cfi_probe.c

讲述linux的初始化过程

	struct cfi_private *retcfi;
	struct flchip chip[MAX_CFI_CHIPS];
	int i;

	memset(&cfi, 0, sizeof(cfi));

	/* The first invocation (with chips == NULL) leaves the device in Query Mode */
	cfi.interleave = cfi_probe_new_chip(map, 0, NULL, NULL);

	if (!cfi.interleave) {
		printk("%s: Found no CFI device at location zero\n", map->name);
		/* Doesn't appear to be CFI-compliant at all */
		return NULL;
	}

	/* Read the Basic Query Structure from the device */

	for (i=0; i<sizeof(struct cfi_ident); i++) {
		((unsigned char *)&cfi.cfiq)[i] = map->read8(map,base + ((0x10 + i)*map->buswidth));
	}

	/* Do any necessary byteswapping */
	cfi.cfiq.P_ID = le16_to_cpu(cfi.cfiq.P_ID);
	cfi.cfiq.P_ADR = le16_to_cpu(cfi.cfiq.P_ADR);
	cfi.cfiq.A_ID = le16_to_cpu(cfi.cfiq.A_ID);
	cfi.cfiq.A_ADR = le16_to_cpu(cfi.cfiq.A_ADR);
	cfi.cfiq.InterfaceDesc = le16_to_cpu(cfi.cfiq.InterfaceDesc);
	cfi.cfiq.MaxBufWriteSize = le16_to_cpu(cfi.cfiq.MaxBufWriteSize);
	
#if 1
	/* Dump the information therein */
	print_cfi_ident(&cfi.cfiq);

	for (i=0; i<cfi.cfiq.NumEraseRegions; i++) {
		__u16 EraseRegionInfoNum = (map->read8(map,base + ((0x2d + (4*i))*map->buswidth))) + 
			(((map->read8(map,(0x2e + (4*i))*map->buswidth)) << 8));
		__u16 EraseRegionInfoSize = (map->read8(map, base + ((0x2f + (4*i))*map->buswidth))) + 
			(map->read8(map, base + ((0x30 + (4*i))*map->buswidth)) << 8);
		
		printk("  Erase Region #%d: BlockSize 0x%4.4X bytes, %d blocks\n",
		       i, EraseRegionInfoSize * 256, EraseRegionInfoNum+1);
	}
	
	printk("\n");
#endif	

	/* Switch the chip back into Read Mode, to make the alias detection work */
	switch(map->buswidth) {
	case 1:
		map->write8(map, 0xff, 0x55);
		break;
	case 2:
		map->write16(map, 0xffff, 0xaa);
		break;
	case 4:
		map->write32(map, 0xffffffff, 0x154);
		break;
	}

	/* OK. We've worked out what it is and we're happy with it. Now see if there are others */

	chip[0].start = 0;
	chip[0].state = FL_READY;
	chip[0].mutex = &chip[0]._spinlock;

	cfi.chipshift =  cfi.cfiq.DevSize;
	cfi.numchips = 1;

	if (!cfi.chipshift) {
		printk("cfi.chipsize is zero. This is bad. cfi.cfiq.DevSize is %d\n", cfi.cfiq.DevSize);
		return NULL;
	}

	for (base = (1<<cfi.chipshift); base < map->size; base += (1<<cfi.chipshift))
		cfi_probe_new_chip(map, base, &chip[0], &cfi);

	retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);

	if (!retcfi)
		return NULL;

	memcpy(retcfi, &cfi, sizeof(cfi));
	memcpy(&retcfi->chips[0], chip, sizeof(struct flchip) * cfi.numchips);
	for (i=0; i< retcfi->numchips; i++) {
		init_waitqueue_head(&retcfi->chips[i].wq);
		spin_lock_init(&retcfi->chips[i]._spinlock);
	}
	return retcfi;
}

static char *vendorname(__u16 vendor) 
{
	switch (vendor) {
	case P_ID_NONE:
		return "None";
		
	case P_ID_INTEL_EXT:
		return "Intel/Sharp Extended";
		
	case P_ID_AMD_STD:
		return "AMD/Fujitsu Standard";
		
	case P_ID_INTEL_STD:
		return "Intel/Sharp Standard";
		
	case P_ID_AMD_EXT:
		return "AMD/Fujitsu Extended";
		
	case P_ID_MITSUBISHI_STD:
		return "Mitsubishi Standard";
		
	case P_ID_MITSUBISHI_EXT:
		return "Mitsubishi Extended";
		
	case P_ID_RESERVED:
		return "Not Allowed / Reserved for Future Use";
		
	default:
		return "Unknown";
	}
}

		
static void print_cfi_ident(struct cfi_ident *cfip)
{
	if (cfip->qry[0] != 'Q' || cfip->qry[1] != 'R' || cfip->qry[2] != 'Y') {
		printk("Invalid CFI ident structure.\n");
		return;
	}	
		
	printk("Primary Vendor Command Set: %4.4X (%s)\n", cfip->P_ID, vendorname(cfip->P_ID));
	if (cfip->P_ADR)
		printk("Primary Algorithm Table at %4.4X\n", cfip->P_ADR);
	else
		printk("No Primary Algorithm Table\n");
	
