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authorwdenk <wdenk>2002-11-03 00:24:07 +0000
committerwdenk <wdenk>2002-11-03 00:24:07 +0000
commitc609719b8d1b2dca590e0ed499016d041203e403 (patch)
tree7ea1755d80903ff972f312a249eb856061d40e15 /board/w7o/init.S
parent5b1d713721c3ea02549940133f09236783dda1f9 (diff)
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+/******************************************************************************
+ *
+ * This source code has been made available to you by IBM on an AS-IS
+ * basis. Anyone receiving this source is licensed under IBM
+ * copyrights to use it in any way he or she deems fit, including
+ * copying it, modifying it, compiling it, and redistributing it either
+ * with or without modifications. No license under IBM patents or
+ * patent applications is to be implied by the copyright license.
+ *
+ * Any user of this software should understand that IBM cannot provide
+ * technical support for this software and will not be responsible for
+ * any consequences resulting from the use of this software.
+ *
+ * Any person who transfers this source code or any derivative work
+ * must include the IBM copyright notice, this paragraph, and the
+ * preceding two paragraphs in the transferred software.
+ *
+ * COPYRIGHT I B M CORPORATION 1995
+ * LICENSED MATERIAL - PROGRAM PROPERTY OF I B M
+ *
+ *****************************************************************************/
+#include <config.h>
+#include <ppc4xx.h>
+
+#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
+
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+
+#include <asm/cache.h>
+#include <asm/mmu.h>
+
+/******************************************************************************
+ * Function: ext_bus_cntlr_init
+ *
+ * Description: Configures EBC Controller and a few basic chip selects.
+ *
+ * CS0 is setup to get the Boot Flash out of the addresss range
+ * so that we may setup a stack. CS7 is setup so that we can
+ * access and reset the hardware watchdog.
+ *
+ * IMPORTANT: For pass1 this code must run from
+ * cache since you can not reliably change a peripheral banks
+ * timing register (pbxap) while running code from that bank.
+ * For ex., since we are running from ROM on bank 0, we can NOT
+ * execute the code that modifies bank 0 timings from ROM, so
+ * we run it from cache.
+ *
+ * Notes: Does NOT use the stack.
+ *****************************************************************************/
+ .section ".text"
+ .align 2
+ .globl ext_bus_cntlr_init
+ .type ext_bus_cntlr_init, @function
+ext_bus_cntlr_init:
+ mflr r0
+ /********************************************************************
+ * Prefetch entire ext_bus_cntrl_init function into the icache.
+ * This is necessary because we are going to change the same CS we
+ * are executing from. Otherwise a CPU lockup may occur.
+ *******************************************************************/
+ bl ..getAddr
+..getAddr:
+ mflr r3 /* get address of ..getAddr */
+
+ /* Calculate number of cache lines for this function */
+ addi r4, 0, (((.Lfe0 - ..getAddr) / CFG_CACHELINE_SIZE) + 2)
+ mtctr r4
+..ebcloop:
+ icbt r0, r3 /* prefetch cache line for addr in r3*/
+ addi r3, r3, CFG_CACHELINE_SIZE /* move to next cache line */
+ bdnz ..ebcloop /* continue for $CTR cache lines */
+
+ /********************************************************************
+ * Delay to ensure all accesses to ROM are complete before changing
+ * bank 0 timings. 200usec should be enough.
+ * 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles.
+ *******************************************************************/
+ addis r3, 0, 0x0
+ ori r3, r3, 0xA000 /* wait 200us from reset */
+ mtctr r3
+..spinlp:
+ bdnz ..spinlp /* spin loop */
+
+ /********************************************************************
+ * Setup External Bus Controller (EBC).
+ *******************************************************************/
+ addi r3, 0, epcr
+ mtdcr ebccfga, r3
+ addis r4, 0, 0xb040 /* Device base timeout = 1024 cycles */
+ ori r4, r4, 0x0 /* Drive CS with external master */
+ mtdcr ebccfgd, r4
+
+ /********************************************************************
+ * Change PCIINT signal to PerWE
+ *******************************************************************/
+ mfdcr r4, cntrl1
+ ori r4, r4, 0x4000
+ mtdcr cntrl1, r4
+
+ /********************************************************************
+ * Memory Bank 0 (Flash Bank 0) initialization
+ *******************************************************************/
+ addi r3, 0, pb0ap
+ mtdcr ebccfga, r3
+ addis r4, 0, CFG_W7O_EBC_PB0AP@h
+ ori r4, r4, CFG_W7O_EBC_PB0AP@l
+ mtdcr ebccfgd, r4
+
+ addi r3, 0, pb0cr
+ mtdcr ebccfga, r3
+ addis r4, 0, CFG_W7O_EBC_PB0CR@h
+ ori r4, r4, CFG_W7O_EBC_PB0CR@l
+ mtdcr ebccfgd, r4
+
+ /********************************************************************
+ * Memory Bank 7 LEDs - NEEDED BECAUSE OF HW WATCHDOG AND LEDs.
+ *******************************************************************/
+ addi r3, 0, pb7ap
+ mtdcr ebccfga, r3
+ addis r4, 0, CFG_W7O_EBC_PB7AP@h
+ ori r4, r4, CFG_W7O_EBC_PB7AP@l
+ mtdcr ebccfgd, r4
+
+ addi r3, 0, pb7cr
+ mtdcr ebccfga, r3
+ addis r4, 0, CFG_W7O_EBC_PB7CR@h
+ ori r4, r4, CFG_W7O_EBC_PB7CR@l
+ mtdcr ebccfgd, r4
+
+ /* We are all done */
+ mtlr r0 /* Restore link register */
+ blr /* Return to calling function */
+.Lfe0: .size ext_bus_cntlr_init,.Lfe0-ext_bus_cntlr_init
+/* end ext_bus_cntlr_init() */
+
+/******************************************************************************
+ * Function: sdram_init
+ *
+ * Description: Configures SDRAM memory banks.
