Merge tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of serial and tty driver updates for 6.15-rc1.
  Include in here are the following:

   - more great tty layer cleanups from Jiri. Someday this will be done,
     but that's not going to be any year soon...

   - kdb debug driver reverts to fix a reported issue

   - lots of .dts binding updates for different devices with serial
     devices

   - lots of tiny updates and tweaks and a few bugfixes for different
     serial drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits)
  tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning
  serial: stm32: do not deassert RS485 RTS GPIO prematurely
  serial: 8250: add driver for NI UARTs
  dt-bindings: serial: snps-dw-apb-uart: document RZ/N1 binding without DMA
  serial: icom: fix code format problems
  serial: sh-sci: Save and restore more registers
  tty: serial: pl011: remove incorrect of_match_ptr annotation
  dt-bindings: serial: snps-dw-apb-uart: Add support for rk3562
  tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register
  tty: caif: removed unused function debugfs_tx()
  serial: 8250_dma: terminate correct DMA in tx_dma_flush()
  tty: serial: fsl_lpuart: rename register variables more specifically
  tty: serial: fsl_lpuart: use port struct directly to simply code
  tty: serial: fsl_lpuart: Use u32 and u8 for register variables
  tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers
  tty: serial: 8250: Add Brainboxes XC devices
  dt-bindings: serial: fsl-lpuart: support i.MX94
  tty: serial: 8250: Add some more device IDs
  dt-bindings: serial: samsung: add exynos7870-uart compatible
  serial: 8250_dw: Comment possible corner cases in serial_out() implementation
  ...

5 files changed, 124 insertions, 127 deletions

diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 51ef131e66b7..5eebbe7a3545 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -257,7 +257,6 @@ extern void kgdb_arch_late(void);
  * hardware breakpoints.
  * @correct_hw_break: Allow an architecture to specify how to correct the
  * hardware debug registers.
- * @enable_nmi: Manage NMI-triggered entry to KGDB
  */
 struct kgdb_arch {
 	unsigned char		gdb_bpt_instr[BREAK_INSTR_SIZE];
@@ -270,8 +269,6 @@ struct kgdb_arch {
 	void	(*disable_hw_break)(struct pt_regs *regs);
 	void	(*remove_all_hw_break)(void);
 	void	(*correct_hw_break)(void);
-
-	void	(*enable_nmi)(bool on);
 };
 
 /**
@@ -306,14 +303,6 @@ extern const struct kgdb_arch		arch_kgdb_ops;
 
 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
 
-#ifdef CONFIG_SERIAL_KGDB_NMI
-extern int kgdb_register_nmi_console(void);
-extern int kgdb_unregister_nmi_console(void);
-#else
-static inline int kgdb_register_nmi_console(void) { return 0; }
-static inline int kgdb_unregister_nmi_console(void) { return 0; }
-#endif
-
 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
 extern struct kgdb_io *dbg_io_ops;
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index ff78efc1f60d..34562eb99931 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -84,7 +84,6 @@ enum serdev_parity {
 struct serdev_controller_ops {
 	ssize_t (*write_buf)(struct serdev_controller *, const u8 *, size_t);
 	void (*write_flush)(struct serdev_controller *);
-	int (*write_room)(struct serdev_controller *);
 	int (*open)(struct serdev_controller *);
 	void (*close)(struct serdev_controller *);
 	void (*set_flow_control)(struct serdev_controller *, bool);
@@ -212,7 +211,6 @@ int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
 void serdev_device_write_wakeup(struct serdev_device *);
 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
 void serdev_device_write_flush(struct serdev_device *);
-int serdev_device_write_room(struct serdev_device *);
 
 /*
  * serdev device driver functions
@@ -273,10 +271,6 @@ static inline ssize_t serdev_device_write(struct serdev_device *sdev,
 	return -ENODEV;
 }
 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
-static inline int serdev_device_write_room(struct serdev_device *sdev)
-{
-	return 0;
-}
 
 #define serdev_device_driver_register(x)
 #define serdev_device_driver_unregister(x)
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 2372f9357240..0a46e4054dec 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -239,7 +239,6 @@ struct tty_struct {
 
 	struct list_head tty_files;
 
-#define N_TTY_BUF_SIZE 4096
 	struct work_struct SAK_work;
 } __randomize_layout;
 
@@ -251,7 +250,7 @@ struct tty_file_private {
 };
 
