sc520: Move RAM sizing code from asm to C
diff --git a/arch/i386/cpu/sc520/sc520_sdram.c b/arch/i386/cpu/sc520/sc520_sdram.c
new file mode 100644
index 0000000..d5ab55d
--- /dev/null
+++ b/arch/i386/cpu/sc520/sc520_sdram.c
@@ -0,0 +1,532 @@
+/*
+ * (C) Copyright 2010
+ * Graeme Russ <graeme.russ@gmail.com>.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/processor-flags.h>
+#include <asm/ic/sc520.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sc520_sdram_info {
+	u8 banks;
+	u8 columns;
+	u8 rows;
+	u8 size;
+};
+
+static void sc520_sizemem(void);
+static void sc520_set_dram_timing(void);
+static void sc520_set_dram_refresh_rate(void);
+static void sc520_enable_dram_refresh(void);
+static void sc520_enable_sdram(void);
+#if CONFIG_SYS_SDRAM_ECC_ENABLE
+static void sc520_enable_ecc(void)
+#endif
+
+int dram_init_f(void)
+{
+	sc520_sizemem();
+	sc520_set_dram_timing();
+	sc520_set_dram_refresh_rate();
+	sc520_enable_dram_refresh();
+	sc520_enable_sdram();
+#if CONFIG_SYS_SDRAM_ECC_ENABLE
+	sc520_enable_ecc();
+#endif
+
+	return 0;
+}
+
+static inline void sc520_dummy_write(void)
+{
+	writew(0x0000, CACHELINESZ);
+}
+static inline void sc520_issue_sdram_op_mode_select(u8 command)
+{
+	writeb(command, &sc520_mmcr->drcctl);
+	sc520_dummy_write();
+}
+
+static inline int check_long(u32 test_long)
+{
+	u8 i;
+	u8 tmp_byte = (u8)(test_long & 0x000000ff);
+
+	for (i = 1; i < 4; i++) {
+		if ((u8)((test_long >> (i * 8)) & 0x000000ff) != tmp_byte)
+				return -1;
+	}
+
+	return 0;
+}
+
+static inline int write_and_test(u32 data, u32 address)
+{
+	writel(data, address);
+	if (readl(address) == data)
+		return 0; /* Good */
+	else
+		return -1; /* Bad */
+}
+
+static void sc520_enable_sdram(void)
+{
+	u32 par_config;
+
+	/* Enable Writes, Caching and Code Execution to SDRAM */
+	par_config = readl(&sc520_mmcr->par[3]);
+	par_config &= ~(SC520_PAR_EXEC_DIS |
+			SC520_PAR_CACHE_DIS |
+			SC520_PAR_WRITE_DIS);
+	writel(par_config, &sc520_mmcr->par[3]);
+
+	par_config = readl(&sc520_mmcr->par[4]);
+	par_config &= ~(SC520_PAR_EXEC_DIS |
+			SC520_PAR_CACHE_DIS |
+			SC520_PAR_WRITE_DIS);
+	writel(par_config, &sc520_mmcr->par[4]);
+}
+
+static void sc520_set_dram_timing(void)
+{
+	u8 drctmctl = 0x00;
+
+#if defined CONFIG_SYS_SDRAM_DRCTMCTL
+	/* just have your hardware designer _GIVE_ you what you need here! */
+	drctmctl = CONFIG_SYS_SDRAM_DRCTMCTL;
+#else
+	switch (CONFIG_SYS_SDRAM_RAS_CAS_DELAY) {
+	case 2:
+		break;
+	case 3:
+		drctmctl |= 0x01;
+		break;
+	case 4:
+	default:
+		drctmctl |= 0x02;
+		break;
+	}
+
+	switch (CONFIG_SYS_SDRAM_PRECHARGE_DELAY) {
+	case 2:
+		break;
+	case 3:
+		drctmctl |= 0x04;
+		break;
+	case 4:
+	default:
+		drctmctl |= 0x08;
+		break;
+
+	case 6:
+		drctmctl |= 0x0c;
+		break;
+	}
+
+	switch (CONFIG_SYS_SDRAM_CAS_LATENCY) {
+	case 2:
+		break;
+	case 3:
+	default:
+		drctmctl |= 0x10;
+		break;
+	}
+#endif
