[U-Boot-Users] Suggestion on flash init

[Wang Jian]

Hi,

After reading many board/*/flash.c and writing customer board driver for
one of my customer, I think the current flash interface can be improved.

I suggest adding a subdir $(TOPDIR)/include/flash/ and putting flash
chip information here. When you use some kinds of flash chips, just
include relevant header files.

If we go further, many information in $(TOPDIR)/include/flash.h can be
put into these header files.

And, even flash operation (non-CFI) sample code can be put into
$(TOPDIR)/contrib/flash/.

The following is an example of AMD Spansion S29AL016M chip.

--snip--
#ifndef _FLASH_S29AL016M_H_ 
#define _FLASH_S29AL016M_H_ 
        
#define FLASH_S29AL016M_T_SECTORS       35
#define FLASH_S29AL016M_B_SECTORS       35
        
#define FLASH_S29AL016M_T_SIZE          0x00200000
#define FLASH_S29AL016M_B_SIZE          0x00200000


int FLASH_S29AL016M_T_BYTE_SA[] = {
        0x000000, 0x010000, 0x020000, 0x030000,
        0x040000, 0x050000, 0x060000, 0x070000,
        0x080000, 0x090000, 0x0A0000, 0x0B0000,
        0x0C0000, 0x0D0000, 0x0E0000, 0x0F0000,
        0x100000, 0x110000, 0x120000, 0x130000,
        0x140000, 0x150000, 0x160000, 0x170000,
        0x180000, 0x190000, 0x1A0000, 0x1B0000,
        0x1C0000, 0x1D0000, 0x1E0000, 0x1F0000,
        0x1F8000, 0x1FA000, 0x1C0000
};

int FLASH_S29AL016M_T_WORD_SA[] = {
        0x000000, 0x008000, 0x010000, 0x018000,
        0x020000, 0x028000, 0x030000, 0x038000,
        0x040000, 0x048000, 0x050000, 0x058000,
        0x060000, 0x068000, 0x070000, 0x078000,
        0x080000, 0x088000, 0x090000, 0x098000,
        0x0A0000, 0x0A8000, 0x0B0000, 0x0B8000,
        0x0C0000, 0x0C8000, 0x0D0000, 0x0D8000,
        0x0E0000, 0x0E8000, 0x0F0000, 0x0F8000,
        0x0FC000, 0x0FD000, 0x0FE000
};

int FLASH_S29AL016M_B_BYTE_SA[] = {
        0x000000, 0x004000, 0x006000, 0x008000,
        0x010000, 0x020000, 0x030000, 0x040000,
        0x050000, 0x060000, 0x070000, 0x080000,
        0x090000, 0x0A0000, 0x0B0000, 0x0C0000,
        0x0D0000, 0x0E0000, 0x0F0000, 0x100000,
        0x110000, 0x120000, 0x130000, 0x140000,
        0x150000, 0x160000, 0x170000, 0x180000,
        0x190000, 0x1A0000, 0x1B0000, 0x1C0000,
        0x1D0000, 0x1E0000, 0x1F0000
};

int FLASH_S29AL016M_B_WORD_SA[] = {
        0x000000, 0x002000, 0x003000, 0x004000,
        0x008000, 0x010000, 0x018000, 0x020000,
        0x028000, 0x030000, 0x038000, 0x040000,
        0x048000, 0x050000, 0x058000, 0x060000,
        0x068000, 0x070000, 0x078000, 0x080000,
        0x088000, 0x090000, 0x098000, 0x0A0000,
        0x0A8000, 0x0B0000, 0x0B8000, 0x0C0000,
        0x0C8000, 0x0D0000, 0x0D8000, 0x0E0000,
        0x0E8000, 0x0F0000, 0x0F8000
};

#endif
--snip--


In flash_get_size()
--snip--
        switch (device) {
        case BYTEME(AMD_ID_S29AL016M_T):
                info->flash_id += FLASH_S29AL016M_T;
                info->sector_count = FLASH_S29AL016M_T_SECTORS;
                info->size = FLASH_S29AL016M_T_SIZE;
                break;

        case BYTEME(AMD_ID_S29AL016M_B):
                info->flash_id += FLASH_S29AL016M_B;
                info->sector_count = FLASH_S29AL016M_B_SECTORS;
                info->size = FLASH_S29AL016M_B_SIZE;
                break;
--snip--


In flash_get_offset()
--snip--
        switch (info->flash_id & FLASH_TYPEMASK) {
        case FLASH_S29AL016M_T:
                for (i = 0; i < info->sector_count; i++) {
                        info->start[i] = base + FLASH_S29AL016M_T_BYTE_SA[i];
                }
                break;
        case FLASH_S29AL016M_B:
                for (i = 0; i < info->sector_count; i++) {
                        info->start[i] = base + FLASH_S29AL016M_B_BYTE_SA[i];
                }
                break;
--snip--

-- 
  lark