tty/serial/serial_core.c

55 static void uart_change_pm(struct uart_state *state,
65 static inline struct uart_port *uart_port_ref(struct uart_state *state)
67 	if (atomic_add_unless(&state->refcount, 1, 0))
68 		return state->uart_port;
74 	if (atomic_dec_and_test(&uport->state->refcount))
75 		wake_up(&uport->state->remove_wait);
78 #define uart_port_lock(state, flags)					\
80 		struct uart_port *__uport = uart_port_ref(state);	\
95 static inline struct uart_port *uart_port_check(struct uart_state *state)
97 	lockdep_assert_held(&state->port.mutex);
98 	return state->uart_port;
114 	struct uart_state *state = port->state;
119 	BUG_ON(!state);
120 	tty_port_tty_wakeup(&state->port);
126 	struct uart_state *state = tty->driver_data;
130 	port = uart_port_lock(state, flags);
136 static void __uart_start(struct uart_state *state)
138 	struct uart_port *port = state->uart_port;
167 	struct uart_state *state = tty->driver_data;
171 	port = uart_port_lock(state, flags);
172 	__uart_start(state);
202 static void uart_change_line_settings(struct tty_struct *tty, struct uart_state *state,
205 	struct uart_port *uport = uart_port_check(state);
241 			__uart_start(state);
250 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
253 	struct uart_port *uport = uart_port_check(state);
262 	 * Make sure the device is in D0 state.
264 	uart_change_pm(state, UART_PM_STATE_ON);
274 	uart_port_lock(state, flags);
275 	if (!state->xmit.buf) {
276 		state->xmit.buf = (unsigned char *) page;
277 		uart_circ_clear(&state->xmit);
301 		uart_change_line_settings(tty, state, NULL);
322 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
325 	struct tty_port *port = &state->port;
332 	retval = uart_port_startup(tty, state, init_hw);
339 	uport = uart_port_check(state);
355 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
357 	struct uart_port *uport = uart_port_check(state);
358 	struct tty_port *port = &state->port;
402 	uart_port_lock(state, flags);
403 	xmit_buf = state->xmit.buf;
404 	state->xmit.buf = NULL;
566 	struct uart_state *state = tty->driver_data;
572 	circ = &state->xmit;
573 	port = uart_port_lock(state, flags);
595 	struct uart_state *state = tty->driver_data;
605 	if (WARN_ON(!state))
608 	port = uart_port_lock(state, flags);
609 	circ = &state->xmit;
628 	__uart_start(state);
635 	struct uart_state *state = tty->driver_data;
640 	port = uart_port_lock(state, flags);
641 	ret = uart_circ_chars_free(&state->xmit);
648 	struct uart_state *state = tty->driver_data;
653 	port = uart_port_lock(state, flags);
654 	ret = uart_circ_chars_pending(&state->xmit);
661 	struct uart_state *state = tty->driver_data;
669 	if (WARN_ON(!state))
674 	port = uart_port_lock(state, flags);
677 	uart_circ_clear(&state->xmit);
681 	tty_port_tty_wakeup(&state->port);
704 	struct uart_state *state = tty->driver_data;
708 	port = uart_port_ref(state);
726 	struct uart_state *state = tty->driver_data;
730 	port = uart_port_ref(state);
755 	struct uart_state *state = tty->driver_data;
759 	port = uart_port_ref(state);
784 	struct uart_state *state = container_of(port, struct uart_state, port);
792 	 * Ensure the state we copy is consistent and no hardware changes
796 	uport = uart_port_check(state);
828 	struct uart_state *state = tty->driver_data;
829 	struct tty_port *port = &state->port;
835 			 struct uart_state *state,
838 	struct uart_port *uport = uart_port_check(state);
927 		uart_shutdown(tty, state);
1025 			uart_change_line_settings(tty, state, NULL);
1028 		retval = uart_startup(tty, state, true);
1040 	struct uart_state *state = tty->driver_data;
