/*
 * FreeRTOS Kernel V10.3.1
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://www.FreeRTOS.org
 * http://aws.amazon.com/freertos
 *
 */

/*
 *  Changes from V3.2.3
 *
 + Modified portENTER_SWITCHING_ISR() to allow use with GCC V4.0.1.
 +
 +  Changes from V3.2.4
 +
 + Removed the use of the %0 parameter within the assembler macros and
 +    replaced them with hard coded registers.  This will ensure the
 +    assembler does not select the link register as the temp register as
 +    was occasionally happening previously.
 +
 + The assembler statements are now included in a single asm block rather
 +    than each line having its own asm block.
 +
 +  Changes from V4.5.0
 +
 + Removed the portENTER_SWITCHING_ISR() and portEXIT_SWITCHING_ISR() macros
 +    and replaced them with portYIELD_FROM_ISR() macro.  Application code
 +    should now make use of the portSAVE_CONTEXT() and portRESTORE_CONTEXT()
 +    macros as per the V4.5.1 demo code.
 */

#ifndef PORTMACRO_H
    #define PORTMACRO_H

    #ifdef __cplusplus
        extern "C" {
    #endif

/*-----------------------------------------------------------
 * Port specific definitions.
 *
 * The settings in this file configure FreeRTOS correctly for the
 * given hardware and compiler.
 *
 * These settings should not be altered.
 *-----------------------------------------------------------
 */

/* Type definitions. */
    #define portCHAR          char
    #define portFLOAT         float
    #define portDOUBLE        double
    #define portLONG          long
    #define portSHORT         short
    #define portSTACK_TYPE    uint32_t
    #define portBASE_TYPE     long

    typedef portSTACK_TYPE   StackType_t;
    typedef long             BaseType_t;
    typedef unsigned long    UBaseType_t;

    #if ( configUSE_16_BIT_TICKS == 1 )
        typedef uint16_t     TickType_t;
        #define portMAX_DELAY    ( TickType_t ) 0xffff
    #else
        typedef uint32_t     TickType_t;
        #define portMAX_DELAY    ( TickType_t ) 0xffffffffUL
    #endif
/*-----------------------------------------------------------*/

/* Hardware specifics. */
    #define portSTACK_GROWTH      ( -1 )
    #define portTICK_PERIOD_MS    ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
    #define portBYTE_ALIGNMENT    8
    #define portYIELD()    asm volatile ( "SWI 0" )
    #define portNOP()      asm volatile ( "NOP" )

/*
 * These define the timer to use for generating the tick interrupt.
 * They are put in this file so they can be shared between "port.c"
 * and "portisr.c".
 */
    #define portTIMER_REG_BASE_PTR      AT91C_BASE_TC0
    #define portTIMER_CLK_ENABLE_BIT    AT91C_PS_TC0
    #define portTIMER_AIC_CHANNEL       ( ( uint32_t ) 4 )
/*-----------------------------------------------------------*/

/* Task utilities. */

/*
 * portRESTORE_CONTEXT, portRESTORE_CONTEXT, portENTER_SWITCHING_ISR
 * and portEXIT_SWITCHING_ISR can only be called from ARM mode, but
 * are included here for efficiency.  An attempt to call one from
 * THUMB mode code will result in a compile time error.
 */

    #define portRESTORE_CONTEXT()                                            \
    {                                                                        \
        extern volatile void * volatile pxCurrentTCB;                        \
        extern volatile uint32_t        ulCriticalNesting;                   \
                                                                             \
        /* Set the LR to the task stack. */                                  \
        asm volatile (                                                       \
            "LDR		R0, =pxCurrentTCB								\n\t"\
            "LDR		R0, [R0]										\n\t"\
            "LDR		LR, [R0]										\n\t"\
                                                                             \
            /* The critical nesting depth is the first item on the stack. */ \
            /* Load it into the ulCriticalNesting variable. */               \
            "LDR		R0, =ulCriticalNesting							\n\t"\
            "LDMFD	LR!, {R1}											\n\t"\
            "STR		R1, [R0]										\n\t"\
                                                                             \
            /* Get the SPSR from the stack. */                               \
            "LDMFD	LR!, {R0}											\n\t"\
            "MSR		SPSR, R0										\n\t"\
                                                                             \
            /* Restore all system mode registers for the task. */            \
            "LDMFD	LR, {R0-R14}^										\n\t"\
            "NOP														\n\t"\
                                                                             \
            /* Restore the return address. */                                \
            "LDR		LR, [LR, #+60]									\n\t"\
                                                                             \
            /* And return - correcting the offset in the LR to obtain the */ \
            /* correct address. */                                           \
            "SUBS	PC, LR, #4											\n\t"\
            );                                                               \
        ( void ) ulCriticalNesting;                                          \
        ( void ) pxCurrentTCB;                                               \
    }
/*-----------------------------------------------------------*/

