pcie_root_port: Allow ACS to be disabled
[qemu/ar7.git] / include / chardev / char-fe.h
blobaa1b864ccda472fff8af07dea27aff65973ab35e
1 #ifndef QEMU_CHAR_FE_H
2 #define QEMU_CHAR_FE_H
4 #include "chardev/char.h"
6 typedef void IOEventHandler(void *opaque, int event);
7 typedef int BackendChangeHandler(void *opaque);
9 /* This is the backend as seen by frontend, the actual backend is
10 * Chardev */
11 struct CharBackend {
12 Chardev *chr;
13 IOEventHandler *chr_event;
14 IOCanReadHandler *chr_can_read;
15 IOReadHandler *chr_read;
16 BackendChangeHandler *chr_be_change;
17 void *opaque;
18 int tag;
19 int fe_open;
22 /**
23 * qemu_chr_fe_init:
25 * Initializes a front end for the given CharBackend and
26 * Chardev. Call qemu_chr_fe_deinit() to remove the association and
27 * release the driver.
29 * Returns: false on error.
31 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp);
33 /**
34 * qemu_chr_fe_deinit:
35 * @b: a CharBackend
36 * @del: if true, delete the chardev backend
38 * Dissociate the CharBackend from the Chardev.
40 * Safe to call without associated Chardev.
42 void qemu_chr_fe_deinit(CharBackend *b, bool del);
44 /**
45 * qemu_chr_fe_get_driver:
47 * Returns: the driver associated with a CharBackend or NULL if no
48 * associated Chardev.
49 * Note: avoid this function as the driver should never be accessed directly,
50 * especially by the frontends that support chardevice hotswap.
51 * Consider qemu_chr_fe_backend_connected() to check for driver existence
53 Chardev *qemu_chr_fe_get_driver(CharBackend *be);
55 /**
56 * qemu_chr_fe_backend_connected:
58 * Returns: true if there is a chardevice associated with @be.
60 bool qemu_chr_fe_backend_connected(CharBackend *be);
62 /**
63 * qemu_chr_fe_backend_open:
65 * Returns: true if chardevice associated with @be is open.
67 bool qemu_chr_fe_backend_open(CharBackend *be);
69 /**
70 * qemu_chr_fe_set_handlers_full:
71 * @b: a CharBackend
72 * @fd_can_read: callback to get the amount of data the frontend may
73 * receive
74 * @fd_read: callback to receive data from char
75 * @fd_event: event callback
76 * @be_change: backend change callback; passing NULL means hot backend change
77 * is not supported and will not be attempted
78 * @opaque: an opaque pointer for the callbacks
79 * @context: a main loop context or NULL for the default
80 * @set_open: whether to call qemu_chr_fe_set_open() implicitely when
81 * any of the handler is non-NULL
82 * @sync_state: whether to issue event callback with updated state
84 * Set the front end char handlers. The front end takes the focus if
85 * any of the handler is non-NULL.
87 * Without associated Chardev, nothing is changed.
89 void qemu_chr_fe_set_handlers_full(CharBackend *b,
90 IOCanReadHandler *fd_can_read,
91 IOReadHandler *fd_read,
92 IOEventHandler *fd_event,
93 BackendChangeHandler *be_change,
94 void *opaque,
95 GMainContext *context,
96 bool set_open,
97 bool sync_state);
99 /**
100 * qemu_chr_fe_set_handlers:
102 * Version of qemu_chr_fe_set_handlers_full() with sync_state = true.
104 void qemu_chr_fe_set_handlers(CharBackend *b,
105 IOCanReadHandler *fd_can_read,
106 IOReadHandler *fd_read,
107 IOEventHandler *fd_event,
108 BackendChangeHandler *be_change,
109 void *opaque,
110 GMainContext *context,
111 bool set_open);
114 * qemu_chr_fe_take_focus:
116 * Take the focus (if the front end is muxed).
118 * Without associated Chardev, nothing is changed.
120 void qemu_chr_fe_take_focus(CharBackend *b);
123 * qemu_chr_fe_accept_input:
125 * Notify that the frontend is ready to receive data
127 void qemu_chr_fe_accept_input(CharBackend *be);
130 * qemu_chr_fe_disconnect:
132 * Close a fd accepted by character backend.
133 * Without associated Chardev, do nothing.
135 void qemu_chr_fe_disconnect(CharBackend *be);
138 * qemu_chr_fe_wait_connected:
140 * Wait for characted backend to be connected, return < 0 on error or
141 * if no associated Chardev.
143 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp);
146 * qemu_chr_fe_set_echo:
147 * @echo: true to enable echo, false to disable echo
149 * Ask the backend to override its normal echo setting. This only really
150 * applies to the stdio backend and is used by the QMP server such that you
151 * can see what you type if you try to type QMP commands.
152 * Without associated Chardev, do nothing.
154 void qemu_chr_fe_set_echo(CharBackend *be, bool echo);
157 * qemu_chr_fe_set_open:
159 * Set character frontend open status. This is an indication that the
160 * front end is ready (or not) to begin doing I/O.
161 * Without associated Chardev, do nothing.
163 void qemu_chr_fe_set_open(CharBackend *be, int fe_open);
166 * qemu_chr_fe_printf:
167 * @fmt: see #printf
169 * Write to a character backend using a printf style interface. This
170 * function is thread-safe. It does nothing without associated
171 * Chardev.
173 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
174 GCC_FMT_ATTR(2, 3);
177 * qemu_chr_fe_add_watch:
178 * @cond: the condition to poll for
179 * @func: the function to call when the condition happens
180 * @user_data: the opaque pointer to pass to @func
182 * If the backend is connected, create and add a #GSource that fires
183 * when the given condition (typically G_IO_OUT|G_IO_HUP or G_IO_HUP)
184 * is active; return the #GSource's tag. If it is disconnected,
185 * or without associated Chardev, return 0.
187 * Note that you are responsible to update the front-end sources if
188 * you are switching the main context with qemu_chr_fe_set_handlers().
190 * Returns: the source tag
192 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
193 GIOFunc func, void *user_data);
196 * qemu_chr_fe_write:
197 * @buf: the data
198 * @len: the number of bytes to send
200 * Write data to a character backend from the front end. This function
201 * will send data from the front end to the back end. This function
202 * is thread-safe.
204 * Returns: the number of bytes consumed (0 if no associated Chardev)
206 int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len);
209 * qemu_chr_fe_write_all:
210 * @buf: the data
211 * @len: the number of bytes to send
213 * Write data to a character backend from the front end. This function will
214 * send data from the front end to the back end. Unlike @qemu_chr_fe_write,
215 * this function will block if the back end cannot consume all of the data
216 * attempted to be written. This function is thread-safe.
218 * Returns: the number of bytes consumed (0 if no associated Chardev)
220 int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len);
223 * qemu_chr_fe_read_all:
224 * @buf: the data buffer
225 * @len: the number of bytes to read
227 * Read data to a buffer from the back end.
229 * Returns: the number of bytes read (0 if no associated Chardev)
231 int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len);
234 * qemu_chr_fe_ioctl:
235 * @cmd: see CHR_IOCTL_*
236 * @arg: the data associated with @cmd
238 * Issue a device specific ioctl to a backend. This function is thread-safe.
240 * Returns: if @cmd is not supported by the backend or there is no
241 * associated Chardev, -ENOTSUP, otherwise the return
242 * value depends on the semantics of @cmd
244 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg);
247 * qemu_chr_fe_get_msgfd:
249 * For backends capable of fd passing, return the latest file descriptor passed
250 * by a client.
252 * Returns: -1 if fd passing isn't supported or there is no pending file
253 * descriptor. If a file descriptor is returned, subsequent calls to
254 * this function will return -1 until a client sends a new file
255 * descriptor.
257 int qemu_chr_fe_get_msgfd(CharBackend *be);
260 * qemu_chr_fe_get_msgfds:
262 * For backends capable of fd passing, return the number of file received
263 * descriptors and fills the fds array up to num elements
265 * Returns: -1 if fd passing isn't supported or there are no pending file
266 * descriptors. If file descriptors are returned, subsequent calls to
267 * this function will return -1 until a client sends a new set of file
268 * descriptors.
270 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int num);
273 * qemu_chr_fe_set_msgfds:
275 * For backends capable of fd passing, set an array of fds to be passed with
276 * the next send operation.
277 * A subsequent call to this function before calling a write function will
278 * result in overwriting the fd array with the new value without being send.
279 * Upon writing the message the fd array is freed.
281 * Returns: -1 if fd passing isn't supported or no associated Chardev.
283 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num);
285 #endif /* QEMU_CHAR_FE_H */