	printk("Alternative Vendor Command Set: %4.4X (%s)\n", cfip->A_ID, vendorname(cfip->A_ID));
	if (cfip->A_ADR)
		printk("Alternate Algorithm Table at %4.4X\n", cfip->A_ADR);
	else
		printk("No Alternate Algorithm Table\n");
		
		
	printk("Vcc Minimum: %x.%x V\n", cfip->VccMin >> 4, cfip->VccMin & 0xf);
	printk("Vcc Maximum: %x.%x V\n", cfip->VccMax >> 4, cfip->VccMax & 0xf);
	if (cfip->VppMin) {
		printk("Vpp Minimum: %x.%x V\n", cfip->VppMin >> 4, cfip->VppMin & 0xf);
		printk("Vpp Maximum: %x.%x V\n", cfip->VppMax >> 4, cfip->VppMax & 0xf);
	}
	else
		printk("No Vpp line\n");
	
	printk("Typical byte/word write timeout: %d 祍\n", 1<<cfip->WordWriteTimeoutTyp);
	printk("Maximum byte/word write timeout: %d 祍\n", (1<<cfip->WordWriteTimeoutMax) * (1<<cfip->WordWriteTimeoutTyp));
	
	if (cfip->BufWriteTimeoutTyp || cfip->BufWriteTimeoutMax) {
		printk("Typical full buffer write timeout: %d 祍\n", 1<<cfip->BufWriteTimeoutTyp);
		printk("Maximum full buffer write timeout: %d 祍\n", (1<<cfip->BufWriteTimeoutMax) * (1<<cfip->BufWriteTimeoutTyp));
	}
	else
		printk("Full buffer write not supported\n");
	
	printk("Typical block erase timeout: %d 祍\n", 1<<cfip->BlockEraseTimeoutTyp);
	printk("Maximum block erase timeout: %d 祍\n", (1<<cfip->BlockEraseTimeoutMax) * (1<<cfip->BlockEraseTimeoutTyp));
	if (cfip->ChipEraseTimeoutTyp || cfip->ChipEraseTimeoutMax) {
		printk("Typical chip erase timeout: %d 祍\n", 1<<cfip->ChipEraseTimeoutTyp); 
		printk("Maximum chip erase timeout: %d 祍\n", (1<<cfip->ChipEraseTimeoutMax) * (1<<cfip->ChipEraseTimeoutTyp));
	}
	else
		printk("Chip erase not supported\n");
	
	printk("Device size: 0x%X bytes (%d Mb)\n", 1 << cfip->DevSize, 1<< (cfip->DevSize - 20));
	printk("Flash Device Interface description: 0x%4.4X\n", cfip->InterfaceDesc);
	switch(cfip->InterfaceDesc) {
	case 0:
		printk("  - x8-only asynchronous interface\n");
		break;
		
	case 1:
		printk("  - x16-only asynchronous interface\n");
		break;
		
	case 2:
		printk("  - supports x8 and x16 via BYTE# with asynchronous interface\n");
		break;
		
	case 3:
		printk("  - x32-only asynchronous interface\n");
		break;
		
	case 65535:
		printk("  - Not Allowed / Reserved\n");
		break;
		
	default:
		printk("  - Unknown\n");
		break;
	}
	
	printk("Max. bytes in buffer write: 0x%x\n", 1<< cfip->MaxBufWriteSize);
	printk("Number of Erase Block Regions: %d\n", cfip->NumEraseRegions);
	
}

static void check_cmd_set(struct map_info *map, int primary, unsigned long base)
{
	__u16 adr;
	struct cfi_private *cfi = map->fldrv_priv;
	__u16 type = primary?cfi->cfiq.P_ID:cfi->cfiq.A_ID;
	char probename[32];
	void (*probe_function)(struct map_info *, int, unsigned long);
	
	if (type == P_ID_NONE || type == P_ID_RESERVED)
		return;
	
	sprintf(probename, "cfi_cmdset_%4.4X", type);
	
	probe_function = inter_module_get_request(probename, probename);
	if (probe_function) {
		(*probe_function)(map, primary, base);
		return;
	}

	/* This was a command set we don't know about. Print only the basic info */
	adr = primary?cfi->cfiq.P_ADR:cfi->cfiq.A_ADR;
	
	if (!adr) {
		printk(" No Extended Query Table\n");
	}
	else if (map->read8(map,base+(adr*map->buswidth)) != (primary?'P':'A') ||
		 map->read8(map,base+((adr+1)*map->buswidth)) != (primary?'R':'L') ||
		 map->read8(map,base+((adr+2)*map->buswidth)) != (primary?'I':'T')) {
		printk ("Invalid Extended Query Table at %4.4X: %2.2X %2.2X %2.2X\n",
			adr,
			map->read8(map,base+(adr*map->buswidth)),
			map->read8(map,base+((adr+1)*map->buswidth)),
			map->read8(map,base+((adr+2)*map->buswidth)));
	}
	else {
		printk(" Extended Query Table version %c.%c\n",
		       map->read8(map,base+((adr+3)*map->buswidth)), 
		       map->read8(map,base+((adr+4)*map->buswidth)));
	}
}

static int __init cfi_probe_init(void)
{
	inter_module_register(im_name, THIS_MODULE, &cfi_probe);
	return 0;
}

static void __exit cfi_probe_exit(void)
{
	inter_module_unregister(im_name);
}

module_init(cfi_probe_init);
module_exit(cfi_probe_exit);