source: rtems/bsps/arm/lpc32xx/start/emc.c

/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup lpc32xx_emc
 *
 * @brief EMC support implementation.
 */

/*
 * Copyright (c) 2010 embedded brains GmbH & Co. KG
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <bsp/emc.h>

#include <bsp.h>
#include <bsp/mmu.h>

static volatile lpc_emc *const emc = &lpc32xx.emc;

static volatile lpc32xx_emc_ahb *const emc_ahb = &lpc32xx.emc_ahb [0];

static void dynamic_init(const lpc32xx_emc_dynamic_config *cfg)
{
  uint32_t chip_begin = LPC32XX_BASE_EMC_DYCS_0;
  uint32_t dynamiccontrol = (cfg->control | EMC_DYN_CTRL_CE | EMC_DYN_CTRL_CS)
    & ~EMC_DYN_CTRL_I_MASK;
  size_t i = 0;

  LPC32XX_SDRAMCLK_CTRL = cfg->sdramclk_ctrl;

  emc->dynamicreadconfig = cfg->readconfig;

  /* Timings */
  emc->dynamictrp = cfg->trp;
  emc->dynamictras = cfg->tras;
  emc->dynamictsrex = cfg->tsrex;
  emc->dynamictwr = cfg->twr;
  emc->dynamictrc = cfg->trc;
  emc->dynamictrfc = cfg->trfc;
  emc->dynamictxsr = cfg->txsr;
  emc->dynamictrrd = cfg->trrd;
  emc->dynamictmrd = cfg->tmrd;
  emc->dynamictcdlr = cfg->tcdlr;
  for (i = 0; i < EMC_DYN_CHIP_COUNT; ++i) {
    if (cfg->chip [i].size != 0) {
      emc->dynamic [i].config = cfg->chip [i].config;
      emc->dynamic [i].rascas = cfg->chip [i].rascas;
    }
  }

  /* NOP period */
  emc->dynamiccontrol = dynamiccontrol | EMC_DYN_CTRL_I_NOP;
  lpc32xx_micro_seconds_delay(cfg->nop_time_in_us);

  /* Precharge */
  emc->dynamiccontrol = dynamiccontrol | EMC_DYN_CTRL_I_PALL;
  emc->dynamicrefresh = 1;
  /* FIXME: Why a delay, why this value? */
  lpc32xx_micro_seconds_delay(10);

  /* Refresh timing */
  emc->dynamicrefresh = cfg->refresh;
  /* FIXME: Why a delay, why this value? */
  lpc32xx_micro_seconds_delay(16);

  /* Set modes */
  for (i = 0; i < EMC_DYN_CHIP_COUNT; ++i) {
    if (cfg->chip [i].size != 0) {
      lpc32xx_set_translation_table_entries(
        (void *) chip_begin,
        (void *) (chip_begin + cfg->chip [i].size),
        LPC32XX_MMU_READ_WRITE
      );
      emc->dynamiccontrol = dynamiccontrol | EMC_DYN_CTRL_I_MODE;
      *(volatile uint32_t *)(chip_begin + cfg->chip [i].mode);
      emc->dynamiccontrol = dynamiccontrol | EMC_DYN_CTRL_I_MODE;
      *(volatile uint32_t *)(chip_begin + cfg->chip [i].extmode);
    }
    chip_begin += 0x20000000;
  }

  emc->dynamiccontrol = cfg->control;
}

void lpc32xx_emc_init(const lpc32xx_emc_dynamic_config *dyn_cfg)
{
  /* Enable buffers in AHB ports */
  emc_ahb [0].control = EMC_AHB_PORT_BUFF_EN;
  emc_ahb [3].control = EMC_AHB_PORT_BUFF_EN;
  emc_ahb [4].control = EMC_AHB_PORT_BUFF_EN;

  /* Set AHB port timeouts */
  emc_ahb [0].timeout = EMC_AHB_TIMEOUT(32);
  emc_ahb [3].timeout = EMC_AHB_TIMEOUT(32);
  emc_ahb [4].timeout = EMC_AHB_TIMEOUT(32);

  /* Enable EMC */
  emc->control = EMC_CTRL_E,
  emc->config = 0;

  dynamic_init(dyn_cfg);
}