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authorH. Nikolaus Schaller <hns@goldelico.com>2012-03-26 20:55:28 +0200
committerH. Nikolaus Schaller <hns@goldelico.com>2012-03-26 20:55:28 +0200
commit92988a21ad4c4c9504295ccb580c9f806134471b (patch)
tree5effc9f14170112450de05c67dafbe8d5034d595 /u-boot/nand_spl/board/amcc/bamboo/sdram.c
parentca2b506783b676c95762c54ea24dcfdaae1947c9 (diff)
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added boot script files to repository
Diffstat (limited to 'u-boot/nand_spl/board/amcc/bamboo/sdram.c')
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diff --git a/u-boot/nand_spl/board/amcc/bamboo/sdram.c b/u-boot/nand_spl/board/amcc/bamboo/sdram.c
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+/*
+ * (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 <asm/ppc4xx.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+
+static void wait_init_complete(void)
+{
+ u32 val;
+
+ do {
+ mfsdram(SDRAM0_MCSTS, val);
+ } while (!(val & 0x80000000));
+}
+
+/*
+ * phys_size_t initdram(int board_type)
+ *
+ * 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.
+ *
+ * Note:
+ * As found out by Eugene O'Brien <eugene.obrien@advantechamt.com>, the fixed
+ * DDR setup has problems (U-Boot crashes randomly upon TFTP), when the DIMM
+ * modules are still plugged in. So it is recommended to remove the DIMM
+ * modules while using the NAND booting code with the fixed SDRAM setup!
+ */
+phys_size_t initdram(int board_type)
+{
+ /*
+ * Soft-reset SDRAM controller.
+ */
+ mtsdr(SDR0_SRST, SDR0_SRST_DMC);
+ mtsdr(SDR0_SRST, 0x00000000);
+
+ /*
+ * Disable memory controller.
+ */
+ mtsdram(SDRAM0_CFG0, 0x00000000);
+
+ /*
+ * Setup some default
+ */
+ mtsdram(SDRAM0_UABBA, 0x00000000); /* ubba=0 (default) */
+ mtsdram(SDRAM0_SLIO, 0x00000000); /* rdre=0 wrre=0 rarw=0 */
+ mtsdram(SDRAM0_DEVOPT, 0x00000000); /* dll=0 ds=0 (normal) */
+ mtsdram(SDRAM0_WDDCTR, 0x00000000); /* wrcp=0 dcd=0 */
+ mtsdram(SDRAM0_CLKTR, 0x40000000); /* clkp=1 (90 deg wr) dcdt=0 */
+
+ /*
+ * Following for CAS Latency = 2.5 @ 133 MHz PLB
+ */
+ mtsdram(SDRAM0_B0CR, 0x00082001);
+ mtsdram(SDRAM0_TR0, 0x41094012);
+ mtsdram(SDRAM0_TR1, 0x8080083d); /* SS=T2 SL=STAGE 3 CD=1 CT=0x00*/
+ mtsdram(SDRAM0_RTR, 0x04100000); /* Interval 7.8µs @ 133MHz PLB */
+ mtsdram(SDRAM0_CFG1, 0x00000000); /* Self-refresh exit, disable PM*/
+
+ /*
+ * Enable the controller, then wait for DCEN to complete
+ */
+ mtsdram(SDRAM0_CFG0, 0x80000000); /* DCEN=1, PMUD=0*/
+ wait_init_complete();
+
+ return CONFIG_SYS_MBYTES_SDRAM << 20;
+}