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// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef DDK_DEVICE_H_
#define DDK_DEVICE_H_
#include <zircon/compiler.h>
#include <zircon/syscalls.h>
#include <zircon/types.h>
#include <zircon/listnode.h>
typedef struct zx_device zx_device_t;
typedef struct zx_driver zx_driver_t;
typedef struct zx_device_prop zx_device_prop_t;
typedef struct zx_protocol_device zx_protocol_device_t;
typedef struct fidl_msg fidl_msg_t;
typedef struct fidl_txn fidl_txn_t;
// Max device name length, not including a null-terminator
// echo -n "mx_device_ops_v0.5" | sha256sum | cut -c1-16
#define DEVICE_OPS_VERSION_0_50 0xc9410d2a24f57424
// echo -n "zx_device_ops_v0.51" | sha256sum | cut -c1-16
#define DEVICE_OPS_VERSION_0_51 0xc4640f7115d2ee49
// Current Version
// TODO: temporary flags used by devcoord to communicate
// with the system bus device.
#define DEVICE_SUSPEND_FLAG_MEXEC 0xdcdc0300
// reboot modifiers
//@ # The Device Protocol
// Device drivers implement a set of hooks (methods) to support the
// operations that may be done on the devices that they publish.
// These are described below, including the action that is taken
// by the default implementation that is used for each hook if the
// driver does not provide its own implementation.
typedef struct zx_protocol_device {
//@ ## version
// This field must be set to `DEVICE_OPS_VERSION`
uint64_t version;
zx_status_t (*get_protocol)(void* ctx, uint32_t proto_id, void* protocol);
//@ ## open
// The open hook is called when a device is opened via the device filesystem,
// or when an existing open connection to a device is cloned (for example,
// when a device fd is shared with another process). The default open hook,
// if a driver does not implement one, simply returns **ZX_OK**.
// Drivers may want to implement open to disallow simultaneous access (by
// failing if the device is already open), or to return a new **device instance**
// instead.
// The optional *dev_out* parameter allows a device to create and return a
// **device instance** child device, which can be used to manage per-instance
// state instead of all client connections interacting with the device itself.
// A child created for return as an instance **must** be created with the
// **DEVICE_ADD_INSTANCE** flag set in the arguments to **device_add()**.
zx_status_t (*open)(void* ctx, zx_device_t** dev_out, uint32_t flags);
//@ ## close
// The close hook is called when a connection to a device is closed. These
// calls will balance the calls to open.
// **Note:** If open returns a **device instance**, the balancing close hook
// that is called is the close hook on the **instance**, not the parent.
// The default close implementation returns **ZX_OK**.
zx_status_t (*close)(void* ctx, uint32_t flags);
//@ ## unbind
// The unbind hook is called when the parent of this device is being removed (due
// to hot unplug, fatal error, etc). At the point unbind is called, it is not
// possible for further open calls to occur, but io operations, etc
// may continue until those client connections are closed.
// The driver should avoid further method calls to its parent device or any
// protocols obtained from that device, and expect that any further such calls
// will return with an error.
// The driver should adjust its state to encourage its client connections to close
// (cause IO to error out, etc), and call **device_remove()** on itself when ready.
// The driver must continue to handle all device hooks until the **release** hook
// is invoked.
void (*unbind)(void* ctx);
//@ ## release
// The release hook is called after this device has been removed by **device_remove()**
// and all open client connections have been closed, and all child devices have been
// removed and released.
// At the point release is invoked, the driver will not receive any further calls
// and absolutely must not use the underlying **zx_device_t** or any protocols obtained
// from that device once this method returns.
// The driver must free all memory and release all resources related to this device
// before returning.
void (*release)(void* ctx);
//@ ## read
// The read hook is an attempt to do a non-blocking read operation.
// On success *actual* must be set to the number of bytes read (which may be less
// than the number requested in *count*), and return **ZX_OK**.
// A successful read of 0 bytes is generally treated as an End Of File notification
// by clients.
// If no data is available now, **ZX_ERR_SHOULD_WAIT** must be returned and when
// data becomes available `device_state_set(DEVICE_STATE_READABLE)` may be used to
// signal waiting clients.
// This hook **must not block**.
// The default read implementation returns **ZX_ERR_NOT_SUPPORTED**.
zx_status_t (*read)(void* ctx, void* buf, size_t count,
zx_off_t off, size_t* actual);
//@ ## write
// The write hook is an attempt to do a non-blocking write operation.
// On success *actual* must be set to the number of bytes written (which may be
// less than the number requested in *count*), and **ZX_OK** should be returned.
