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

From 3450c0a0a881b4b37776a3d22917aa7752bfd980 Mon Sep 17 00:00:00 2001
From: Lei Wen <leiwen@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@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
---
 drivers/mtd/nand/pxa3xx_nand.c |   56 ++++++++++++++++++---------------------
 1 files changed, 26 insertions(+), 30 deletions(-)

On Wed, Jul 28, 2010 at 1:56 PM, Haojian Zhuang
<haojian.zhuang@gmail.com> wrote:
> From 3450c0a0a881b4b37776a3d22917aa7752bfd980 Mon Sep 17 00:00:00 2001
> From: Lei Wen <leiwen@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@marvell.com>
> Signed-off-by: Haojian Zhuang <haojian.zhuang@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.