RFC: arm pcm043 1315.6 IM950 timing (Numonyx Axcell Errata)

[Teresa Gamez]

Hello Tim,

Am Dienstag, den 23.08.2011, 14:21 +0200 schrieb Tim Sander:
> Hi
> 
> I just found out that Phytec has some patches in its BSP and i think especially the patches
> IM590_cfi_workaround for "Numonyx Axcell P33/P30 Specification Update" make me a little nervous.
> 
> We had some Problems getting the latest HW Revision of PCM043 (1315.6) up and
> running and so i found these patches. I have ported some other patches i found
> (which i will send later today) but i don't know enough about CFI to apply this patch
> logically to the barebox tree nevertheless heres my educated guess:
> (I am not sure if the patch belongs into intel CFI but since Numonyx has been owned by
> intel partly...)

I'm right now working on updating the pcm043 barebox to work with 
new hardware revisions. Including updates for NOR Flash support. 

I have also made a patch quite similar to yours. This problem seems 
to occur only with NOR Flashes having a date code around 39/2010 and earlier.
It took me some time to find a module which does have this problem 
(I just got it today and have not checked it yet). 
On newer NOR Flashes I could not see any affect/advantage with this workaround.
I'll test your patch with this module.

But adding this workaround will not be enough to support newer NOR flashes.
The CS values need to be changed and support for u32 commands have to 
be added to cfi_flash. I'll send patches the next days. 

Teresa

> 
> commit bfa486c0bd90055222b4a2702bfb0d6a0fe59d8e
> Author: Tim Sander <tim.sander at hbm.com>
> Date:   Tue Aug 23 14:03:49 2011 +0200
> 
>     IM590 cfi workaround
> 
> diff --git a/drivers/nor/cfi_flash_intel.c b/drivers/nor/cfi_flash_intel.c
> index c3cbad5..30a54e6 100644
> --- a/drivers/nor/cfi_flash_intel.c
> +++ b/drivers/nor/cfi_flash_intel.c
> @@ -132,12 +132,30 @@ static int intel_flash_status_check (struct flash_info *info, flash_sect_t secto
>  static int intel_flash_real_protect (struct flash_info *info, long sector, int prot)
>  {
>         flash_write_cmd (info, sector, 0, FLASH_CMD_CLEAR_STATUS);
> +       //flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT);
> +       /*
> +       * see errata called
> +       * "Numonyx Axcell P33/P30 Specification Update" :)
> +       */
> +       flash_write_cmd (info, sector, 0, FLASH_CMD_READ_ID);
> +       flash_isequal (info, sector, FLASH_OFFSET_PROTECT, prot);
> +       /*
> +       * cmd must come before FLASH_CMD_PROTECT + 20us
> +       * Disable interrupts which might cause a timeout here.
> +       */
> +#ifdef CONFIG_USE_IRQ
> +       int flag = disable_interrupts ();
> +#endif
>         flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT);
>         if (prot)
>                 flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT_SET);
>         else
>                 flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT_CLEAR);
> -
> +       
> +#ifdef CONFIG_USE_IRQ
> +       if(flag)
> +               enable_interrupts();
> +#endif
>         return 0;
>  }
> 
> 
> This patch is against u-boot-v2-rc10 *not* againts barebox as reference. It is taken from the 
> PD10.1.2 BSP for PCM043.
> Index: u-boot-2.0.0-rc10/drivers/nor/cfi_flash.c        
> ===================================================================
> --- u-boot-2.0.0-rc10.orig/drivers/nor/cfi_flash.c  2011-01-28 10:52:14.881458149 +0100
> +++ u-boot-2.0.0-rc10/drivers/nor/cfi_flash.c   2011-01-28 11:09:40.241981535 +0100
> @@ -599,14 +599,34 @@
>  static int flash_real_protect (flash_info_t * info, long sector, int prot)
>  {
>     int retcode = 0;
> +   unsigned short cmd;
> 
>     flash_write_cmd (info, sector, 0, FLASH_CMD_CLEAR_STATUS);
> -   flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT);
> +   /*
> +    * see errata called
> +    * "Numonyx Axcell P33/P30 Specification Update" :)
> +    */
> +   flash_write_cmd (info, sector, 0, FLASH_CMD_READ_ID);
> +   flash_isequal (info, sector, FLASH_OFFSET_PROTECT, prot);
> +   /*
> +    * cmd must come before FLASH_CMD_PROTECT + 20us
> +    * Disable interrupts which might cause a timeout here.
> +    */
> +#ifdef CONFIG_USE_IRQ
> +   int flag = disable_interrupts ();
> +#endif
>     if (prot)
> -       flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT_SET);
> +       cmd = FLASH_CMD_PROTECT_SET;
>     else
> -       flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT_CLEAR);
> +       cmd = FLASH_CMD_PROTECT_CLEAR;
> 
> +   flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT);
> +   flash_write_cmd (info, sector, 0, cmd);
> +#ifdef CONFIG_USE_IRQ
> +   /* re-enable interrupts if necessary */
> +   if (flag)
> +       enable_interrupts ();
> +#endif
>     if ((retcode =
>          flash_full_status_check (info, sector, info->erase_blk_tout,
>                       prot ? "protect" : "unprotect")) == 0) {
> 
> --
> Please CC as i'm not subscribed to the list.
> 
> Best regards
> Tim
> 
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