spd_sdram.c

		 *
		 * sdram_cfg[0]   = 1 (ddr sdram logic enable)
		 * sdram_cfg[1]   = 1 (self-refresh-enable)
		 * sdram_cfg[5:7] = (SDRAM type = DDR SDRAM)
		 *			010 DDR 1 SDRAM
		 *			011 DDR 2 SDRAM
		 */
		sdram_type = (mem_type == SPD_MEMTYPE_DDR) ? 2 : 3;
		sdram_cfg_1 = (0
			       | (1 << 31)		/* Enable */
			       | (1 << 30)		/* Self refresh */
			       | (sdram_type << 24)	/* SDRAM type */
			       );

		/*
		 * sdram_cfg[3] = RD_EN - registered DIMM enable
		 *   A value of 0x26 indicates micron registered
		 *   DIMMS (micron.com)
		 */
		mod_attr = no_dimm2 ? spd1.mod_attr : spd2.mod_attr;
		if (mem_type == SPD_MEMTYPE_DDR && mod_attr == 0x26) {
			sdram_cfg_1 |= 0x10000000;		/* RD_EN */
		}

#if defined(CONFIG_DDR_ECC)

		config = no_dimm2 ? spd1.config : spd2.config;

		/*
		 * If the user wanted ECC (enabled via sdram_cfg[2])
		 */
		if (config == 0x02) {
			ddr->err_disable = 0x00000000;
			asm volatile("sync;isync;");
			ddr->err_sbe = 0x00ff0000;
			ddr->err_int_en = 0x0000000d;
			sdram_cfg_1 |= 0x20000000;		/* ECC_EN */
		}
#endif

		/*
		 * Set 1T or 2T timing based on 1 or 2 modules
		 */
		{
			if (!(no_dimm1 || no_dimm2)) {
				/*
				 * 2T timing,because both DIMMS are present.
				 * Enable 2T timing by setting sdram_cfg[16].
				 */
				sdram_cfg_1 |= 0x8000;		/* 2T_EN */
			}
		}

		/*
		 * 200 painful micro-seconds must elapse between
		 * the DDR clock setup and the DDR config enable.
		 */
		udelay(200);

		/*
		 * Go!
		 */
		ddr->sdram_cfg_1 = sdram_cfg_1;

		asm volatile("sync;isync");
		udelay(500);

		debug("DDR: sdram_cfg   = 0x%08x\n", ddr->sdram_cfg_1);


#if defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER)
		d_init = 1;
		debug("DDR: memory initializing\n");

		/*
		 * Poll until memory is initialized.
		 * 512 Meg at 400 might hit this 200 times or so.
		 */
		while ((ddr->sdram_cfg_2 & (d_init << 4)) != 0) {
			udelay(1000);
		}
		debug("DDR: memory initialized\n\n");
#endif

		debug("Enabled DDR Controller %d\n", ddr_num);
		return 1;
	}
}


long int
spd_sdram(void)
{
	int memsize_ddr1_dimm1 = 0;
	int memsize_ddr1_dimm2 = 0;
	int memsize_ddr2_dimm1 = 0;
	int memsize_ddr2_dimm2 = 0;
	int memsize_total = 0;
	int memsize_ddr1 = 0;
	int memsize_ddr2 = 0;
	unsigned int ddr1_enabled = 0;
	unsigned int ddr2_enabled = 0;
	unsigned int law_size_ddr1;
	unsigned int law_size_ddr2;
	volatile immap_t *immap = (immap_t *)CFG_IMMR;
	volatile ccsr_local_mcm_t *mcm = &immap->im_local_mcm;

