; 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.
;
GET Hdr:ListOpts
GET Hdr:Macros
GET Hdr:System
GET Hdr:Machine.<Machine>
GET Hdr:ImageSize.<ImageSize>
$GetIO
GET Hdr:OSEntries
GET Hdr:HALEntries
GET Hdr:HALDevice
GET Hdr:RTCDevice
GET hdr.omap3530
GET hdr.StaticWS
GET hdr.Timers
GET hdr.PRCM
AREA |Asm$$Code|, CODE, READONLY, PIC
EXPORT RTC_Init
IMPORT TPSRead
IMPORT TPSWrite
; Note - debug stuff won't work since we don't get passed a HAL workspace pointer!
; IMPORT DebugHALPrint
; IMPORT DebugHALPrintReg
; IMPORT DebugMemDump
; IMPORT DebugHALPrintByte
; TWL/TPS RTC IIC address
TPSRTC_IIC * &4b
; Some RTC registers
SECONDS_REG * &1C
RTC_CTRL_REG * &29
RTC_STATUS_REG * &2a
MACRO
CallOS $entry, $tailcall
ASSERT $entry <= HighestOSEntry
[ "$tailcall"=""
MOV lr, pc
|
[ "$tailcall"<>"tailcall"
! 0, "Unrecognised parameter to CallOS"
]
]
LDR pc, OSentries + 4*$entry
MEND
RTC_Init
; Just register our HAL Device with the OS
MOV a1, #0
ADR a2, RTCDevice
CallOS OS_AddDevice, tailcall
RTCDevice
DCW HALDeviceType_SysPeri + HALDeviceSysPeri_RTC
DCW HALDeviceID_RTC_TPS65950
DCD HALDeviceBus_Ser + HALDeviceSerBus_IIC
DCD 0 ; API version
DCD RTCDesc
DCD 0 ; Address - N/A
% 12 ; Reserved
DCD RTCActivate
DCD RTCDeactivate
DCD RTCReset
DCD RTCSleep
DCD -1 ; Interrupt N/A
DCD 0
% 8
DCB RTCTimeFormat_BCD
DCB RTCFormatFlags_BCD_1BasedDay+RTCFormatFlags_BCD_1BasedMonth+RTCFormatFlags_BCD_YearLOIsGood ; todo - add RTCFormatFlags_BCD_NeedsYearHelp once NVRAM is implemented
% 2
DCD RTCReadTime
DCD RTCWriteTime
RTCDesc
DCB "TPS65950-compatible real-time clock",0
ALIGN
RTCActivate
MOV a1, #1
RTCDeactivate
RTCReset
MOV pc, lr
RTCSleep
MOV a1, #0 ; Previously at full power
MOV pc, lr
RTCReadTime
; In:
; a1 = HALDevice ptr
; a2 = RTCTimeStruct ptr
; a3 = IICOp func ptr
; a4 = kernel workspace ptr
; Out:
; a1 = return code
; RTCTimeStruct updated
Push "v1-v3,lr"
MOV v1, a3
MOV v2, a4
MOV v3, a2
; Reading the time safely involves several transfers:
; 1. Read RTC_STATUS_REG. If bit 1 is clear, the RTC is stopped and we can just assume its contents are invalid.
; 2. Set RTC_CTRL_REG=&41 (RTC running, GET_TIME set, 24hr mode). GET_TIME will read the time from the RTC circuitry and latch it into the time registers (the regular time registers, NOT the alarm ones as stated by the manual!)
; 3. Read the time regs to read latched time.
; There's no need to clear GET_TIME either, as it is cleared automatically by the HW.