+	writeb(drctmctl, &sc520_mmcr->drctmctl);
+
+	/* Issue load mode register command */
+	sc520_issue_sdram_op_mode_select(0x03);
+}
+
+static void sc520_set_dram_refresh_rate(void)
+{
+	u8 drctl;
+
+	drctl = readb(&sc520_mmcr->drcctl);
+	drctl &= 0xcf;
+
+	switch (CONFIG_SYS_SDRAM_REFRESH_RATE) {
+	case 78:
+		break;
+	case 156:
+	default:
+		drctl |= 0x10;
+		break;
+	case 312:
+		drctl |= 0x20;
+		break;
+	case 624:
+		drctl |= 0x30;
+		break;
+	}
+
+	writeb(drctl, &sc520_mmcr->drcctl);
+}
+
+static void sc520_enable_dram_refresh(void)
+{
+	u8 drctl;
+
+	drctl = readb(&sc520_mmcr->drcctl);
+	drctl &= 0x30; /* keep refresh rate */
+	drctl |= 0x08; /* enable refresh, normal mode */
+
+	writeb(drctl, &sc520_mmcr->drcctl);
+}
+
+static void sc520_get_bank_info(int bank, struct sc520_sdram_info *bank_info)
+{
+	u32 col_data;
+	u32 row_data;
+
+	u32 drcbendadr;
+	u16 drccfg;
+
+	u8 banks = 0x00;
+	u8 columns = 0x00;
+	u8 rows = 0x00;
+
+	bank_info->banks = 0x00;
+	bank_info->columns = 0x00;
+	bank_info->rows = 0x00;
+	bank_info->size = 0x00;
+
+	if ((bank < 0) || (bank > 3)) {
+		printf("Bad Bank ID\n");
+		return;
+	}
+
+	/* Save configuration */
+	drcbendadr = readl(&sc520_mmcr->drcbendadr);
+	drccfg = readw(&sc520_mmcr->drccfg);
+
+	/* Setup SDRAM Bank to largest possible size */
+	writew(0x000b << (bank * 4), &sc520_mmcr->drccfg);
+
+	/* Set ending address for this bank */
+	writel(0x000000ff << (bank * 8), &sc520_mmcr->drcbendadr);
+
+	/* write col 11 wrap adr */
+	if (write_and_test(COL11_DATA, COL11_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write col 10 wrap adr */
+	if (write_and_test(COL10_DATA, COL10_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write col 9 wrap adr */
+	if (write_and_test(COL09_DATA, COL09_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write col 8 wrap adr */
+	if (write_and_test(COL08_DATA, COL08_ADR) != 0)
+		goto restore_and_exit;
+
+	col_data = readl(COL11_ADR);
+
+	/* All four bytes in the read long must be the same */
+	if (check_long(col_data) < 0)
+		goto restore_and_exit;
+
+	if ((col_data >= COL08_DATA) && (col_data <= COL11_DATA))
+		columns = (u8)(col_data & 0x000000ff);
+	else
+		goto restore_and_exit;
+
+	/* write row 14 wrap adr */
+	if (write_and_test(ROW14_DATA, ROW14_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write row 13 wrap adr */
+	if (write_and_test(ROW13_DATA, ROW13_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write row 12 wrap adr */
+	if (write_and_test(ROW12_DATA, ROW12_ADR) != 0)
+		goto restore_and_exit;
+
+	/* write row 11 wrap adr */
+	if (write_and_test(ROW11_DATA, ROW11_ADR) != 0)
+		goto restore_and_exit;
+
+	if (write_and_test(ROW10_DATA, ROW10_ADR) != 0)
+		goto restore_and_exit;
+
+	/*
+	 * read data @ row 12 wrap adr to determine number of banks,
+	 * and read data @ row 14 wrap adr to determine number of rows.
+	 * if data @ row 12 wrap adr is not AA, 11 or 12 we have bad RAM.