1041 	struct tty_port *port = &state->port;
1053 	retval = uart_set_info(tty, port, state, ss);
1062  * @state: UART being queried
1066 			struct uart_state *state, unsigned int __user *value)
1068 	struct uart_port *uport = uart_port_check(state);
1080 	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
1089 	struct uart_state *state = tty->driver_data;
1090 	struct tty_port *port = &state->port;
1095 	uport = uart_port_check(state);
1113 	struct uart_state *state = tty->driver_data;
1114 	struct tty_port *port = &state->port;
1119 	uport = uart_port_check(state);
1134 	struct uart_state *state = tty->driver_data;
1135 	struct tty_port *port = &state->port;
1140 	uport = uart_port_check(state);
1152 static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state)
1154 	struct tty_port *port = &state->port;
1169 	uport = uart_port_check(state);
1177 		uart_shutdown(tty, state);
1196 		ret = uart_startup(tty, state, true);
1225 static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1228 	struct tty_port *port = &state->port;
1236 	uport = uart_port_ref(state);
1286 	struct uart_state *state = tty->driver_data;
1290 	uport = uart_port_ref(state);
1586 	struct uart_state *state = tty->driver_data;
1587 	struct tty_port *port = &state->port;
1599 		ret = uart_do_autoconfig(tty, state);
1617 		ret = uart_wait_modem_status(state, arg);
1629 	uport = uart_port_check(state);
1643 		ret = uart_get_lsr_info(tty, state, uarg);
1655 		ret = uart_set_iso7816_config(state->uart_port, uarg);
1659 		ret = uart_get_iso7816_config(state->uart_port, uarg);
1676 	struct uart_state *state = tty->driver_data;
1678 	struct tty_port *port = &state->port;
1683 	mutex_lock(&state->port.mutex);
1684 	uport = uart_port_check(state);
1687 	mutex_unlock(&state->port.mutex);
1693 	struct uart_state *state = tty->driver_data;
1699 	mutex_lock(&state->port.mutex);
1700 	uport = uart_port_check(state);
1729 	uart_change_line_settings(tty, state, old_termios);
1745 	mutex_unlock(&state->port.mutex);
1755 	struct uart_state *state = tty->driver_data;
1757 	if (!state) {
1761 		state = drv->state + tty->index;
1762 		port = &state->port;
1776 	struct uart_state *state = container_of(port, struct uart_state, port);
1777 	struct uart_port *uport = uart_port_check(state);
1805 	uart_circ_clear(&state->xmit);
1806 	buf = state->xmit.buf;
1807 	state->xmit.buf = NULL;
1812 	uart_change_pm(state, UART_PM_STATE_OFF);
1817 	struct uart_state *state = tty->driver_data;
1821 	port = uart_port_ref(state);
1885 	struct uart_state *state = tty->driver_data;
1886 	struct tty_port *port = &state->port;
1893 	uport = uart_port_check(state);
1898 		uart_shutdown(tty, state);
1905 			uart_change_pm(state, UART_PM_STATE_OFF);
1915 	struct uart_state *state = container_of(port, struct uart_state, port);
1916 	struct uart_port *uport = uart_port_check(state);
1938 	struct uart_state *state = container_of(port, struct uart_state, port);
1942 	uport = uart_port_ref(state);
1962 	struct uart_state *state = container_of(port, struct uart_state, port);
1965 	uport = uart_port_ref(state);
1975 	struct uart_state *state = drv->state + tty->index;
1977 	tty->driver_data = state;
1994 	struct uart_state *state = tty->driver_data;
1997 	retval = tty_port_open(&state->port, tty, filp);
2006 	struct uart_state *state = container_of(port, struct uart_state, port);
2010 	uport = uart_port_check(state);
2017 	ret = uart_startup(tty, state, false);
2041 	struct uart_state *state = drv->state + i;
2042 	struct tty_port *port = &state->port;
2050 	uport = uart_port_check(state);
2068 		pm_state = state->pm_state;
