summaryrefslogtreecommitdiff
path: root/board/sc3/init.S
diff options
context:
space:
mode:
Diffstat (limited to 'board/sc3/init.S')
-rw-r--r--board/sc3/init.S382
1 files changed, 382 insertions, 0 deletions
diff --git a/board/sc3/init.S b/board/sc3/init.S
new file mode 100644
index 0000000000..e7b3c83949
--- /dev/null
+++ b/board/sc3/init.S
@@ -0,0 +1,382 @@
+/*------------------------------------------------------------------------------+
+ *
+ * This souce code has been made available to you by EuroDesign
+ * (www.eurodsn.de). It's based on the original IBM source code, so
+ * this follows:
+ *
+ * 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>
+
+/**
+ * ext_bus_cntlr_init - Initializes the External Bus Controller for the external peripherals
+ *
+ * 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.
+ *
+ * Bank 0 - Boot-Flash
+ * Bank 1 - NAND-Flash
+ * Bank 2 - ISA bus
+ * Bank 3 - Second Flash
+ * Bank 4 - USB controller
+ */
+ .globl ext_bus_cntlr_init
+ext_bus_cntlr_init:
+/*
+ * We need the current boot up configuration to set correct
+ * timings into internal flash and external flash
+ */
+ mfdcr r24,strap /* xxxx xxxx xxxx xxx? ?xxx xxxx xxxx xxxx
+ 0 0 -> 8 bit external ROM
+ 0 1 -> 16 bit internal ROM */
+ addi r4,0,2
+ srw r24,r24,r4 /* shift right r24 two positions */
+ andi. r24,r24,0x06000
+/*
+ * All calculations are based on 33MHz EBC clock.
+ *
+ * First, create a "very slow" timing (~250ns) with burst mode enabled
+ * This is need for the external flash access
+ */
+ lis r25,0x0800
+ ori r25,r25,0x0280 /* 0000 1000 0xxx 0000 0000 0010 100x xxxx = 0x03800280
+/*
+ * Second, create a fast timing:
+ * 90ns first cycle - 3 clock access
+ * and 90ns burst cycle, plus 1 clock after the last access
+ * This is used for the internal access
+ */
+ lis r26,0x8900
+ ori r26,r26,0x0280 /* 1000 1001 0xxx 0000 0000 0010 100x xxxx
+/*
+ * We can't change settings on CS# if we currently use them.
+ * -> load a few instructions into cache and run this code from cache
+ */
+ mflr r4 /* save link register */
+ bl ..getAddr
+..getAddr:
+ mflr r3 /* get address of ..getAddr */
+ mtlr r4 /* restore link register */
+ addi r4,0,14 /* set ctr to 10; used to prefetch */
+ mtctr r4 /* 10 cache lines to fit this function
+ in cache (gives us 8x10=80 instructions) */
+..ebcloop:
+ icbt r0,r3 /* prefetch cache line for addr in r3 */
+ addi r3,r3,32 /* move to next cache line */
+ bdnz ..ebcloop /* continue for 10 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
+ */
+ lis r3,0x0
+ ori r3,r3,0xA000 /* ensure 200usec have passed since reset */
+ mtctr r3
+..spinlp:
+ bdnz ..spinlp /* spin loop */
+
+/*-----------------------------------------------------------------------
+ * Memory Bank 0 (BOOT-ROM) initialization
+ * 0xFFEF00000....0xFFFFFFF
+ * We only have to change the timing. Mapping is ok by boot-strapping
+ *----------------------------------------------------------------------- */
+
+ li r4,pb0ap /* PB0AP=Peripheral Bank 0 Access Parameters */
+ mtdcr ebccfga,r4
+
+ mr r4,r26 /* assume internal fast flash is boot flash */
+ cmpwi r24,0x2000 /* assumption true? ... */
+ beq 1f /* ...yes! */
+ mr r4,r25 /* ...no, use the slow variant */
+ mr r25,r26 /* use this for the other flash */
+1:
+ mtdcr ebccfgd,r4 /* change timing now */
+
+ li r4,pb0cr /* PB0CR=Peripheral Bank 0 Control Register */
+ mtdcr ebccfga,r4
+ mfdcr r4,ebccfgd
+ lis r3,0x0001
+ ori r3,r3,0x8000 /* allow reads and writes */
+ or r4,r4,r3
+ mtdcr ebccfgd,r4
+
+/*-----------------------------------------------------------------------
+ * Memory Bank 3 (Second-Flash) initialization
+ * 0xF0000000...0xF01FFFFF -> 2MB
+ *----------------------------------------------------------------------- */
+
+ li r4,pb3ap /* Peripheral Bank 1 Access Parameter */
+ mtdcr ebccfga,r4
+ mtdcr ebccfgd,r2 /* change timing */
+
+ li r4,pb3cr /* Peripheral Bank 1 Configuration Registers */
+ mtdcr ebccfga,r4
+
+ lis r4,0xF003
+ ori r4,r4,0x8000
+/*
+ * Consider boot configuration
+ */
+ xori r24,r24,0x2000 /* invert current bus width */
+ or r4,r4,r24
+ mtdcr ebccfgd,r4
+
+/*-----------------------------------------------------------------------
+ * Memory Bank 1 (NAND-Flash) initialization
+ * 0x77D00000...0x77DFFFFF -> 1MB
+ * - the write/read pulse to the NAND can be as short as 25ns, bus the cycle time is always 50ns
+ * - the setup time is 0ns
+ * - the hold time is 15ns
+ * ->
+ * - TWT = 0
+ * - CSN = 0
+ * - OEN = 0
+ * - WBN = 0
+ * - WBF = 0
+ * - TH = 1
+ * ----> 2 clocks per cycle = 60ns cycle (30ns active, 30ns hold)
+ *----------------------------------------------------------------------- */
+
+ li r4,pb1ap /* Peripheral Bank 1 Access Parameter */
+ mtdcr ebccfga,r4
+
+ lis r4,0x0000
+ ori r4,r4,0x0200
+ mtdcr ebccfgd,r4
+
+ li r4,pb1cr /* Peripheral Bank 1 Configuration Registers */
+ mtdcr ebccfga,r4
+
+ lis r4,0x77D1
+ ori r4,r4,0x8000
+ mtdcr ebccfgd,r4
+
+
+/* USB init (without acceleration) */
+#ifndef CONFIG_ISP1161_PRESENT
+ li r4,pb4ap /* PB4AP=Peripheral Bank 4 Access Parameters */
+ mtdcr ebccfga,r4
+ lis r4,0x0180
+ ori r4,r4,0x5940
+ mtdcr ebccfgd,r4
+#endif
+
+/*-----------------------------------------------------------------------
+ * Memory Bank 2 (ISA Access) initialization (plus memory bank 6 and 7)
+ * 0x78000000...0x7BFFFFFF -> 64 MB
+ * Wir arbeiten bei 33 MHz -> 30ns
+ *-----------------------------------------------------------------------
+
+ A7 (ppc notation) or A24 (standard notation) decides about
+ the type of access:
+ A7/A24=0 -> memory cycle
+ A7/ /A24=1 -> I/O cycle
+*/
+ li r4,pb2ap /* PB2AP=Peripheral Bank 2 Access Parameters */
+ mtdcr ebccfga,r4
+/*
+ We emulate an ISA access
+
+ 1. Address active
+ 2. wait 0 EBC clocks -> CSN=0
+ 3. set CS#
+ 4. wait 0 EBC clock -> OEN/WBN=0
+ 5. set OE#/WE#
+ 6. wait 4 clocks (ca. 90ns) and for Ready signal
+ 7. hold for 4 clocks -> TH=4
+*/
+
+#if 1
+/* faster access to isa-bus */
+ lis r4,0x0180
+ ori r4,r4,0x5940
+#else
+ lis r4,0x0100
+ ori r4,r4,0x0340
+#endif
+ mtdcr ebccfgd,r4
+
+#ifdef IDE_USES_ISA_EMULATION
+ li r25,pb5ap /* PB5AP=Peripheral Bank 5 Access Parameters */
+ mtdcr ebccfga,r25
+ mtdcr ebccfgd,r4
+#endif
+
+ li r25,pb6ap /* PB6AP=Peripheral Bank 6 Access Parameters */
+ mtdcr ebccfga,r25
+ mtdcr ebccfgd,r4
+ li r25,pb7ap /* PB7AP=Peripheral Bank 7 Access Parameters */
+ mtdcr ebccfga,r25
+ mtdcr ebccfgd,r4
+
+ li r25,pb2cr /* PB2CR=Peripheral Bank 2 Configuration Register */
+ mtdcr ebccfga,r25
+
+ lis r4,0x780B
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+/*
+ * the other areas are only 1MiB in size
+ */
+ lis r4,0x7401
+ ori r4,r4,0xA000
+
+ li r25,pb6cr /* PB6CR=Peripheral Bank 6 Configuration Register */
+ mtdcr ebccfga,r25
+ lis r4,0x7401
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+
+ li r25,pb7cr /* PB7CR=Peripheral Bank 7 Configuration Register */
+ mtdcr ebccfga,r25
+ lis r4,0x7411
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+
+#ifndef CONFIG_ISP1161_PRESENT
+ li r25,pb4cr /* PB4CR=Peripheral Bank 4 Configuration Register */
+ mtdcr ebccfga,r25
+ lis r4,0x7421
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+#endif
+#ifdef IDE_USES_ISA_EMULATION
+ li r25,pb5cr /* PB5CR=Peripheral Bank 5 Configuration Register */
+ mtdcr ebccfga,r25
+ lis r4,0x0000
+ ori r4,r4,0x0000
+ mtdcr ebccfgd,r4
+#endif
+
+/*-----------------------------------------------------------------------
+ * Memory bank 4: USB controller Philips ISP6111
+ * 0x77C00000 ... 0x77CFFFFF
+ *
+ * The chip is connected to:
+ * - CPU CS#4
+ * - CPU IRQ#2
+ * - CPU DMA 3
+ *
+ * Timing:
+ * - command to first data: 300ns. Software must ensure this timing!
