[U-Boot] [PATCH 1/2] mtd: nand: Introduce CONFIG_SYS_NAND_BUSWIDTH_16BIT

[U-Boot] [PATCH 1/2] mtd: nand: Introduce CONFIG_SYS_NAND_BUSWIDTH_16BIT

[Fabio Estevam]

Introduce CONFIG_SYS_NAND_BUSWIDTH_16BIT option so that any NAND controller 
driver could use it when a 16-bit NAND is deployed.

drivers/mtd/nand/ndfc has CONFIG_SYS_NDFC_16BIT, so just rename it, so that
other NAND drivers could reuse the same symbol.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 README                  |    6 +++---
 drivers/mtd/nand/ndfc.c |    4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/README b/README
index d8cb394..1e265c9 100644
--- a/README
+++ b/README
@@ -3713,9 +3713,9 @@ Low Level (hardware related) configuration options:
 - CONFIG_SYS_SRIOn_MEM_SIZE:
 		Size of SRIO port 'n' memory region
 
-- CONFIG_SYS_NDFC_16
-		Defined to tell the NDFC that the NAND chip is using a
-		16 bit bus.
+- CONFIG_SYS_NAND_BUSWIDTH_16BIT
+		Defined to tell the NAND controller that the NAND chip is using
+ 		a 16 bit bus.
 
 - CONFIG_SYS_NDFC_EBC0_CFG
 		Sets the EBC0_CFG register for the NDFC. If not defined
diff --git a/drivers/mtd/nand/ndfc.c b/drivers/mtd/nand/ndfc.c
index 6ebbb5e..213d2c9 100644
--- a/drivers/mtd/nand/ndfc.c
+++ b/drivers/mtd/nand/ndfc.c
@@ -156,7 +156,7 @@ static uint8_t ndfc_read_byte(struct mtd_info *mtd)
 
 	struct nand_chip *chip = mtd->priv;
 
-#ifdef CONFIG_SYS_NDFC_16BIT
+#ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT
 	return (uint8_t) readw(chip->IO_ADDR_R);
 #else
 	return readb(chip->IO_ADDR_R);
@@ -218,7 +218,7 @@ int board_nand_init(struct nand_chip *nand)
 	nand->ecc.bytes = 3;
 	nand->select_chip = ndfc_select_chip;
 
-#ifdef CONFIG_SYS_NDFC_16BIT
+#ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT
 	nand->options |= NAND_BUSWIDTH_16;
 #endif
 
-- 
1.7.9.5

[U-Boot] [PATCH 2/2] mtd: nand: mxc_nand: Fix is_16bit_nand()

[Fabio Estevam]

Currently is_16bit_nand() is a per SoC function and it decides the bus nand 
width by reading some boot related registers.

This method works when NAND is the boot medium, but does not work if another
boot medium is used. For example: booting from a SD card and then using NAND
to store the environment variables, would lead to the following error:

NAND bus width 16 instead 8 bit
No NAND device found!!!
0 MiB

Use CONFIG_SYS_NAND_BUSWIDTH_16BIT symbol to decide the bus width.

If it is defined in the board file, then consider 16-bit NAND bus-width, 
otherwise assume 8-bit NAND is used.

This also aligns with Documentation/devicetree/bindings/mtd/nand.txt, which
states:

nand-bus-width : 8 or 16 bus width if not present 8

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 drivers/mtd/nand/mxc_nand.c |   37 +++----------------------------------
 1 file changed, 3 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d0ded48..bb475f2 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -98,45 +98,14 @@ static struct nand_ecclayout nand_hw_eccoob2k = {
 #endif
 #endif
 
-#ifdef CONFIG_MX27
 static int is_16bit_nand(void)
 {
-	struct system_control_regs *sc_regs =
-		(struct system_control_regs *)IMX_SYSTEM_CTL_BASE;
-
-	if (readl(&sc_regs->fmcr) & NF_16BIT_SEL)
-		return 1;
-	else
-		return 0;
-}
-#elif defined(CONFIG_MX31)
-static int is_16bit_nand(void)
-{
-	struct clock_control_regs *sc_regs =
-		(struct clock_control_regs *)CCM_BASE;
-
-	if (readl(&sc_regs->rcsr) & CCM_RCSR_NF16B)
-		return 1;
-	else
-		return 0;
-}
-#elif defined(CONFIG_MX25) || defined(CONFIG_MX35)
-static int is_16bit_nand(void)
-{
-	struct ccm_regs *ccm = (struct ccm_regs *)IMX_CCM_BASE;
-
-	if (readl(&ccm->rcsr) & CCM_RCSR_NF_16BIT_SEL)
-		return 1;
-	else
-		return 0;
-}
+#if defined(CONFIG_SYS_NAND_BUSWIDTH_16BIT)
+	return 1;
 #else
-#warning "8/16 bit NAND autodetection not supported"
-static int is_16bit_nand(void)
-{
 	return 0;
-}
 #endif
+}
 
 static uint32_t *mxc_nand_memcpy32(uint32_t *dest, uint32_t *source, size_t size)
 {
-- 
1.7.9.5

[U-Boot] [PATCH 1/2] mtd: nand: Introduce CONFIG_SYS_NAND_BUSWIDTH_16BIT

[Scott Wood]

On 02/26/2013 12:17:01 PM, Fabio Estevam wrote:
> Introduce CONFIG_SYS_NAND_BUSWIDTH_16BIT option so that any NAND  
> controller
> driver could use it when a 16-bit NAND is deployed.
> 
> drivers/mtd/nand/ndfc has CONFIG_SYS_NDFC_16BIT, so just rename it,  
> so that
> other NAND drivers could reuse the same symbol.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  README                  |    6 +++---
>  drivers/mtd/nand/ndfc.c |    4 ++--
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/README b/README
> index d8cb394..1e265c9 100644
> --- a/README
> +++ b/README
> @@ -3713,9 +3713,9 @@ Low Level (hardware related) configuration  
> options:
>  - CONFIG_SYS_SRIOn_MEM_SIZE:
>  		Size of SRIO port 'n' memory region
> 
> -- CONFIG_SYS_NDFC_16
> -		Defined to tell the NDFC that the NAND chip is using a
> -		16 bit bus.
> +- CONFIG_SYS_NAND_BUSWIDTH_16BIT
> +		Defined to tell the NAND controller that the NAND chip  
> is using
> + 		a 16 bit bus.

Mention here that not all drivers use this symbol, and provide a list  
of those that do.

E.g. on fsl_ifc, we already have this information elsewhere on a  
per-chip basis.

-Scott