Re: [U-Boot] mtd/cfi: SST39VF3201B flash model not properly handled
Dear Stefan Roese, > > as Wolfgang Denx suggested me, i am trying to use the u-boot CFI driver > > with > > a CFI flash (SSTVF3201B). > > Yes. But please take a look at the CONFIG_FLASH_CFI_LEGACY config > option. This enables the legacy CFI flash devices. And IIRC the SST > flash chips are supported via this driver/extension. > > > This flash chip allows erasing/writing blocks of 4 KBytes (called "sectors" > > in the SST datasheet), or 64 KBytes (called "blocks"). > > > > The command sequence table for this flash shows 2 different commands to > > Please see my comment above. And grep for CONFIG_FLASH_CFI_LEGACY to see > how its used in the config header. And if necessary, you can always > extend the CFI configuration in the JEDEC source: > > drivers/mtd/jedec_flash.c thaks for the hint, anyway seems i am unfortunate whit this flash chip: first of all, i would understand why a flash chip is defined/handled as leagacy. Can someone kindly clarify this ? SST39VF3201B is a 2M x 16, CFI compliant. CFI legacy dont seems anyway to support 0x50 command for erasing a sector, i grepped and found "only" a CMD_CLEAR_STATUS as 0x50 that don't seems to fit the case. But the code is not trivial, and i can miss something of course. Also, legacy flash_info_t don't have any field to define the erase sector command. But still, i am not sure this chip should be considered legacy. I grepped for *3201* SST chip, only baord that seems to use it is esd/common and this board has her own flash.c But still, has been suggested me to use CFI driver, so i need to know what the u-boot community would prefer as approach. Still a note. I found issues in Linux also for this chip (STT39VF3201B) and had to ask for a patch on the command set to allow the correct erase command to be used. So how should i proceed ? Many thanks. Best Regards Angelo Dureghello ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] mtd/cfi: SST39VF3201B flash model not properly handled
Hi Angelo, On 11/29/2012 01:03 PM, Angelo Dureghello wrote: > as Wolfgang Denx suggested me, i am trying to use the u-boot CFI driver with > a CFI flash (SSTVF3201B). Yes. But please take a look at the CONFIG_FLASH_CFI_LEGACY config option. This enables the legacy CFI flash devices. And IIRC the SST flash chips are supported via this driver/extension. > This flash chip allows erasing/writing blocks of 4 KBytes (called "sectors" > in the SST datasheet), or 64 KBytes (called "blocks"). > > The command sequence table for this flash shows 2 different commands to > operate on these 2 kind of blocks. 0x50 is for "sector erase" and "0x30" (the > command used from u-boot CFI driver as AMD_CMD_ERASE_SECTOR) is for the > 64KB "block" erase. > > The issue: > now, u-boot CFI driver works fine on 64KB boundary ranges, but if i expect > to erase a 4KB sector size i get a full 64KB block erased. > > Proposed solution: > Initially, a single sector size definition would be good enough for this > chip, > so the user should specify if he wants a 64 or 4 KB sector to be used, using > some CFG_X. > CFI driver, through queries, should be able to identify this particular chip > so that it can be handled in a specific way from the CFI driver (cmd 0x50 for > 4KB secotrs, or 0x30 for 64KB secotrs). > > I am thinking about to post a patch on this. > Anyway, until new AMCORE board patch is not accepted, there is the chance > this can result as a "dead code" if no-one use this flash chip except me. > > So, before i start, please let me know how to proceed, maybe is better to use > a specific flash.c for my board for now ? > Or if you think a patch can be useful, any suggestion on how to implement it > is really welcome. Please see my comment above. And grep for CONFIG_FLASH_CFI_LEGACY to see how its used in the config header. And if necessary, you can always extend the CFI configuration in the JEDEC source: drivers/mtd/jedec_flash.c Thanks, Stefan ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
