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
  25 struct 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  */
  50 extern unsigned long sdram_init(void *sdram_base,
  51                         const struct sdram_config *config);
  52
  53 #endif /* __ASM_AVR32_SDRAM_H */