arm: atmel: add ddr2 initialization function

The MPDDRC supports different type of SDRAM
This patch add ddr2 initialization function

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>

2 files changed, 135 insertions, 0 deletions

diff --git a/arch/arm/cpu/at91-common/Makefile b/arch/arm/cpu/at91-common/Makefile
new file mode 100644
index 0000000..671a05e
--- /dev/null
+++ b/arch/arm/cpu/at91-common/Makefile
@@ -0,0 +1,11 @@
+#
+# (C) Copyright 2000-2008
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# (C) Copyright 2013 Atmel Corporation
+#		     Bo Shen <voice.shen@atmel.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_SPL_BUILD) += mpddrc.o
diff --git a/arch/arm/cpu/at91-common/mpddrc.c b/arch/arm/cpu/at91-common/mpddrc.c
new file mode 100644
index 0000000..8136396
--- /dev/null
+++ b/arch/arm/cpu/at91-common/mpddrc.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2013 Atmel Corporation
+ *		      Bo Shen <voice.shen@atmel.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/atmel_mpddrc.h>
+
+static inline void atmel_mpddr_op(int mode, u32 ram_address)
+{
+	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
+
+	writel(mode, &mpddr->mr);
+	writel(0, ram_address);
+}
+
+int ddr2_init(const unsigned int ram_address,
+	      const struct atmel_mpddr *mpddr_value)
+{
+	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
+	u32 ba_off, cr;
+
+	/* Compute bank offset according to NC in configuration register */
+	ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
+	if (!(mpddr_value->cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED))
+		ba_off += ((mpddr->cr & ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;
+
+	ba_off += (mpddr_value->md & ATMEL_MPDDRC_MD_DBW_MASK) ? 1 : 2;
+
+	/* Program the memory device type into the memory device register */
+	writel(mpddr_value->md, &mpddr->md);
+
+	/* Program the configuration register */
+	writel(mpddr_value->cr, &mpddr->cr);
+
+	/* Program the timing register */
+	writel(mpddr_value->tpr0, &mpddr->tpr0);
+	writel(mpddr_value->tpr1, &mpddr->tpr1);
+	writel(mpddr_value->tpr2, &mpddr->tpr2);
+
+	/* Issue a NOP command */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+	/* A 200 us is provided to precede any signal toggle */
+	udelay(200);
+
+	/* Issue a NOP command */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+	/* Issue an all banks precharge command */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
+
+	/* Issue an extended mode register set(EMRS2) to choose operation */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x2 << ba_off));
+
+	/* Issue an extended mode register set(EMRS3) to set EMSR to 0 */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x3 << ba_off));
+
+	/*
+	 * Issue an extended mode register set(EMRS1) to enable DLL and
+	 * program D.I.C (output driver impedance control)
+	 */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x1 << ba_off));
+
+	/* Enable DLL reset */
+	cr = readl(&mpddr->cr);
+	writel(cr | ATMEL_MPDDRC_CR_DLL_RESET_ENABLED, &mpddr->cr);
+
+	/* A mode register set(MRS) cycle is issued to reset DLL */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
+
+	/* Issue an all banks precharge command */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);
+
+	/* Two auto-refresh (CBR) cycles are provided */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
+
+	/* Disable DLL reset */
+	cr = readl(&mpddr->cr);
+	writel(cr & (~ATMEL_MPDDRC_CR_DLL_RESET_ENABLED), &mpddr->cr);
+
+	/* A mode register set (MRS) cycle is issued to disable DLL reset */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
+
+	/* Set OCD calibration in default state */
+	cr = readl(&mpddr->cr);
+	writel(cr | ATMEL_MPDDRC_CR_OCD_DEFAULT, &mpddr->cr);
+
+	/*
+	 * An extended mode register set (EMRS1) cycle is issued
+	 * to OCD default value
+	 */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x1 << ba_off));
+
+	 /* OCD calibration mode exit */
+	cr = readl(&mpddr->cr);
+	writel(cr & (~ATMEL_MPDDRC_CR_OCD_DEFAULT), &mpddr->cr);
+
+	/*
+	 * An extended mode register set (EMRS1) cycle is issued
+	 * to enable OCD exit
+	 */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x1 << ba_off));
+
+	/* A nornal mode command is provided */
+	atmel_mpddr_op(ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
+
+	/* Perform a write access to any DDR2-SDRAM address */
+	writel(0, ram_address);
+
+	/* Write the refresh rate */
+	writel(mpddr_value->rtr, &mpddr->rtr);
+
+	return 0;
+}