Re: [PATCH v2 6/7] mtd: sh_flctl: Add FLHOLDCR register

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Bastian,

Thanks for the patch.

On Saturday 11 February 2012 12:45:04 Bastian Hecht wrote:
> Add a register used in new FLCTL hardware and a feature flag for it.
> 
> Signed-off-by: Bastian Hecht <hechtb@gmail.com>
> ---
> changelog: the write to the register has been moved due to patch 5.
> 
>  drivers/mtd/nand/sh_flctl.c  |    3 +++
>  include/linux/mtd/sh_flctl.h |   12 ++++++++++++
>  2 files changed, 15 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
> index 1af41fd..40dda26 100644
> --- a/drivers/mtd/nand/sh_flctl.c
> +++ b/drivers/mtd/nand/sh_flctl.c
> @@ -688,6 +688,8 @@ static void flctl_select_chip(struct mtd_info *mtd, int
> chipnr) break;
>  	case 0:
>  		writel(flctl->flcmncr_val | CE0_ENABLE, FLCMNCR(flctl));
> +		if (flctl->holden)
> +			writel(HOLDEN, FLHOLDCR(flctl));

Can't this be done at probe time (maybe in flctl_chip_init_tail()) ? You could 
then get rid of the flctl->holden field and use platform data directly.

>  		break;
>  	default:
>  		BUG();
> @@ -845,6 +847,7 @@ static int __devinit flctl_probe(struct platform_device
> *pdev) flctl->pdev = pdev;
>  	flctl->flcmncr_val = pdata->flcmncr_val;
>  	flctl->hwecc = pdata->has_hwecc;
> +	flctl->holden = pdata->use_holden;
> 
>  	nand->options = NAND_NO_AUTOINCR;
> 
> diff --git a/include/linux/mtd/sh_flctl.h b/include/linux/mtd/sh_flctl.h
> index 107fd8a..6046443 100644
> --- a/include/linux/mtd/sh_flctl.h
> +++ b/include/linux/mtd/sh_flctl.h
> @@ -38,6 +38,7 @@
>  #define FLDTFIFO(f)		(f->reg + 0x24)
>  #define FLECFIFO(f)		(f->reg + 0x28)
>  #define FLTRCR(f)		(f->reg + 0x2C)
> +#define FLHOLDCR(f)		(f->reg + 0x38)
>  #define	FL4ECCRESULT0(f)	(f->reg + 0x80)
>  #define	FL4ECCRESULT1(f)	(f->reg + 0x84)
>  #define	FL4ECCRESULT2(f)	(f->reg + 0x88)
> @@ -109,6 +110,15 @@
>  #define TRSTRT		(0x1 << 0)	/* translation start */
>  #define TREND		(0x1 << 1)	/* translation end */
> 
> +/*
> + * FLHOLDCR control bits
> + *
> + * HOLDEN: Bus Occupancy Enable (inverted)
> + * Enable this bit when the external bus might be used in between
> transfers. + * If not set and the bus gets used by other modules, a
> deadlock occurs. + */
> +#define HOLDEN		(0x1 << 0)
> +
>  /* FL4ECCCR control bits */
>  #define	_4ECCFA		(0x1 << 2)	/* 4 symbols correct fault */
>  #define	_4ECCEND	(0x1 << 1)	/* 4 symbols end */
> @@ -138,6 +148,7 @@ struct sh_flctl {
> 
>  	unsigned page_size:1;	/* NAND page size (0 = 512, 1 = 2048) */
>  	unsigned hwecc:1;	/* Hardware ECC (0 = disabled, 1 = enabled) */
> +	unsigned holden:1;	/* Hardware has FLHOLDCR and HOLDEN is set */
>  };
> 
>  struct sh_flctl_platform_data {
> @@ -146,6 +157,7 @@ struct sh_flctl_platform_data {
>  	unsigned long		flcmncr_val;
> 
>  	unsigned has_hwecc:1;
> +	unsigned use_holden:1;
>  };
> 
>  static inline struct sh_flctl *mtd_to_flctl(struct mtd_info *mtdinfo)

-- 
Regards,

Laurent Pinchart