; Copyright 2009 Castle Technology Ltd
;
; Licensed under the Apache License, Version 2.0 (the "License");
; you may not use this file except in compliance with the License.
; You may obtain a copy of the License at
;
; http://www.apache.org/licenses/LICENSE-2.0
;
; Unless required by applicable law or agreed to in writing, software
; distributed under the License is distributed on an "AS IS" BASIS,
; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; See the License for the specific language governing permissions and
; limitations under the License.
;
; This is currently set up to provide only 1 serial port - UART3
EXPORT HAL_UARTPorts
EXPORT HAL_UARTStartUp
EXPORT HAL_UARTShutdown
EXPORT HAL_UARTFeatures
EXPORT HAL_UARTReceiveByte
EXPORT HAL_UARTTransmitByte
EXPORT HAL_UARTLineStatus
EXPORT HAL_UARTInterruptEnable
EXPORT HAL_UARTRate
EXPORT HAL_UARTFormat
EXPORT HAL_UARTFIFOSize
EXPORT HAL_UARTFIFOClear
EXPORT HAL_UARTFIFOEnable
EXPORT HAL_UARTFIFOThreshold
EXPORT HAL_UARTInterruptID
EXPORT HAL_UARTBreak
EXPORT HAL_UARTModemControl
EXPORT HAL_UARTModemStatus
EXPORT HAL_UARTDevice
GET Hdr:ListOpts
GET Hdr:Macros
GET Hdr:System
GET Hdr:Machine.<Machine>
GET Hdr:ImageSize.<ImageSize>
GET Hdr:Proc
GET Hdr:OSEntries
GET hdr.omap3530
GET hdr.StaticWS
GET hdr.UART
; Put base address into the a1, given port number in a1
MACRO
$label BaseAddr
LDR a1, L4_UART3_Log
MEND
AREA |Asm$$Code|, CODE, READONLY, PIC
; int Ports(void)
;
; Return array of UART port physical addresses.
;
HAL_UARTPorts
MOV a1, #1
MOV pc, lr
; void StartUp(int port)
;
HAL_UARTStartUp
BaseAddr
MOV a2, #0
STRB a2, [a1, #UART_IER]
STRB a2, [a1, #UART_FCR]
STRB a2, UARTFCRSoftCopy
MOV a2, #OUT2
STRB a2, [a1, #UART_MCR]
MOV a2, #WLS_8
STRB a2, [a1, #UART_LCR]
MOV pc, lr
; void Shutdown(int port)
;
HAL_UARTShutdown
BaseAddr
MOV a2, #0
STRB a2, [a1, #UART_IER]
STRB a2, [a1, #UART_FCR]
STRB a2, [a1, #UART_MCR]
MOV pc, lr
; int Features(int port)
;
; Bit 0: FIFOs available
; Bit 1: DMA available
; Bit 2: Modem lines available
;
HAL_UARTFeatures
MOV a1, #2_101
MOV pc, lr
; int ReceiveByte(int port, int *status)
;
; Returns the next byte from the FIFO (if enabled) or the holding register.
; If status is non-NULL, the line status associated with the byte is
; read (see LineStatus). The return value is only meaningful if a
; received byte is available (bit 0 of *status will be set).
;
HAL_UARTReceiveByte
BaseAddr
TEQ a2, #0
LDRNEB a3, [a1, #UART_LSR] ; Read int state if returning status
LDRB a1, [a1, #UART_RBR]
STRNE a3, [a2]
MOV pc, lr
; void TransmitByte(int port, int byte)
;
HAL_UARTTransmitByte
BaseAddr
STRB a2, [a1, #UART_THR]
MOV pc, lr
; int LineStatus(int port)
;
; Bit 0: Receiver Data Ready
; Bit 1: Overrun Error
; Bit 2: Parity Error
; Bit 3: Framing Error
; Bit 4: Break Error
; Bit 5: Transmitter Holding Register Empty
; Bit 6: Transmitter Empty (including FIFO)
; Bit 7: FIFO contains a Parity, Framing or Break error
;
; Parity, Framing and Break errors are associated with each byte received.
; Whether the values reported here are associated with the last byte
; read using ReceiveByte or with the next byte to be read is undefined.
; You should request the status using ReceiveByte to ensure accurate
; identification of bytes with errors.
;
; Error bits are cleared whenever status is read, using either LineStatus
; or ReceiveByte with status non-NULL.
;
HAL_UARTLineStatus
BaseAddr
LDRB a1, [a1, #UART_LSR]
MOV pc, lr
; int InterruptEnable(int port, int eor, int mask)
;
; Enables interrupts. Bits are:
;
; Bit 0: Received Data Available (and Character Timeout)
; Bit 1: Transmitter Holding Register Empty
; Bit 2: Received Line Status
; Bit 3: Modem Status
;
; Returns previous state.
