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/* mc.c -- Simulation of Memory Controller
	 Copyright (C) 2001 by Marko Mlinar, markom@opencores.org
 
	 This file is part of OpenRISC 1000 Architectural Simulator.
 
	 This program is free software; you can redistribute it and/or modify
	 it under the terms of the GNU General Public License as published by
	 the Free Software Foundation; either version 2 of the License, or
	 (at your option) any later version.
 
	 This program is distributed in the hope that it will be useful,
	 but WITHOUT ANY WARRANTY; without even the implied warranty of
	 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
	 GNU General Public License for more details.
 
	 You should have received a copy of the GNU General Public License
	 along with this program; if not, write to the Free Software
	 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
 
/* Enable memory controller, via:
  section mc
    enable = 1
    POC = 0x13243545
  end
 
   Limitations:
    - memory refresh is not simulated
 */
 
#include "mc.h"
#include "abstract.h"
#include "sim-config.h"
 
extern struct dev_memarea *dev_list;
 
static struct mc mc;
 
void set_csc_tms (int cs, unsigned long csc, unsigned long tms) {
  struct dev_memarea *mem_dev = dev_list;
 
  while (mem_dev) {
    if (mem_dev->chip_select == cs) {
      mem_dev->addr_mask = 0xe0000000 | mc.ba_mask << 21;
      mem_dev->addr_compare = ((csc >> MC_CSC_SEL_OFFSET) & 0xff) << 21;
      mem_dev->valid = (csc >> MC_CSC_EN_OFFSET) & 0x01;
 
      if ((csc >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_ASYNC) {
        mem_dev->delayr = (tms & 0xff) + ((tms >> 8) & 0x0f);
        mem_dev->delayw = ((tms >> 12)  & 0x0f) + ((tms >> 16) & 0x0f) + ((tms >> 20) & 0x3f);
      } else if ((csc >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SDRAM) {
        mem_dev->delayr = 3 + ((tms >> 4) & 0x03);
        mem_dev->delayw = 3 + ((tms >> 4) & 0x03);
      } else if ((csc >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SSRAM) {
        mem_dev->delayr = 2;
        mem_dev->delayw = 2;
      } else if ((csc >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SYNC) {
        mem_dev->delayr = 2;
        mem_dev->delayw = 2;
      }
      return;
    }
    mem_dev = mem_dev->next;
  }
}
 
/* Set a specific MC register with value. */
void mc_write_word(unsigned long addr, unsigned long value)
{
	int chipsel;
 
	debug(5, "mc_write_word(%x,%08x)\n", addr, (unsigned)value);
 
  addr -= config.mc.baseaddr;
 
	switch (addr) {
	  case MC_CSR:
	    mc.csr = value;
	    break;
	  case MC_POC:
	    fprintf (stderr, "warning: write to MC's POC register!");
	    break;	    
	  case MC_BA_MASK:
	    mc.ba_mask = value & MC_BA_MASK_VALID;
      for (chipsel = 0; chipsel < N_CE; chipsel++)
        set_csc_tms (chipsel, mc.csc[chipsel], mc.tms[chipsel]);
	    break;
		default:
		  if (addr >= MC_CSC(0) && addr <= MC_TMS(N_CE - 1)) {
		    addr -= MC_CSC(0);
		    if ((addr >> 2) & 1)
		      mc.tms[addr >> 3] = value;
		    else
		      mc.csc[addr >> 3] = value;
 
		    set_csc_tms (addr >> 3, mc.csc[addr >> 3], mc.tms[addr >> 3]);
		    break;
		  } else
		  	debug(1, "write out of range (addr %x)\n", addr + config.mc.baseaddr);
	} 
}
 
/* Read a specific MC register. */
unsigned long mc_read_word(unsigned long addr)
{
	unsigned char value = 0;
	int chipsel;
 
	debug(5, "mc_read_word(%x)\n", addr);
 
  addr -= config.mc.baseaddr;
 
	switch (addr) {
	  case MC_CSR:
	    value = mc.csr;
	    break;
	  case MC_POC:
	    value = mc.poc;
	    break;	    
	  case MC_BA_MASK:
	    value = mc.ba_mask;
	    break;
		default:
		  if (addr >= MC_CSC(0) && addr <= MC_TMS(N_CE - 1)) {
		    addr -= MC_CSC(0);
		    if ((addr >> 2) & 1)
		      value = mc.tms[addr >> 3];
		    else
		      value = mc.csc[addr >> 3];
		  } else
  			debug(1, "read out of range (addr %x)\n", addr + config.mc.baseaddr);
	    break;
	}
	return value;
}
 
/* Read POC register and init memory controler regs. */
void mc_reset()
{
  struct dev_memarea *mem_dev = dev_list;
 
  if (config.mc.enabled) {
  	printf("Resetting memory controller.\n");
  	memset(&mc, 0, sizeof(struct mc));
 
    mc.poc = config.mc.POC;
 
    /* Set CS0 */
    mc.csc[0] = (((config.mc.POC & 0x0c) >> 2) << MC_CSC_MEMTYPE_OFFSET) | ((config.mc.POC & 0x03) << MC_CSC_BW_OFFSET) | 1;
 
    if ((mc.csc[0] >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_ASYNC) {
      mc.tms[0] = MC_TMS_ASYNC_VALID;
    } else if ((mc.csc[0] >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SDRAM) {
      mc.tms[0] = MC_TMS_SDRAM_VALID;
    } else if ((mc.csc[0] >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SSRAM) {
      mc.tms[0] = MC_TMS_SSRAM_VALID;
    } else if ((mc.csc[0] >> MC_CSC_MEMTYPE_OFFSET) && 0x07 == MC_CSC_MEMTYPE_SYNC) {
      mc.tms[0] = MC_TMS_SYNC_VALID;
    }
 
    while (mem_dev) {
      mem_dev->valid = 0;
      mem_dev = mem_dev->next;
    }
 
    set_csc_tms (0, mc.csc[0], mc.tms[0]);
 
   	register_memoryarea(config.mc.baseaddr, MC_ADDR_SPACE, 4, mc_read_word, mc_write_word);
  }
}
 
inline void mc_clock()
{
}