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>
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 @@
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;
+}