[U-Boot] [PATCH v3 0/3] mtd: nand: mxs: Calculate ECC strength dynamically

[U-Boot] [PATCH v3 0/3] mtd: nand: mxs: Calculate ECC strength dynamically

[Jörg Krause]

This patchset is based on the patch from Peng Fan:
"[U-Boot,1/2] mtd:mxs:nand calculate ecc strength dynamically"
https://patchwork.ozlabs.org/patch/422756/

Instead of hard-coding every possible oob size / ECC strength combination
calculate the ECC strength dynamically to be aligned with the Linux Kernel
MTD NAND driver. Also adds the calculation to tools/mxsboot to be aligned
with the U-Boot MTD NAND driver.

J?rg Krause (2):
  mtd: nand: mxs: Replace magic number for bits per ECC level with macro
  tools: mxsboot: Calculate ECC strength dynamically

Peng Fan (1):
  mtd:mxs:nand calculate ecc strength dynamically

 drivers/mtd/nand/mxs_nand.c | 35 +++++++++++++++--------------------
 tools/mxsboot.c             | 39 ++++++++++++++++++++++++---------------
 2 files changed, 39 insertions(+), 35 deletions(-)

-- 
2.3.5

[U-Boot] [PATCH v3 1/3] mtd:mxs:nand calculate ecc strength dynamically

[Jörg Krause]

From: Peng Fan <Peng.Fan@freescale.com>

Calculate ecc strength according oobsize, but not hardcoded
which is not aligned with kernel driver

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Signed-off-by: Ye.Li <b37916@freescale.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
---
Changes for v3:
   - squashed "[U-Boot,v2,3/4] mtd: nand: mxs: Add comment for calculating
     ECC strength"
     https://patchwork.ozlabs.org/patch/460926/
   - Coding Style cleanup
Changes for v2:
   - None (original patch from Peng Fan)
---
 drivers/mtd/nand/mxs_nand.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c
index 7a064ab..a463de7 100644
--- a/drivers/mtd/nand/mxs_nand.c
+++ b/drivers/mtd/nand/mxs_nand.c
@@ -146,26 +146,20 @@ static uint32_t mxs_nand_aux_status_offset(void)
 static inline uint32_t mxs_nand_get_ecc_strength(uint32_t page_data_size,
 						uint32_t page_oob_size)
 {
-	if (page_data_size == 2048) {
-		if (page_oob_size == 64)
-			return 8;
+	int ecc_strength;
 
-		if (page_oob_size == 112)
-			return 14;
-	}
-
-	if (page_data_size == 4096) {
-		if (page_oob_size == 128)
-			return 8;
-
-		if (page_oob_size == 218)
-			return 16;
-
-		if (page_oob_size == 224)
-			return 16;
-	}
+	/*
+	 * Determine the ECC layout with the formula:
+	 *	ECC bits per chunk = (total page spare data bits) /
+	 *		(bits per ECC level) / (chunks per page)
+	 * where:
+	 *	total page spare data bits =
+	 *		(page oob size - meta data size) * (bits per byte)
+	 */
+	ecc_strength = ((page_oob_size - MXS_NAND_METADATA_SIZE) * 8)
+			/ (13 * mxs_nand_ecc_chunk_cnt(page_data_size));
 
-	return 0;
+	return round_down(ecc_strength, 2);
 }
 
 static inline uint32_t mxs_nand_get_mark_offset(uint32_t page_data_size,
-- 
2.3.5

[U-Boot] [PATCH v3 2/3] mtd: nand: mxs: Replace magic number for bits per ECC level with macro

[Jörg Krause]

Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
---
Changes for v3:
   - Replace space with tab for macro definition
Changes for v2:
   - New patch
---
 drivers/mtd/nand/mxs_nand.c | 7 ++++---
 tools/mxsboot.c             | 3 ++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c
index a463de7..aa06446 100644
--- a/drivers/mtd/nand/mxs_nand.c
+++ b/drivers/mtd/nand/mxs_nand.c
@@ -36,7 +36,7 @@
 #define	MXS_NAND_CHUNK_DATA_CHUNK_SIZE_SHIFT	0
 #endif
 #define	MXS_NAND_METADATA_SIZE			10
-
+#define	MXS_NAND_BITS_PER_ECC_LEVEL		13
 #define	MXS_NAND_COMMAND_BUFFER_SIZE		32
 
