;========================================================================
;   FILE: usbkey.asm
;
;   This file contains the code that implements the usb-specific
;   routines to handle key scans.
;========================================================================
;BTH v1.68
;
;major modifications to handle MM and power key reporting
;
;


USB_NO_REPORT:      equ 0
USB_REPORT_ERROR:   equ 1
USB_REPORT_KEY:     equ 2


;========================================================================
; Send_Keyboard2_Report sends a power or MM key report out on endpoint 2
;========================================================================
Send_Keyboard2_Report:
	mov		A, [usb_power_idle_period_ctr]          ; if idle_period is zero, then we only send
	cmp		A, 0									; reports on change
	jz		.mm										; so skip reset
    dec     A
    mov     [usb_power_idle_period_ctr],A			;  else decrement idle period
    jnz     .mm										;  if idle period  expired
    mov     A,[usb_power_idle_period]				;  reset idle period
    mov     [usb_power_idle_period_ctr],A
	mov		A,TX_POWER_MASK							;  set flag indicating transmission required
	or		[usb_tx_flags],A
.mm:
	mov		A, [usb_mm_idle_period_ctr]				; if idle_period is zero, then we only send
	cmp		A, 0									; reports on change
	jz		.xmit									; so skip rest
	dec     A
	mov     [usb_mm_idle_period_ctr],A				;  else decrement idle period
	jnz     .xmit									;  if idle period  expired
	mov     A,[usb_mm_idle_period]					;  reset idle period
	mov     [usb_mm_idle_period_ctr],A
	mov		A,TX_MM_MASK							;  set flag indicating transmit required
	or		[usb_tx_flags],A
.xmit:
    mov		A,[KB_PROTOCOL]
    cmp		A,BOOT_PROTOCOL
    jz		.exit									;don't report  in boot mode
    mov     A,[usb_current_state]					;don't report  if error situation
    cmp     A,USB_REPORT_ERROR
    jz      .exit
	iord	EP_A2_Mode								; are we currently transmitting a report?
	and		A, USB_MODE_MASK
	cmp		A, ACKIN
	jz		.exit									; yes, then exit 
	mov		A,[usb_tx_flags]						; if power, sleep, or wake keys
	AND		A,(TX_POWER_MASK | TX_MM_MASK)
	jz		.exit
	AND		A,TX_POWER_MASK
    jz		.mm1									;
 	mov		A,~TX_POWER_MASK
	and		[usb_tx_flags],A
	mov		A,EndpointA2
	call	Copy_power_buffer
	iord	EP_A2_Counter		
	and		A, DATATOGGLE							; keep data toggle setting
	or		A, POWER_REPORT_LEN						; packet size
	jmp		.send
.mm1:
 	mov		A,~TX_MM_MASK
	and		[usb_tx_flags],A
	mov		A,EndpointA2
	call	Copy_MM_buffer
	iord	EP_A2_Counter		
	and		A, DATATOGGLE						; keep data toggle setting
	or		A, MM_REPORT_LEN					; packet size
.send:
	iowr	EP_A2_Counter
	mov	A, ACKIN								; enable packet transmission 
	iowr	EP_A2_Mode
.exit:
	ret


;========================================================================
; Send keyboard report to host
;========================================================================
Send_Keyboard_Report:
    mov     A,[usb_tx_flags]
	AND		A,TX_KBD_MASK
	cmp		A,0								; if nothing to report 
    jz		.idle							; check idle status
    
    cmp		A,USB_REPORT_ERROR				; else if we've got to send an error report
    jnz		.send

    cmp		A,[last_key_report]				; and the last one sent was not an error
    jnz		.send							; we can send this one too

