diff options
Diffstat (limited to 'cpu/ppc4xx/start.S')
| -rw-r--r-- | cpu/ppc4xx/start.S | 177 |
1 files changed, 175 insertions, 2 deletions
diff --git a/cpu/ppc4xx/start.S b/cpu/ppc4xx/start.S index c334f93..afe8635 100644 --- a/cpu/ppc4xx/start.S +++ b/cpu/ppc4xx/start.S @@ -297,7 +297,7 @@ _start_440: mflr r1 mtspr srr0,r1 rfi -#endif +#endif /* CONFIG_440 */ /* * r3 - 1st arg to board_init(): IMMP pointer @@ -504,7 +504,7 @@ _start: #endif /* CONFIG_IOP480 */ /*****************************************************************************/ -#if defined(CONFIG_405GP) || defined(CONFIG_405CR) || defined(CONFIG_405) +#if defined(CONFIG_405GP) || defined(CONFIG_405CR) || defined(CONFIG_405) || defined(CONFIG_405EP) /*----------------------------------------------------------------------- */ /* Clear and set up some registers. */ /*----------------------------------------------------------------------- */ @@ -551,6 +551,17 @@ _start: bl ext_bus_cntlr_init #endif +#if defined(CONFIG_405EP) + /*----------------------------------------------------------------------- */ + /* DMA Status, clear to come up clean */ + /*----------------------------------------------------------------------- */ + addis r3,r0, 0xFFFF /* Clear all existing DMA status */ + ori r3,r3, 0xFFFF + mtdcr dmasr, r3 + + bl ppc405ep_init /* do ppc405ep specific init */ +#endif /* CONFIG_405EP */ + #if defined(CFG_OCM_DATA_ADDR) && defined(CFG_OCM_DATA_SIZE) /******************************************************************** * Setup OCM - On Chip Memory @@ -693,6 +704,7 @@ _start: #endif /* CONFIG_405GP || CONFIG_405CR */ +/*****************************************************************************/ .globl _start_of_vectors _start_of_vectors: @@ -1437,3 +1449,164 @@ trap_reloc: stw r0, 4(r7) blr + + +/**************************************************************************/ +/* PPC405EP specific stuff */ +/**************************************************************************/ +#ifdef CONFIG_405EP +ppc405ep_init: + /* + !----------------------------------------------------------------------- + ! Check FPGA for PCI internal/external arbitration + ! If board is set to internal arbitration, update cpc0_pci + !----------------------------------------------------------------------- + */ + addi r3,0,CPC0_PCI_HOST_CFG_EN +#ifdef CONFIG_BUBINGA405EP + addis r5,r0,FPGA_REG1@h /* set offset for FPGA_REG1 */ + ori r5,r5,FPGA_REG1@l + lbz r5,0x0(r5) /* read to get PCI arb selection */ + andi. r6,r5,FPGA_REG1_PCI_INT_ARB /* using internal arbiter ?*/ + beq ..pci_cfg_set /* if not set, then bypass reg write*/ +#endif + ori r3,r3,CPC0_PCI_ARBIT_EN +..pci_cfg_set: + mtdcr CPC0_PCI, r3 /* Enable internal arbiter*/ + + /* + !----------------------------------------------------------------------- + ! Check to see if chip is in bypass mode. + ! If so, write stored CPC0_PLLMR0 and CPC0_PLLMR1 values and perform a + ! CPU reset Otherwise, skip this step and keep going. + ! Note: Running BIOS in bypass mode is not supported since PLB speed + ! will not be fast enough for the SDRAM (min 66MHz) + !----------------------------------------------------------------------- + */ + mfdcr r5, CPC0_PLLMR1 + rlwinm r4,r5,1,0x1 /* get system clock source (SSCS) */ + cmpi cr0,0,r4,0x1 + + beq pll_done /* if SSCS =b'1' then PLL has */ + /* already been set */ + /* and CPU has been reset */ + /* so skip to next section */ + +#ifdef CONFIG_BUBINGA405EP + /* + !