xlli_lowlev_init.s

pxa270的bootloader,linux下的,好不容易搞到的

        str     r2, [r4, #xlli_MDREFR_offset]   @ write updated MDREFR
        ldr     r2, [r4, #xlli_MDREFR_offset]   @ read back

        bic     r2, r2, #xlli_MDREFR_SLFRSH     @ Disable self refresh
        str     r2, [r4, #xlli_MDREFR_offset]   @ write updated MDREFR
        ldr     r2, [r4, #xlli_MDREFR_offset]   @ read back

        orr     r2, r2, #xlli_MDREFR_E1PIN      @ Assert E1PIN to enable SDCKE[1]
        str     r2, [r4, #xlli_MDREFR_offset]   @ write updated MDREFR (finished with value in r2)
        ldr     r2, [r4, #xlli_MDREFR_offset]   @ read back

        nop                                     @ Do not remove!
        nop                                     @ Do not remove!
@
@ ***** STEP 4 *****
@
@ Appropriately configure, but don't enable, each SDRAM partition pair
@
        ldr     r1, =xlli_MDCNFG_value          @ Fetch platform value for MDCNFG

        bic     r1, r1,  #(xlli_MDCNFG_DE0 | xlli_MDCNFG_DE1)   @ Disable all
        bic     r1, r1,  #(xlli_MDCNFG_DE2 | xlli_MDCNFG_DE3)   @ SDRAM banks
@
@       Check for conditional def for 32 vs 16 bit bus width
@
        .ifdef xlli_SDRAM_16BIT               @ Set bus width to 16 bits?
        orr     r1, r1,  #xlli_MDCNFG_DWID0     @ Set banks 0/1 for 16 bit width
        .else
        bic     r1, r1,  #xlli_MDCNFG_DWID0     @ Set banks 0/1 for 32 bit width
        .endif

        str     r1, [r4, #xlli_MDCNFG_offset]   @ Write w/o enabling SDRAM banks

@
@ ***** STEP 5 *****  (Delay at least 200 uS)
@
        ldr     r2,  =xlli_OSTREGS_PHYSICAL_BASE @ Load OS timer base address
        ldr     r3,  [r2, #xlli_OSCR0_offset]    @ Fetch starting value of OSCR0
        add     r3,  r3,  #0x300                 @ Really 0x2E1 is about 200usec, so 0x300 should be plenty
xlli_5:  ldr     r1,  [r2, #xlli_OSCR0_offset]    @ Fetch current OSCR0 value
        cmp     r1,  r3                          @ Is the timer past the time out value?
        bmi     xlli_5                           @ No - Loop until it is
@
@ ***** STEP 6 ***** (Make sure DCACHE is disabled)
@
        mrc     p15, 0, r2, c1, c0, 0           @ load r2 contents of register 1 in CP 15
        bic     r2,  r2,  #xlli_CONTROL_DCACHE  @ Disable D-Cache
        mcr     p15, 0, r2, c1, c0, 0           @ Write back to CP15
@
@ ***** STEP 7 *****
@
@ Access memory *not yet enabled* for CBR refresh cycles (8)
@ - CBR is generated for all banks
@
        ldr     r1, =xlli_SDRAM_PHYSICAL_BASE
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]

        str     r1, [r1]  @  Fix for erratum #116. Makes up for ineffective 1st mem access.
                          @  This is being left in for Bulverde for the moment
@
@ ***** STEP 8 *****
@
@  Re-enable D-cache if desired (we don't)

@
@ ***** STEP 9 *****
@
@ Re-enable SDRAM partitions
@
        ldr     r2,  [r4, #xlli_MDCNFG_offset]   @ Fetch the current MDCNFG value
        orr     r2,  r2,  #xlli_MDCNFG_DE0       @ Enable SDRAM bank 0
        str     r2,  [r4, #xlli_MDCNFG_offset]   @ Write back MDCNFG, enabling the SDRAM bank(s)
@
@ ***** STEP 10 *****
@
@ Write the MDMRS register to trigger an MRS command to all enabled banks of SDRAM.
@
@
        ldr     r1,  =xlli_MDMRS_value           @ Fetch platform MDMRS value
        str     r1,  [r4, #xlli_MDMRS_offset]    @ Write the MDMRS value back
@
@ ***** STEP 11 *****
@
@ In systems with SDRAM or Synchronous Flash, optionally enable auto-power-down by setting MDREFR:APD
@
        ldr     r3,  [r4, #xlli_MDREFR_offset]   @ Get MDREFR value
        orr     r3,  r3,  #xlli_MDREFR_APD       @ enable auto power down
        str     r3,  [r4, #xlli_MDREFR_offset]   @ Write value back

        mov     pc,  lr                         @ return to calling routine

        .endfunc

        .ltorg

@**************************************************************************************************
@
@ ***********************************************
@ **********                           **********
@ ********** RESTART MEMORY CONTROLLER **********
@ **********                           **********
@ ***********************************************
@
@ This command restarts the memory controller and should be called after a frequency change sequence
@ or when memory controller settings have been changed (such as xlli_mem_Tmax and xlli_memTopt).
@

