[U-Boot] [PATCH v3 2/2] mtd: nand: mxc_nand: Fix is_16bit_nand()
Benoît Thébaudeau
benoit.thebaudeau at advansee.com
Wed Feb 27 01:08:36 CET 2013
Hi Fabio,
On Tuesday, February 26, 2013 11:37:45 PM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
>
> 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 at freescale.com>
> ---
> Changes since v2:
> - Fix typo "if not present 82"
> Changes since v1:
> - Add an entry into README
> README | 3 ++-
> drivers/mtd/nand/mxc_nand.c | 37 +++----------------------------------
> 2 files changed, 5 insertions(+), 35 deletions(-)
>
> diff --git a/README b/README
> index bdd2c81..1a6a7a5 100644
> --- a/README
> +++ b/README
> @@ -3717,8 +3717,9 @@ Low Level (hardware related) configuration options:
> Defined to tell the NAND controller that the NAND chip is using
> a 16 bit bus.
> Not all NAND drivers use this symbol.
> - Example of driver that uses it:
> + Example of drivers that use it:
> - drivers/mtd/nand/ndfc.c
> + - drivers/mtd/nand/mxc_nand.c
>
> - CONFIG_SYS_NDFC_EBC0_CFG
> Sets the EBC0_CFG register for the NDFC. If not defined
> 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
For this series:
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
I will integrate it as is at the beginning of the v8 of my series as planned,
unless it is applied before. I hope to post my v8 before the end of the week.
Best regards,
Benoît
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