.idle:										; else check idle status 
	mov		A, [kbd_idle_period_ctr]		; if idle_period is zero, then we only send
	cmp		A, 0							; reports on change
	jz		.exit							; exit task

    dec     A
    mov     [kbd_idle_period_ctr],A			; decrement idle period

    jnz     .exit							; and exit if idle period not expired
      
    mov      A,[last_key_report]			; otherwize get type of last report


.send:										;ok, we're REALLY  going to send a new report
 	push	A

	iord	EP_A1_Mode						; are we currently transmitting a report?
	and		A, USB_MODE_MASK
	cmp		A, ACKIN
    pop		A								; pop current request into A
	jz		.out           					; yes, then exit (so we don't mess up
											; the current transmission)
											; 
    mov		[last_key_report],A
	mov		A,~TX_KBD_MASK
    and     [usb_tx_flags],A
	mov		A,KBBuffer
	call	Copy_report_buffer				; copy report buffer 
	call	Enable_EP1_Transmission			; enable EP1 transmission
.out: 
    mov		A,[kbd_idle_period]
    mov		[kbd_idle_period_ctr],A			;reset idle period
.exit:
	ret



;========================================================================
; Copy report_buffer copies key buffer to endpoint buffer pointed to by contents of A
;
; A points to either EP0 buffer (for getreport function)
;   or EP1 (for normal key reporting)
;========================================================================
Copy_report_buffer:
	push	X
	mov		X, 7                            ;count 8 of the darn things
	add		A,7								;advance base address
copy_report_buffer_loop:
	push	X								;save count
	push	A								;push buffer base address
    mov     A,[last_key_report]             
    cmp     A,USB_REPORT_ERROR
    jz      .error
 	mov		A, [X + usb_report_buffer]      ;assume we're sending a key stroke
    jmp     .next 
.error:                          
    mov     A,X
    index   key_error_buffer                ;else get error code byte
.next:
	pop		X								;pop buffer base into X
	mov		[X], A							;put key code into ep buffer
	mov		A,X								;put buffer base address back into A
	dec		A								;decrement buffer address
	pop		X								;get back index
	dec		X
	jnc		copy_report_buffer_loop         ;do next one

	pop		X

	ret
;========================================================================
; Copy_power_buffer copies  power buffer to endpoint buffer pointed to by contents of A
;
; A points to either EP0 buffer (for getreport function)
;   or EP1 (for normal key reporting)
;========================================================================
Copy_power_buffer:
	push	X									;save X
	mov		X,A									;get index to ep buffer
	mov		A,POWER_REPORT_ID					; set report ID 
	mov		[X],A
	mov		A,[usb_power_keys]					; get power keys
  	mov		[X+1],A
	pop		X									;restore X
	ret
;========================================================================
; Copy_MM_buffer copies  MM buffer to endpoint buffer pointed to by contents of A
;
; A points to either EP0 buffer (for getreport function)
;   or EP1 (for normal key reporting)
;========================================================================
Copy_MM_buffer:
	push	X
	mov		X,A
	mov		A,MM_REPORT_ID		 				; set report ID 
	mov		[X],A
	mov		A,[usb_mm_keys]						; get bit field
  	mov		[X+1],A
	mov		A,[usb_mm_keys+1]					; get bit field
  	mov		[X+2],A
	pop		X
	ret

XPAGEOFF	
key_error_buffer:
    db      00,00,01,01,01,01,01,01
XPAGEON	

;========================================================================
; Enable transmission from EP1 FIFO
;========================================================================
Enable_EP1_Transmission:
	push	A								; save accumulator on stack
	iord	EP_A1_Counter              
      and	A, DATATOGGLE					; keep data toggle setting
	or		A, 8h                           ; packet size
	iowr	EP_A1_Counter

	mov		A, ACKIN						; enable packet transmission 
	iowr	EP_A1_Mode

	pop		A                               ; restore accumulator
	ret										; return
	
;========================================================================
; FUNCTION:usb_scan_keys
;
;   This is the main entry point for the start of key scanning.
;   This function calls the key scanner, which will generate calls to
;   usbkey_putkey from the internal scanning loop of the key scanner.
;
;
;
;========================================================================
usbkey_scan_keys:
    call    ksc_scan_keys                           ; scan the keys
    jc      .send_error                             ; phantom situation,send error to host
    
	mov     A, [usb_key_count]                      ; are there more than 6 keys pressed?
	cmp     A, 7
	jnc    .send_error                              ; yes, then send error to host
	
    mov     A,0                                     ; no errors, clear the error byte
    mov     [usb_current_state],A                   ; and return
    jmp     .exit