[PATCH 03/29] pxa3xx_nand: introduce default timing to reduce read id times

[Eric Miao]

On Wed, Jul 28, 2010 at 1:56 PM, Haojian Zhuang
<haojian.zhuang at gmail.com> wrote:
> From 3450c0a0a881b4b37776a3d22917aa7752bfd980 Mon Sep 17 00:00:00 2001
> From: Lei Wen <leiwen at marvell.com>
> Date: Tue, 22 Jun 2010 20:20:16 +0800
> Subject: [PATCH 03/29] pxa3xx_nand: introduce default timing to reduce
> read id times
>
> We certainly don't need to send read id command times by times, since
> we already know what the id is after the first read id...
>
> So create a default timing which could ensure it would successfully read
> id out all supported chip. Then follow the build-in table to reconfigure
> the timing.
>
> Signed-off-by: Lei Wen <leiwen at marvell.com>
> Signed-off-by: Haojian Zhuang <haojian.zhuang at marvell.com>
> ---
>  drivers/mtd/nand/pxa3xx_nand.c |   56 ++++++++++++++++++---------------------
>  1 files changed, 26 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index 52cec28..b605147 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -190,15 +190,18 @@ static struct pxa3xx_nand_cmdset default_cmdset = {
>  };
>
>  static struct pxa3xx_nand_timing __devinitdata timing[] = {
> -       { 10,  0, 20, 40, 30, 40, 11123, 110, 10, },
> -       { 10, 25, 15, 25, 15, 30, 25000,  60, 10, },
> -       { 10, 35, 15, 25, 15, 25, 25000,  60, 10, },
> +       { 40, 80, 60, 100, 80, 100, 90000, 400, 40, },
> +       { 10,  0, 20,  40, 30,  40, 11123, 110, 10, },
> +       { 10, 25, 15,  25, 15,  30, 25000,  60, 10, },
> +       { 10, 35, 15,  25, 15,  25, 25000,  60, 10, },
>  };
>
> -#define NAND_SETTING_SAMSUNG     &default_cmdset, &timing[0]
> -#define NAND_SETTING_MICRON      &default_cmdset, &timing[1]
> -#define NAND_SETTING_ST          &default_cmdset, &timing[2]
> +#define NAND_SETTING_DEFAULT     &default_cmdset, &timing[0]
> +#define NAND_SETTING_SAMSUNG     &default_cmdset, &timing[1]
> +#define NAND_SETTING_MICRON      &default_cmdset, &timing[2]
> +#define NAND_SETTING_ST          &default_cmdset, &timing[3]
>  static struct pxa3xx_nand_flash __devinitdata builtin_flash_types[] = {
> +       {      0,   0, 2048,  8,  8,    0, NAND_SETTING_DEFAULT, },
>        { 0x46ec,  32,  512, 16, 16, 4096, NAND_SETTING_SAMSUNG, },
>        { 0xdaec,  64, 2048,  8,  8, 2048, NAND_SETTING_SAMSUNG, },
>        { 0xd7ec, 128, 4096,  8,  8, 8192, NAND_SETTING_SAMSUNG, },
> @@ -948,36 +951,29 @@ static int pxa3xx_nand_detect_flash(struct
> pxa3xx_nand_info *info,
>                if (pxa3xx_nand_detect_config(info) == 0)
>                        return 0;
>
> -       for (i = 0; i<pdata->num_flash; ++i) {
> -               f = pdata->flash + i;
> -
> -               if (pxa3xx_nand_config_flash(info, f))
> -                       continue;
> -
> -               if (__readid(info, &id))
> -                       continue;
> -
> -               if (id == f->chip_id)
> -                       return 0;
> -       }
> -
> -       for (i = 0; i < ARRAY_SIZE(builtin_flash_types); i++) {
> -
> -               f = &builtin_flash_types[i];
> -
> -               if (pxa3xx_nand_config_flash(info, f))
> -                       continue;
> -
> -               if (__readid(info, &id))
> -                       continue;
> -
> -               if (id == f->chip_id)
> +       /* we use default timing to detect id */
> +       f = &builtin_flash_types[0];

This is not intuitive when referencing an array item, probably define a
macro for this:

#define DEFAULT_FLASH_TYPE (&builtin_flash_types[0])

right after the builtin_flash_types array, with comment to explain
that this only works when probing/detecting.

> +       pxa3xx_nand_config_flash(info, f);
> +       if (__readid(info, &id))
> +               goto fail_detect;
> +
> +       for (i=0; i<ARRAY_SIZE(builtin_flash_types) + pdata->num_flash - 1; i++) {
> +               /* we first choose the flash definition from platfrom */
> +               if (i < pdata->num_flash)
> +                       f = pdata->flash + i;
> +               else
> +                       f = &builtin_flash_types[i - pdata->num_flash + 1];

Or

f = (i < pdata->num_flash) ? ...

> +               if (f->chip_id == id) {
> +                       dev_info(&info->pdev->dev, "detect chip id: 0x%x\n", id);
> +                       pxa3xx_nand_config_flash(info, f);
>                        return 0;
> +               }
>        }
>
>        dev_warn(&info->pdev->dev,
>                 "failed to detect configured nand flash; found %04x instead of\n",
>                 id);
> +fail_detect:
>        return -ENODEV;
>  }
>
> --
> 1.7.0.4
>

Otherwise looks good to me.