[gpio] Refactor the GPIO protocol

This is a first step in a move toward using protocols to represent
individual resources. A similar change will be made to the I2C protocol
to bring it in line with how I2C is used on x86 platforms.

From the client's point of view, an instance of the ZX_PROTOCOL_GPIO
protocol now represents a single pin. The protocol remains the same,
except the "uint32_t index" has been removed from all the protocol functions.

For devices that have only one GPIO resource assigned to them, the driver
can simply call device_get_protocol() to access the GPIO protocol for the pin.
To for devices with more than one GPIO pins, a new API in the platform bus called
pdev_get_protocol() must be used instead.

In addition, we add a new protocol ZX_PROTOCOL_GPIO_IMPL, which is now
implemented by the GPIO drivers. This protocol is essentially the same as
the old GPIO protocol, except "index" has been renamed "pin".
Board drivers may use this protocol directly when doing low level system
configuration, specifying pin numbers directly.

TEST: Booted on VIM2 and Hikey.
On VIM2, USB, display, ethernet and the GPIO test driver are working properly
On Hikey, the system boots and USB is functional.

Change-Id: I44f1bc11ad9793543361a2d19d7a2de4458c334b

[dev][platform-bus] Clean up proxy error reporting

The platform_proxy_cb_t callback now has void return type,
since the status is already included in the platform_proxy_rsp_t struct

ZX-2602 #done

TEST: manual testing on VIM2.
Change-Id: I642542fcf5d8aa5c1a7cef45f92222871341f7cf

[ddk][i2c] Add arbitrary number of RWs support to I2C protocol

Augment the I2C protocol transact function to allow more than 2
write and/or read operations in one transaction. Rename the old
transact to write_read.

Test: Astro light sensor (uses I2C based interface) readings work

Change-Id: I3c83025b7ca697551638ed9824cb7547e37afc4b

[platform-bus][aml-canvas] Add support for proxying SOC-specific protocols

This change adds support to the platform bus driver for proxying
SOC-specific protocols to platform devices without modifying the
platform bus source code. It also removes support for the Amlogic canvas
protocol from the platform bus driver and uses this new proxying support instead.

The Amlogic canvas driver is now split into two drivers:
the canvas implementation driver and the canvas proxy driver.
The implementation driver runs in the platform bus devhost and implements the main
functionality of the driver. The proxy driver runs in the devhosts of the
drivers that are clients of the canvas protocol and is responsible for proxying
the canvas protocol to the implementation driver.

To make this work we add a new protocol ZX_PROTOCOL_PLATFORM_PROXY
and add new support to ZX_PROTOCOL_PLATFORM_BUS.
In ZX_PROTOCOL_PLATFORM_BUS, the pbus_register_protocol() API now adds an
optional callback of type platform_proxy_cb_t. This callback handles
RPCs from a protocol proxy driver.

The new protocol ZX_PROTOCOL_PLATFORM_PROXY is used for protocol proxy drivers
to communicate with the platform bus in the client devhosts.
When the proxy driver loads, it calls platform_proxy_register_protocol()
to register its protocol implementation with the platform bus proxy driver.
When the client driver calls a protocol API implemented by the proxy driver,
the proxy driver calls platform_proxy_proxy() to proxy the protocol
to the implementation driver in the platform device devhost, via the channel
that connects the two devhosts.

Support for proxying the Amlogic canvas protocol is now removed from the
platform bus driver, since we are using this new mechanism instead.

Within the platform bus driver, we add a new class ProxyClient.
This is a subclass of ddk::Device that is used for binding the
protocol proxy drivers. In the case where a platform device relies on
SOC-specific protocols implemented using this new mechanism,
the platform bus proxy driver creates a PlatformProxyClient for each
of the protocols and waits for them all to register their protocols
via the ZX_PROTOCOL_PLATFORM_PROXY protocol before creating the
ProxyDevice object to bind the platform device driver.

Below illustrates the parts of the device tree is changed by this CL:

BEFORE:
[04:02:1] pid=1785 /boot/driver/platform-bus.so
<04:02:1> pid=2881 /boot/driver/platform-bus.proxy.so
[vim2-display] pid=2881 /boot/driver/vim-display.so
[display-controller] pid=2881 /boot/driver/display.so

AFTER:
[04:02:1] pid=1850 /boot/driver/platform-bus.so
<04:02:1> pid=3024 /boot/driver/platform-bus.proxy.so
[ProxyClient[7043414e]] pid=3024 /boot/driver/platform-bus.proxy.so
[aml-canvas-proxy] pid=3024 /boot/driver/aml-canvas.proxy.so
[ProxyDevice] pid=3024 /boot/driver/platform-bus.proxy.so
[vim2-display] pid=3024 /boot/driver/vim-display.so
[display-controller] pid=3024 /boot/driver/display.so

In the AFTER subtree, the platform proxy driver inserts a new root device that has
both the aml-canvas and vim2-display drivers as children.

TEST: manual testing on VIM2 and astro

Change-Id: Ibfa925948491fb3793dd934ee5737ace7903edb9

[ddk] Rename ZX_PROTOCOL_CANVAS to ZX_PROTOCOL_AMLOGIC_CANVAS

To make it clear that this is an SOC-specific protocol

TEST: boot on VIM2
Change-Id: I0b6c785f77980524d5921fb2a2feda1a8984f8ce

[platform-bus] Remove proxying of USB mode switch protocol

This protocol is only being used for Hikey960, which needs to change some GPIOs
when switching USB mode. But now that we have support for child platform devices,
this logic can be pushed out of the board driver and into a platform device driver
which has the dwc3 driver as a child.

TEST: manual testing on hikey960 and imx8m-evk
Change-Id: Ia3c1b9540d0813d3d873f22007e3e22efb219975

[dev][platform-bus] Use separate classes for platform devices and protocol implementation devices

The class PlatformDevice in the platform bus driver was used for two purposes:

1) To implement platform devices, which run in separate devhosts.
In this role the class did not need to implement the platform device protocol,
but instead responded to proxied requests via the rxrpc callback from the PlatformProxy
class in the other devhost.

2) To bind platform protocol implementation drivers, which run in the same devhost and do require
a local platform device protocol implementation.

To simplify the code, the PlatformDevice class implements use case 1), and a new class called
ProtocolDevice implements use case 2.

In addition, protocol implementation drivers are now given a restricted version of the
platform bus protocol that disables pbus_device_add() and pbus_protocol_device_add().
There is no good use case for protocol implementation drivers to use these,
so lets not allow it.

TEST: manual testing on qemu, VIM2 and gauss.

Change-Id: I2cbe1bf0d47fac00f37093275eee4db450776f78

[dev][platform-bus] Clean-up and simplify platform bus protocol:

- Remove "flags" parameter from pbus_device_add().
Now platform devices can only be started in new devhosts.

- Add new API pbus_protocol_device_add(), for binding drivers that implement
platform bus protocols like GPIO and I2C_IMPL.
pbus_protocol_device_add() is equivalent to pbus_device_add(PDEV_ADD_PBUS_DEVHOST)
followed by pbus_wait_protocol().

- Remove pbus_wait_protocol(). pbus_protocol_device_add() does the wait for you automatically.

- Rename pbus_set_protocol() to pbus_register_protocol()

These changes will hopefully make the platform bus protocol easier
to understand and use.
I found two places where people accidentally using PDEV_ADD_PBUS_DEVHOST
inappropriately (probably copy & paste errors), which resulted in
the entire network stack and storage stack running in the platform bus devhost.
Hopefully this change will make it impossible for mistakes like that to happen again.

While doing this I also noticed that the gauss nand driver and vim2 ethernet driver
were running in the platform bus devhost. This change fixes that.

Also removed some remnants of the pbus_device_enable() API, which has been removed previously.