2070 			uart_change_pm(state, UART_PM_STATE_ON);
2075 			uart_change_pm(state, pm_state);
2352  * uart_change_pm - set power state of the port
2354  * @state: port descriptor
2355  * @pm_state: new state
2359 static void uart_change_pm(struct uart_state *state,
2362 	struct uart_port *port = uart_port_check(state);
2364 	if (state->pm_state != pm_state) {
2366 			port->ops->pm(port, pm_state, state->pm_state);
2367 		state->pm_state = pm_state;
2388 	struct uart_state *state = drv->state + uport->line;
2389 	struct tty_port *port = &state->port;
2458 	uart_change_pm(state, UART_PM_STATE_OFF);
2468 	struct uart_state *state = drv->state + uport->line;
2469 	struct tty_port *port = &state->port;
2506 			uart_change_pm(state, UART_PM_STATE_ON);
2521 		uart_change_pm(state, UART_PM_STATE_ON);
2533 					uart_change_line_settings(tty, state, NULL);
2547 				uart_shutdown(tty, state);
2603 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2644 		uart_change_pm(state, UART_PM_STATE_ON);
2675 			uart_change_pm(state, UART_PM_STATE_OFF);
2684 	struct uart_state *state = drv->state + line;
2694 	tport = &state->port;
2697 	port = uart_port_check(state);
2704 	pm_state = state->pm_state;
2705 	uart_change_pm(state, UART_PM_STATE_ON);
2710 		 * e.g. state->xmit is still uninitialized.
2724 		uart_change_pm(state, pm_state);
2732 	struct uart_state *state = drv->state + line;
2736 	port = uart_port_ref(state);
2748 	struct uart_state *state = drv->state + line;
2751 	port = uart_port_ref(state);
2810  * tty layer, and initialise the core driver per-port state.
2825 	BUG_ON(drv->state);
2831 	drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2832 	if (!drv->state)
2857 	 * Initialise the UART state(s).
2860 		struct uart_state *state = drv->state + i;
2861 		struct tty_port *port = &state->port;
2872 		tty_port_destroy(&drv->state[i].port);
2875 	kfree(drv->state);
2899 		tty_port_destroy(&drv->state[i].port);
2900 	kfree(drv->state);
2901 	drv->state = NULL;
3052 	struct uart_state *state = container_of(port, struct uart_state, port);
3057 	uport = uart_port_check(state);
3069 	struct uart_state *state = container_of(port, struct uart_state, port);
3079 	uport = uart_port_check(state);
3151 	struct uart_state *state;
3160 	state = drv->state + uport->line;
3161 	port = &state->port;
3164 	if (state->uart_port) {
3169 	/* Link the port to the driver state table and vice versa */
3170 	atomic_set(&state->refcount, 1);
3171 	init_waitqueue_head(&state->remove_wait);
3172 	state->uart_port = uport;
3173 	uport->state = state;
3175 	state->pm_state = UART_PM_STATE_UNDEFINED;
3196 	uart_configure_port(drv, state, uport);
3248 	struct uart_state *state = drv->state + uport->line;
3249 	struct tty_port *port = &state->port;
3254 	uart_port = uart_port_check(state);
3297 	WARN_ON(atomic_dec_return(&state->refcount) < 0);
3298 	wait_event(state->remove_wait, !atomic_read(&state->refcount));
3299 	state->uart_port = NULL;
3352 	struct uart_state *state;
3358 		state = drv->state + i;
3359 		if (!state->uart_port || !state->uart_port->port_dev)
3362 		if (state->uart_port->dev == phys_dev &&
3363 		    state->uart_port->ctrl_id == ctrl_id)
3364 			return serial_core_get_ctrl_dev(state->uart_port->port_dev);
3475  * uart_handle_dcd_change - handle a change of carrier detect state
3483 	struct tty_port *port = &uport->state->port;
3510  * uart_handle_cts_change - handle a change of clear-to-send state
3547  * @status: state of the serial port RX buffer (LSR for 8250)
3555 	struct tty_port *tport = &port->state->port;
3654 	 * to get to a defined state with the following properties: