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Diffstat (limited to 'board/sc3/init.S')
| -rw-r--r-- | board/sc3/init.S | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/board/sc3/init.S b/board/sc3/init.S new file mode 100644 index 0000000..e7b3c83 --- /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 |