TEST: boot up on qemu, VIM2, gauss and astro and verified platform devices all start up properly

Change-Id: I580269bc6f53a63348ba8ab580259b1ba56dd393

[dev][platform-bus] clang format, and remove obsolete comment

TEST: boot VIM2 successfully
Change-Id: Idc2aed5c649a929bf3baaf9ceb5c82dbaae2182e

[dev][platform-bus] Remove support for proxying the SCPI protocol

The aml-scpi driver now runs in the same devhost as the vim-thermal
driver, so this proxying is no longer necessary.

TEST: manual testing on VIM2. Thermal driver loads and initializes properly.

Change-Id: Idea760b43ea1463cdeebe41b06affa37b9fe7aa7

[dev][platform-bus] Provide platform bus resources platform device children

Currently the platform bus allows creating a list of platform devices,
each running in a separate devhost.
These devices are provided by the bus with various resources
(MMIO buffers, interrupt handles, GPIOs, I2C channels, etc).
However we have use cases where a platform device may have child devices
that also need resources from the platform bus.

This change allows children of platform devices to access platform bus resources.
To do this, the board driver can pass a list of child devices via the pbus_dev_t
structure passed via pbus_device_add(). These children can also have children,
allowing for a tree of platform devices in the same devhost, rather than just one.
To facilitate this, a platform device must use a new platform device protocol
pdev_device_add() to create the child device rather than calling the DDK
device_add() directly.
The behavior of pdev_device_add() is the same as device_add(), except it inserts
a layer between the parent and child device to allow device_get_protocol()
to return protocols that are implemented by the platform bus
(for example, ZX_PROTOCOL_PLATFORM_DEV, ZX_PROTOCOL_GPIO, etc.)
This allows the children of of platform devices to also be platform devices,
while simultaneously allowing access to the protocol(s) implemented by the
parent device.

This change also adds four drivers to the qemu build to test this new functionality.
The qemu-bus board driver adds a platform device called "parent".
"parent" then creates a child device called "child-1", which in turn has
two children called "child-2" and "child-3".
All of these devices are platform devices and all four of the corresponding drivers
test to make sure that they can access the platform device protocol and map
their own unique MMIO regions.

TEST: manual testing on qemu, vim2 and gauss

Change-Id: Iaa4cd2afb06512dd0a9f9e06ca91c84c348e352f

[dev][platform-bus] Refactor proxying protocol

Proxy request and response structs are now broken up by protocol,
with common headers.
This is first step in modularizing platform bus support for protocol proxying.

TESTS: manual testing on vim2, gauss and qemu

Change-Id: Ic42ac51a03d608cbd481c00a8bcf6e191690c2e7

[dev][platform-bus] Add platform device support for board info

pdev_get_board_info() returns board vendor and product IDs, board name,
and a board revision number optionally set by the board driver.

TEST: Added test to VIM2 display driver.

ZX-2452 #done

Change-Id: Ia417acc3afede145a7a256ab3d71415c236d8230

[dev][platform-bus] Finish port to C++

The remainder of the driver now uses ddktl and other C++ features.

TEST: running on qemu, VIM2 and gauss
Change-Id: Icd1825baa8e76f60e78a9014d95b2a753db7be25

[dev][platform-bus] Compile in C++

Minimal changes to compile in C++ instead of C
Subsequent CLs will actually start using C++ language features.

TEST: Boot on VIM2

Change-Id: I9ea5f93b7c4ff2ecb51056d6d2504a207fdac775

[sync] Apply C API rubric to libsync

Test: No behavior change
Change-Id: I30a413f7fb5d3f4e741e5204532b82e73595c086

[ddk][platform-bus] Misc driver metadata cleanup

Rename "boot_metadata" to "metadata" in the plaform bus and device protocols,
since not all metadata provided by the platform bus comes from the bootloader.

Rename DEVICE_METADATA_DRIVER_DATA to DEVICE_METADATA_PRIVATE to clarify
that this signifies that the metadata type is local to a particular driver
or protocol.

