xref: /openbmc/u-boot/arch/arm/mach-at91/mpddrc.c (revision 83d290c56fab2d38cd1ab4c4cc7099559c1d5046)

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2013 Atmel Corporation
 *		      Bo Shen <voice.shen@atmel.com>
 *
 * Copyright (C) 2015 Atmel Corporation
 *		      Wenyou Yang <wenyou.yang@atmel.com>
 */

#include <common.h>
#include <asm/io.h>
#include <asm/arch/atmel_mpddrc.h>

#define SAMA5D3_MPDDRC_VERSION		0x140

static inline void atmel_mpddr_op(const struct atmel_mpddr *mpddr,
	      int mode,
	      u32 ram_address)
{
	writel(mode, &mpddr->mr);
	writel(0, ram_address);
}

static int ddr2_decodtype_is_seq(const unsigned int base, u32 cr)
{
	struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
	u16 version = readl(&mpddr->version) & 0xffff;

	if ((version >= SAMA5D3_MPDDRC_VERSION) &&
	    (cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED))
		return 0;

	return 1;
}


int ddr2_init(const unsigned int base,
	      const unsigned int ram_address,
	      const struct atmel_mpddrc_config *mpddr_value)
{
	const struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;

	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 (ddr2_decodtype_is_seq(base, 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 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(mpddr, 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(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);

	/* Issue an all banks precharge command */
	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);

	/* Issue an extended mode register set(EMRS2) to choose operation */
	atmel_mpddr_op(mpddr, 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(mpddr, 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(mpddr, 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(mpddr, ATMEL_MPDDRC_MR_MODE_LMR_CMD, ram_address);

	/* Issue an all banks precharge command */
	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_PRCGALL_CMD, ram_address);

	/* Two auto-refresh (CBR) cycles are provided */
	atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_RFSH_CMD, ram_address);
	atmel_mpddr_op(mpddr, 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(mpddr, 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(mpddr, 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(mpddr, ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD,
		       ram_address + (0x1 << ba_off));

	/* A nornal mode command is provided */
	atmel_mpddr_op(mpddr, 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;
}

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(base, 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;
}