source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/AdvancedAta/PDC20x30.asm@ 590

; Project name  :   XTIDE Universal BIOS
; Description   :   Functions for initializing Promise
;                   PDC 20230 and 20630 VLB IDE Controllers.

;
; XTIDE Universal BIOS and Associated Tools
; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
;

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; PDC20x30_DetectControllerForIdeBaseInBX
;   Parameters:
;       BX:     IDE Base Port
;   Returns:
;       AX:     ID WORD for detected controller
;       DX:     Controller base port
;       CF:     Set if PDC detected
;   Corrupts registers:
;       BX (only when PDC detected)
;--------------------------------------------------------------------
PDC20x30_DetectControllerForIdeBaseInBX:
    mov     dx, bx
    call    EnablePdcProgrammingMode
    jnz     SHORT DisablePdcProgrammingMode.Return  ; PDC controller not detected
;   ePUSH_T ax, DisablePdcProgrammingMode           ; Uncomment this if GetPdcIDtoAX needs to be a real function
    ; Fall to GetPdcIDtoAX

;--------------------------------------------------------------------
; Programming mode must be enabled for this function.
; This function also enables PDC 20630 extra registers.
;
; GetPdcIDtoAX
;   Parameters:
;       DX:     IDE Base port
;   Returns:
;       AH:     PDC ID
;   Corrupts registers:
;       AL, BX
;--------------------------------------------------------------------
GetPdcIDtoAX:
    push    dx

    ; Try to enable PDC 20630 extra registers
    add     dx, BYTE LOW_CYLINDER_REGISTER
    in      al, dx
    or      al, FLG_PDCLCR_ENABLE_EXTRA_REGISTERS
    out     dx, al

    ; Try to access PDC 20630 registers to see if they are available
    ; Hopefully this does not cause problems for systems with PDC 20230
    add     dx, BYTE PDC20630_INDEX_REGISTER - LOW_CYLINDER_REGISTER
    mov     al, PDCREG7_STATUS  ; Try to access PDC 20630 status register
    out     dx, al
    xchg    bx, ax
    in      al, dx              ; Does index register contain status register index?
    cmp     al, bl
    mov     ah, ID_PDC20630
    eCMOVNE ah, ID_PDC20230

    pop     dx
;   ret                         ; Uncomment this to make GetPdcIDtoAX a real function
    ; Fall to DisablePdcProgrammingMode


;--------------------------------------------------------------------
; DisablePdcProgrammingMode
;   Parameters:
;       DX:     Base port
;   Returns:
;       CF:     Set
;   Corrupts registers:
;       AL
;--------------------------------------------------------------------
DisablePdcProgrammingMode:
    add     dx, BYTE HIGH_CYLINDER_REGISTER
    in      al, dx
    add     dx, -HIGH_CYLINDER_REGISTER     ; Sets CF for PDC20x30_DetectControllerForIdeBaseInBX
.Return:
    ret


;--------------------------------------------------------------------
; EnablePdcProgrammingMode
;   Parameters:
;       DX:     Base port
;   Returns:
;       CF:     Cleared
;       ZF:     Set if programming mode enabled
;   Corrupts registers:
;       AL
;--------------------------------------------------------------------
EnablePdcProgrammingMode:
    ; Set bit 7 to sector count register
    inc     dx
    inc     dx
    in      al, dx  ; 1F2h (SECTOR_COUNT_REGISTER)
    or      al, 80h
    out     dx, al

    ; PDC detection sequence (should delay be added between register reads?)
    add     dx, BYTE HIGH_CYLINDER_REGISTER - SECTOR_COUNT_REGISTER
    in      al, dx  ; 1F5h
    cli
    sub     dx, BYTE HIGH_CYLINDER_REGISTER - SECTOR_COUNT_REGISTER
    in      al, dx  ; 1F2h
    add     dx, STANDARD_CONTROL_BLOCK_OFFSET + (ALTERNATE_STATUS_REGISTER_in - SECTOR_COUNT_REGISTER)
    in      al, dx  ; 3F6h
    in      al, dx  ; 3F6h
    sub     dx, STANDARD_CONTROL_BLOCK_OFFSET + (ALTERNATE_STATUS_REGISTER_in - SECTOR_COUNT_REGISTER)
    in      al, dx  ; 1F2h
    in      al, dx  ; 1F2h
    sti

    ; PDC20230C and PDC20630 clears the bit we set at the beginning
    in      al, dx
    dec     dx
    dec     dx      ; Base port
    test    al, 80h ; Clears CF
    ret


