diff options
Diffstat (limited to 'nand_spl/board/amcc/bamboo/sdram.c')
-rw-r--r-- | nand_spl/board/amcc/bamboo/sdram.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/nand_spl/board/amcc/bamboo/sdram.c b/nand_spl/board/amcc/bamboo/sdram.c new file mode 100644 index 0000000..4f09072 --- /dev/null +++ b/nand_spl/board/amcc/bamboo/sdram.c @@ -0,0 +1,92 @@ +/* + * (C) Copyright 2007 + * Stefan Roese, DENX Software Engineering, sr@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 <ppc4xx.h> +#include <asm/processor.h> +#include <asm/io.h> + +static void wait_init_complete(void) +{ + u32 val; + + do { + mfsdram(mem_mcsts, val); + } while (!(val & 0x80000000)); +} + +/* + * early_sdram_init() + * + * As the name already indicates, this function is called very early + * from start.S and configures the SDRAM with fixed values. This is needed, + * since the 440EP has no internal SRAM and the 4kB NAND_SPL loader has + * not enough free space to implement the complete I2C SPD DDR autodetection + * routines. Therefore the Bamboo only supports the onboard 64MBytes of SDRAM + * when booting from NAND flash. + */ +void early_sdram_init(void) +{ + /* + * Soft-reset SDRAM controller. + */ + mtsdr(sdr_srst, SDR0_SRST_DMC); + mtsdr(sdr_srst, 0x00000000); + + /* + * Disable memory controller. + */ + mtsdram(mem_cfg0, 0x00000000); + + /* + * Setup some default + */ + mtsdram(mem_uabba, 0x00000000); /* ubba=0 (default) */ + mtsdram(mem_slio, 0x00000000); /* rdre=0 wrre=0 rarw=0 */ + mtsdram(mem_devopt, 0x00000000); /* dll=0 ds=0 (normal) */ + mtsdram(mem_wddctr, 0x00000000); /* wrcp=0 dcd=0 */ + mtsdram(mem_clktr, 0x40000000); /* clkp=1 (90 deg wr) dcdt=0 */ + + /* + * Following for CAS Latency = 2.5 @ 133 MHz PLB + */ + mtsdram(mem_b0cr, 0x00082001); + mtsdram(mem_tr0, 0x41094012); + mtsdram(mem_tr1, 0x8080083d); /* SS=T2 SL=STAGE 3 CD=1 CT=0x00*/ + mtsdram(mem_rtr, 0x04100000); /* Interval 7.8µs @ 133MHz PLB */ + mtsdram(mem_cfg1, 0x00000000); /* Self-refresh exit, disable PM*/ + + /* + * Enable the controller, then wait for DCEN to complete + */ + mtsdram(mem_cfg0, 0x80000000); /* DCEN=1, PMUD=0*/ + wait_init_complete(); +} + +long int initdram(int board_type) +{ + /* + * Nothing to do here, just return size of fixed SDRAM setup + */ + return CFG_MBYTES_SDRAM << 20; +} |