 /**
- * DOC: TTY Struct Flags
+ * enum tty_struct_flags - TTY Struct Flags
  *
  * These bits are used in the :c:member:`tty_struct.flags` field.
  *
@@ -260,62 +259,64 @@ struct tty_file_private {
  * tty->write.  Thus, you must use the inline functions set_bit() and
  * clear_bit() to make things atomic.
  *
- * TTY_THROTTLED
+ * @TTY_THROTTLED:
  *	Driver input is throttled. The ldisc should call
  *	:c:member:`tty_driver.unthrottle()` in order to resume reception when
  *	it is ready to process more data (at threshold min).
  *
- * TTY_IO_ERROR
+ * @TTY_IO_ERROR:
  *	If set, causes all subsequent userspace read/write calls on the tty to
  *	fail, returning -%EIO. (May be no ldisc too.)
  *
- * TTY_OTHER_CLOSED
+ * @TTY_OTHER_CLOSED:
  *	Device is a pty and the other side has closed.
  *
- * TTY_EXCLUSIVE
+ * @TTY_EXCLUSIVE:
  *	Exclusive open mode (a single opener).
  *
- * TTY_DO_WRITE_WAKEUP
+ * @TTY_DO_WRITE_WAKEUP:
  *	If set, causes the driver to call the
  *	:c:member:`tty_ldisc_ops.write_wakeup()` method in order to resume
  *	transmission when it can accept more data to transmit.
  *
- * TTY_LDISC_OPEN
+ * @TTY_LDISC_OPEN:
  *	Indicates that a line discipline is open. For debugging purposes only.
  *
- * TTY_PTY_LOCK
+ * @TTY_PTY_LOCK:
  *	A flag private to pty code to implement %TIOCSPTLCK/%TIOCGPTLCK logic.
  *
- * TTY_NO_WRITE_SPLIT
+ * @TTY_NO_WRITE_SPLIT:
  *	Prevent driver from splitting up writes into smaller chunks (preserve
  *	write boundaries to driver).
  *
- * TTY_HUPPED
+ * @TTY_HUPPED:
  *	The TTY was hung up. This is set post :c:member:`tty_driver.hangup()`.
  *
- * TTY_HUPPING
+ * @TTY_HUPPING:
  *	The TTY is in the process of hanging up to abort potential readers.
  *
- * TTY_LDISC_CHANGING
+ * @TTY_LDISC_CHANGING:
  *	Line discipline for this TTY is being changed. I/O should not block
  *	when this is set. Use tty_io_nonblock() to check.
  *
- * TTY_LDISC_HALTED
+ * @TTY_LDISC_HALTED:
  *	Line discipline for this TTY was stopped. No work should be queued to
  *	this ldisc.
  */
-#define TTY_THROTTLED		0
-#define TTY_IO_ERROR		1
-#define TTY_OTHER_CLOSED	2
-#define TTY_EXCLUSIVE		3
-#define TTY_DO_WRITE_WAKEUP	5
-#define TTY_LDISC_OPEN		11
-#define TTY_PTY_LOCK		16
-#define TTY_NO_WRITE_SPLIT	17
-#define TTY_HUPPED		18
-#define TTY_HUPPING		19
-#define TTY_LDISC_CHANGING	20
-#define TTY_LDISC_HALTED	22
+enum tty_struct_flags {
+	TTY_THROTTLED,
+	TTY_IO_ERROR,
+	TTY_OTHER_CLOSED,
+	TTY_EXCLUSIVE,
+	TTY_DO_WRITE_WAKEUP,
+	TTY_LDISC_OPEN,
+	TTY_PTY_LOCK,
+	TTY_NO_WRITE_SPLIT,
+	TTY_HUPPED,
+	TTY_HUPPING,
+	TTY_LDISC_CHANGING,
+	TTY_LDISC_HALTED,
+};
 
 static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
 {
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index d4cdc089f6c3..188ee9b768eb 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -17,6 +17,92 @@ struct serial_icounter_struct;
 struct serial_struct;
 