+	 * if data @ row 12 wrap == AA, we only have 2 banks, NOT 4
+	 * if data @ row 12 wrap == 11 or 12, we have 4 banks,
+	 */
+	row_data = readl(ROW12_ADR);
+
+	/* All four bytes in the read long must be the same */
+	if (check_long(row_data) != 0)
+		goto restore_and_exit;
+
+	switch (row_data) {
+	case ROW10_DATA:
+		banks = 2;
+		break;
+
+	case ROW11_DATA:
+	case ROW12_DATA:
+		banks = 4;
+		break;
+
+	default:
+		goto restore_and_exit;
+	}
+
+	row_data = readl(ROW14_ADR);
+
+	/* All four bytes in the read long must be the same */
+	if (check_long(row_data) != 0)
+		goto restore_and_exit;
+
+	switch (row_data) {
+	case ROW11_DATA:
+	case ROW12_DATA:
+	case ROW13_DATA:
+	case ROW14_DATA:
+		rows = (u8)(row_data & 0x000000ff);
+		break;
+
+	default:
+		goto restore_and_exit;
+	}
+
+	bank_info->banks = banks;
+	bank_info->columns = columns;
+	bank_info->rows = rows;
+
+	if ((bank_info->banks != 0) &&
+	    (bank_info->columns != 0) &&
+	    (bank_info->rows != 0)) {
+		bank_info->size = bank_info->rows;
+		bank_info->size >>= (11 - bank_info->columns);
+		bank_info->size++;
+	}
+
+restore_and_exit:
+	/* Restore configuration */
+	writel(drcbendadr, &sc520_mmcr->drcbendadr);
+	writew(drccfg, &sc520_mmcr->drccfg);
+}
+
+static void sc520_setup_sizemem(void)
+{
+	u8 i;
+
+	/* Disable write buffer */
+	writeb(0x00, &sc520_mmcr->dbctl);
+
+	/* Disable ECC */
+	writeb(0x00, &sc520_mmcr->eccctl);
+
+	/* Set slowest SDRAM timing */
+	writeb(0x1e, &sc520_mmcr->drctmctl);
+
+	/* Issue a NOP to all SDRAM banks */
+	sc520_issue_sdram_op_mode_select(0x01);
+
+	/* Delay for 100 microseconds */
+	udelay(100);
+
+	/* Issue 'All Banks Precharge' command */
+	sc520_issue_sdram_op_mode_select(0x02);
+
+	/* Issue 2 'Auto Refresh Enable' command */
+	sc520_issue_sdram_op_mode_select(0x04);
+	sc520_dummy_write();
+
+	/* Issue 'Load Mode Register' command */
+	sc520_issue_sdram_op_mode_select(0x03);
+
+	/* Issue 8 more 'Auto Refresh Enable' commands */
+	sc520_issue_sdram_op_mode_select(0x04);
+	for (i = 0; i < 7; i++)
+		sc520_dummy_write();
+
+	/* Set control register to 'Normal Mode' */
+	writeb(0x00, &sc520_mmcr->drcctl);
+}
+
+static void sc520_sizemem(void)
+{
+	struct sc520_sdram_info sdram_info[4];
+	u8 bank_config = 0x00;
+	u8 end_addr = 0x00;
+	u16 drccfg = 0x0000;
+	u32 drcbendadr = 0x00000000;
+	u8 i;
+
+	/* Use PARs to disable caching of maximum allowable 256MB SDRAM */
+	writel(SC520_SDRAM1_PAR | SC520_PAR_CACHE_DIS, &sc520_mmcr->par[3]);
+	writel(SC520_SDRAM2_PAR | SC520_PAR_CACHE_DIS, &sc520_mmcr->par[4]);
+
+	sc520_setup_sizemem();
+
+	gd->ram_size = 0;
+
+	/* Size each SDRAM bank */
+	for (i = 0; i <= 3; i++) {
+		sc520_get_bank_info(i, &sdram_info[i]);
+
+		if (sdram_info[i].banks != 0) {
+			/* Update Configuration register */
+			bank_config = sdram_info[i].columns - 8;
+
+			if (sdram_info[i].banks == 4)
+				bank_config |= 0x08;
+
+			drccfg |= bank_config << (i * 4);
+