#ifdef CONFIG_DDR_INTERLEAVE
	unsigned int law_size_interleaved;
	volatile ccsr_ddr_t *ddr1 = &immap->im_ddr1;
	volatile ccsr_ddr_t *ddr2 = &immap->im_ddr2;

	memsize_ddr1_dimm1 = spd_init(SPD_EEPROM_ADDRESS1,
				      1, 1,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr1_dimm1;

	memsize_ddr2_dimm1 = spd_init(SPD_EEPROM_ADDRESS3,
				      2, 1,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr2_dimm1;

	if (memsize_ddr1_dimm1 != memsize_ddr2_dimm1) {
		if (memsize_ddr1_dimm1 <  memsize_ddr2_dimm1)
			memsize_total -= memsize_ddr1_dimm1;
		else
			memsize_total -= memsize_ddr2_dimm1;
		debug("Total memory available for interleaving 0x%08lx\n",
		      memsize_total * 1024 * 1024);
		debug("Adjusting CS0_BNDS to account for unequal DIMM sizes in interleaved memory\n");
		ddr1->cs0_bnds = ((memsize_total * 1024 * 1024) - 1) >> 24;
		ddr2->cs0_bnds = ((memsize_total * 1024 * 1024) - 1) >> 24;
		debug("DDR1: cs0_bnds   = 0x%08x\n", ddr1->cs0_bnds);
		debug("DDR2: cs0_bnds   = 0x%08x\n", ddr2->cs0_bnds);
	}

	ddr1_enabled = enable_ddr(1);
	ddr2_enabled = enable_ddr(2);

	/*
	 * Both controllers need to be enabled for interleaving.
	 */
	if (ddr1_enabled && ddr2_enabled) {
		law_size_interleaved = 19 + __ilog2(memsize_total);

		/*
		 * Set up LAWBAR for DDR 1 space.
		 */
		mcm->lawbar1 = ((CFG_DDR_SDRAM_BASE >> 12) & 0xfffff);
		mcm->lawar1 = (LAWAR_EN
			       | LAWAR_TRGT_IF_DDR_INTERLEAVED
			       | (LAWAR_SIZE & law_size_interleaved));
		debug("DDR: LAWBAR1=0x%08x\n", mcm->lawbar1);
		debug("DDR: LAWAR1=0x%08x\n", mcm->lawar1);
		debug("Interleaved memory size is 0x%08lx\n", memsize_total);

#ifdef	CONFIG_DDR_INTERLEAVE
#if (CFG_PAGE_INTERLEAVING == 1)
		printf("Page ");
#elif (CFG_BANK_INTERLEAVING == 1)
		printf("Bank ");
#elif (CFG_SUPER_BANK_INTERLEAVING == 1)
		printf("Super-bank ");
#else
		printf("Cache-line ");
#endif
#endif
		printf("Interleaved");
		return memsize_total * 1024 * 1024;
	}  else {
		printf("Interleaved memory not enabled - check CS0 DIMM slots for both controllers.\n");
		return 0;
	}

#else
	/*
	 * Call spd_sdram() routine to init ddr1 - pass I2c address,
	 * controller number, dimm number, and starting address.
	 */
	memsize_ddr1_dimm1 = spd_init(SPD_EEPROM_ADDRESS1,
				      1, 1,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr1_dimm1;

	memsize_ddr1_dimm2 = spd_init(SPD_EEPROM_ADDRESS2,
				      1, 2,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr1_dimm2;

	/*
	 * Enable the DDR controller - pass ddr controller number.
	 */
	ddr1_enabled = enable_ddr(1);

	/* Keep track of memory to be addressed by DDR1 */
	memsize_ddr1 = memsize_ddr1_dimm1 + memsize_ddr1_dimm2;

	/*
	 * First supported LAW size is 16M, at LAWAR_SIZE_16M == 23.  Fnord.
	 */
	if (ddr1_enabled) {
		law_size_ddr1 = 19 + __ilog2(memsize_ddr1);

		/*
		 * Set up LAWBAR for DDR 1 space.
		 */
		mcm->lawbar1 = ((CFG_DDR_SDRAM_BASE >> 12) & 0xfffff);
		mcm->lawar1 = (LAWAR_EN
			       | LAWAR_TRGT_IF_DDR1
			       | (LAWAR_SIZE & law_size_ddr1));
		debug("DDR: LAWBAR1=0x%08x\n", mcm->lawbar1);
		debug("DDR: LAWAR1=0x%08x\n", mcm->lawar1);
	}

#if  (CONFIG_NUM_DDR_CONTROLLERS > 1)
	memsize_ddr2_dimm1 = spd_init(SPD_EEPROM_ADDRESS3,
				      2, 1,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr2_dimm1;

	memsize_ddr2_dimm2 = spd_init(SPD_EEPROM_ADDRESS4,
				      2, 2,
				      (unsigned int)memsize_total * 1024*1024);
	memsize_total += memsize_ddr2_dimm2;

	ddr2_enabled = enable_ddr(2);