;
HAL_UARTInterruptEnable
BaseAddr
PHPSEI ip, a4
LDRB a4, [a1, #UART_IER]
AND a3, a4, a3
EOR a3, a2, a3
STRB a3, [a1, #UART_IER]
PLP ip
MOV a1, a4
MOV pc, lr
; int Rate(int port, int baud16)
;
; Sets the rate, in units of 1/16 of a baud. Returns the previous rate.
; Use -1 to read.
;
HAL_UARTRate
Entry "v1,v3"
BaseAddr
PHPSEI ip, a4
LDRB v3, [a1, #UART_LCR]
ORR a4, v3, #DLAB ; Access divisor latch registers
STRB a4, [a1, #UART_LCR]
LDRB a3, [a1, #UART_DLL] ; Read the current baud rate
LDRB a4, [a1, #UART_DLM]
LDR v1, =UARTCLK
ADD a4, a3, a4, LSL#8
DivRem a3, v1, a4, lr ; a3 now contains baud rate * 16
CMP v1, a4, LSR#1 ; If the remainder is greater than 1/2
ADDGE a3, a3, #1 ; the divisor, round up
CMN a2, #1 ; Don't write if we're reading!
BEQ %FT10
; We need to program 48MHz / (16 * baud rate)
LDR v1, =UARTCLK ; This was corrupted by the above DIVREM
DivRem a4, v1, a2, lr
CMP v1, a2, LSR#1 ; If the remainder is greater than 1/2
ADDGE a4, a4, #1 ; the divisor, round up
STRB a4, [a1, #UART_DLL]
MOV a4, a4, LSR#8
STRB a4, [a1, #UART_DLM]
10 STRB v3, [a1, #UART_LCR] ; Turn off divisor latch access
MOV a1, a3 ; Return previous state
PLP ip
EXIT
; int Format(int port, int format)
;
; Bits 0-1: Bits per word 0=>5, 1=>6, 2=>7, 3=>8
; Bit 2: Stop length 0=>1, 1=>2 (1.5 if 5 bits)
; Bit 3: Parity enabled
; Bits 4-5: Parity: 0 => Odd (or disabled)
; 1 => Even
; 2 => Mark (parity bit = 1)
; 3 => Space (parity bit = 0)
;
; Returns previous format. -1 to read.
;
HAL_UARTFormatMask * SPA+EPS+PEN+STP+WLS
HAL_UARTFormat
BaseAddr
PHPSEI ip, a3
LDRB a3, [a1, #UART_LCR]
CMP a2, #-1
AND a4, a3, #HAL_UARTFormatMask ; a4 = relevant bits of current LCR
BIC a3, a3, #HAL_UARTFormatMask ; a3 = other bits of current LCR
ANDNE a2, a2, #HAL_UARTFormatMask ; a2 = relevant bits on entry
ORRNE a2, a2, a3
STRNEB a2, [a1, #UART_LCR]
PLP ip
MOV a1, a4
MOV pc, lr
; void FIFOSize(int port, int *rx, int *tx)
;
; Returns the size of the RX and TX FIFOs. Either parameter may be NULL.
; Note that the size of the TX FIFO is the total amount of data that can
; be sent immediately when the Transmitter Holding Register Empty
; status holds. (So an unusual UART that had a transmit threshold
; should return total FIFO size minus threshold).
;
HAL_UARTFIFOSize
BaseAddr
MOV a1, #64
TEQ a2, #0
STRNE a1, [a2]
TEQ a3, #0
STRNE a1, [a3]
MOV pc, lr
; void FIFOClear(int port, int flags)
;
; Clears the input FIFO (if bit 0 set) and the output FIFO (if bit 1 set).
;
HAL_UARTFIFOClear
BaseAddr
AND a2, a2, #2_11
PHPSEI ip, a3
LDRB a3, UARTFCRSoftCopy
ORR a3, a3, a2, LSL #1
STRB a3, [a1, #UART_FCR]
PLP ip
MOV pc, lr
; int FIFOEnable(int port, int enable)
;
; Enables or disables the RX and TX FIFOs: 0 => disable, 1 => enable
; -1 => read status. Returns previous status.
