BroadcomMailbox Class Reference

Broadcom System-on-Chip Mailbox interface. More...

#include <BroadcomMailbox.h>

Public Types
enum	Result { Success , IOError }
	Result codes. More...
enum	Channel {   PowerManagement = 0 , FrameBuffer = 1 , VirtualUART = 2 , VCHIQ = 3 ,   LED = 4 , Button = 5 , TouchScreen = 6 , VCProperty = 8 ,   ARMProperty = 9 }
	Mailbox channels. More...

Public Member Functions
	BroadcomMailbox ()
	Constructor.
Result	initialize ()
	Initialize the Mailbox.
Result	read (Channel channel, u32 *message) const
	Read 28-bit message.
Result	write (Channel channel, u32 message)
	Write 28-bit message.

Private Types
enum	Register { Read = 0x0880 , Status = 0x0898 , Config = 0x089c , Write = 0x08a0 }
	Hardware registers. More...
enum	StatusFlags { Full = 0x80000000 , Empty = 0x40000000 }
	Status register flags. More...

Private Attributes
ARMIO	m_io
	I/O object.

Static Private Attributes
static const Address	Base = 0xb000
	Register base offset for the Mailbox.
static const uint	ChannelMask = 0xf
	Channel Mask when reading or writing (lowest 4-bits).

Detailed Description

Broadcom System-on-Chip Mailbox interface.

The Mailbox on the BCM2835 is a message-based interface between the ARM and the GPU. It provides channels for sending and receiving messages.

See also

https://github.com/raspberrypi/firmware/wiki/Mailboxes

https://github.com/raspberrypi/firmware/wiki/Accessing-mailboxes

https://github.com/torvalds/linux/blob/master/drivers/mailbox/bcm2835-mailbox.c

Definition at line 47 of file BroadcomMailbox.h.

Member Enumeration Documentation

Channel

enum BroadcomMailbox::Channel

Mailbox channels.

Enumerator
PowerManagement
FrameBuffer
VirtualUART
VCHIQ
LED
Button
TouchScreen
VCProperty
ARMProperty

Definition at line 91 of file BroadcomMailbox.h.

Register

enum BroadcomMailbox::Register

private

Hardware registers.

Enumerator
Read
Status
Config
Write

Definition at line 60 of file BroadcomMailbox.h.

Result

enum BroadcomMailbox::Result

Result codes.

Enumerator
Success
IOError

Definition at line 82 of file BroadcomMailbox.h.

StatusFlags

enum BroadcomMailbox::StatusFlags

private

Status register flags.

Enumerator
Full
Empty

Definition at line 71 of file BroadcomMailbox.h.

Constructor & Destructor Documentation

BroadcomMailbox()

BroadcomMailbox::BroadcomMailbox

(

)

Constructor.

Definition at line 21 of file BroadcomMailbox.cpp.

Member Function Documentation

initialize()

BroadcomMailbox::Result BroadcomMailbox::initialize

(

)

Initialize the Mailbox.

Returns

Result code.

Definition at line 25 of file BroadcomMailbox.cpp.

References Base, Config, Memory::Device, IOError, m_io, IO::map(), PAGESIZE, Memory::Readable, Success, IO::Success, Memory::User, Memory::Writable, and ARMIO::write().

Referenced by BroadcomPower::initialize().

read()

BroadcomMailbox::Result BroadcomMailbox::read	(	Channel	channel,
		u32 *	message
	)		const

Read 28-bit message.

Parameters

channel
message	28-bit message on output

Returns

Result code.

Definition at line 37 of file BroadcomMailbox.cpp.

References ChannelMask, Empty, m_io, ARMIO::read(), Read, Status, and Success.

Referenced by BroadcomPower::enable().

write()

BroadcomMailbox::Result BroadcomMailbox::write	(	Channel	channel,
		u32	message
	)

Write 28-bit message.

Parameters

channel	Channel to write to.
message	28-bit message to write.

Returns

Result code.

Definition at line 54 of file BroadcomMailbox.cpp.

References Full, m_io, ARMIO::read(), Status, Success, ARMIO::write(), and Write.

Referenced by BroadcomPower::enable(), and BroadcomPower::initialize().

Field Documentation

Base

const Address BroadcomMailbox::Base = 0xb000

staticprivate

Register base offset for the Mailbox.

Definition at line 52 of file BroadcomMailbox.h.

Referenced by initialize().

ChannelMask

const uint BroadcomMailbox::ChannelMask = 0xf

staticprivate

Channel Mask when reading or writing (lowest 4-bits).

Definition at line 55 of file BroadcomMailbox.h.

Referenced by read().

m_io

ARMIO BroadcomMailbox::m_io

private

I/O object.

Definition at line 141 of file BroadcomMailbox.h.

Referenced by initialize(), read(), and write().

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The documentation for this class was generated from the following files:

• lib/libarch/arm/broadcom/BroadcomMailbox.h
• lib/libarch/arm/broadcom/BroadcomMailbox.cpp