 /**
+ * enum tty_driver_flag -- TTY Driver Flags
+ *
+ * These are flags passed to tty_alloc_driver().
+ *
+ * @TTY_DRIVER_INSTALLED:
+ *	Whether this driver was succesfully installed. This is a tty internal
+ *	flag. Do not touch.
+ *
+ * @TTY_DRIVER_RESET_TERMIOS:
+ *	Requests the tty layer to reset the termios setting when the last
+ *	process has closed the device. Used for PTYs, in particular.
+ *
+ * @TTY_DRIVER_REAL_RAW:
+ *	Indicates that the driver will guarantee not to set any special
+ *	character handling flags if this is set for the tty:
+ *
+ *	``(IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || !INPCK)``
+ *
+ *	That is, if there is no reason for the driver to
+ *	send notifications of parity and break characters up to the line
+ *	driver, it won't do so.  This allows the line driver to optimize for
+ *	this case if this flag is set.  (Note that there is also a promise, if
+ *	the above case is true, not to signal overruns, either.)
+ *
+ * @TTY_DRIVER_DYNAMIC_DEV:
+ *	The individual tty devices need to be registered with a call to
+ *	tty_register_device() when the device is found in the system and
+ *	unregistered with a call to tty_unregister_device() so the devices will
+ *	be show up properly in sysfs.  If not set, all &tty_driver.num entries
+ *	will be created by the tty core in sysfs when tty_register_driver() is
+ *	called.  This is to be used by drivers that have tty devices that can
+ *	appear and disappear while the main tty driver is registered with the
+ *	tty core.
+ *
+ * @TTY_DRIVER_DEVPTS_MEM:
+ *	Don't use the standard arrays (&tty_driver.ttys and
+ *	&tty_driver.termios), instead use dynamic memory keyed through the
+ *	devpts filesystem. This is only applicable to the PTY driver.
+ *
+ * @TTY_DRIVER_HARDWARE_BREAK:
+ *	Hardware handles break signals. Pass the requested timeout to the
+ *	&tty_operations.break_ctl instead of using a simple on/off interface.
+ *
+ * @TTY_DRIVER_DYNAMIC_ALLOC:
+ *	Do not allocate structures which are needed per line for this driver
+ *	(&tty_driver.ports) as it would waste memory. The driver will take
+ *	care. This is only applicable to the PTY driver.
+ *
+ * @TTY_DRIVER_UNNUMBERED_NODE:
+ *	Do not create numbered ``/dev`` nodes. For example, create
+ *	``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
+ *	driver for a single tty device is being allocated.
+ */
+enum tty_driver_flag {
+	TTY_DRIVER_INSTALLED		= BIT(0),
+	TTY_DRIVER_RESET_TERMIOS	= BIT(1),
+	TTY_DRIVER_REAL_RAW		= BIT(2),
+	TTY_DRIVER_DYNAMIC_DEV		= BIT(3),
+	TTY_DRIVER_DEVPTS_MEM		= BIT(4),
+	TTY_DRIVER_HARDWARE_BREAK	= BIT(5),
+	TTY_DRIVER_DYNAMIC_ALLOC	= BIT(6),
+	TTY_DRIVER_UNNUMBERED_NODE	= BIT(7),
+};
+
+enum tty_driver_type {
+	TTY_DRIVER_TYPE_SYSTEM,
+	TTY_DRIVER_TYPE_CONSOLE,
+	TTY_DRIVER_TYPE_SERIAL,
+	TTY_DRIVER_TYPE_PTY,
+	TTY_DRIVER_TYPE_SCC,
+	TTY_DRIVER_TYPE_SYSCONS,
+};
+
+enum tty_driver_subtype {
+	SYSTEM_TYPE_TTY = 1,
+	SYSTEM_TYPE_CONSOLE,
+	SYSTEM_TYPE_SYSCONS,
+	SYSTEM_TYPE_SYSPTMX,
+
+	PTY_TYPE_MASTER = 1,
+	PTY_TYPE_SLAVE,
+
+	SERIAL_TYPE_NORMAL = 1,
+};
+
+/**
  * struct tty_operations -- interface between driver and tty
  *
  * @lookup: ``struct tty_struct *()(struct tty_driver *self, struct file *,
@@ -414,8 +500,8 @@ struct tty_operations {
  * @major: major /dev device number (zero for autoassignment)
  * @minor_start: the first minor /dev device number
  * @num: number of devices allocated
- * @type: type of tty driver (%TTY_DRIVER_TYPE_)
- * @subtype: subtype of tty driver (%SYSTEM_TYPE_, %PTY_TYPE_, %SERIAL_TYPE_)
+ * @type: type of tty driver (enum tty_driver_type)
+ * @subtype: subtype of tty driver (enum tty_driver_subtype)
  * @init_termios: termios to set to each tty initially (e.g. %tty_std_termios)
  * @flags: tty driver flags (%TTY_DRIVER_)
  * @proc_entry: proc fs entry, used internally
@@ -447,8 +533,8 @@ struct tty_driver {
 	int	major;
 	int	minor_start;
 	unsigned int	num;
-	short	type;
-	short	subtype;
+	enum tty_driver_type type;
+	enum tty_driver_subtype subtype;
 	struct ktermios init_termios;
 	unsigned long	flags;
 	struct proc_dir_entry *proc_entry;
@@ -478,7 +564,13 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 void tty_driver_kref_put(struct tty_driver *driver);
 
-/* Use TTY_DRIVER_* flags below */
+/**
+ * tty_alloc_driver - allocate tty driver
+ * @lines: count of lines this driver can handle at most
+ * @flags: some of enum tty_driver_flag, will be set in driver->flags
+ *
+ * Returns: struct tty_driver or a PTR-encoded error (use IS_ERR() and friends).
+ */
 #define tty_alloc_driver(lines, flags) \
 		__tty_alloc_driver(lines, THIS_MODULE, flags)
 
