u-boot/arch/arm/cpu/arm926ejs/lpc32xx/dram.c
Albert ARIBAUD \(3ADEV\) 412ae53aad lpc32xx: add support for board work_92105
Work_92105 from Work Microwave is an LPC3250-
based board with the following features:
- 64MB or 128MB SDR DRAM
- 1 GB SLC NAND, managed through MLC controller.
- Ethernet
- Ethernet + PHY SMSC8710
- I2C:
  - EEPROM (24M01-compatible)
  - RTC (DS1374-compatible)
  - Temperature sensor (DS620)
  - DACs (2 x MAX518)
- SPI (through SSP interface)
  - Port expander MAX6957
- LCD display (HD44780-compatible), controlled
  through the port expander and DACs

This board has SPL support, and uses the LPC32XX boot
image format.

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
2015-04-10 14:23:39 +02:00

77 lines
2.5 KiB
C

/*
* LPC32xx dram init
*
* (C) Copyright 2014 DENX Software Engineering GmbH
* Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
*
* This is called by SPL to gain access to the SDR DRAM.
*
* This code runs from SRAM.
*
* Actual CONFIG_LPC32XX_SDRAM_* parameters must be provided
* by the board configuration file.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <netdev.h>
#include <asm/arch/cpu.h>
#include <asm/arch/clk.h>
#include <asm/arch/wdt.h>
#include <asm/arch/emc.h>
#include <asm/io.h>
static struct clk_pm_regs *clk = (struct clk_pm_regs *)CLK_PM_BASE;
static struct emc_regs *emc = (struct emc_regs *)EMC_BASE;
void ddr_init(struct emc_dram_settings *dram)
{
uint32_t ck;
/* Enable EMC interface and choose little endian mode */
writel(1, &emc->ctrl);
writel(0, &emc->config);
/* Select maximum EMC Dynamic Memory Refresh Time */
writel(0x7FF, &emc->refresh);
/* Determine CLK */
ck = get_sdram_clk_rate();
/* Configure SDRAM */
writel(dram->cmddelay, &clk->sdramclk_ctrl);
writel(dram->config0, &emc->config0);
writel(dram->rascas0, &emc->rascas0);
writel(dram->rdconfig, &emc->read_config);
/* Set timings */
writel((ck / dram->trp) & 0x0000000F, &emc->t_rp);
writel((ck / dram->tras) & 0x0000000F, &emc->t_ras);
writel((ck / dram->tsrex) & 0x0000007F, &emc->t_srex);
writel((ck / dram->twr) & 0x0000000F, &emc->t_wr);
writel((ck / dram->trc) & 0x0000001F, &emc->t_rc);
writel((ck / dram->trfc) & 0x0000001F, &emc->t_rfc);
writel((ck / dram->txsr) & 0x000000FF, &emc->t_xsr);
writel(dram->trrd, &emc->t_rrd);
writel(dram->tmrd, &emc->t_mrd);
writel(dram->tcdlr, &emc->t_cdlr);
/* Dynamic refresh */
writel((((ck / dram->refresh) >> 4) & 0x7FF), &emc->refresh);
udelay(10);
/* Force all clocks, enable inverted ck, issue NOP command */
writel(0x00000193, &emc->control);
udelay(100);
/* Keep all clocks enabled, issue a PRECHARGE ALL command */
writel(0x00000113, &emc->control);
/* Fast dynamic refresh for at least a few SDRAM ck cycles */
writel((((128) >> 4) & 0x7FF), &emc->refresh);
udelay(10);
/* set correct dynamic refresh timing */
writel((((ck / dram->refresh) >> 4) & 0x7FF), &emc->refresh);
udelay(10);
/* set normal mode to CAS=3 */
writel(0x00000093, &emc->control);
readl(EMC_DYCS0_BASE | dram->mode);
/* set extended mode to all zeroes */
writel(0x00000093, &emc->control);
readl(EMC_DYCS0_BASE | dram->emode);
/* stop forcing clocks, keep inverted clock, issue normal mode */
writel(0x00000010, &emc->control);
}