LXR uboot/arch/avr32/include/asm/sdram.h

   1/*
   2 * Copyright (C) 2006 Atmel Corporation
   3 *
   4 * See file CREDITS for list of people who contributed to this
   5 * project.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License as
   9 * published by the Free Software Foundation; either version 2 of
  10 * the License, or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20 * MA 02111-1307 USA
  21 */
  22#ifndef __ASM_AVR32_SDRAM_H
  23#define __ASM_AVR32_SDRAM_H
  24
  25struct sdram_config {
  26        /* Number of data bits. */
  27        enum {
  28                SDRAM_DATA_16BIT = 16,
  29                SDRAM_DATA_32BIT = 32,
  30        } data_bits;
  31
  32        /* Number of address bits */
  33        uint8_t row_bits, col_bits, bank_bits;
  34
  35        /* SDRAM timings in cycles */
  36        uint8_t cas, twr, trc, trp, trcd, tras, txsr;
  37
  38        /* SDRAM refresh period in cycles */
  39        unsigned long refresh_period;
  40};
  41
  42/*
  43 * Attempt to initialize the SDRAM controller using the specified
  44 * parameters. Return the expected size of the memory area based on
  45 * the number of address and data bits.
  46 *
  47 * The caller should verify that the configuration is correct by
  48 * running a memory test, e.g. get_ram_size().
  49 */
  50extern unsigned long sdram_init(void *sdram_base,
  51                        const struct sdram_config *config);
  52
  53#endif /* __ASM_AVR32_SDRAM_H */
  54