Merge tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver patchset for 3.18-rc1.

  Lots of little things in here, some good work from Peter Hurley on the
  tty core, and in lots of drivers.  There are also lots of other driver
  updates in here as well, full details in the changelogs.

  All have been in the linux-next tree for a while"

* tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (99 commits)
  Revert "serial/core: Initialize the console pm state"
  tty: serial: 8250: use 32bit variable for rpm_tx_active
  tty: serial: msm: Add earlycon support
  serial/core: Initialize the console pm state
  serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)
  serial: of-serial: add PM suspend/resume support
  m68k: AMIGA_BUILTIN_SERIAL should depend on TTY
  asm/uapi: Add definition of TIOC[SG]RS485
  tty/metag_da: Add console_poll module parameter
  serial: 8250_pci: remove rts_n override from Baytrail quirk
  serial: cadence: Add generic earlycon support
  serial: imx: change the wait even to interruptiable
  serial: imx: terminate the RX DMA when the UART is suspending
  serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
  serial: 8250: Add Quark X1000 to 8250_pci.c
  tty: omap-serial: pull out calculation from baud_is_mode16
  tty: omap-serial: fix division by zero
  xen_hvc: no reason to write the type key on xenstore
  tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
  tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
  ...

5 files changed, 45 insertions, 5 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 008388f920d7..64c7425afbce 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -362,6 +362,10 @@ extern void lockdep_trace_alloc(gfp_t mask);
 		WARN_ON(debug_locks && !lockdep_is_held(l));	\
 	} while (0)
 
+#define lockdep_assert_held_once(l)	do {				\
+		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
+	} while (0)
+
 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
 
 #else /* !CONFIG_LOCKDEP */
@@ -412,6 +416,7 @@ struct lock_class_key { };
 #define lockdep_depth(tsk)	(0)
 
 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
+#define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
 
 #define lockdep_recursing(tsk)			(0)
 
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index f93649e22c43..3df10d5f154b 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -84,6 +84,7 @@ struct uart_8250_port {
 	unsigned char		mcr_mask;	/* mask of user bits */
 	unsigned char		mcr_force;	/* mask of forced bits */
 	unsigned char		cur_iotype;	/* Running I/O type */
+	unsigned int		rpm_tx_active;
 
 	/*
 	 * Some bits in registers are cleared on a read, so they must
@@ -96,10 +97,13 @@ struct uart_8250_port {
 	unsigned char		msr_saved_flags;
 
 	struct uart_8250_dma	*dma;
+	struct serial_rs485     rs485;
 
 	/* 8250 specific callbacks */
 	int			(*dl_read)(struct uart_8250_port *);
 	void			(*dl_write)(struct uart_8250_port *, int);
+	int			(*rs485_config)(struct uart_8250_port *,
+						struct serial_rs485 *rs485);
 };
 
 static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)
@@ -121,6 +125,8 @@ extern void serial8250_early_out(struct uart_port *port, int offset, int value);
 extern int setup_early_serial8250_console(char *cmdline);
 extern void serial8250_do_set_termios(struct uart_port *port,
 		struct ktermios *termios, struct ktermios *old);
+extern int serial8250_do_startup(struct uart_port *port);
+extern void serial8250_do_shutdown(struct uart_port *port);
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
 			     unsigned int oldstate);
 extern int fsl8250_handle_irq(struct uart_port *port);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index cf3a1e789bf5..21c2e05c1bc3 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -112,6 +112,7 @@ struct uart_icount {
 };
 
 typedef unsigned int __bitwise__ upf_t;
+typedef unsigned int __bitwise__ upstat_t;
 
 struct uart_port {
 	spinlock_t		lock;			/* port lock */
@@ -122,6 +123,10 @@ struct uart_port {
 	void			(*set_termios)(struct uart_port *,
 				               struct ktermios *new,
 				               struct ktermios *old);
+	int			(*startup)(struct uart_port *port);
+	void			(*shutdown)(struct uart_port *port);
+	void			(*throttle)(struct uart_port *port);
+	void			(*unthrottle)(struct uart_port *port);
 	int			(*handle_irq)(struct uart_port *);
 	void			(*pm)(struct uart_port *, unsigned int state,
 				      unsigned int old);
@@ -152,6 +157,7 @@ struct uart_port {
 	unsigned long		sysrq;			/* sysrq timeout */
 #endif
 
