rpi-mailbox-interface.c

/*

    Part of the Raspberry-Pi Bare Metal Tutorials
    Copyright (c) 2015, Brian Sidebotham
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice,
        this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright notice,
        this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

*/

#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include "rpi-mailbox.h"
#include "rpi-mailbox-interface.h"

/* Make sure the property tag buffer is aligned to a 16-byte boundary because
   we only have 28-bits available in the property interface protocol to pass
   the address of the buffer to the VC. */
static int pt[8192] __attribute__((aligned(16)));
static int pt_index = 0;


void RPI_PropertyInit( void )
{
    /* Fill in the size on-the-fly */
    pt[PT_OSIZE] = 12;

    /* Process request (All other values are reserved!) */
    pt[PT_OREQUEST_OR_RESPONSE] = 0;

    /* First available data slot */
    pt_index = 2;

    /* NULL tag to terminate tag list */
    pt[pt_index] = 0;
}

/**
    @brief Add a property tag to the current tag list. Data can be included. All data is uint32_t
    @param tag
*/
void RPI_PropertyAddTag( rpi_mailbox_tag_t tag, ... )
{
    va_list vl;
    va_start( vl, tag );

    pt[pt_index++] = tag;

    switch( tag )
    {
        case TAG_GET_FIRMWARE_VERSION:
        case TAG_GET_BOARD_MODEL:
        case TAG_GET_BOARD_REVISION:
        case TAG_GET_BOARD_MAC_ADDRESS:
        case TAG_GET_BOARD_SERIAL:
        case TAG_GET_ARM_MEMORY:
        case TAG_GET_VC_MEMORY:
        case TAG_GET_DMA_CHANNELS:
            /* Provide an 8-byte buffer for the response */
            pt[pt_index++] = 8;
            pt[pt_index++] = 0; /* Request */
            pt_index += 2;
            break;

        case TAG_GET_CLOCKS:
        case TAG_GET_COMMAND_LINE:
            /* Provide a 256-byte buffer */
            pt[pt_index++] = 256;
            pt[pt_index++] = 0; /* Request */
            pt_index += 256 >> 2;
            break;

        case TAG_ALLOCATE_BUFFER:
        case TAG_GET_MAX_CLOCK_RATE:
        case TAG_GET_MIN_CLOCK_RATE:
        case TAG_GET_CLOCK_RATE:
            pt[pt_index++] = 8;
            pt[pt_index++] = 0; /* Request */
            pt[pt_index++] = va_arg( vl, int );
            pt[pt_index++] = 0;
            break;

        case TAG_SET_CLOCK_RATE:
            pt[pt_index++] = 12;
            pt[pt_index++] = 0; /* Request */
            pt[pt_index++] = va_arg( vl, int ); /* Clock ID */
            pt[pt_index++] = va_arg( vl, int ); /* Rate (in Hz) */
            pt[pt_index++] = va_arg( vl, int ); /* Skip turbo setting if == 1 */
            break;

        case TAG_GET_PHYSICAL_SIZE:
        case TAG_SET_PHYSICAL_SIZE:
        case TAG_TEST_PHYSICAL_SIZE:
        case TAG_GET_VIRTUAL_SIZE:
        case TAG_SET_VIRTUAL_SIZE:
        case TAG_TEST_VIRTUAL_SIZE:
        case TAG_GET_VIRTUAL_OFFSET:
        case TAG_SET_VIRTUAL_OFFSET:
            pt[pt_index++] = 8;
            pt[pt_index++] = 0; /* Request */

            if( ( tag == TAG_SET_PHYSICAL_SIZE ) ||
                ( tag == TAG_SET_VIRTUAL_SIZE ) ||
                ( tag == TAG_SET_VIRTUAL_OFFSET ) ||
                ( tag == TAG_TEST_PHYSICAL_SIZE ) ||
                ( tag == TAG_TEST_VIRTUAL_SIZE ) )
            {
                pt[pt_index++] = va_arg( vl, int ); /* Width */
                pt[pt_index++] = va_arg( vl, int ); /* Height */
            }
            else
            {
                pt_index += 2;
            }
            break;

