SEP0718 Nand flash驱动
SEP0718的Nand控制器在使用上基本和SEP4020一样（比如DMA操作）。
移植过程中没出现什么大问题，只有有一点点需要注意：
1）ID寄存器可以读到32ib数据，而id和manf只需要8bit，无用数据需要清空
2）CONF1和CONF2寄存器需要重新配置，否则默认开了硬件ECC校验
1 copy /driver/mtd/nand/sep4020.c to sep0718_nand.c
2 modify /driver/mtd/nand/kconfig
add
config MTD_NAND_SEP0718
tristate "Support for Southeast University SEP0718 easic board"
depends on MTD_NAND && ARCH_SEP0718
help
This enables the driver for the SEU SEP0718 easic
board to access the onboard NAND Flash.
3 modify /driver/mtd/nand/Makefile
add
obj-$(CONFIG_MTD_NAND_SEP0718) += sep0718_nand.o
4 make menuconfig
│ │ --- Memory Technology Device (MTD) support │ │
│ │ [ ] Debugging │ │
│ │ <*> MTD concatenating support │ │
│ │ [*] MTD partitioning support │ │
│ │ < > MTD tests support │ │
│ │ < > RedBoot partition table parsing (NEW) │ │
│ │ [ ] Command line partition table parsing (NEW) │ │
│ │ < > ARM Firmware Suite partition parsing (NEW) │ │
│ │ < > TI AR7 partitioning support (NEW) │ │
│ │ *** User Modules And Translation Layers *** │ │
│ │ <*> Direct char device access to MTD devices │ │
│ │ -*- Common interface to block layer for MTD 'translation layers' │ │
│ │ <*> Caching block device access to MTD devices │ │
│ │ < > FTL (Flash Translation Layer) support │ │
│ │ < > NFTL (NAND Flash Translation Layer) support │ │
│ │ < > INFTL (Inverse NAND Flash Translation Layer) support │ │
│ │ < > Resident Flash Disk (Flash Translation Layer) support │ │
│ │ < > NAND SSFDC (SmartMedia) read only translation layer │ │
│ │ < > Log panic/oops to an MTD buffer │ │
│ │ RAM/ROM/Flash chip drivers ---> │ │
│ │ Mapping drivers for chip access ---> │ │
│ │ Self-contained MTD device drivers ---> │ │
│ │ <*> NAND Device Support ---> │ │
│ │ < > OneNAND Device Support ---> │ │
│ │ LPDDR flash memory drivers ---> │ │
│ │ UBI - Unsorted block images --->
│ │ --- NAND Device Support │ │
│ │ [ ] Verify NAND page writes (NEW) │ │
│ │ [ ] NAND ECC Smart Media byte order (NEW) │ │
│ │ [ ] Enable chip ids for obsolete ancient NAND devices (NEW) │ │
│ │ <*> Support for Southeast University SEP0718 easic board │ │
│ │ < > DiskOnChip 2000, Millennium and Millennium Plus (NAND reimplementation) (EXPERIMENTAL) (NEW) │ │
│ │ < > Support for NAND Flash Simulator (NEW) │ │
│ │ < > Support for generic platform NAND driver (NEW)
5 modify sep0718_nand.c
del
line 387 useless We do not use gpio to control the wp
//*(volatile unsigned long*)GPIO_PORTG_SEL_V |= 0x0080;
//*(volatile unsigned long*)GPIO_PORTG_DATA_V |= 0x0080;
//*(volatile unsigned long*)GPIO_PORTG_DIR_V &= ~0x0080;
line 272 need repair
static void sep4020_emi_init(void)
{
*(volatile unsigned long*)NAND_CONF1_V = (6<<24) + (3<<20) + (0<<15) + (1<<14) +(8<<8) + (5<<4) + (7<<0);
//0x06302857;//TW2R:6个时钟周期； TALE：4个地址； TWB：8； 读脉冲：5个； 写脉冲：7个；
*(volatile unsigned long*)NAND_CONF2_V = (4<<18) + (20<<12) + (3<<8) + (1<<6) + (1<<4) + (3<<0);
//0x00514353;//page:512bytes; ecc:soft; TRR:4; TAR:20; TREH:3; CLH:1; TALH:1; TWH:3
}
6 modify /driver/mtd/nand/nand_base.c
line2333
#ifdef CONFIG_MTD_NAND_SEP0718
/* Read manufacturer and device IDs for sep0718 */
*maf_id = chip->read_byte(mtd);
dev_id = (*(volatile unsigned long*)NAND_ID1_V)>>8;
dev_id &= 0xff;
#else
/* Read manufacturer and device IDs */
*maf_id = chip->read_byte(mtd);
dev_id = chip->read_byte(mtd);
#endif
line2354
#ifdef CONFIG_MTD_NAND_SEP0718
/* Read manufacturer and device IDs for sep0718 */
tmp_manf = chip->read_byte(mtd);
tmp_id = (*(volatile unsigned long*)NAND_ID1_V)>>8;
tmp_id &= 0xff;
#else
tmp_manf = chip->read_byte(mtd);
tmp_id = chip->read_byte(mtd);
#endif
7 Build the kernel ,it seems work well ,even yaffs could go through with it.
by rockie cheng
