, Felipe Balbi
chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by
processing the data passed during Read/Write accesses.
All H/W ECC schemes use GPMC controller for ECC syndrome calculation,but each
ecc-scheme implements its own calback to config, process and fetch ECC syndrome.
This patch merges omap3_calculate_ecc_bch8() into omap_calculate_ecc_bch()
to re-use common code between BCH8_HW and BCH8_HW_DETECTION_SW
+---------------------+-------------------------------------------------------+
|ecc-scheme | implementations for nand_chip->calculate() |
+---------------------+-------------------------------------------------------+
|HAM1_ECC | omap_calculate_ecc() |
+---------------------+-------------------------------------------------------+
|BCH4_HW_DETECTION_SW | omap_calculate_ecc_bch() |
|BCH4_HW | omap_calculate_ecc_bch() |
|BCH8_HW_DETECTION_SW | omap3_calculate_ecc_bch8() -> omap_calculate_ecc_bch()|
|BCH8_HW | omap_calculate_ecc_bch() |
+---------------------+-------------------------------------------------------+
Signed-off-by: Pekon Gupta <pekon@ti.com>
---
drivers/mtd/nand/omap2.c | 59 ++++++++----------------------------------------
1 file changed, 10 insertions(+), 49 deletions(-)
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 26db491..72d5f23 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -142,6 +142,8 @@ static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
#endif
static u8 bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
+static u8 bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2,
+ 0x97, 0x79, 0xe5, 0x24, 0xb5};
/* oob info generated runtime depending on ecc algorithm and layout selected */
static struct nand_ecclayout omap_oobinfo;
@@ -1123,54 +1125,6 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
}
#endif
-#ifdef CONFIG_MTD_NAND_ECC_BCH
-/**
- * omap3_calculate_ecc_bch8 - Generate 13 bytes of ECC bytes
- * @mtd: MTD device structure
- * @dat: The pointer to data on which ecc is computed
- * @ecc_code: The ecc_code buffer
- */
-static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
- u_char *ecc_code)
-{
- struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
- mtd);
- unsigned long nsectors, val1, val2, val3, val4;
- int i;
-
- nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
-
- for (i = 0; i < nsectors; i++) {
-
- /* Read hw-computed remainder */
- val1 = readl(info->reg.gpmc_bch_result0[i]);
- val2 = readl(info->reg.gpmc_bch_result1[i]);
- val3 = readl(info->reg.gpmc_bch_result2[i]);
- val4 = readl(info->reg.gpmc_bch_result3[i]);
-
- /*
- * Add constant polynomial to remainder, in order to get an ecc
- * sequence of 0xFFs for a buffer filled with 0xFFs.
- */
- *ecc_code++ = 0xef ^ (val4 & 0xFF);
- *ecc_code++ = 0x51 ^ ((val3 >> 24) & 0xFF);
- *ecc_code++ = 0x2e ^ ((val3 >> 16) & 0xFF);
- *ecc_code++ = 0x09 ^ ((val3 >> 8) & 0xFF);
- *ecc_code++ = 0xed ^ (val3 & 0xFF);
- *ecc_code++ = 0x93 ^ ((val2 >> 24) & 0xFF);
- *ecc_code++ = 0x9a ^ ((val2 >> 16) & 0xFF);
- *ecc_code++ = 0xc2 ^ ((val2 >> 8) & 0xFF);
- *ecc_code++ = 0x97 ^ (val2 & 0xFF);
- *ecc_code++ = 0x79 ^ ((val1 >> 24) & 0xFF);
- *ecc_code++ = 0xe5 ^ ((val1 >> 16) & 0xFF);
- *ecc_code++ = 0x24 ^ ((val1 >> 8) & 0xFF);
- *ecc_code++ = 0xb5 ^ (val1 & 0xFF);
- }
-
- return 0;
-}
-#endif /* CONFIG_MTD_NAND_ECC_BCH */
-
/**
* omap_calculate_ecc_bch - Generate bytes of ECC bytes
* @mtd: MTD device structure
@@ -1195,6 +1149,7 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