+			/* Update End Address register */
+			end_addr += sdram_info[i].size;
+			drcbendadr |= (end_addr | 0x80) << (i * 8);
+
+			gd->ram_size += sdram_info[i].size << 22;
+		}
+
+		/* Issue 'All Banks Precharge' command */
+		sc520_issue_sdram_op_mode_select(0x02);
+
+		/* Set control register to 'Normal Mode' */
+		writeb(0x00, &sc520_mmcr->drcctl);
+	}
+
+	writel(drcbendadr, &sc520_mmcr->drcbendadr);
+	writew(drccfg, &sc520_mmcr->drccfg);
+
+	/* Clear PARs preventing caching of SDRAM */
+	writel(0x00000000, &sc520_mmcr->par[3]);
+	writel(0x00000000, &sc520_mmcr->par[4]);
+}
+
+#if CONFIG_SYS_SDRAM_ECC_ENABLE
+static void sc520_enable_ecc(void)
+
+	/* A nominal memory test: just a byte at each address line */
+	movl	%eax, %ecx
+	shrl	$0x1, %ecx
+	movl	$0x1, %edi
+memtest0:
+	movb	$0xa5, (%edi)
+	cmpb	$0xa5, (%edi)
+	jne	out
+	shrl	$0x1, %ecx
+	andl	%ecx, %ecx
+	jz	set_ecc
+	shll	$0x1, %edi
+	jmp	memtest0
+
+set_ecc:
+	/* clear all ram with a memset */
+	movl	%eax, %ecx
+	xorl	%esi, %esi
+	xorl	%edi, %edi
+	xorl	%eax, %eax
+	shrl	$0x2, %ecx
+	cld
+	rep	stosl
+
+	/* enable read, write buffers */
+	movb	$0x11, %al
+	movl	$DBCTL, %edi
+	movb	%al, (%edi)
+
+	/* enable NMI mapping for ECC */
+	movl	$ECCINT, %edi
+	movb	$0x10, %al
+	movb	%al, (%edi)
+
+	/* Turn on ECC */
+	movl	$ECCCTL, %edi
+	movb	$0x05, %al
+	movb	%al,(%edi)
+
+out:
+	jmp	init_ecc_ret
+}
+#endif
+
+int dram_init(void)
+{
+	ulong dram_ctrl;
+	ulong dram_present = 0x00000000;
+
+	/*
+	 * We read-back the configuration of the dram
+	 * controller that the assembly code wrote
+	 */
+	dram_ctrl = readl(&sc520_mmcr->drcbendadr);
+
+	gd->bd->bi_dram[0].start = 0;
+	if (dram_ctrl & 0x80) {
+		/* bank 0 enabled */
+		gd->bd->bi_dram[1].start = (dram_ctrl & 0x7f) << 22;
+		dram_present = gd->bd->bi_dram[1].start;
+		gd->bd->bi_dram[0].size = gd->bd->bi_dram[1].start;
+	} else {
+		gd->bd->bi_dram[0].size = 0;
+		gd->bd->bi_dram[1].start = gd->bd->bi_dram[0].start;
+	}
+
+	if (dram_ctrl & 0x8000) {
+		/* bank 1 enabled */
+		gd->bd->bi_dram[2].start = (dram_ctrl & 0x7f00) << 14;
+		dram_present = gd->bd->bi_dram[2].start;
+		gd->bd->bi_dram[1].size = gd->bd->bi_dram[2].start -
+				gd->bd->bi_dram[1].start;
+	} else {
+		gd->bd->bi_dram[1].size = 0;
+		gd->bd->bi_dram[2].start = gd->bd->bi_dram[1].start;
+	}
+
+	if (dram_ctrl & 0x800000) {
+		/* bank 2 enabled */
+		gd->bd->bi_dram[3].start = (dram_ctrl & 0x7f0000) << 6;
+		dram_present = gd->bd->bi_dram[3].start;
+		gd->bd->bi_dram[2].size = gd->bd->bi_dram[3].start -
+				gd->bd->bi_dram[2].start;
+	} else {
+		gd->bd->bi_dram[2].size = 0;
+		gd->bd->bi_dram[3].start = gd->bd->bi_dram[2].start;
+	}
+
+	if (dram_ctrl & 0x80000000) {
+		/* bank 3 enabled */
+		dram_present  = (dram_ctrl & 0x7f000000) >> 2;
+		gd->bd->bi_dram[3].size = dram_present -
+				gd->bd->bi_dram[3].start;
+	} else {
+		gd->bd->bi_dram[3].size = 0;
+	}
+
+	gd->ram_size = dram_present;
+
+	return 0;
+}