;
HAL_UARTFIFOEnable
BaseAddr
PHPSEI ip, a3
LDRB a3, UARTFCRSoftCopy
ASSERT FIFOEN=1
AND a4, a3, #FIFOEN
CMP a2, #-1
BEQ %FT10
CMP a2, #0
BICEQ a3, a3, #FIFOEN
ORRNE a3, a3, #FIFOEN
STRB a3, [a1, #UART_FCR]
STRB a3, UARTFCRSoftCopy
10 MOV a1, a4
PLP ip
MOV pc, lr
; int FIFOThreshold(int port, int threshold)
;
; Sets the receive threshold level for the FIFO RX interrupt. For OMAP3530
; this is 8, 16, 56 or 60 bytes. Returns previous value. -1 to read.
;
HAL_UARTFIFOThreshold
BaseAddr
PHPSEI ip, a3
LDRB a3, UARTFCRSoftCopy
ANDS a4, a3, #FIFOTHR
BIC a3, a3, #FIFOTHR
ASSERT FIFOTHR_8 = 0
MOVEQ a4, #8
BEQ %FT10
CMP a4, #FIFOTHR_56
MOVLO a4, #16
MOVEQ a4, #56
MOVHI a4, #60
10 CMP a2, #-1
BEQ %FT20
CMP a2, #16
ADDGE a3, a3, #FIFOTHR_16
CMP a2, #56
ADDGE a3, a3, #FIFOTHR_56-FIFOTHR_16
CMP a2, #60
ADDGE a3, a3, #FIFOTHR_60-FIFOTHR_56
STRB a3, [a1, #UART_FCR]
STRB a3, UARTFCRSoftCopy
20 MOV a1, a4
PLP ip
MOV pc, lr
; int InterruptID(int port)
;
; Returns the highest priority interrupt currently asserted. In order
; of priority:
;
; 3 => Receiver Line Status (Cleared by ReceiveByte)
; 2 => Received Data Available (Cleared by reading enough data)
; 6 => Character Timeout (received data waiting)
; 1 => Transmitter Holding Register Empty (Cleared by this call)
; 0 => Modem Status (Cleared by ModemStatus)
; -1 => No Interrupt
;
; The Modem Status interrupt occurs when the CTS, DSR or DCD inputs
; change, or when RI goes from high to low (ie bits 0 to 3 of ModemStatus
; are set).
;
HAL_UARTInterruptID
BaseAddr
LDRB a4, [a1, #UART_IIR]
TST a4, #1
MOVEQ a1, a4, LSR #1
ANDEQ a1, a1, #7
MOVNE a1, #-1
MOV pc, lr
; int Break(int port, int enable)
;
; Activates (1) or deactivates (0) a break condition. -1 to read,
; returns previous state.
;
HAL_UARTBreak
BaseAddr
PHPSEI ip, a3
LDRB a3, [a1, #UART_LCR]
ANDS a4, a3, #BCR
MOVNE a4, #1
CMP a2, #-1
BEQ %FT10
CMP a2, #0
BICEQ a3, a3, #BCR
ORRNE a3, a3, #BCR
STRB a3, [a1, #UART_LCR]
10 MOV a1, a4
PLP ip
MOV pc, lr
; int ModemControl(int port, int eor, int mask)
;
; Modifies the modem control outputs.
;
; Bit 0: DTR
; Bit 1: RTS
;
; Note that these are logical outputs, although the physical pins may be
; inverted. So 1 indicates a request to send. Returns previous state.
; Needs to clear the modem interrupt status.
;
HAL_UARTModemControl
BaseAddr
PHPSEI ip, a3
LDRB a3, [a1, #UART_MCR]
CMP a2, #-1
AND a4, a3, #DTR+RTS ; a4 = relevant bits of current MCR
BIC a3, a3, #DTR+RTS ; a3 = other bits of current MCR
ANDNE a2, a2, #DTR+RTS ; a2 = relevant bits on entry
ORRNE a2, a2, a3
STRNEB a2, [a1, #UART_MCR]
PLP ip
MOV a1, a4
MOV pc, lr
; int ModemStatus(int port)
;
; Reads the modem status inputs.
;
; Bit 0: CTS changed since last call
; Bit 1: DSR changed since last call
; Bit 2: RI changed from high to low since last call
; Bit 3: DCD changed since last call
; Bit 4: CTS
; Bit 5: DSR
; Bit 6: RI
; Bit 7: DCD
;
; Note that these are logical inputs, although the physical pins may be
; inverted. So 1 indicates a Clear To Send condition. This must also clear
; the modem interrupt status.
;
HAL_UARTModemStatus
BaseAddr
LDRB a1, [a1, #UART_MSR]
MOV pc, lr
; int Device(int port)
;
; Return the device number allocated to the UART port
;
HAL_UARTDevice
MOV a1, #74
MOV pc, lr
END