$Revision: 425 $
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; PCI32.INC ;;
;; ;;
;; 32 bit PCI driver code ;;
;; ;;
;; Version 0.2 December 21st, 2002 ;;
;; ;;
;; Author: Victor Prodan, victorprodan@yahoo.com ;;
;; Credits: ;;
;; Ralf Brown ;;
;; Mike Hibbett, mikeh@oceanfree.net ;;
;; ;;
;; See file COPYING for details ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;***************************************************************************
; Function
; pci_api:
;
; Description
; entry point for system PCI calls
;***************************************************************************
align 4
pci_api:
cmp [pci_access_enabled],1
jne no_pci_access_for_applications
or al,al
jnz pci_fn_1
; PCI function 0: get pci version (AH.AL)
movzx eax,word [0x2F0000+0x9022]
ret
pci_fn_1:
cmp al,1
jnz pci_fn_2
; PCI function 1: get last bus in AL
mov al,[0x2F0000+0x9021]
ret
pci_fn_2:
cmp al,2
jne pci_fn_3
; PCI function 2: get pci access mechanism
mov al,[0x2F0000+0x9020]
ret
pci_fn_3:
cmp al,4
jz pci_read_reg ;byte
cmp al,5
jz pci_read_reg ;word
cmp al,6
jz pci_read_reg ;dword
cmp al,8
jz pci_write_reg ;byte
cmp al,9
jz pci_write_reg ;word
cmp al,10
jz pci_write_reg ;dword
no_pci_access_for_applications:
mov eax,-1
ret
;***************************************************************************
; Function
; pci_make_config_cmd
;
; Description
; creates a command dword for use with the PCI bus
; bus # in ah
; device+func in bh (dddddfff)
; register in bl
;
; command dword returned in eax ( 10000000 bbbbbbbb dddddfff rrrrrr00 )
;***************************************************************************
align 4
pci_make_config_cmd:
shl eax,8 ; move bus to bits 16-23
mov ax,bx ; combine all
and eax,0xffffff
or eax,0x80000000
ret
;***************************************************************************
; Function
; pci_read_reg:
;
; Description
; read a register from the PCI config space into EAX/AX/AL
; IN: ah=bus,device+func=bh,register address=bl
; number of bytes to read (1,2,4) coded into AL, bits 0-1
;***************************************************************************
align 4
pci_read_reg:
cmp byte [0x2F0000+0x9020],2 ;what mechanism will we use?
je pci_read_reg_2
; mechanism 1
push esi ; save register size into ESI
mov esi,eax
and esi,3
call pci_make_config_cmd
mov ebx,eax
; get current state
mov dx,0xcf8
in eax, dx
push eax
; set up addressing to config data
mov eax,ebx
and al,0xfc ; make address dword-aligned
out dx,eax
; get requested DWORD of config data
mov dl,0xfc
and bl,3
or dl,bl ; add to port address first 2 bits of register address
or esi,esi
jz pci_read_byte1
cmp esi,1
jz pci_read_word1
cmp esi,2
jz pci_read_dword1
jmp pci_fin_read1
pci_read_byte1:
in al,dx
jmp pci_fin_read1
pci_read_word1:
in ax,dx
jmp pci_fin_read1
pci_read_dword1:
in eax,dx
jmp pci_fin_read1
pci_fin_read1:
; restore configuration control
xchg eax,[esp]
mov dx,0xcf8
out dx,eax
pop eax
pop esi
ret
pci_read_reg_2:
test bh,128 ;mech#2 only supports 16 devices per bus
jnz pci_read_reg_err
push esi ; save register size into ESI
mov esi,eax
and esi,3
push eax
;store current state of config space
mov dx,0xcf8
in al,dx
mov ah,al
mov dl,0xfa
in al,dx
xchg eax,[esp]
; out 0xcfa,bus
mov al,ah
out dx,al
; out 0xcf8,0x80
mov dl,0xf8
mov al,0x80
out dx,al
; compute addr
shr bh,3 ; func is ignored in mechanism 2
or bh,0xc0
mov dx,bx
or esi,esi
jz pci_read_byte2
cmp esi,1
jz pci_read_word2
cmp esi,2
jz pci_read_dword2
jmp pci_fin_read2
pci_read_byte2:
in al,dx
jmp pci_fin_read2
pci_read_word2:
in ax,dx
jmp pci_fin_read2
pci_read_dword2:
in eax,dx
; jmp pci_fin_read2
pci_fin_read2:
; restore configuration space
xchg eax,[esp]
mov dx,0xcfa
out dx,al
mov dl,0xf8
mov al,ah
out dx,al
pop eax
pop esi
ret
pci_read_reg_err:
xor eax,eax
dec eax
ret
;***************************************************************************
; Function
; pci_write_reg:
;
; Description
; write a register from ECX/CX/CL into the PCI config space
; IN: ah=bus,device+func=bh,register address (dword aligned)=bl,
; value to write in ecx
; number of bytes to write (1,2,4) coded into AL, bits 0-1
;***************************************************************************
align 4
pci_write_reg:
cmp byte [0x2F0000+0x9020],2 ;what mechanism will we use?
je pci_write_reg_2
; mechanism 1
push esi ; save register size into ESI
mov esi,eax
and esi,3
call pci_make_config_cmd
mov ebx,eax
; get current state into ecx
mov dx,0xcf8
in eax, dx
push eax
; set up addressing to config data
mov eax,ebx
and al,0xfc ; make address dword-aligned
out dx,eax
; write DWORD of config data
mov dl,0xfc
and bl,3
or dl,bl
mov eax,ecx
or esi,esi
jz pci_write_byte1
cmp esi,1
jz pci_write_word1
cmp esi,2
jz pci_write_dword1
jmp pci_fin_write1
pci_write_byte1:
out dx,al
jmp pci_fin_write1
pci_write_word1:
out dx,ax
jmp pci_fin_write1
pci_write_dword1:
out dx,eax
jmp pci_fin_write1
pci_fin_write1:
; restore configuration control
pop eax
mov dl,0xf8
out dx,eax
xor eax,eax
pop esi
ret
pci_write_reg_2:
test bh,128 ;mech#2 only supports 16 devices per bus
jnz pci_write_reg_err
push esi ; save register size into ESI
mov esi,eax
and esi,3
push eax
;store current state of config space
mov dx,0xcf8
in al,dx
mov ah,al
mov dl,0xfa
in al,dx
xchg eax,[esp]
; out 0xcfa,bus
mov al,ah
out dx,al
; out 0xcf8,0x80
mov dl,0xf8
mov al,0x80
out dx,al
; compute addr
shr bh,3 ; func is ignored in mechanism 2
or bh,0xc0
mov dx,bx
; write register
mov eax,ecx
or esi,esi
jz pci_write_byte2
cmp esi,1
jz pci_write_word2
cmp esi,2
jz pci_write_dword2
jmp pci_fin_write2
pci_write_byte2:
out dx,al
jmp pci_fin_write2
pci_write_word2:
out dx,ax
jmp pci_fin_write2
pci_write_dword2:
out dx,eax
jmp pci_fin_write2
pci_fin_write2:
; restore configuration space
pop eax
mov dx,0xcfa
out dx,al
mov dl,0xf8
mov al,ah
out dx,al
xor eax,eax
pop esi
ret
pci_write_reg_err:
xor eax,eax
dec eax
ret