;--------------------------------------------------------------------
; PDC20x30_GetMaxPioModeToALandMinPioCycleTimeToBX
;   Parameters:
;       AX:     ID WORD specific for detected controller
;   Returns:
;       AL:     Max supported PIO mode
;       AH:     FLGH_DPT_IORDY if IORDY supported, zero otherwise
;       BX:     Min PIO cycle time (only if ZF set)
;       ZF:     Set if PIO limit necessary
;               Cleared if no need to limit timings
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
PDC20x30_GetMaxPioModeToALandMinPioCycleTimeToBX:
    cmp     ah, ID_PDC20630
    je      SHORT .Return       ; No need to limit anything
    mov     ax, 2               ; Limit PIO to 2 for ID_PDC20230
    mov     bx, PIO_2_MIN_CYCLE_TIME_NS
    stc
.Return:
    ret


;--------------------------------------------------------------------
; PDC20x30_InitializeForDPTinDSDI
;   Parameters:
;       DS:DI:  Ptr to DPT for Single or Slave Drive
;   Returns:
;       AH:     Int 13h return status
;       CF:     Cleared if success or no controller to initialize
;               Set if error
;   Corrupts registers:
;       AL, BX, CX, DX
;--------------------------------------------------------------------
PDC20x30_InitializeForDPTinDSDI:
%ifdef USE_386
    xor     ch, ch
    test    BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE
    setnz   cl
%else
    xor     cx, cx
    test    BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE
    jz      SHORT .NotSlave
    inc     cx
.NotSlave:
%endif

    mov     dx, [di+DPT.wBasePort]
    call    EnablePdcProgrammingMode
    call    SetSpeedForDriveInCX
    cmp     BYTE [di+DPT_ADVANCED_ATA.wControllerID+1], ID_PDC20630
    jne     SHORT .InitializationCompleted
    call    SetPdc20630SpeedForDriveInCX
.InitializationCompleted:
    mov     dx, [di+DPT.wBasePort]
    call    DisablePdcProgrammingMode
    xor     ah, ah
    ret


;--------------------------------------------------------------------
; SetSpeedForDriveInCX
;   Parameters:
;       CX:     0 for master, 1 for slave drive
;       DX:     IDE Base port
;       DS:DI:  Ptr to DPT
;   Returns:
;       DX:     Sector Number Register
;   Corrupts registers:
;       AX, BX
;--------------------------------------------------------------------
SetSpeedForDriveInCX:
    eMOVZX  bx, BYTE [di+DPT_ADVANCED_ATA.bPioMode]
    MIN_U   bl, 2   ; Limit to PIO2
    mov     bl, [cs:bx+.rgbPioModeToPDCspeedValue]

    add     dx, BYTE SECTOR_NUMBER_REGISTER
    mov     bh, ~MASK_PDCSCR_DEV1SPEED  ; Assume slave
    inc     cx
    loop    .SetSpeed
    eSHL_IM bl, POS_PDCSCR_DEV0SPEED
    mov     bh, ~MASK_PDCSCR_DEV0SPEED
.SetSpeed:
    in      al, dx
    and     al, bh
    or      al, bl
    cmp     bl, 7
    jb      SHORT .OutputNewValue
    or      al, FLG_PDCSCR_UNKNOWN_BIT7 ; Flag for PIO 2 and above?
.OutputNewValue:
    out     dx, al
    ret

.rgbPioModeToPDCspeedValue:
    db      0       ; PIO 0
    db      4       ; PIO 1
    db      7       ; PIO 2


;--------------------------------------------------------------------
; SetPdc20630SpeedForDriveInCX
;   Parameters:
;       CX:     0 for master, 1 for slave drive
;       DS:DI:  Ptr to DPT
;       DX:     Sector Number Register
;   Returns:
;       DX:     Low Cylinder Register
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
SetPdc20630SpeedForDriveInCX:
    inc     dx      ; LOW_CYLINDER_REGISTER
    mov     ah, ~(FLG_PDCLCR_DEV0SPEED_BIT4 | FLG_PDCLCR_DEV0IORDY)
    ror     ah, cl
    in      al, dx
    and     al, ah  ; Clear drive specific bits
    cmp     BYTE [di+DPT_ADVANCED_ATA.bPioMode], 2
    jbe     .ClearBitsOnly
    not     ah
    or      al, ah
.ClearBitsOnly:
    out     dx, al
    ret