+ *
+ * Serial Presence Detect, "SPD," reads the SDRAM EEPROM
+ * via the IIC bus and then configures the SDRAM memory
+ * banks appropriately. If Auto Memory Configuration is
+ * is not used, it is assumed that a 4MB 11x8x2, non-ECC,
+ * SDRAM is soldered down.
+ *
+ * Notes: Expects that the stack is already setup.
+ *****************************************************************************/
+ .section ".text"
+ .align 2
+ .globl sdram_init
+ .type sdram_init, @function
+sdram_init:
+ /* save the return info on stack */
+ mflr r0 /* Get link register */
+ stwu r1, -8(r1) /* Save back chain and move SP */
+ stw r0, +12(r1) /* Save link register */
+
+ /*
+ * First call spd_sdram to try to init SDRAM according to the
+ * contents of the SPD EEPROM. If the SPD EEPROM is blank or
+ * erronious, spd_sdram returns 0 in R3.
+ */
+ bl spd_sdram
+ addic. r3, r3, 0 /* Check for error, save dram size */
+ bne ..sdri_done /* If it worked, we're done... */
+
+ /********************************************************************
+ * If SPD detection fails, we'll default to 4MB, 11x8x2, as this
+ * is the SMALLEST SDRAM size the 405 supports. We can do this
+ * because W7O boards have soldered on RAM, and there will always
+ * be some amount present. If we were using DIMMs, we should hang
+ * the board instead, since it doesn't have any RAM to continue
+ * running with.
+ *******************************************************************/
+
+ /*
+ * Disable memory controller to allow
+ * values to be changed.
+ */
+ addi r3, 0, mem_mcopt1
+ mtdcr memcfga, r3
+ addis r4, 0, 0x0
+ ori r4, r4, 0x0
+ mtdcr memcfgd, r4
+
+ /*
+ * Set MB0CF for ext bank 0. (0-4MB) Address Mode 5 since 11x8x2
+ * All other banks are disabled.
+ */
+ addi r3, 0, mem_mb0cf
+ mtdcr memcfga, r3
+ addis r4, 0, 0x0000 /* BA=0x0, SZ=4MB */
+ ori r4, r4, 0x8001 /* Mode is 5, 11x8x2or4, BE=Enabled */
+ mtdcr memcfgd, r4
+
+ /* Clear MB1CR,MB2CR,MB3CR to turn other banks off */
+ addi r4, 0, 0 /* Zero the data reg */
+
+ addi r3, r3, 4 /* Point to MB1CF reg */
+ mtdcr memcfga, r3 /* Set the address */
+ mtdcr memcfgd, r4 /* Zero the reg */
+
+ addi r3, r3, 4 /* Point to MB2CF reg */
+ mtdcr memcfga, r3 /* Set the address */
+ mtdcr memcfgd, r4 /* Zero the reg */
+
+ addi r3, r3, 4 /* Point to MB3CF reg */
+ mtdcr memcfga, r3 /* Set the address */
+ mtdcr memcfgd, r4 /* Zero the reg */
+
+ /********************************************************************
+ * Set the SDRAM Timing reg, SDTR1 and the refresh timer reg, RTR.
+ * To set the appropriate timings, we assume sdram is
+ * 100MHz (pc100 compliant).
+ *******************************************************************/
+
+ /*
+ * Set up SDTR1
+ */
+ addi r3, 0, mem_sdtr1
+ mtdcr memcfga, r3
+ addis r4, 0, 0x0086 /* SDTR1 value for 100Mhz */
+ ori r4, r4, 0x400D
+ mtdcr memcfgd, r4
+
+ /*
+ * Set RTR
+ */
+ addi r3, 0, mem_rtr
+ mtdcr memcfga, r3
+ addis r4, 0, 0x05F0 /* RTR refresh val = 15.625ms@100Mhz */
+ mtdcr memcfgd, r4
+
+ /********************************************************************
+ * Delay to ensure 200usec have elapsed since reset. Assume worst
+ * case that the core is running 200Mhz:
+ * 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles
+ *******************************************************************/
+ addis r3, 0, 0x0000
+ ori r3, r3, 0xA000 /* Wait 200us from reset */
+ mtctr r3
+..spinlp2:
+ bdnz ..spinlp2 /* spin loop */
+
+ /********************************************************************
+ * Set memory controller options reg, MCOPT1.
+ *******************************************************************/
+ addi r3, 0, mem_mcopt1
+ mtdcr memcfga, r3
+ addis r4, 0, 0x80E0 /* DC_EN=1,SRE=0,PME=0,MEMCHK=0 */
+ ori r4, r4, 0x0000 /* REGEN=0,DRW=00,BRPF=01,ECCDD=1 */
+ mtdcr memcfgd, r4 /* EMDULR=1 */
+
+..sdri_done:
+ /* restore and return */
+ lwz r0, +12(r1) /* Get saved link register */
+ addi r1, r1, +8 /* Remove frame from stack */
+ mtlr r0 /* Restore link register */
+ blr /* Return to calling function */
+.Lfe1: .size sdram_init,.Lfe1-sdram_init
+/* end sdram_init() */
+