MOV a1, #TPSRTC_IIC*2
SUB sp, sp, #4 ; temp small buffer on stack
MOV a3, #1
MOV a4, #RTC_STATUS_REG
MOV a2, sp
BL TPSRead
CMP a1, #ECOMPLETED
LDRB ip, [a2]
MOV a1, #RTCRetCode_InvalidTime
MOVNE a1, #RTCRetCode_Error
EOR ip, ip, #2
TSTEQ ip, #2
ADDNE sp, sp, #4
Pull "v1-v3,pc", NE
MOV ip, #&41
STR ip, [a2]
MOV a1, #TPSRTC_IIC*2
MOV a4, #RTC_CTRL_REG
BL TPSWrite
CMP a1, #ECOMPLETED
MOVNE a1, #RTCRetCode_Error
ADD sp, sp, #4
Pull "v1-v3,pc", NE
MOV a1, #TPSRTC_IIC*2
; We can read the time directly into the RTCTimeStruct buffer
ASSERT RTCTimeStruct_BCD_Minutes=RTCTimeStruct_BCD_Seconds+1
ASSERT RTCTimeStruct_BCD_Hours=RTCTimeStruct_BCD_Seconds+2
ASSERT RTCTimeStruct_BCD_DayOfMonth=RTCTimeStruct_BCD_Seconds+3
ASSERT RTCTimeStruct_BCD_Month=RTCTimeStruct_BCD_Seconds+4
ASSERT RTCTimeStruct_BCD_YearLO=RTCTimeStruct_BCD_Seconds+5
ADD a2, v3, #RTCTimeStruct_BCD_Seconds
MOV a3, #6
MOV a4, #SECONDS_REG
BL TPSRead
CMP a1, #ECOMPLETED
MOVNE a1, #RTCRetCode_Error
Pull "v1-v3,pc", NE
ASSERT ECOMPLETED = 0
STRB a1, [v3, #RTCTimeStruct_BCD_Centiseconds] ; No centisecond time
; Construct a fakey YearHI by looking at YearLO
; Anything 70 or above is considered 1970+, else 2000+
; This should work OK, since RISC OS clamps the time to 1970 for unix compatability (or it does on boot, at least)
LDRB a2, [v3, #RTCTimeStruct_BCD_YearLO]
CMP a2, #&70
MOVGE a3, #&19
MOVLT a3, #&20
STRB a3, [v3, #RTCTimeStruct_BCD_YearHI]
ASSERT RTCRetCode_OK = 0
Pull "v1-v3,pc"
RTCWriteTime
; In:
; a1 = HALDevice ptr
; a2 = RTCTimeStruct ptr
; a3 = IICOp func ptr
; a4 = kernel workspace ptr
; Out:
; a1 = return code
Push "v1-v3,lr"
MOV v1, a3
MOV v2, a4
MOV v3, a2
; Writing the time safely involves several transfers:
; 1. Write 0 to RTC_CTRL_REG to stop the clock (just in case there are any issues with the clock updating while it's being written to)
; 2. Write the new time values
; 3. Write 1 to RTC_CTRL_REG to start the clock
MOV a1, #TPSRTC_IIC*2
MOV ip, #0
STR ip, [sp,#-4]! ; temp small buffer on stack
MOV a3, #1
MOV a4, #RTC_CTRL_REG
MOV a2, sp
BL TPSWrite
CMP a1, #ECOMPLETED
MOVNE a1, #RTCRetCode_Error
ADDNE sp, sp, #4
Pull "v1-v3,pc", NE
MOV a1, #TPSRTC_IIC*2
; We can write the time directly from the RTCTimeStruct buffer
ASSERT RTCTimeStruct_BCD_Minutes=RTCTimeStruct_BCD_Seconds+1
ASSERT RTCTimeStruct_BCD_Hours=RTCTimeStruct_BCD_Seconds+2
ASSERT RTCTimeStruct_BCD_DayOfMonth=RTCTimeStruct_BCD_Seconds+3
ASSERT RTCTimeStruct_BCD_Month=RTCTimeStruct_BCD_Seconds+4
ASSERT RTCTimeStruct_BCD_YearLO=RTCTimeStruct_BCD_Seconds+5
ADD a2, v3, #RTCTimeStruct_BCD_Seconds
MOV a3, #6
MOV a4, #SECONDS_REG
; Sometimes we don't write the time, so skip those bytes if necessary
LDRB ip, [a2]
CMP ip, #255
ADDEQ a2, a2, #3
SUBEQ a3, a3, #3
ADDEQ a4, a4, #3
; Sometimes we don't write the date either
LDRB ip, [v3, #RTCTimeStruct_BCD_DayOfMonth]
CMP ip, #255
SUBEQS a3, a3, #3
BEQ %FT01 ; Nothing left to write!
BL TPSWrite
CMP a1, #ECOMPLETED
MOVNE a1, #RTCRetCode_Error
ADDNE sp, sp, #4
Pull "v1-v3,pc", NE
01
MOV a3, #1
STR a3, [sp]
MOV a2, sp
MOV a4, #RTC_CTRL_REG
MOV a1, #TPSRTC_IIC*2
BL TPSWrite
CMP a1, #ECOMPLETED
ASSERT RTCRetCode_OK = ECOMPLETED
MOVNE a1, #RTCRetCode_Error
ADD sp, sp, #4
Pull "v1-v3,pc"
EXPORT ReadTimeForNVRAM
IMPORT IIC_DoOp_Poll
; int ReadTimeForNVRAM (struct rtctime*)
; Reads BCD time into given rtctime struct
; Returns zero on success, non-zero on failure
ReadTimeForNVRAM
MOV a2, a1
ADRL a1, RTCDevice
LDR a3, HALInitialised
CMP a3, #0
ADREQL a3, IIC_DoOp_Poll
LDRNE a3, OSentries + 4 * OS_IICOpV
B RTCReadTime
END