 #define	MXS_NAND_BCH_TIMEOUT			10000
@@ -135,7 +135,7 @@ static uint32_t mxs_nand_ecc_chunk_cnt(uint32_t page_data_size)
 
 static uint32_t mxs_nand_ecc_size_in_bits(uint32_t ecc_strength)
 {
-	return ecc_strength * 13;
+	return ecc_strength * MXS_NAND_BITS_PER_ECC_LEVEL;
 }
 
 static uint32_t mxs_nand_aux_status_offset(void)
@@ -157,7 +157,8 @@ static inline uint32_t mxs_nand_get_ecc_strength(uint32_t page_data_size,
 	 *		(page oob size - meta data size) * (bits per byte)
 	 */
 	ecc_strength = ((page_oob_size - MXS_NAND_METADATA_SIZE) * 8)
-			/ (13 * mxs_nand_ecc_chunk_cnt(page_data_size));
+			/ (MXS_NAND_BITS_PER_ECC_LEVEL *
+				mxs_nand_ecc_chunk_cnt(page_data_size));
 
 	return round_down(ecc_strength, 2);
 }
diff --git a/tools/mxsboot.c b/tools/mxsboot.c
index 6d48cfb..aaa872b 100644
--- a/tools/mxsboot.c
+++ b/tools/mxsboot.c
@@ -48,6 +48,7 @@ static uint32_t sd_sector = 2048;
 #define	MXS_NAND_DMA_DESCRIPTOR_COUNT		4
 #define	MXS_NAND_CHUNK_DATA_CHUNK_SIZE		512
 #define	MXS_NAND_METADATA_SIZE			10
+#define	MXS_NAND_BITS_PER_ECC_LEVEL		13
 #define	MXS_NAND_COMMAND_BUFFER_SIZE		32
 
 struct mx28_nand_fcb {
@@ -127,7 +128,7 @@ struct mx28_sd_config_block {
 
 static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength)
 {
-	return ecc_strength * 13;
+	return ecc_strength * MXS_NAND_BITS_PER_ECC_LEVEL;
 }
 
 static inline uint32_t mx28_nand_get_ecc_strength(uint32_t page_data_size,
-- 
2.3.5

[U-Boot] [PATCH v3 3/3] tools: mxsboot: Calculate ECC strength dynamically

[Jörg Krause]

Calculating the ECC strength dynamically to be aligned with the mxs NAND
driver and the Linux Kernel.

Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
---
Changes for v3:
   - Coding Style cleanup
Changes for v2:
   - New patch
---
 tools/mxsboot.c | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/tools/mxsboot.c b/tools/mxsboot.c
index aaa872b..53de452 100644
--- a/tools/mxsboot.c
+++ b/tools/mxsboot.c
@@ -14,6 +14,10 @@
 
 #include "compiler.h"
 
+/* Taken from <linux/kernel.h> */
+#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+#define round_down(x, y) ((x) & ~__round_mask(x, y))
+
 /*
  * Default BCB layout.
  *
@@ -126,6 +130,11 @@ struct mx28_sd_config_block {
 	struct mx28_sd_drive_info	drv_info[1];
 };
 
+static inline uint32_t mx28_nand_ecc_chunk_cnt(uint32_t page_data_size)
+{
+	return page_data_size / MXS_NAND_CHUNK_DATA_CHUNK_SIZE;
+}
+
 static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength)
 {
 	return ecc_strength * MXS_NAND_BITS_PER_ECC_LEVEL;
@@ -134,21 +143,21 @@ static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength)
 static inline uint32_t mx28_nand_get_ecc_strength(uint32_t page_data_size,
 						uint32_t page_oob_size)
 {
-	if (page_data_size == 2048)
-		return 8;
-
-	if (page_data_size == 4096) {
-		if (page_oob_size == 128)
-			return 8;
+	int ecc_strength;
 
-		if (page_oob_size == 218)
-			return 16;
-
-		if (page_oob_size == 224)
-			return 16;
-	}
+	/*
+	 * Determine the ECC layout with the formula:
+	 *	ECC bits per chunk = (total page spare data bits) /
+	 *		(bits per ECC level) / (chunks per page)
+	 * where:
+	 *	total page spare data bits =
+	 *		(page oob size - meta data size) * (bits per byte)
+	 */
+	ecc_strength = ((page_oob_size - MXS_NAND_METADATA_SIZE) * 8)
+			/ (MXS_NAND_BITS_PER_ECC_LEVEL *
+				mx28_nand_ecc_chunk_cnt(page_data_size));
 
-	return 0;
+	return round_down(ecc_strength, 2);
 }
 
 static inline uint32_t mx28_nand_get_mark_offset(uint32_t page_data_size,
-- 
2.3.5

[U-Boot] [PATCH v3 2/3] mtd: nand: mxs: Replace magic number for bits per ECC level with macro

[Marek Vasut]

On Wednesday, April 15, 2015 at 09:27:22 AM, J?rg Krause wrote:
> Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
> ---
> Changes for v3:
>    - Replace space with tab for macro definition
> Changes for v2:
>    - New patch
> ---

Reviewed-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut

[U-Boot] [PATCH v3 3/3] tools: mxsboot: Calculate ECC strength dynamically

[Marek Vasut]

On Wednesday, April 15, 2015 at 09:27:23 AM, J?rg Krause wrote:
> Calculating the ECC strength dynamically to be aligned with the mxs NAND
> driver and the Linux Kernel.
> 
> Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>

Reviewed-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut