1 files changed, 74 insertions, 0 deletions
diff --git a/arch/arm/mach-lpc32xx/dram.c b/arch/arm/mach-lpc32xx/dram.c
new file mode 100644
index 0000000000..1602237923
--- /dev/null
+++ b/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);
+}