.func xlli_mem_restart
xlli_mem_restart:

        ldr     r4,  =xlli_MEMORY_CONFIG_BASE    @ Get memory controller base address
        ldr     r2,  [r4, #xlli_MDREFR_offset]   @ Get MDREFR value
        bic     r3,  r2, #xlli_MDREFR_E0PIN      @ Clear E0PIN to disable SDCKE[0]
        bic     r3,  r3, #xlli_MDREFR_E1PIN      @ Clear E1PIN to disable SDCKE[1]
        b       xlli_5A
@
@       The next line should start on a cache line boundary so we don't accidently hang the system
@
        .p2align 5
xlli_5A: str     r3,  [r4, #xlli_MDREFR_offset]   @ Write value back with E0PIN and E1PIN cleared
        str     r2,  [r4, #xlli_MDREFR_offset]   @ Write value back with E0PIN and E1PIN set
@
@ Disable all SDRAM banks
@
        ldr     r1, [r4, #xlli_MDCNFG_offset]    @ Fetch platform value for MDCNFG
        bic     r1, r1,  #(xlli_MDCNFG_DE0 | xlli_MDCNFG_DE1)   @ Disable all
        bic     r1, r1,  #(xlli_MDCNFG_DE2 | xlli_MDCNFG_DE3)   @ SDRAM banks
        str     r1, [r4, #xlli_MDCNFG_offset]   @ Write w/o enabling SDRAM banks
@
@ Access memory *not yet enabled* for CBR refresh cycles (8)
@ - CBR is generated for all banks
@
        ldr     r1, =xlli_SDRAM_PHYSICAL_BASE
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]
        str     r1, [r1]

        str     r1, [r1]  @  Fix for erratum #116. Makes up for ineffective 1st mem access.
                          @  This is being left in for Bulverde for the moment
@
@ Re-enable SDRAM partition(s)
@
        ldr     r2,  [r4, #xlli_MDCNFG_offset]   @ Fetch the current MDCNFG value
        orr     r2,  r2,  #xlli_MDCNFG_DE0       @ Enable SDRAM bank 0
        str     r2,  [r4, #xlli_MDCNFG_offset]   @ Write back MDCNFG, enabling the SDRAM bank(s)
@
@ Write the MDMRS register to trigger an MRS command to all enabled banks of SDRAM.
@
@
        ldr     r1,  [r4, #xlli_MDMRS_offset]    @ Fetch platform MDMRS value
        str     r1,  [r4, #xlli_MDMRS_offset]    @ Write the MDMRS value back
@
        ldr     r3,  [r4, #xlli_MDREFR_offset]   @ Get MDREFR value
        str     r3,  [r4, #xlli_MDREFR_offset]   @ Write value back

        mov     pc,  lr                         @ return to calling routine
        .endfunc


@**************************************************************************************************
@
@ ********************************************************
@ **********                                    **********
@ ********** MAXIMIZE MEMORY CONTROLLER VALUES  **********
@ **********                                    **********
@ ********************************************************
@
@ NOTE: This function maximizes the timing values in the memory controller so the frequency change
@       sequence can be done safely without the risk of a system hang. Once the frequency change
@       sequence is complete, xlli__mem_Topt may be called to set the optimal timing values.
@
@       This function does not need to be called if the new MemClk frequency is going to be higher
@       than the present MemClk frequency. However, the overhead of this function is minimal so
@       it is suggested this function be called before any change frequency sequence.
@
@       r1, r2, and r3 are used and not preserved.
@
.func xlli_mem_Tmax
xlli_mem_Tmax:

