1 files changed, 122 insertions, 15 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index bb6f073bc159..0a0f6e21d40e 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -467,9 +467,10 @@ struct uart_port {
 	unsigned int		fifosize;		/* tx fifo size */
 	unsigned char		x_char;			/* xon/xoff char */
 	unsigned char		regshift;		/* reg offset shift */
+
 	unsigned char		iotype;			/* io access style */
-	unsigned char		quirks;			/* internal quirks */
 
+#define UPIO_UNKNOWN		((unsigned char)~0U)	/* UCHAR_MAX */
 #define UPIO_PORT		(SERIAL_IO_PORT)	/* 8b I/O port access */
 #define UPIO_HUB6		(SERIAL_IO_HUB6)	/* Hub6 ISA card */
 #define UPIO_MEM		(SERIAL_IO_MEM)		/* driver-specific */
@@ -479,7 +480,9 @@ struct uart_port {
 #define UPIO_MEM32BE		(SERIAL_IO_MEM32BE)	/* 32b big endian */
 #define UPIO_MEM16		(SERIAL_IO_MEM16)	/* 16b little endian */
 
-	/* quirks must be updated while holding port mutex */
+	unsigned char		quirks;			/* internal quirks */
+
+	/* internal quirks must be updated while holding port mutex */
 #define UPQ_NO_TXEN_TEST	BIT(0)
 
 	unsigned int		read_status_mask;	/* driver specific */
@@ -588,6 +591,85 @@ struct uart_port {
 	void			*private_data;		/* generic platform data pointer */
 };
 
+/**
+ * uart_port_lock - Lock the UART port
+ * @up:		Pointer to UART port structure
+ */
+static inline void uart_port_lock(struct uart_port *up)
+{
+	spin_lock(&up->lock);
+}
+
+/**
+ * uart_port_lock_irq - Lock the UART port and disable interrupts
+ * @up:		Pointer to UART port structure
+ */
+static inline void uart_port_lock_irq(struct uart_port *up)
+{
+	spin_lock_irq(&up->lock);
+}
+
+/**
+ * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts
+ * @up:		Pointer to UART port structure
+ * @flags:	Pointer to interrupt flags storage
+ */
+static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags)
+{
+	spin_lock_irqsave(&up->lock, *flags);
+}
+
+/**
+ * uart_port_trylock - Try to lock the UART port
+ * @up:		Pointer to UART port structure
+ *
+ * Returns: True if lock was acquired, false otherwise
+ */
+static inline bool uart_port_trylock(struct uart_port *up)
+{
+	return spin_trylock(&up->lock);
+}
+
+/**
+ * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts
+ * @up:		Pointer to UART port structure
+ * @flags:	Pointer to interrupt flags storage
+ *
+ * Returns: True if lock was acquired, false otherwise
+ */
+static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags)
+{
+	return spin_trylock_irqsave(&up->lock, *flags);
+}
+
+/**
+ * uart_port_unlock - Unlock the UART port
+ * @up:		Pointer to UART port structure
+ */
+static inline void uart_port_unlock(struct uart_port *up)
+{
+	spin_unlock(&up->lock);
+}
+
+/**
+ * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts
+ * @up:		Pointer to UART port structure
+ */
+static inline void uart_port_unlock_irq(struct uart_port *up)
+{
+	spin_unlock_irq(&up->lock);
+}
+
+/**
+ * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts
+ * @up:		Pointer to UART port structure
+ * @flags:	The saved interrupt flags for restore
+ */
+static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags)
+{
+	spin_unlock_irqrestore(&up->lock, flags);
+}
+
 static inline int serial_port_in(struct uart_port *up, int offset)
 {
 	return up->serial_in(up, offset);
@@ -669,8 +751,17 @@ struct uart_driver {
 
 void uart_write_wakeup(struct uart_port *port);
 
-#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test,      \
-		for_post)						      \
+/**
+ * enum UART_TX_FLAGS -- flags for uart_port_tx_flags()
+ *
+ * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer
+ */
+enum UART_TX_FLAGS {
+	UART_TX_NOSTOP = BIT(0),
+};
+
+#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done,	      \
+		       for_test, for_post)				      \
 ({									      \
 	struct uart_port *__port = (uport);				      \
 	struct circ_buf *xmit = &__port->state->xmit;			      \
@@ -698,7 +789,8 @@ void uart_write_wakeup(struct uart_port *port);
 	if (pending < WAKEUP_CHARS) {					      \
 		uart_write_wakeup(__port);				      \
 									      \
-		if (pending == 0)					      \
+		if (!((flags) & UART_TX_NOSTOP) && pending == 0 &&	      \
+		    __port->ops->tx_empty(__port))			      \
 			__port->ops->stop_tx(__port);			      \
 	}								      \
 									      \
@@ -733,7 +825,7 @@ void uart_write_wakeup(struct uart_port *port);
  */
 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \
 	unsigned int __count = (count);					      \
-	__uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count,	      \
+	__uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count,     \
 			__count--);					      \
 })
 
@@ -747,8 +839,21 @@ void uart_write_wakeup(struct uart_port *port);
  * See uart_port_tx_limited() for more details.
  */
 #define uart_port_tx(port, ch, tx_ready, put_char)			\
-	__uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({}))
+	__uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))
 
+
+/**
+ * uart_port_tx_flags -- transmit helper for uart_port with flags
+ * @port: uart port
+ * @ch: variable to store a character to be written to the HW
+ * @flags: %UART_TX_NOSTOP or similar
+ * @tx_ready: can HW accept more data function
+ * @put_char: function to write a character
+ *
+ * See uart_port_tx_limited() for more details.
+ */
+#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char)		\
+	__uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))
 /*
  * Baud rate helpers.
  */
@@ -773,9 +878,9 @@ static inline unsigned long uart_fifo_timeout(struct uart_port *port)
 }
 
 /* Base timer interval for polling */
-static inline int uart_poll_timeout(struct uart_port *port)
+static inline unsigned long uart_poll_timeout(struct uart_port *port)
 {
-	int timeout = uart_fifo_timeout(port);
+	unsigned long timeout = uart_fifo_timeout(port);
 
 	return timeout > 6 ? (timeout / 2 - 2) : 1;
 }
@@ -858,6 +963,8 @@ int uart_register_driver(struct uart_driver *uart);
 void uart_unregister_driver(struct uart_driver *uart);
 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
+int uart_read_port_properties(struct uart_port *port);
+int uart_read_and_validate_port_properties(struct uart_port *port);
 bool uart_match_port(const struct uart_port *port1,
 		const struct uart_port *port2);
 
@@ -956,14 +1063,14 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 	u8 sysrq_ch;
 
 	if (!port->has_sysrq) {
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 		return;
 	}
 
 	sysrq_ch = port->sysrq_ch;
 	port->sysrq_ch = 0;
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	if (sysrq_ch)
 		handle_sysrq(sysrq_ch);
@@ -975,14 +1082,14 @@ static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port
 	u8 sysrq_ch;
 
 	if (!port->has_sysrq) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		return;
 	}
 
 	sysrq_ch = port->sysrq_ch;
 	port->sysrq_ch = 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (sysrq_ch)
 		handle_sysrq(sysrq_ch);
@@ -998,12 +1105,12 @@ static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
 }
 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 {
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 }
 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
 		unsigned long flags)
 {
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 #endif	/* CONFIG_MAGIC_SYSRQ_SERIAL */