diff options
Diffstat (limited to 'arch/x86/cpu/sc520/sc520_sdram.c')
| -rw-r--r-- | arch/x86/cpu/sc520/sc520_sdram.c | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/arch/x86/cpu/sc520/sc520_sdram.c b/arch/x86/cpu/sc520/sc520_sdram.c new file mode 100644 index 000000000..f3623f53f --- /dev/null +++ b/arch/x86/cpu/sc520/sc520_sdram.c @@ -0,0 +1,532 @@ +/* + * (C) Copyright 2010,2011 + * 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; +} |