// If it is not possible to write data at present **ZX_ERR_SHOULD_WAIT** must
// be returned and when it is again possible to write,
// `device_state_set(DEVICE_STATE_WRITABLE)` may be used to signal waiting clients.
// This hook **must not block**.
// The default write implementation returns **ZX_ERR_NOT_SUPPORTED**.
zx_status_t (*write)(void* ctx, const void* buf, size_t count,
zx_off_t off, size_t* actual);
//@ ## get_size
// If the device is seekable, the get_size hook should return the size of the device.
// This is the offset at which no more reads or writes are possible.
// The default implementation returns 0.
zx_off_t (*get_size)(void* ctx);
//@ ## ioctl
// The ioctl hook allows support for device-specific operations.
// These, like read and write, must not block.
// On success, **ZX_OK** must be returned and *out_actual* must be set
// to the number of output bytes provided (0 if none).
// The default ioctl implementation returns **ZX_ERR_NOT_SUPPORTED**.
zx_status_t (*ioctl)(void* ctx, uint32_t op,
const void* in_buf, size_t in_len,
void* out_buf, size_t out_len, size_t* out_actual);
// Stops the device and puts it in a low power mode
zx_status_t (*suspend)(void* ctx, uint32_t flags);
// Restarts the device after being suspended
zx_status_t (*resume)(void* ctx, uint32_t flags);
//@ ## rxrpc
// Only called for bus devices.
// When the "shadow" of a busdev sends an rpc message, the
// device that is shadowing is notified by the rxrpc op and
// should attempt to read and respond to a single message on
// the provided channel.
// Any error return from this method will result in the channel
// being closed and the remote "shadow" losing its connection.
// This method is called with ZX_HANDLE_INVALID for the channel
// when a new client connects -- at which point any state from
// the previous client should be torn down.
zx_status_t (*rxrpc)(void* ctx, zx_handle_t channel);
//@ ## message
// Process a FIDL rpc message. This is used to handle class or
// device specific messaging.{Node,File,Device} are
// handles by the devhost itself.
// The entire message becomes the responsibility of the driver,
// including the handles.
// The txn provided to respond to the message is only valid for
// the duration of the message() call. It must not be cached
// and used later.
// If this method returns anything other than ZX_OK, the underlying
// connection is closed.
zx_status_t (*message)(void* ctx, fidl_msg_t* msg, fidl_txn_t* txn);
} zx_protocol_device_t;
// Device Accessors
const char* device_get_name(zx_device_t* dev);
zx_device_t* device_get_parent(zx_device_t* dev);
// protocols look like:
// typedef struct {
// protocol_xyz_ops_t* ops;
// void* ctx;
// } protocol_xyz_t;
zx_status_t device_get_protocol(const zx_device_t* dev, uint32_t proto_id, void* protocol);
// Direct Device Ops Functions
zx_status_t device_read(zx_device_t* dev, void* buf, size_t count,
zx_off_t off, size_t* actual);
zx_status_t device_write(zx_device_t* dev, const void* buf, size_t count,
zx_off_t off, size_t* actual);
zx_off_t device_get_size(zx_device_t* dev);
// Device Metadata Support
// retrieves metadata for a specific device
// searches parent devices to find a match
zx_status_t device_get_metadata(zx_device_t* dev, uint32_t type, void* buf, size_t buflen,
size_t* actual);
// retrieves metadata size for a specific device
// searches parent devices to find a match
zx_status_t device_get_metadata_size(zx_device_t* dev, uint32_t type, size_t* out_size);
// Adds metadata to a specific device.
zx_status_t device_add_metadata(zx_device_t* dev, uint32_t type, const void* data, size_t length);
// Adds metadata to be provided to future devices matching the specified topo path.
// Drivers may use this to publish metadata to a driver with a topo path that matches
// itself or one of its children. Only drivers running in the "sys" devhost may publish
// metadata to arbitrary topo paths.
zx_status_t device_publish_metadata(zx_device_t* dev, const char* path, uint32_t type,
const void* data, size_t length);
// Device State Change Functions. These match up with the signals defined in
// the fuchsia.device.Controller interface.
//@ #### Device State Bits
void device_state_clr_set(zx_device_t* dev, zx_signals_t clearflag, zx_signals_t setflag);
//@ #### device_state_set
static inline void device_state_set(zx_device_t* dev, zx_signals_t stateflag) {
device_state_clr_set(dev, 0, stateflag);
static inline void device_state_clr(zx_device_t* dev, zx_signals_t stateflag) {
device_state_clr_set(dev, stateflag, 0);
#endif // DDK_DEVICE_H_