----------------------------------------------------------------------- + ! Read NVRAM to get value to write in PLLMR. + ! If value has not been correctly saved, write default value + ! Default config values (assuming on-board 33MHz SYS_CLK) are above. + ! See CPU_DEFAULT_200 and CPU_DEFAULT_266 above. + ! + ! WARNING: This code assumes the first three words in the nvram_t + ! structure in openbios.h. Changing the beginning of + ! the structure will break this code. + ! + !----------------------------------------------------------------------- + */ + addis r3,0,NVRAM_BASE@h + addi r3,r3,NVRAM_BASE@l + + lwz r4, 0(r3) + addis r5,0,NVRVFY1@h + addi r5,r5,NVRVFY1@l + cmp cr0,0,r4,r5 /* Compare 1st NVRAM Magic number*/ + bne ..no_pllset + addi r3,r3,4 + lwz r4, 0(r3) + addis r5,0,NVRVFY2@h + addi r5,r5,NVRVFY2@l + cmp cr0,0,r4,r5 /* Compare 2 NVRAM Magic number */ + bne ..no_pllset + addi r3,r3,8 /* Skip over conf_size */ + lwz r4, 4(r3) /* Load PLLMR1 value from NVRAM */ + lwz r3, 0(r3) /* Load PLLMR0 value from NVRAM */ + rlwinm r5,r4,1,0x1 /* get system clock source (SSCS) */ + cmpi cr0,0,r5,1 /* See if PLL is locked */ + beq pll_write +..no_pllset: +#endif /* CONFIG_BUBINGA405EP */ + + addis r3,0,PLLMR0_DEFAULT@h /* PLLMR0 default value */ + ori r3,r3,PLLMR0_DEFAULT@l /* */ + addis r4,0,PLLMR1_DEFAULT@h /* PLLMR1 default value */ + ori r4,r4,PLLMR1_DEFAULT@l /* */ + + b pll_write /* Write the CPC0_PLLMR with new value */ + +pll_done: + /* + !----------------------------------------------------------------------- + ! Clear Soft Reset Register + ! This is needed to enable PCI if not booting from serial EPROM + !----------------------------------------------------------------------- + */ + addi r3, 0, 0x0 + mtdcr CPC0_SRR, r3 + + addis r3,0,0x0010 + mtctr r3 +pci_wait: + bdnz pci_wait + + blr /* return to main code */ + +/* +!----------------------------------------------------------------------------- +! Function: pll_write +! Description: Updates the value of the CPC0_PLLMR according to CMOS27E documentation +! That is: +! 1. Pll is first disabled (de-activated by putting in bypass mode) +! 2. PLL is reset +! 3. Clock dividers are set while PLL is held in reset and bypassed +! 4. PLL Reset is cleared +! 5. Wait 100us for PLL to lock +! 6. A core reset is performed +! Input: r3 = Value to write to CPC0_PLLMR0 +! Input: r4 = Value to write to CPC0_PLLMR1 +! Output r3 = none +!----------------------------------------------------------------------------- +*/ +pll_write: + mfdcr r5, CPC0_UCR + andis. r5,r5,0xFFFF + ori r5,r5,0x0101 /* Stop the UART clocks */ + mtdcr CPC0_UCR,r5 /* Before changing PLL */ + + mfdcr r5, CPC0_PLLMR1 + rlwinm r5,r5,0,0x7FFFFFFF /* Disable PLL */ + mtdcr CPC0_PLLMR1,r5 + oris r5,r5,0x4000 /* Set PLL Reset */ + mtdcr CPC0_PLLMR1,r5 + + mtdcr CPC0_PLLMR0,r3 /* Set clock dividers */ + rlwinm r5,r4,0,0x3FFFFFFF /* Reset & Bypass new PLL dividers */ + oris r5,r5,0x4000 /* Set PLL Reset */ + mtdcr CPC0_PLLMR1,r5 /* Set clock dividers */ + rlwinm r5,r5,0,0xBFFFFFFF /* Clear PLL Reset */ + mtdcr CPC0_PLLMR1,r5 + + /* + ! Wait min of 100us for PLL to lock. + ! See CMOS 27E databook for more info. + ! At 200MHz, that means waiting 20,000 instructions + */ + addi r3,0,20000 /* 2000 = 0x4e20 */ + mtctr r3 +pll_wait: + bdnz pll_wait + + oris r5,r5,0x8000 /* Enable PLL */ + mtdcr CPC0_PLLMR1,r5 /* Engage */ + + /* + * Reset CPU to guarantee timings are OK + * Not sure if this is needed... + */ + addis r3,0,0x1000 + mtspr dbcr0,r3 /* This will cause a CPU core reset, and */ + /* execution will continue from the poweron */ + /* vector of 0xfffffffc */ +#endif /* CONFIG_405EP */ |