        case TAG_GET_ALPHA_MODE:
        case TAG_SET_ALPHA_MODE:
        case TAG_GET_DEPTH:
        case TAG_SET_DEPTH:
        case TAG_GET_PIXEL_ORDER:
        case TAG_SET_PIXEL_ORDER:
        case TAG_GET_PITCH:
            pt[pt_index++] = 4;
            pt[pt_index++] = 0; /* Request */

            if( ( tag == TAG_SET_DEPTH ) ||
                ( tag == TAG_SET_PIXEL_ORDER ) ||
                ( tag == TAG_SET_ALPHA_MODE ) )
            {
                /* Colour Depth, bits-per-pixel \ Pixel Order State */
                pt[pt_index++] = va_arg( vl, int );
            }
            else
            {
                pt_index += 1;
            }
            break;

        case TAG_GET_OVERSCAN:
        case TAG_SET_OVERSCAN:
            pt[pt_index++] = 16;
            pt[pt_index++] = 0; /* Request */

            if( ( tag == TAG_SET_OVERSCAN ) )
            {
                pt[pt_index++] = va_arg( vl, int ); /* Top pixels */
                pt[pt_index++] = va_arg( vl, int ); /* Bottom pixels */
                pt[pt_index++] = va_arg( vl, int ); /* Left pixels */
                pt[pt_index++] = va_arg( vl, int ); /* Right pixels */
            }
            else
            {
                pt_index += 4;
            }
            break;

        default:
            /* Unsupported tags, just remove the tag from the list */
            pt_index--;
            break;
    }

    /* Make sure the tags are 0 terminated to end the list and update the buffer size */
    pt[pt_index] = 0;

    va_end( vl );
}


int RPI_PropertyProcess( void )
{
    int result;

#if( PRINT_PROP_DEBUG == 1 )
    printf( "%s Length: %d\r\n", __func__, pt[PT_OSIZE] );
#endif
    /* Fill in the size of the buffer */
    pt[PT_OSIZE] = ( pt_index + 1 ) << 2;
    pt[PT_OREQUEST_OR_RESPONSE] = 0;

#if( PRINT_PROP_DEBUG == 1 )
    for( i = 0; i < (pt[PT_OSIZE] >> 2); i++ )
        printf( "Request: %3d %8.8X\r\n", i, pt[i] );
#endif
    RPI_Mailbox0Write( MB0_TAGS_ARM_TO_VC, (unsigned int)pt );

    result = RPI_Mailbox0Read( MB0_TAGS_ARM_TO_VC );

#if( PRINT_PROP_DEBUG == 1 )
    for( i = 0; i < (pt[PT_OSIZE] >> 2); i++ )
        printf( "Response: %3d %8.8X\r\n", i, pt[i] );
#endif
    return result;
}


rpi_mailbox_property_t* RPI_PropertyGet( rpi_mailbox_tag_t tag )
{
    static rpi_mailbox_property_t property;
    int* tag_buffer = NULL;

    property.tag = tag;

    /* Get the tag from the buffer. Start at the first tag position  */
    int index = 2;

    while( index < ( pt[PT_OSIZE] >> 2 ) )
    {
        /* printf( "Test Tag: [%d] %8.8X\r\n", index, pt[index] ); */
        if( pt[index] == tag )
        {
            tag_buffer = &pt[index];
            break;
        }

        /* Progress to the next tag if we haven't yet discovered the tag */
        index += ( pt[index + 1] >> 2 ) + 3;
    }

    /* Return NULL of the property tag cannot be found in the buffer */
    if( tag_buffer == NULL )
        return NULL;

    /* Return the required data */
    property.byte_length = tag_buffer[T_ORESPONSE] & 0xFFFF;
    memcpy( property.data.buffer_8, &tag_buffer[T_OVALUE], property.byte_length );

    return &property;
}