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Diffstat (limited to 'board/incaip/incaip.c')
-rw-r--r-- | board/incaip/incaip.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/board/incaip/incaip.c b/board/incaip/incaip.c new file mode 100644 index 0000000..72f1c21 --- /dev/null +++ b/board/incaip/incaip.c @@ -0,0 +1,129 @@ +/* + * (C) Copyright 2003 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * 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 <command.h> +#include <asm/addrspace.h> +#include <asm/inca-ip.h> + + +static ulong max_sdram_size(void) +{ + /* The only supported SDRAM data width is 16bit. + */ +#define CFG_DW 2 + + /* The only supported number of SDRAM banks is 4. + */ +#define CFG_NB 4 + + ulong cfgpb0 = *INCA_IP_SDRAM_MC_CFGPB0; + int cols = cfgpb0 & 0xF; + int rows = (cfgpb0 & 0xF0) >> 4; + ulong size = (1 << (rows + cols)) * CFG_DW * CFG_NB; + + return size; +} + +/* + * Check memory range for valid RAM. A simple memory test determines + * the actually available RAM size between addresses `base' and + * `base + maxsize'. Some (not all) hardware errors are detected: + * - short between address lines + * - short between data lines + */ + +static long int dram_size(long int *base, long int maxsize) +{ + volatile long int *addr; + ulong cnt, val; + ulong save[32]; /* to make test non-destructive */ + unsigned char i = 0; + + for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) { + addr = base + cnt; /* pointer arith! */ + + save[i++] = *addr; + *addr = ~cnt; + } + + /* write 0 to base address */ + addr = base; + save[i] = *addr; + *addr = 0; + + /* check at base address */ + if ((val = *addr) != 0) { + *addr = save[i]; + return (0); + } + + for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) { + addr = base + cnt; /* pointer arith! */ + + val = *addr; + *addr = save[--i]; + + if (val != (~cnt)) { + return (cnt * sizeof (long)); + } + } + return (maxsize); +} + +long int initdram(int board_type) +{ + int rows, cols, best_val = *INCA_IP_SDRAM_MC_CFGPB0; + ulong size, max_size = 0; + ulong our_address; + + asm volatile ("move %0, $25" : "=r" (our_address) :); + + /* Can't probe for RAM size unless we are running from Flash. + */ + if (PHYSADDR(our_address) < PHYSADDR(PHYS_FLASH_1)) + { + return max_sdram_size(); + } + + for (cols = 0x8; cols <= 0xC; cols++) + { + for (rows = 0xB; rows <= 0xD; rows++) + { + *INCA_IP_SDRAM_MC_CFGPB0 = (0x14 << 8) | + (rows << 4) | cols; + size = dram_size((ulong *)CFG_SDRAM_BASE, + max_sdram_size()); + + if (size > max_size) + { + best_val = *INCA_IP_SDRAM_MC_CFGPB0; + max_size = size; + } + } + } + + *INCA_IP_SDRAM_MC_CFGPB0 = best_val; + return max_size; +} + |