1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* 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);
}
|
