u-boot/arch/arm/cpu/arm1136/mx35/mx35_sdram.c

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/*
* Copyright (C) 2012, Stefano Babic <sbabic@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 <asm/io.h>
#include <asm/errno.h>
#include <asm/arch/imx-regs.h>
#include <linux/types.h>
#include <asm/arch/sys_proto.h>
#define ESDCTL_DDR2_EMR2 0x04000000
#define ESDCTL_DDR2_EMR3 0x06000000
#define ESDCTL_PRECHARGE 0x00000400
#define ESDCTL_DDR2_EN_DLL 0x02000400
#define ESDCTL_DDR2_RESET_DLL 0x00000333
#define ESDCTL_DDR2_MR 0x00000233
#define ESDCTL_DDR2_OCD_DEFAULT 0x02000780
enum {
SMODE_NORMAL = 0,
SMODE_PRECHARGE,
SMODE_AUTO_REFRESH,
SMODE_LOAD_REG,
SMODE_MANUAL_REFRESH
};
#define set_mode(x, en, m) (x | (en << 31) | (m << 28))
static inline void dram_wait(unsigned int count)
{
volatile unsigned int wait = count;
while (wait--)
;
}
void mx3_setup_sdram_bank(u32 start_address, u32 ddr2_config,
u32 row, u32 col, u32 dsize, u32 refresh)
{
struct esdc_regs *esdc = (struct esdc_regs *)ESDCTL_BASE_ADDR;
u32 *cfg_reg, *ctl_reg;
u32 val;
u32 ctlval;
switch (start_address) {
case CSD0_BASE_ADDR:
cfg_reg = &esdc->esdcfg0;
ctl_reg = &esdc->esdctl0;
break;
case CSD1_BASE_ADDR:
cfg_reg = &esdc->esdcfg1;
ctl_reg = &esdc->esdctl1;
break;
default:
return;
}
/* The MX35 supports 11 up to 14 rows */
if (row < 11 || row > 14 || col < 8 || col > 10)
return;
ctlval = (row - 11) << 24 | (col - 8) << 20 | (dsize << 16);
/* Initialize MISC register for DDR2 */
val = ESDC_MISC_RST | ESDC_MISC_MDDR_EN | ESDC_MISC_MDDR_DL_RST |
ESDC_MISC_DDR_EN | ESDC_MISC_DDR2_EN;
writel(val, &esdc->esdmisc);
val &= ~(ESDC_MISC_RST | ESDC_MISC_MDDR_DL_RST);
writel(val, &esdc->esdmisc);
/*
* according to DDR2 specs, wait a while before
* the PRECHARGE_ALL command
*/
dram_wait(0x20000);
/* Load DDR2 config and timing */
writel(ddr2_config, cfg_reg);
/* Precharge ALL */
writel(set_mode(ctlval, 1, SMODE_PRECHARGE),
ctl_reg);
writel(0xda, start_address + ESDCTL_PRECHARGE);
/* Load mode */
writel(set_mode(ctlval, 1, SMODE_LOAD_REG),
ctl_reg);
writeb(0xda, start_address + ESDCTL_DDR2_EMR2); /* EMRS2 */
writeb(0xda, start_address + ESDCTL_DDR2_EMR3); /* EMRS3 */
writeb(0xda, start_address + ESDCTL_DDR2_EN_DLL); /* Enable DLL */
writeb(0xda, start_address + ESDCTL_DDR2_RESET_DLL); /* Reset DLL */
/* Precharge ALL */
writel(set_mode(ctlval, 1, SMODE_PRECHARGE),
ctl_reg);
writel(0xda, start_address + ESDCTL_PRECHARGE);
/* Set mode auto refresh : at least two refresh are required */
writel(set_mode(ctlval, 1, SMODE_AUTO_REFRESH),
ctl_reg);
writel(0xda, start_address);
writel(0xda, start_address);
writel(set_mode(ctlval, 1, SMODE_LOAD_REG),
ctl_reg);
writeb(0xda, start_address + ESDCTL_DDR2_MR);
writeb(0xda, start_address + ESDCTL_DDR2_OCD_DEFAULT);
/* OCD mode exit */
writeb(0xda, start_address + ESDCTL_DDR2_EN_DLL); /* Enable DLL */
/* Set normal mode */
writel(set_mode(ctlval, 1, SMODE_NORMAL) | refresh,
ctl_reg);
dram_wait(0x20000);
/* Do not set delay lines, only for MDDR */
}