for (i = 0; i < nsectors; i++) {
ecc_code = ecc_calc;
switch (ecc_opt) {
+ case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
case OMAP_ECC_BCH8_CODE_HW:
bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
@@ -1243,6 +1198,12 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
/* Set 8th ECC byte as 0x0 for ROM compatibility */
ecc_calc[eccbytes - 1] = 0x0;
break;
+ case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
+ /* Add constant polynomial to remainder, so that
+ * ECC of blank pages results in 0x0 on reading back */
+ for (i = 0; i < eccbytes; i++)
+ ecc_calc[i] ^= bch8_polynomial[i];
+ break;
case OMAP_ECC_BCH8_CODE_HW:
/* Set 14th ECC byte as 0x0 for ROM compatibility */
ecc_calc[eccbytes - 1] = 0x0;
@@ -1862,7 +1823,7 @@ static int omap_nand_probe(struct platform_device *pdev)
nand_chip->ecc.strength = 8;
nand_chip->ecc.hwctl = omap3_enable_hwecc_bch;
nand_chip->ecc.correct = nand_bch_correct_data;
- nand_chip->ecc.calculate = omap3_calculate_ecc_bch8;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
/* define ECC layout */
ecclayout->eccbytes = nand_chip->ecc.bytes *
(mtd->writesize /
--
1.8.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes
2014-01-07 13:45 [PATCH v5 0/4] mtd: nand: omap: optimize chip->ecc.calculate() for H/W ECC schemes Pekon Gupta
` (3 preceding siblings ...)
2014-01-07 13:45 ` [PATCH v5 4/4] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch8 " Pekon Gupta
@ 2014-01-08 8:08 ` Stefan Roese
4 siblings, 0 replies; 6+ messages in thread
From: Stefan Roese @ 2014-01-08 8:08 UTC (permalink / raw)
To: Pekon Gupta, Brian Norris; +Cc: linux-mtd, Felipe Balbi
On 07.01.2014 14:45, Pekon Gupta wrote:
> This patch series is split version of earlier patch:
> http://lists.infradead.org/pipermail/linux-mtd/2013-November/050240.html
>
> chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by
> processing the data passed during Read/Write accesses.
> Though all H/W ECC schemes in OMAP NAND use GPMC controller for ECC calculation
> But each of them implements its own callback to process and fetch ECC syndrome.
>
> This patch tries to merge common code for different BCHx_ECC schemes into single
> omap_calculate_ecc_bch(). This imporves scalability for future ecc-schemes.
> +----------------------+----------------------------+
> | ecc-scheme | nand_chip->ecc.calculate |
> +----------------------+----------------------------+
> | HAM1_ECC | omap_calculate_ecc() |
> | BCH4_HW_DETECTION_SW | omap3_calculate_ecc_bch4() |
> | BCH4_HW | omap3_calculate_ecc_bch() |
> | BCH8_HW_DETECTION_SW | omap3_calculate_ecc_bch8() |
> | BCH8_HW | omap3_calculate_ecc_bch() |
> +----------------------+----------------------------+
>
>
> Pekon Gupta (4):
> mtd: nand: omap: ecc.calculate: rename omap3_calculate_ecc_bch to
> omap_calculate_ecc_bch
> mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for
> BCHx_HW ecc-scheme
> mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch4 in
> omap_calculate_ecc_bch
> mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch8 in
> omap_calculate_ecc_bch
>
> drivers/mtd/nand/omap2.c | 187 +++++++++++++++--------------------------------
> 1 file changed, 60 insertions(+), 127 deletions(-)
Thanks Pekon. This works just fine on our AM335x based board. So, for
the complete patch series:
Tested-by: Stefan Roese <sr@denx.de>
Thanks,
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread