Files
aqhomecontrol/avr/modules/uart_bitbang/main.asm
2024-10-20 23:35:26 +02:00

424 lines
11 KiB
NASM

; ***************************************************************************
; copyright : (C) 2024 by Martin Preuss
; email : martin@libchipcard.de
;
; ***************************************************************************
; * This file is part of the project "AqHome". *
; * Please see toplevel file COPYING of that project for license details. *
; ***************************************************************************
; UART_BitBang_Init
; UART_BitBang_Fini
; UART_BitBang_Run
; UART_BitBang_SendPacket
; UART_BitBang_GetNextReceivedPacket
; UART_BitBang_ReleaseReceivedPacket
; ***************************************************************************
; data
.dseg
uartBitbangDataBegin:
uartBitbangRecvBuffersUsed: .byte 1
uartBitbangRecvBuffersWritePos: .byte 1
uartBitbangRecvBuffersReadPos: .byte 1
uartBitbangRecvBuffers: .byte COM2_BUFFER_SIZE*UART_BITBANG_BUFFER_NUM
uartBitbangDataEnd:
; ***************************************************************************
; code
.cseg
; ---------------------------------------------------------------------------
; @routine UART_BitBang_Init
;
; @return CFLAG set if okay, clear on error
; @clobbers R16, R17, X, Y
UART_BitBang_Init:
; preset SRAM data area
ldi xh, HIGH(uartBitbangDataBegin)
ldi xl, LOW(uartBitbangDataBegin)
clr r16
ldi r17, (uartBitbangDataEnd-uartBitbangDataBegin)
rcall Utils_FillSram
; setup pins and interrupts
cbi COM_TXD_DATA, COM_TXD_PIN ; disable internal pullup for TXD
cbi COM_TXD_DDR, COM_TXD_PIN ; set TXD port as input
cbi COM_RXD_OUTPUT, COM_RXD_PIN ; disable internal pullup for RXD
cbi COM_RXD_DDR, COM_RXD_PIN ; set RXD port as input
cbi COM_ATTN_OUTPUT, COM_ATTN_PIN ; disable internal pullup for ATTN
cbi COM_ATTN_DDR, COM_ATTN_PIN ; set ATTN port as input
sbi COM_IRQ_ADDR_ATTN, COM_IRQ_BIT_ATTN ; enable pin change irq for ATTN line
in r16, GIMSK ; enable pin change irq PCIE0 or PCIE1
ori r16, (1<<COM_IRQ_GIMSK_ATTN)
out GIMSK, R16
ldi r16, (1<<COM_IRQ_GIFR_ATTN) ; clear pending irq by writing 1 to ATTN bit
out GIFR, r16
sec
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_BitBang_Fini
;
; @return CFLAG set if okay, clear on error
; @clobbers R16, R17, X, Y
UART_BitBang_Fini:
cbi COM_TXD_DDR, COM_TXD_PIN ; set TXD port as input
cbi COM_RXD_DDR, COM_RXD_PIN ; set RXD port as input
cbi COM_ATTN_DDR, COM_ATTN_PIN ; set ATTN port as input
cbi COM_IRQ_ADDR_ATTN, COM_IRQ_BIT_ATTN ; disable pin change irq for ATTN line
in r16, GIMSK ; enable pin change irq PCIE0 or PCIE1
andi r16, ~(1<<COM_IRQ_GIMSK_ATTN)
out GIMSK, R16
ldi r16, (1<<COM_IRQ_GIFR_ATTN) ; clear pending irq by writing 1 to ATTN bit
out GIFR, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_BitBang_Run
;
; @clobbers any
UART_BitBang_Run:
clc
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_BitBang_SendPacket
; Send packet, if line free.
;
; @param X buffer to send
; @return CFLAG: set if okay (packet sent), cleared on error
; @clobbers r22, x (r18, r19, r22)
UART_BitBang_SendPacket:
push r15
in r15, SREG
cli
rcall UART_BitBang_SendPacket_noIrqs
brcc UART_BitBang_SendPacket_retErr
out SREG, r15
pop r15
sec
ret
UART_BitBang_SendPacket_retErr:
out SREG, r15
pop r15
clc
ret
UART_BitBang_SendPacket_noIrqs:
rcall uartBitbang_SendPacket
brcs UART_BitBang_SendPacket_okay
cpi r16, COM2_ERROR_BUSY
breq UART_BitBang_SendPacket_busyError
cpi r16, COM2_ERROR_COLLISION
breq UART_BitBang_SendPacket_collError
; fall-through
UART_BitBang_SendPacket_busyError:
ldi xl, LOW(com2StatsBusyError)
ldi xh, HIGH(com2StatsBusyError)
rjmp UART_BitBang_SendPacket_incCounterRetNc
UART_BitBang_SendPacket_collError:
ldi xl, LOW(com2StatsCollisions)
ldi xh, HIGH(com2StatsCollisions)
UART_BitBang_SendPacket_incCounterRetNc:
rcall Utils_IncrementCounter16 ; (r18, r19, r22)
clc
ret
UART_BitBang_SendPacket_okay:
ldi xl, LOW(com2StatsPacketsOut)
ldi xh, HIGH(com2StatsPacketsOut)
rcall Utils_IncrementCounter16 ; (r18, r19, r22)
sec
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_BitBang_GetNextReceivedPacket
;
; Get next received packet from receiption buffers.
; Call @ref UART_BitBang_ReleaseReceivedPacket to release the packet buffer.
;
; @return CFLAG set if okay (packet received), cleared on error
; @return X pointer to packet received
; @clobbers r16, r17
UART_BitBang_GetNextReceivedPacket:
lds r16, uartBitbangRecvBuffersUsed
tst r16
breq UART_BitBang_GetNextReceivedPacket_retNc ; no buffers in use
lds r16, uartBitbangRecvBuffersReadPos
rcall uartBitbang_BufferPosToX ; get current read buffer to X (R16, R17)
sec
ret
UART_BitBang_GetNextReceivedPacket_retNc:
clc
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_BitBang_ReleaseReceivedPacket
;
; Release first packet in queue from from receiption buffers (i.e. the one returned
; by @ref UART_BitBang_GetNextReceivedPacket)
;
; @clobbers r16, r17, r21
UART_BitBang_ReleaseReceivedPacket:
rjmp uartBitbang_BufferDeallocFront ; (r16, r17, r21)
; @end
; ---------------------------------------------------------------------------
; @routine uartBitbang_ReceivePacket
;
; Receive packet.
;
; @return CFLAG set if okay (packet received), cleared on error
; @clobbers r16, r17, x (r18, r19, r20, r21, r22)
uartBitbang_ReceivePacket:
rcall uartBitbang_BufferAlloc ; (r16, r17, r21)
brcs uartBitbang_ReceivePacket_bufferAvailable
ldi xl, LOW(com2StatsNoBufferError) ; buffer in use, don't release
ldi xh, HIGH(com2StatsNoBufferError) ; just increment error counter
rcall Utils_IncrementCounter16 ; (r18, r19, 22)
clc
ret
uartBitbang_ReceivePacket_bufferAvailable:
push xl
push xh
lds r16, com2Address
ldi r17, (COM2_BUFFER_SIZE-3) ; buffer size minus dst addr, payload len, crc byte
rcall uartBitbang_ReceivePacketIntoBuffer ; r16, r17, r18, X (r19, r20, r21, r22)
pop xh
pop xl
brcc uartBitbang_ReceivePacket_error
rcall com2CheckMessageInBuffer ; (R16, R17, R18, R19, R20, X)
brcc uartBitbang_ReceivePacket_dataError
; everything okay
ldi xl, LOW(com2StatsPacketsIn)
ldi xh, HIGH(com2StatsPacketsIn)
rcall Utils_IncrementCounter16 ; (r18, r19, 22)
sec
ret
uartBitbang_ReceivePacket_error:
cpi r16, COM2_ERROR_NOTFORME
breq uartBitbang_ReceivePacket_notForMe
cpi r16, COM2_ERROR_DATAERROR
breq uartBitbang_ReceivePacket_dataError
;cpi r16, COM2_ERROR_IOERROR
;breq uartBitbang_ReceivePacket_ioError
;rjmp uartBitbang_ReceivePacket_retnc
rjmp uartBitbang_ReceivePacket_ioError ; default to IO ERROR
uartBitbang_ReceivePacket_ioError:
ldi xl, LOW(com2StatsIoError)
ldi xh, HIGH(com2StatsIoError)
rjmp uartBitbang_ReceivePacket_incCounterDeallocNc
uartBitbang_ReceivePacket_dataError:
ldi xl, LOW(com2StatsContentError)
ldi xh, HIGH(com2StatsContentError)
rjmp uartBitbang_ReceivePacket_incCounterDeallocNc
uartBitbang_ReceivePacket_notForMe:
ldi xl, LOW(com2StatsNotForMe)
ldi xh, HIGH(com2StatsNotForMe)
rjmp uartBitbang_ReceivePacket_incCounterDeallocNc
uartBitbang_ReceivePacket_incCounterDeallocNc:
rcall Utils_IncrementCounter16 ; (r18, r19, 22)
uartBitbang_ReceivePacket_deallocRetnc:
rcall uartBitbang_BufferDeallocBack
uartBitbang_ReceivePacket_retnc:
clc
ret
; @end
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Buffer Management
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; ---------------------------------------------------------------------------
; @routine uartBitbang_BufferAlloc
;
; Allocate a transfer buffer.
;
; @return CFLAG set if okay, clear otherwise
; @return X pointer to allocated buffer in SRAM
; @clobbers r16, r17, r21
uartBitbang_BufferAlloc:
COM2_M_BufferAlloc UART_BITBANG_BUFFER_NUM, \
com2MaxRecvBuffersUsed, \
uartBitbangRecvBuffersUsed, \
uartBitbangRecvBuffersWritePos, \
uartBitbang_BufferPosToX
ret
; @end
; ---------------------------------------------------------------------------
; @routine uartBitbang_BufferDeallocBack
;
; Release a transfer buffer at the end of the list by decreasing the write pos.
; This releases the last allocated buffer!
;
; @return CFLAG set if okay, clear otherwise
; @clobbers r16, r17, r21
uartBitbang_BufferDeallocBack:
COM2_M_BufferDeallocBack UART_BITBANG_BUFFER_NUM, uartBitbangRecvBuffersUsed, uartBitbangRecvBuffersWritePos
ret
; @end
; ---------------------------------------------------------------------------
; @routine uartBitbang_BufferDeallocFront
;
; Release a transfer buffer by increasing the read pos.
;
; @return CFLAG set if okay, clear otherwise
; @clobbers r16, r17, r21
uartBitbang_BufferDeallocFront:
COM2_M_BufferDeallocFront UART_BITBANG_BUFFER_NUM, uartBitbangRecvBuffersUsed, uartBitbangRecvBuffersReadPos
ret
; @end
; ---------------------------------------------------------------------------
; @routine uartBitbang_BufferPosToX
;
; Get a pointer to the SRAM position of the given buffer.
; CAVE: Code must correspond to COM2_BUFFER_SIZE!!
;
; @param R16 buffer number (starting with 0)
; @return X pointer to buffer in SRAM
; @clobbers R16, R17
uartBitbang_BufferPosToX:
COM2_M_BufferPosToX uartBitbangRecvBuffers
ret
; @end
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; ISR
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
uartBitbangIsrPcint0:
push r15
in r15, SREG
sbic COM_ATTN_INPUT, COM_ATTN_PIN
rjmp uartBitbangIsrPcint0_end
; low, read packet
push r1
push r16
push r17
push r18
push r19
push r20
push r21
push r22
push xh
push xl
push r15
rcall uartBitbang_ReceivePacket ; (r16, r17, r18, r19, r20, r21, r22, x)
pop r15
lds xl, com2Interrupts
lds xh, com2Interrupts+1
adiw xh:xl, 1
sts com2Interrupts, xl
sts com2Interrupts+1, xh
pop xl
pop xh
pop r22
pop r21
pop r20
pop r19
pop r18
pop r17
pop r16
pop r1
uartBitbangIsrPcint0_end:
out SREG, r15
pop r15
reti
; set routine functions
.equ COMIO_Init = UART_BitBang_Init
.equ COMIO_Fini = UART_BitBang_Fini
.equ COMIO_Run = UART_BitBang_Run
.equ COMIO_SendPacket = UART_BitBang_SendPacket
.equ COMIO_GetNextReceivedPacket = UART_BitBang_GetNextReceivedPacket
.equ COMIO_ReleaseReceivedPacket = UART_BitBang_ReleaseReceivedPacket