    #define portSAVE_CONTEXT()                                            \
    {                                                                     \
        extern volatile void * volatile pxCurrentTCB;                     \
        extern volatile uint32_t        ulCriticalNesting;                \
                                                                          \
        /* Push R0 as we are going to use the register. */                \
        asm volatile (                                                    \
            "STMDB	SP!, {R0}											\n\t"\
                                                                          \
            /* Set R0 to point to the task stack pointer. */              \
            "STMDB	SP,{SP}^											\n\t"\
            "NOP														\n\t"\
            "SUB	SP, SP, #4											\n\t"\
            "LDMIA	SP!,{R0}											\n\t"\
                                                                          \
            /* Push the return address onto the stack. */                 \
            "STMDB	R0!, {LR}											\n\t"\
                                                                          \
            /* Now we have saved LR we can use it instead of R0. */       \
            "MOV	LR, R0												\n\t"\
                                                                          \
            /* Pop R0 so we can save it onto the system mode stack. */    \
            "LDMIA	SP!, {R0}											\n\t"\
                                                                          \
            /* Push all the system mode registers onto the task stack. */ \
            "STMDB	LR,{R0-LR}^											\n\t"\
            "NOP														\n\t"\
            "SUB	LR, LR, #60											\n\t"\
                                                                          \
            /* Push the SPSR onto the task stack. */                      \
            "MRS	R0, SPSR											\n\t"\
            "STMDB	LR!, {R0}											\n\t"\
                                                                          \
            "LDR	R0, =ulCriticalNesting								\n\t"\
            "LDR	R0, [R0]											\n\t"\
            "STMDB	LR!, {R0}											\n\t"\
                                                                          \
            /* Store the new top of stack for the task. */                \
            "LDR	R0, =pxCurrentTCB									\n\t"\
            "LDR	R0, [R0]											\n\t"\
            "STR	LR, [R0]											\n\t"\
            );                                                            \
        ( void ) ulCriticalNesting;                                       \
        ( void ) pxCurrentTCB;                                            \
    }

    #define portYIELD_FROM_ISR()    vTaskSwitchContext()

/* Critical section handling. */

/*
 * The interrupt management utilities can only be called from ARM mode.  When
 * THUMB_INTERWORK is defined the utilities are defined as functions in
 * portISR.c to ensure a switch to ARM mode.  When THUMB_INTERWORK is not
 * defined then the utilities are defined as macros here - as per other ports.
 */

    #ifdef THUMB_INTERWORK

        extern void vPortDisableInterruptsFromThumb( void ) __attribute__( ( naked ) );
        extern void vPortEnableInterruptsFromThumb( void ) __attribute__( ( naked ) );

        #define portDISABLE_INTERRUPTS()    vPortDisableInterruptsFromThumb()
        #define portENABLE_INTERRUPTS()     vPortEnableInterruptsFromThumb()

    #else

        #define portDISABLE_INTERRUPTS()                                     \
    asm volatile (                                                           \
        "STMDB	SP!, {R0}		\n\t"       /* Push R0.						*/\
        "MRS	R0, CPSR		\n\t"       /* Get CPSR.					*/\
        "ORR	R0, R0, #0xC0	\n\t"       /* Disable IRQ, FIQ.			*/\
        "MSR	CPSR, R0		\n\t"       /* Write back modified value.	*/\
        "LDMIA	SP!, {R0}			")      /* Pop R0.						*/

        #define portENABLE_INTERRUPTS()                                      \
    asm volatile (                                                           \
        "STMDB	SP!, {R0}		\n\t"       /* Push R0.						*/\
        "MRS	R0, CPSR		\n\t"       /* Get CPSR.					*/\
        "BIC	R0, R0, #0xC0	\n\t"       /* Enable IRQ, FIQ.				*/\
        "MSR	CPSR, R0		\n\t"       /* Write back modified value.	*/\
        "LDMIA	SP!, {R0}			")      /* Pop R0.						*/

    #endif /* THUMB_INTERWORK */

    extern void vPortEnterCritical( void );
    extern void vPortExitCritical( void );

    #define portENTER_CRITICAL()    vPortEnterCritical();
    #define portEXIT_CRITICAL()     vPortExitCritical();

/*-----------------------------------------------------------*/

/* Task function macros as described on the FreeRTOS.org WEB site. */
    #define portTASK_FUNCTION_PROTO( vFunction, pvParameters )    void vFunction( void * pvParameters )
    #define portTASK_FUNCTION( vFunction, pvParameters )          void vFunction( void * pvParameters )

    #ifdef __cplusplus
        }
    #endif

#endif /* PORTMACRO_H */