Remove unused pbus_publish_boot_metadata() from platform bus protocol

Test: manual testing on VIM2

Change-Id: If969bb0005da7cb66901a796effc8231a8cb2ebe

[amlogic][canvas] Add canvas driver for AMLOGIC

- Added a canvas protocol
- Modified the VIM2 display driver to use the canvas
protocol instead of local canvas driver
- Removed local vim2 canvas driver

ZX-2154 #done

Test: Boot up on VIM2 board with HDMI monitor attached
Change-Id: I9e2328513fafecd1a440985f84ee41fce0c35ab9

[dev] Switch drivers to use <zircon/boot/image.h> instead of deprecated bootdata.h

Tested on VIM2 and x86 qemu

Change-Id: I5d22e3ccf0389e05eb77fd3d3810a4e993c85767

[vim2][mailbox][scpi] Introduce Mailbox & SCPI Protocol

Breaking down the fan-control thermal prototype driver
into 3 parts.

1st layer would be the Mailbox driver which would
provide communication between the two on-board
processors.

2nd layer would be the SCPI driver (System Control and
Power Interface) which would use the mailbox protocol
to set/get system configuration such as frequency/voltage
and thermal parameters.

3rd layer would be the Fan-control driver which uses
the SCPI protocol to get the temperature and controls
the fan via the GPIO protocol based on it.

(TODO): Expose the fan-ctl & SCPI interface as IOCTL's in a later CL

Change-Id: Ia0175fdfe76048d7cb789e3898e50d9cffb3cee3

[dev][platform-bus] Add support for extracting device metadata from bootdata

BOOTDATA_PARTITION_MAP and BOOTDATA_MAC_ADDRESS records in the bootdata
can now be added as device metadata via two different mechanisms:

1) Add a pbus_boot_metadata_t containing matching information to the pbus_dev_t
passed to pbus_device_add()

2) Call pbus_publish_boot_metadata() to publish a bootdata record to the
specified device path.

Change-Id: I18b6972a2f536fc84135649ba6401bed627c9311

[devmgr][platform-bus] Pass bootdata VMO handle to platform bus driver

platform-bus now extracts bootdata_platform_id from the bootdata
itself instead of having devmgr pass it in the driver create arguments.
This will allow us to pass other information to the platform bus driver
in the future.

Change-Id: I4ea011608173632d389623d865e09cc9a26e323b

[ddk][serial] Move serial protocol support out of platform bus driver

Instead of implementing UARTs as platform device resources in platform bus,
We now have a generic serial driver that implements ZX_PROTOCOL_SERIAL
on top of the lower level ZX_PROTOCOL_SERIAL_IMPL protocol.
This allows the possibility of using the generic seral protocol support
on x86 as well as SOC based platforms.

In order to make this work, we add some new generic device properties to our binding rules:
BIND_DEVICE_VID, BIND_DEVICE_PID and BIND_DEVICE_CLASS.
In this CL we use BIND_DEVICE_CLASS to specify the serial port type
(for example Bluetooth HCI versus generic serial port)
and BIND_DEVICE_VID and BIND_DEVICE_PID to specify which Bluetooth firmware
to use in the case of HCI.

We also simplify the serial protocols by eliminating port numbers from the APIs.
Now serial drivers support only one serial port each, so we now have separate
driver instances per serial port.
This is necessary to maintain the flexibility of running serial port clients
in separate devhosts after decoupling from the platform bus.

Change-Id: Ife2c611a1340ec99440595e45d79bdcf63979644

[ddk][i2c] Phase 1 of i2c protocol clean-up

- Add new protocol ZX_PROTOCOL_I2C_IMPL for i2c drivers to implement
This is a simpler protocol to implement than the existing ZX_PROTOCOL_I2C protocol

- Convert the aml-i2c and dw-i2c drivers to implement ZX_PROTOCOL_I2C_IMPL
instead of the higher level ZX_PROTOCOL_I2C protocol

- Move logic for queueing i2c transactions from the i2c drivers
to the platform bus driver

Change-Id: Ic16d18ec331f73cfccce560c1423a1db78472670

[ddk][serial] Rename ZX_PROTOCOL_SERIAL_DRIVER to ZX_PROTOCOL_SERIAL_IMPL

Change-Id: Ic0766df427c649c39483c35d6bc2c2838e7d08a5

[dev][platform-bus] Add IOMMU support

Add a new ZX_PROTOCOL_IOMMU, which platform board drivers can use
to implement platform specific IOMMU functionality.
If no IOMMU protocol is set by the board driver, the platform bus
uses a default implementation based on a dummy IOMMU.

Platform device drivers can now access BTIs via the pdev_get_bti()
API in the platform device protocol.
Similarly, board drivers can assign BTIs to the platform devices they create
via the pbus_dev_t struct passed to pbus_device_add().

Also modified the vim, hikey and gauss board drivers to assign BTIs
to all platform devices where the the driver will need to perform DMA.

ZX-693

Change-Id: Id3decaba2ad5bda2c2dc49280e94e674bee1ae56

[ddk][clk][protocol] Initial Clock Protocol

Initial implementation for a platform clock protocol. Only implements enable/disable for now.

Change-Id: If74b24ca6dd59ad7e7b437b15582b700fa5548ac

[dev][platform-bus] Add support for new serial protocols

The socket based ZX_PROTOCOL_SERIAL is implemented on top of the
lower level ZX_PROTOCOL_SERIAL_DRIVER protocol in platform-serial.c
and is proxied across devhost boundaries to platform devices.

Change-Id: Ib19c4cba16cabbb259600d6af0b0c864105f9551

[dev][platform-bus] Add support for binding platform devices in platform bus devhost

Passing the PDEV_ADD_PBUS_DEVHOST flag to pbus_device_add() will create a
platform device node in the platform bus's devhost rather than creating a new devhost.
These devices have access to the ZX_PROTOCOL_PLATFORM_BUS protocol
in addition to ZX_PROTOCOL_PLATFORM_DEV.
The standard separate devhost case remains unchanged.

Change-Id: Iea54655e6f5cded475e044655347d9ec0d8cbdee

[dev][platform-bus] Replace pbus_set_interface with pbus_set_protocol

The interface provided by the board driver to the platform bus
only supports retrieving protocols from the board driver,
so it is simpler to just have the board drivers set protocols
on the platform bus driver instead.

Change-Id: I2d0a04504102c4a49082b3d4eeba3cf4380dacab

[dev][platform-bus] Add support for proxying the i2c protocol to platform devices

Change-Id: I5d76a551a9ad77481a20d9d8fe4313761347dee8

[platform][gpio] Use device relative indices for GPIOs

This insulates generic drivers from the platform's GPIO numbering
and also restricts drivers from accessing GPIOs that are not assigned to them
by the platform bus.

Also removed unused id fields from pbus_mmio_t and pbus_irq_t.

Change-Id: I9be4fdbe5d5447a0eb689a5c5715f22fa1e2f820

[dev][platform-bus] Add proxying support for the GPIO protocol

Change-Id: I3b0e005fce841a9e21f393be70f235d481f27c8a

[dev][platform-bus] Simplify storage of platform device resources

The previous method of storing them all at the end of the
platform_dev_t struct wouldn't scale well as we add more resource types
to the platform device protocol.

Change-Id: Id3e40b42eac9aebbe8565fc73214a26e53501376

[dev][platform-bus] Run platform devices in separate devhosts

The platform bus driver now proxies the platform device
and USB mode switch protocols.
usb_mode_switch_get_initial_mode() now returns a zx_status_t.

Still to do: proxy the GPIO protocol

Change-Id: If989338bd77299b2797e83e9121a856fe00ace5a

[ddk][platform-bus] Add API for reading the platform's board name

SOC drivers might need this to handle board specific differences

Change-Id: I9442203b8e6773fc2b22075c9bd7ee790663bb12

[dev][platform-bus] Remove most of the MDI support

We are now only using MDI to retrieve the platform VID and PID,
and that will be going away soon too.

Also removed unnecessary creation of child resources for MMIOs and IRQs

Change-Id: I3186a6ef392b167f022a2dddaa69e860600060a3

[dev][platform-bus] Support for programatic creation of platform devices

Adds support for platform bus implementor driver creating platform devices
rather than using the MDI.

Change-Id: Ie685085c96a034050b001b423b2a410125896063

[ddk][platform-bus] Add platform bus protocol

Currently the platform device protocol ZX_PROTOCOL_PLATFORM_DEV
is used for binding both platform device drivers as well as
drivers implementing platform bus functionality.
In this change we add a new protocol ZX_PROTOCOL_PLATFORM_BUS
for binding platform bus implementor drivers.
APIs specific to platform bus implementors has moved from the
platform device protocol to the new platform bus protocol.

Change-Id: I7ba90cb888206f28a1a2fe2d0edff52bbe4f22b1

[dev][platform-bus] Fix problem disabling and re-enabling platform devices

Remove platform_dev_release() and clean-up devices when platform bus unbinds
rather than when a platform device is removed.
Otherwise it is impossible to re-enable the device.

Change-Id: I6a2927e8bab12aedfba914f4d87d4fa60ab0f1e6

[dev][platform-bus] Add support for dynamically enabling and disabling platform devices

The platform bus implementation driver can now enable or disable a platform device
using the new pdev_device_enable() API. This will add or remove the DDK device for a
platform device. A new "enabled" flag in the MDI can be used to specify that a
platform device not be enabled at startup.

We will use this to dynamically add and remove the platform device for XHCI when
switching between USB host and peripheral roles.

Change-Id: I126ea70b0dba6573230528899a00fd21320ee6ea

[dev] Rename "mxdev" to "zxdev" in ddktl and various drivers.

Change-Id: I000e42c26d9f8379de40447690694a35f6be93e2

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[dev][platform-bus] Add support for GPIOs

The platform bus driver can now read configuration information for
GPIO drivers and passes this information to the platform bus driver
via pbus_interface_t.
This allows platform bus implementation drivers to implement GPIO
support and make it available to platform devices via
Platform devices can then access the pdev_get_protocol() API.

Change-Id: I505bccb9bace5f99eadd511fe877fb7c24457131

[dev][platform-bus] Fold platform bus protocol into the platform device protocol

The platform device protocol is now used for the device specific bus driver
to bind to the platform bus.
Now this driver to MX_PROTOCOL_PLATFORM_DEV with special device ID PDEV_BUS_IMPLEMENTOR_DID

Change-Id: I6151310b1a6e787825d9731fb1b93d0edc91e792

[dev][platform-bus] Start on device specific implementation support

The platform bus driver provides generic support for loading a number
of platform devices and can provide MMIO regions and IRQs to these
devices based on information in the MDI.
This change takes the first step toward expanding this to support
platform specific services like GPIOs, clocks, I2C etc.

To do this, the platform bus driver will require a platform specific
driver to bind against it. This driver will make these additional services
available to the platform bus driver, which will then make them available
to platform devices via the platform device protocol.

In this change we are mostly just adding the skeleton for this new structure.
APIs for GPIOs, I2Cs, etc. will be added in subsequent changes.

The platform specific implementation driver binds to the platform bus driver
by matching against the MX_PROTOCOL_PLATFORM_BUS protocol and the
BIND_PLATFORM_DEV_VID property.
In this change, the bcm-mailbox driver now binds as the platorm specific
bus driver rather than as a platform device.
In subsequent changes, the BCM GPIO and I2C suppport to the mailbox driver.

As soon as the platform specific driver binds, it registers a pbus_interface_t
protocol with the platform bus driver, which will be used for providing
all its platform specific services to platform devices.
The platform bus driver will wait until the pbus_interface_t is registered
before adding the platform devices to ensure that all necessary services
are available when drivers bind to the platform devices.

The platform bus driver can also provide MMIO and IRQ resources to the
platform specific driver. This is done by specifying them in a new "bus" node
in the MDI.

This change also refactors the platform bus driver into multiple source files
and replaces the platform device register_protocol/find_protocol mechanism
with a get_protocol API in the pbus_interface_t protocol.
The bcm-mailbox driver now uses this for providing the bcm bus protocol
to the BCM platform drivers.

Change-Id: Ibfe5caeae425d9d97edd20760d3d7724e8d4f1bb