@@ -494,84 +586,6 @@ static inline void tty_set_operations(struct tty_driver *driver,
 	driver->ops = op;
 }
 
-/**
- * DOC: TTY Driver Flags
- *
- * TTY_DRIVER_RESET_TERMIOS
- *	Requests the tty layer to reset the termios setting when the last
- *	process has closed the device. Used for PTYs, in particular.
- *
- * TTY_DRIVER_REAL_RAW
- *	Indicates that the driver will guarantee not to set any special
- *	character handling flags if this is set for the tty:
- *
- *	``(IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || !INPCK)``
- *
- *	That is, if there is no reason for the driver to
- *	send notifications of parity and break characters up to the line
- *	driver, it won't do so.  This allows the line driver to optimize for
- *	this case if this flag is set.  (Note that there is also a promise, if
- *	the above case is true, not to signal overruns, either.)
- *
- * TTY_DRIVER_DYNAMIC_DEV
- *	The individual tty devices need to be registered with a call to
- *	tty_register_device() when the device is found in the system and
- *	unregistered with a call to tty_unregister_device() so the devices will
- *	be show up properly in sysfs.  If not set, all &tty_driver.num entries
- *	will be created by the tty core in sysfs when tty_register_driver() is
- *	called.  This is to be used by drivers that have tty devices that can
- *	appear and disappear while the main tty driver is registered with the
- *	tty core.
- *
- * TTY_DRIVER_DEVPTS_MEM
- *	Don't use the standard arrays (&tty_driver.ttys and
- *	&tty_driver.termios), instead use dynamic memory keyed through the
- *	devpts filesystem. This is only applicable to the PTY driver.
- *
- * TTY_DRIVER_HARDWARE_BREAK
- *	Hardware handles break signals. Pass the requested timeout to the
- *	&tty_operations.break_ctl instead of using a simple on/off interface.
- *
- * TTY_DRIVER_DYNAMIC_ALLOC
- *	Do not allocate structures which are needed per line for this driver
- *	(&tty_driver.ports) as it would waste memory. The driver will take
- *	care. This is only applicable to the PTY driver.
- *
- * TTY_DRIVER_UNNUMBERED_NODE
- *	Do not create numbered ``/dev`` nodes. For example, create
- *	``/dev/ttyprintk`` and not ``/dev/ttyprintk0``. Applicable only when a
- *	driver for a single tty device is being allocated.
- */
-#define TTY_DRIVER_INSTALLED		0x0001
-#define TTY_DRIVER_RESET_TERMIOS	0x0002
-#define TTY_DRIVER_REAL_RAW		0x0004
-#define TTY_DRIVER_DYNAMIC_DEV		0x0008
-#define TTY_DRIVER_DEVPTS_MEM		0x0010
-#define TTY_DRIVER_HARDWARE_BREAK	0x0020
-#define TTY_DRIVER_DYNAMIC_ALLOC	0x0040
-#define TTY_DRIVER_UNNUMBERED_NODE	0x0080
-
-/* tty driver types */
-#define TTY_DRIVER_TYPE_SYSTEM		0x0001
-#define TTY_DRIVER_TYPE_CONSOLE		0x0002
-#define TTY_DRIVER_TYPE_SERIAL		0x0003
-#define TTY_DRIVER_TYPE_PTY		0x0004
-#define TTY_DRIVER_TYPE_SCC		0x0005	/* scc driver */
-#define TTY_DRIVER_TYPE_SYSCONS		0x0006
-
-/* system subtypes (magic, used by tty_io.c) */
-#define SYSTEM_TYPE_TTY			0x0001
-#define SYSTEM_TYPE_CONSOLE		0x0002
-#define SYSTEM_TYPE_SYSCONS		0x0003
-#define SYSTEM_TYPE_SYSPTMX		0x0004
-
-/* pty subtypes (magic, used by tty_io.c) */
-#define PTY_TYPE_MASTER			0x0001
-#define PTY_TYPE_SLAVE			0x0002
-
-/* serial subtype definitions */
-#define SERIAL_TYPE_NORMAL	1
-
 int tty_register_driver(struct tty_driver *driver);
 void tty_unregister_driver(struct tty_driver *driver);
 struct device *tty_register_device(struct tty_driver *driver, unsigned index,
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index af01e89074b2..c5cccc3fc1e8 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -39,7 +39,6 @@ do {								\
 int ldsem_down_read(struct ld_semaphore *sem, long timeout);
 int ldsem_down_read_trylock(struct ld_semaphore *sem);
 int ldsem_down_write(struct ld_semaphore *sem, long timeout);
-int ldsem_down_write_trylock(struct ld_semaphore *sem);
 void ldsem_up_read(struct ld_semaphore *sem);
 void ldsem_up_write(struct ld_semaphore *sem);