+	/* flags must be updated while holding port mutex */
 	upf_t			flags;
 
 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
@@ -187,6 +193,13 @@ struct uart_port {
 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 
+	/* status must be updated while holding port lock */
+	upstat_t		status;
+
+#define UPSTAT_CTS_ENABLE	((__force upstat_t) (1 << 0))
+#define UPSTAT_DCD_ENABLE	((__force upstat_t) (1 << 1))
+
+	int			hw_stopped;		/* sw-assisted CTS flow state */
 	unsigned int		mctrl;			/* current modem ctrl settings */
 	unsigned int		timeout;		/* character-based timeout */
 	unsigned int		type;			/* port type */
@@ -347,11 +360,16 @@ int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
 static inline int uart_tx_stopped(struct uart_port *port)
 {
 	struct tty_struct *tty = port->state->port.tty;
-	if(tty->stopped || tty->hw_stopped)
+	if (tty->stopped || port->hw_stopped)
 		return 1;
 	return 0;
 }
 
+static inline bool uart_cts_enabled(struct uart_port *uport)
+{
+	return uport->status & UPSTAT_CTS_ENABLE;
+}
+
 /*
  * The following are helper functions for the low level drivers.
  */
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 84132942902a..5171ef8f7b85 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -252,6 +252,7 @@ struct tty_struct {
 	struct rw_semaphore termios_rwsem;
 	struct mutex winsize_mutex;
 	spinlock_t ctrl_lock;
+	spinlock_t flow_lock;
 	/* Termios values are protected by the termios rwsem */
 	struct ktermios termios, termios_locked;
 	struct termiox *termiox;	/* May be NULL for unsupported */
@@ -261,8 +262,13 @@ struct tty_struct {
 	unsigned long flags;
 	int count;
 	struct winsize winsize;		/* winsize_mutex */
-	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
-	unsigned char ctrl_status;	/* ctrl_lock */
+	unsigned long stopped:1,	/* flow_lock */
+		      flow_stopped:1,
+		      unused:BITS_PER_LONG - 2;
+	int hw_stopped;
+	unsigned long ctrl_status:8,	/* ctrl_lock */
+		      packet:1,
+		      unused_ctrl:BITS_PER_LONG - 9;
 	unsigned int receive_room;	/* Bytes free for queue */
 	int flow_change;
 
@@ -397,7 +403,9 @@ extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 extern char *tty_name(struct tty_struct *tty, char *buf);
 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 extern int tty_check_change(struct tty_struct *tty);
+extern void __stop_tty(struct tty_struct *tty);
 extern void stop_tty(struct tty_struct *tty);
+extern void __start_tty(struct tty_struct *tty);
 extern void start_tty(struct tty_struct *tty);
 extern int tty_register_driver(struct tty_driver *driver);
 extern int tty_unregister_driver(struct tty_driver *driver);
@@ -411,6 +419,7 @@ extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
 			     int buflen);
 extern void tty_write_message(struct tty_struct *tty, char *msg);
+extern int tty_send_xchar(struct tty_struct *tty, char ch);
 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
 extern int tty_chars_in_buffer(struct tty_struct *tty);
 extern int tty_write_room(struct tty_struct *tty);
@@ -495,8 +504,6 @@ extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
 extern struct mutex tty_mutex;
 extern spinlock_t tty_files_lock;
 
-extern void tty_write_unlock(struct tty_struct *tty);
-extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 
 extern void tty_port_init(struct tty_port *port);
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index e48c608a8fa8..92e337c18839 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -152,6 +152,8 @@
  * 	This routine notifies the tty driver that it should stop
  * 	outputting characters to the tty device.  
  *
+ *	Called with ->flow_lock held. Serialized with start() method.
+ *
  *	Optional:
  *
  *	Note: Call stop_tty not this method.
@@ -161,6 +163,8 @@
  * 	This routine notifies the tty driver that it resume sending
  *	characters to the tty device.
  *
+ *	Called with ->flow_lock held. Serialized with stop() method.
+ *
  *	Optional:
  *
  *	Note: Call start_tty not this method.