+ * - Write pulse: 26ns
+ * - Read pulse: 33ns
+ * - read cycle time: 150ns
+ * - write cycle time: 140ns
+ *
+ * Note: All calculations are based on 33MHz EBC clock. One '#' or '_' is 30ns
+ *
+ * |- 300ns --|
+ * |---- 420ns ---|---- 420ns ---| cycle
+ * CS ############:###____#######:###____#######
+ * OE ############:####___#######:####___#######
+ * WE ############:####__########:####__########
+ *
+ * ----> 2 clocks RD/WR pulses: 60ns
+ * ----> CSN: 3 clock, 90ns
+ * ----> OEN: 1 clocks (read cycle)
+ * ----> WBN: 1 clocks (write cycle)
+ * ----> WBE: 2 clocks
+ * ----> TH: 7 clock, 210ns
+ * ----> TWT: 7 clocks
+ *----------------------------------------------------------------------- */
+
+#ifdef CONFIG_ISP1161_PRESENT
+
+ li r4,pb4ap /* PB4AP=Peripheral Bank 4 Access Parameters */
+ mtdcr ebccfga,r4
+
+ lis r4,0x030D
+ ori r4,r4,0x5E80
+ mtdcr ebccfgd,r4
+
+ li r4,pb4cr /* PB2CR=Peripheral Bank 4 Configuration Register */
+ mtdcr ebccfga,r4
+
+ lis r4,0x77C1
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+
+#endif
+
+#ifndef IDE_USES_ISA_EMULATION
+
+/*-----------------------------------------------------------------------
+ * Memory Bank 5 used for IDE access
+ *
+ * Timings for IDE Interface
+ *
+ * SETUP / LENGTH / HOLD - cycles valid for 33.3 MHz clk -> 30ns cycle time
+ * 70 165 30 PIO-Mode 0, [ns]
+ * 3 6 1 [Cycles] ----> AP=0x040C0200
+ * 50 125 20 PIO-Mode 1, [ns]
+ * 2 5 1 [Cycles] ----> AP=0x03080200
+ * 30 100 15 PIO-Mode 2, [ns]
+ * 1 4 1 [Cycles] ----> AP=0x02040200
+ * 30 80 10 PIO-Mode 3, [ns]
+ * 1 3 1 [Cycles] ----> AP=0x01840200
+ * 25 70 10 PIO-Mode 4, [ns]
+ * 1 3 1 [Cycles] ----> AP=0x01840200
+ *
+ *----------------------------------------------------------------------- */
+
+ li r4,pb5ap
+ mtdcr ebccfga,r4
+ lis r4,0x040C
+ ori r4,r4,0x0200
+ mtdcr ebccfgd,r4
+
+ li r4,pb5cr /* PB2CR=Peripheral Bank 2 Configuration Register */
+ mtdcr ebccfga,r4
+
+ lis r4,0x7A01
+ ori r4,r4,0xA000
+ mtdcr ebccfgd,r4
+#endif
+/*
+ * External Peripheral Control Register
+ */
+ li r4,epcr
+ mtdcr ebccfga,r4
+
+ lis r4,0xB84E
+ ori r4,r4,0xF000
+ mtdcr ebccfgd,r4
+/*
+ * drive POST code
+ */
+ lis r4,0x7900
+ ori r4,r4,0x0080
+ li r3,0x0001
+ stb r3,0(r4) /* 01 -> external bus controller is initialized */
+ nop /* pass2 DCR errata #8 */
+ blr