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/*
* (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));
}
/*
* phys_size_t initdram(int board_type)
*
* 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.
*
* Note:
* As found out by Eugene O'Brien <eugene.obrien@advantechamt.com>, the fixed
* DDR setup has problems (U-Boot crashes randomly upon TFTP), when the DIMM
* modules are still plugged in. So it is recommended to remove the DIMM
* modules while using the NAND booting code with the fixed SDRAM setup!
*/
phys_size_t initdram(int board_type)
{
/*
* 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();
return CONFIG_SYS_MBYTES_SDRAM << 20;
}
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