        ldr     r1,  =xlli_MEMORY_CONFIG_BASE   @ Get memory controller base address
        ldr     r3,  =0x7FF07FF0                @ Maximize bits for RDF, RDN and RRR
@
        ldr     r2,  [r1, #xlli_MSC0_offset]    @ Get MSC0 value
        orr     r2,  r2,  r3                    @ Set all the RDF, RDN and RRR bits
        str     r2,  [r1, #xlli_MSC0_offset]    @ Set the new MSC0 value
        ldr     r2,  [r1, #xlli_MSC0_offset]    @ Read MSC0 value back to lock the values
@
        ldr     r2,  [r1, #xlli_MSC1_offset]    @ Get MSC1 value
        orr     r2,  r2,  r3                    @ Set all the RDF, RDN and RRR bits
        str     r2,  [r1, #xlli_MSC1_offset]    @ Set the new MSC1 value
        ldr     r2,  [r1, #xlli_MSC1_offset]    @ Read MSC1 value back to lock the values
@
        ldr     r2,  [r1, #xlli_MSC2_offset]    @ Get MSC2 value
        orr     r2,  r2,  r3                    @ Set all the RDF, RDN and RRR bits
        str     r2,  [r1, #xlli_MSC2_offset]    @ Set the new MSC2 value
        ldr     r2,  [r1, #xlli_MSC2_offset]    @ Read MSC2 value back to lock the values
@
        ldr     r3,  =0x03000300                @ Set up mask bits for DTC0 and DTC2
        ldr     r2,  [r1, #xlli_MDCNFG_offset]  @ Get present MDCNFG value
        orr     r2,  r2,  r3                    @ Clear the DTC0 and DTC2 bits
        str     r2,  [r1, #xlli_MDCNFG_offset]  @ Write back the MDCNFG value
@
        ldr     r3,  =0xFFF                     @ Set up mask bits for DRI value
        ldr     r2,  [r1, #xlli_MDREFR_offset]  @ Get present MDREFR value
        bic     r2,  r2,  r3                    @ Clear all the DRI bits
        orr     r2,  r2,  #0x13                 @ Set to lowest safe value
        str     r2,  [r1, #xlli_MDREFR_offset]  @ Write back the MDREFR value

        mov     pc,  lr                         @ return to calling routine

        .endfunc

@**************************************************************************************************
@
@ ***********************************************************
@ **********                                       **********
@ ********** SET OPTIMAL MEMORY CONTROLLER VALUES  **********
@ **********                                       **********
@ ***********************************************************
@
@ NOTE: This function sets the TIMING values in the memory controller to the optimum values based on
@       the frequency of the MemClk. This function should be called AFTER the frequency change
@       sequence is complete to get optimal performance out of the memory system.
@
@       If changing the core frequency to a value that increases the MemClk speed, it is strongly
@       suggested that xlli_MSCx_max be called before the frequency change sequence. Once the
@       frequency chage sequence is complete, this routine may be called to reset the optimal
@       values for the memory system and the memory controller restarted.
@
@       r1 through r8 are used and not preserved.
@
.func xlli_mem_Topt
xlli_mem_Topt:

        ldr     r1,  =xlli_CLKREGS_PHYSICAL_BASE  @ Get base address of clock registers
        ldr     r2,  [r1, #xlli_CCSR_offset]      @ Get current clock status
        and     r2,  r2,  #0x1F                   @ r2 now contains the CCSR L value

        ldr     r3,  [r1, #xlli_CCCR_offset]      @ Get the current CCCR for the "A" bit
        and     r3,  r3,  #xlli_CCCR_A_Bit_Mask
        mov     r3,  r3,  LSR #0x19               @ Move down to bit position 0 to make comparison easy (LSL by 25)
@
@       Check for the "B" bit from CCCR (CP14,R6)
@
        mrc     p14, 0, r1, c6, c0, 0             @ Get data in CP14, Register 6
        and     r1,  r1,  #0x8                    @ Grab just the "B" bit
        mov     r1,  r1,  LSR #0x2                @ move it to bit position 1
        orr     r9, r3, r1                        @ At this point r9 contains the A-bit at pos. 0 & B-bit at pos. 1

        ldr     r1,  =xlli_MEMORY_CONFIG_BASE     @ Load r1 with memory controller base address
@
@       The MemClk speed is determined by the L, A and B values.
@       Unfortunaly, the only practical way to do this is to rip through all the legal
@       values and load a register when there is a match. Illegal values result in no change
@
        ldr     r3,  =0x7FF07FF0                @ Bit mask for RDF, RDN and RRR (MSC0)
        ldr     r4,  [r1, #xlli_MSC0_offset]    @ Get present MSC0 value
        bic     r4,  r4,  r3                    @ Clear the RDF, RDN and RRR bits

        ldr     r5,  =0x03000300                @ DTC0, DTC2 bit mask (MDCNFG)
        ldr     r6,  [r1, #xlli_MDCNFG_offset]  @ Get present MDCNFG value
        bic     r6,  r6,  r5                    @ Clear DTC0, DTC2

        ldr     r7,  =0xC0200FFF                @ DRI and RESERVED bit mask (MDREFR)
        ldr     r8,  [r1, #xlli_MDREFR_offset]  @ Get present MDREFR value
        bic     r8,  r8,  r7                    @ Clear DRI and RESERVED bits