diff options
author | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
---|---|---|
committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/arch/arm/mach-lpc32xx/dram.c | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/arch/arm/mach-lpc32xx/dram.c')
-rw-r--r-- | roms/u-boot/arch/arm/mach-lpc32xx/dram.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/roms/u-boot/arch/arm/mach-lpc32xx/dram.c b/roms/u-boot/arch/arm/mach-lpc32xx/dram.c new file mode 100644 index 000000000..160223792 --- /dev/null +++ b/roms/u-boot/arch/arm/mach-lpc32xx/dram.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 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. + */ + +#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> +#include <linux/delay.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); +} |