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/*
* 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;
}
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