	/* Keep track of memory to be addressed by DDR2 */
	memsize_ddr2 = memsize_ddr2_dimm1 + memsize_ddr2_dimm2;

	if (ddr2_enabled) {
		law_size_ddr2 = 19 + __ilog2(memsize_ddr2);

		/*
		 * Set up LAWBAR for DDR 2 space.
		 */
		if (ddr1_enabled)
			mcm->lawbar8 = (((memsize_ddr1 * 1024 * 1024) >> 12)
					& 0xfffff);
		else
			mcm->lawbar8 = ((CFG_DDR_SDRAM_BASE >> 12) & 0xfffff);

		mcm->lawar8 = (LAWAR_EN
			       | LAWAR_TRGT_IF_DDR2
			       | (LAWAR_SIZE & law_size_ddr2));
		debug("\nDDR: LAWBAR8=0x%08x\n", mcm->lawbar8);
		debug("DDR: LAWAR8=0x%08x\n", mcm->lawar8);
	}
#endif /* CONFIG_NUM_DDR_CONTROLLERS > 1 */

	debug("\nMemory sizes are DDR1 = 0x%08lx, DDR2 = 0x%08lx\n",
	      memsize_ddr1, memsize_ddr2);

	/*
	 * If neither DDR controller is enabled return 0.
	 */
	if (!ddr1_enabled && !ddr2_enabled)
		return 0;

	printf("Non-interleaved");
	return memsize_total * 1024 * 1024;

#endif /* CONFIG_DDR_INTERLEAVE */
}


#endif /* CONFIG_SPD_EEPROM */


#if defined(CONFIG_DDR_ECC) && !defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER)

/*
 * Initialize all of memory for ECC, then enable errors.
 */

void
ddr_enable_ecc(unsigned int dram_size)
{
	uint *p = 0;
	uint i = 0;
	volatile immap_t *immap = (immap_t *)CFG_IMMR;
	volatile ccsr_ddr_t *ddr1= &immap->im_ddr1;

	dma_init();

	for (*p = 0; p < (uint *)(8 * 1024); p++) {
		if (((unsigned int)p & 0x1f) == 0) {
			ppcDcbz((unsigned long) p);
		}
		*p = (unsigned int)CONFIG_MEM_INIT_VALUE;
		if (((unsigned int)p & 0x1c) == 0x1c) {
			ppcDcbf((unsigned long) p);
		}
	}

	dma_xfer((uint *)0x002000, 0x002000, (uint *)0); /* 8K */
	dma_xfer((uint *)0x004000, 0x004000, (uint *)0); /* 16K */
	dma_xfer((uint *)0x008000, 0x008000, (uint *)0); /* 32K */
	dma_xfer((uint *)0x010000, 0x010000, (uint *)0); /* 64K */
	dma_xfer((uint *)0x020000, 0x020000, (uint *)0); /* 128k */
	dma_xfer((uint *)0x040000, 0x040000, (uint *)0); /* 256k */
	dma_xfer((uint *)0x080000, 0x080000, (uint *)0); /* 512k */
	dma_xfer((uint *)0x100000, 0x100000, (uint *)0); /* 1M */
	dma_xfer((uint *)0x200000, 0x200000, (uint *)0); /* 2M */
	dma_xfer((uint *)0x400000, 0x400000, (uint *)0); /* 4M */

	for (i = 1; i < dram_size / 0x800000; i++) {
		dma_xfer((uint *)(0x800000*i), 0x800000, (uint *)0);
	}

	/*
	 * Enable errors for ECC.
	 */
	debug("DMA DDR: err_disable = 0x%08x\n", ddr1->err_disable);
	ddr1->err_disable = 0x00000000;
	asm volatile("sync;isync");
	debug("DMA DDR: err_disable = 0x%08x\n", ddr1->err_disable);
}

#endif	/* CONFIG_DDR_ECC  && ! CONFIG_ECC_INIT_VIA_DDRCONTROLLER */