arm: at91/spl: mpddrc: add mpddrc DDR3-SDRAM initialization

The DDR3-SDRAM initialization sequence is implemented in
accordance with the DDR3-SRAM/DDR3L-SDRAM initialization section
described in the SAMA5D2 datasheet.

Add registers and definitions of mpddrc controller, which is used
to support DDR3 devices.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Andreas Bießmann <andreas.devel@googlemail.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/mpddrc.c b/arch/arm/mach-at91/mpddrc.c
index 9ba2a00..1e1ff1d 100644
--- a/arch/arm/mach-at91/mpddrc.c
+++ b/arch/arm/mach-at91/mpddrc.c
@@ -2,6 +2,9 @@
  * Copyright (C) 2013 Atmel Corporation
  *		      Bo Shen <voice.shen@atmel.com>
  *
+ * Copyright (C) 2015 Atmel Corporation
+ *		      Wenyou Yang <wenyou.yang@atmel.com>
+ *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
@@ -135,3 +138,89 @@ int ddr2_init(const unsigned int base,
 
 	return 0;
 }
+
+int ddr3_init(const unsigned int base,
+	      const unsigned int ram_address,
+	      const struct atmel_mpddrc_config *mpddr_value)
+{
+	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
+	u32 ba_off;
+
+	/* Compute bank offset according to NC in configuration register */
+	ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
+	if (ddr2_decodtype_is_seq(mpddr_value->cr))
+		ba_off += ((mpddr_value->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 */
+	writel(mpddr_value->md, &mpddr->md);
+
+	/*
+	 * Program features of the DDR3-SDRAM device and timing parameters
+	 */
+	writel(mpddr_value->cr, &mpddr->cr);
+
+	writel(mpddr_value->tpr0, &mpddr->tpr0);
+	writel(mpddr_value->tpr1, &mpddr->tpr1);
+	writel(mpddr_value->tpr2, &mpddr->tpr2);
+
+	/* A NOP command is issued to the DDR3-SRAM */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+	/* A pause of at least 500us must be observed before a single toggle. */
+	udelay(500);
+
+	/* A NOP command is issued to the DDR3-SDRAM */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+	/*
+	 * An Extended Mode Register Set (EMRS2) cycle is issued to choose
+	 * between commercial or high temperature operations.
+	 */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x2 << ba_off));
+	/*
+	 * Step 7: An Extended Mode Register Set (EMRS3) cycle is issued to set
+	 * the Extended Mode Register to 0.
+	 */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x3 << ba_off));
+	/*
+	 * An Extended Mode Register Set (EMRS1) cycle is issued to disable and
+	 * to program O.D.S. (Output Driver Strength).
+	 */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
+		       ram_address + (0x1 << ba_off));
+
+	/*
+	 * Write a one to the DLL bit (enable DLL reset) in the MPDDRC
+	 * Configuration Register.
+	 */
+
+	/* A Mode Register Set (MRS) cycle is issued to reset DLL. */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);
+
+	udelay(50);
+
+	/*
+	 * A Calibration command (MRS) is issued to calibrate RTT and RON
+	 * values for the Process Voltage Temperature (PVT).
+	 */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_DEEP_CMD, ram_address);
+
+	/* A Normal Mode command is provided. */
+	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
+
+	/* Perform a write access to any DDR3-SDRAM address. */
+	writel(0, ram_address);
+
+	/*
+	 * Write the refresh rate into the COUNT field in the MPDDRC
+	 * Refresh Timer Register (MPDDRC_RTR):
+	 */
+	writel(mpddr_value->rtr, &mpddr->rtr);
+
+	return 0;
+}