diff options
Diffstat (limited to 'arch/arm/cpu/arm1136/mx35/mx35_sdram.c')
| -rw-r--r-- | arch/arm/cpu/arm1136/mx35/mx35_sdram.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm1136/mx35/mx35_sdram.c b/arch/arm/cpu/arm1136/mx35/mx35_sdram.c new file mode 100644 index 0000000..f7e682c --- /dev/null +++ b/arch/arm/cpu/arm1136/mx35/mx35_sdram.c @@ -0,0 +1,137 @@ +/* + * 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 */ +} |
