[U-Boot] U-boot: Erase/read/write issue with S25fl256S flash device
Jagan Teki
jagannadh.teki at gmail.com
Fri Jun 14 16:38:28 CEST 2013
On 14-06-2013 20:03, Sourav Poddar wrote:
>
> Hi,
>
> On Wednesday 12 June 2013 01:00 PM, Sourav Poddar wrote:
>> Hi,
>>
>> I am working on qspi flash device S25FL256S at u-boot level. I am
>> trying to
>> make use of the existing spi_flash.c framework available at u-boot for
>> erasing/reading/writing
>> into the flash device.
>>
>> There are several issues(mentioned below), which I faced while using
>> S25FL256s flash device
>> with my dra7xx board which has a qspi controller to which the above
>> mentioned flash device is attached.
>>
>> 1. Erase (spi_flash_cmd_erase)
>>
>> Issuing a command something like this..
>>
>> sf erase 0x0 0x50000
>> - erases only first 0x20000 bytes of flash device, anything above
>> that is not erase. I need to
>> issue separate commands after 0x20000 for every 0x10000 bytes.
>>
>> Am i missing anything here?
>>
>> 2. read
>>
>> sf read 81000000 0 0x10000
>>
>> Read is not happening properly. The last few byte along the 4k
>> boundary always shows zero.
>> Above 4k bytes, read is not happening.
>>
>> For ex:
>> DRA752 EVM # md 81000f00
>> 81000f00: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f10: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f20: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f30: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f40: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f50: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f60: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f70: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f80: ffffffff ffffffff ffffffff ffffffff ................
>> 81000f90: ffffffff ffffffff ffffffff ffffffff ................
>> 81000fa0: ffffffff ffffffff ffffffff ffffffff ................
>> 81000fb0: ffffffff ffffffff ffffffff ffffffff ................
>> 81000fc0: ffffffff ffffffff ffffffff ffffffff ................
>> 81000fd0: ffffffff ffffffff ffffffff ffffffff ................
>> 81000fe0: ffffffff ffffffff ffffffff ffffffff ................
>> 81000ff0: ffffffff ffffffff 00ffffff 00000000 ................
>>
>> In this dump, if you see 81000ff0 the last column shows 000000 which is
>> not expected. and it happens along every 4k bytes.
>>
>>
>> So, to get rid of the above issue, I switched to page read with the
>> below patch[1],
>> which is giving me the correct result.
>> [1]:
>> @@ -147,17 +153,40 @@ int spi_flash_read_common(struct spi_flash
>> *flash, const u8 *cmd,
>> int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
>> size_t len, void *data)
>> {
>> - u8 cmd[5];
>> + unsigned long page_addr, byte_addr, page_size;
>> + size_t chunk_len, actual;
>> + int ret = 0;
>> + u8 cmd[4];
>>
>> /* Handle memory-mapped SPI */
>> if (flash->memory_map)
>> memcpy(data, flash->memory_map + offset, len);
>> + page_size = flash->page_size;
>> + page_addr = offset / page_size;
>> + byte_addr = offset % page_size;
>> +
>> + cmd[0] = CMD_READ_ARRAY_SLOW;
>> + for (actual = 0; actual < len; actual += chunk_len) {
>> + chunk_len = min(len - actual, page_size - byte_addr);
>> +
>> + cmd[1] = page_addr >> 8;
>> + cmd[2] = page_addr;
>> + cmd[3] = byte_addr;
>> +
>> + ret = spi_flash_read_common(flash, cmd, sizeof(cmd),
>> data + actual, chunk_len);
>> + if (ret < 0) {
>> + debug("SF: read failed");
>> + break;
>> + }
>>
>> - cmd[0] = CMD_READ_ARRAY_FAST;
>> - spi_flash_addr(offset, cmd);
>> - cmd[4] = 0x00;
>> + byte_addr += chunk_len;
>> + if (byte_addr == page_size) {
>> + page_addr++;
>> + byte_addr = 0;
>> + }
>> + }
>>
>> - return spi_flash_read_common(flash, cmd, sizeof(cmd), data, len);
>> + return ret;
>> }
>>
>> Any idea about this?
>>
>> 3. write (spi_flash_cmd_write_multi)
>> write not happening properly.
>>
>> observations: only able to write single page, anything after a page is
>> not getting
>> written.
>> Workaround:
>> I did a write disable latch at the end of every write cycle(page
>> program) and enable it
>> again for the next loop. With this, I see I get rid of the above issue.
>>
>> @@ -117,6 +117,12 @@ int spi_flash_cmd_write_multi(struct spi_flash
>> *flash, u32 offset,
>> if (ret)
>> break;
>>
>> + ret = spi_flash_cmd_write_disable(flash);
>> + if (ret < 0) {
>> + printf("SF: disabling write failed\n");
>> + break;
>> + }
>> +
>>
>>
>> Have anyone seen the above mentioned issues regarding
>> read/write/erase? OR is there any
>> configurations that I might be missing ?
>>
> Any Input on this?
Please wait, I am pushing some changes tonight or so.
We will continue this thread, after testing your part with these new
changes.
I will intimate you once the push done.
--
Thanks,
Jagan.
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