summaryrefslogtreecommitdiff
path: root/nand_spl/board/amcc/bamboo/sdram.c
diff options
context:
space:
mode:
Diffstat (limited to 'nand_spl/board/amcc/bamboo/sdram.c')
-rw-r--r--nand_spl/board/amcc/bamboo/sdram.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/nand_spl/board/amcc/bamboo/sdram.c b/nand_spl/board/amcc/bamboo/sdram.c
new file mode 100644
index 0000000..4f09072
--- /dev/null
+++ b/nand_spl/board/amcc/bamboo/sdram.c
@@ -0,0 +1,92 @@
+/*
+ * (C) Copyright 2007
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <ppc4xx.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+
+static void wait_init_complete(void)
+{
+ u32 val;
+
+ do {
+ mfsdram(mem_mcsts, val);
+ } while (!(val & 0x80000000));
+}
+
+/*
+ * early_sdram_init()
+ *
+ * As the name already indicates, this function is called very early
+ * from start.S and configures the SDRAM with fixed values. This is needed,
+ * since the 440EP has no internal SRAM and the 4kB NAND_SPL loader has
+ * not enough free space to implement the complete I2C SPD DDR autodetection
+ * routines. Therefore the Bamboo only supports the onboard 64MBytes of SDRAM
+ * when booting from NAND flash.
+ */
+void early_sdram_init(void)
+{
+ /*
+ * Soft-reset SDRAM controller.
+ */
+ mtsdr(sdr_srst, SDR0_SRST_DMC);
+ mtsdr(sdr_srst, 0x00000000);
+
+ /*
+ * Disable memory controller.
+ */
+ mtsdram(mem_cfg0, 0x00000000);
+
+ /*
+ * Setup some default
+ */
+ mtsdram(mem_uabba, 0x00000000); /* ubba=0 (default) */
+ mtsdram(mem_slio, 0x00000000); /* rdre=0 wrre=0 rarw=0 */
+ mtsdram(mem_devopt, 0x00000000); /* dll=0 ds=0 (normal) */
+ mtsdram(mem_wddctr, 0x00000000); /* wrcp=0 dcd=0 */
+ mtsdram(mem_clktr, 0x40000000); /* clkp=1 (90 deg wr) dcdt=0 */
+
+ /*
+ * Following for CAS Latency = 2.5 @ 133 MHz PLB
+ */
+ mtsdram(mem_b0cr, 0x00082001);
+ mtsdram(mem_tr0, 0x41094012);
+ mtsdram(mem_tr1, 0x8080083d); /* SS=T2 SL=STAGE 3 CD=1 CT=0x00*/
+ mtsdram(mem_rtr, 0x04100000); /* Interval 7.8µs @ 133MHz PLB */
+ mtsdram(mem_cfg1, 0x00000000); /* Self-refresh exit, disable PM*/
+
+ /*
+ * Enable the controller, then wait for DCEN to complete
+ */
+ mtsdram(mem_cfg0, 0x80000000); /* DCEN=1, PMUD=0*/
+ wait_init_complete();
+}
+
+long int initdram(int board_type)
+{
+ /*
+ * Nothing to do here, just return size of fixed SDRAM setup
+ */
+ return CFG_MBYTES_SDRAM << 20;
+}