uart_get_icount() and uart_carrier_raised() open code
uart_port_ref_lock(). Use the helper instead.

The difference is we use _irqsave() variants of a spinlock now. But
that's "safer" than _irq().

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250425111315.1036184-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

uart_port_lock() and uart_port_unlock() are (at the same time) defined
as:
* functions in include/linux/serial_core.h
* macros in drivers/tty/serial/serial_core.c

The former are sane uart port lock wrappers.

The latter _lock() does something completely different: it inspects
a uart_state, obtains a uart_port from it, and increases its reference
count. And if that all succeeded, the port is locked too.

Similarly, the _unlock() counterpart first unlocks and then decrements
the refcount too.

This state is REALLY CONFUSING.

So rename the latter (local .c macros):
* uart_port_lock() -> uart_port_ref_lock(), and
* uart_port_unlock() -> uart_port_unlock_deref().

Now, the forbidden while-at-it part: convert from a macro to an inline
-- do it here as the passed 'flags' have to be pointer to ulong now. So
we avoid doubled changes on identical LOCs.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250425111315.1036184-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The inline-defined constants look weird. Instead, define a proper enum
for them and type uart_port::iotype as that enum. This allows for proper
checking in switch-case labels (somewhere, a default or UPIO_UNKNOWN
label needs to be added/handled).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250425111315.1036184-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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
  ...

Pull printk updates from Petr Mladek:

 - New option "printk.debug_non_panic_cpus" allows to store printk
   messages from non-panic CPUs during panic. It might be useful when
   panic() fails. It is disabled by default because it increases the
   chance to see the messages printed before panic() and on the
   panic-CPU.

 - New build option "CONFIG_NULL_TTY_DEFAULT_CONSOLE" allows to build
   kernel without the virtual terminal support which prefers ttynull
   over serial console.

 - Do not unblank suspended consoles.

 - Some code clean up.

* tag 'printk-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk/panic: Add option to allow non-panic CPUs to write to the ring buffer.
  printk: Add an option to allow ttynull to be a default console device
  printk: Check CON_SUSPEND when unblanking a console
  printk: Rename console_start to console_resume
  printk: Rename console_stop to console_suspend
  printk: Rename resume_console to console_resume_all
  printk: Rename suspend_console to console_suspend_all

change_irq and change_port are boolean variables. Mark them as such
(instead of uint).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-32-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

uart_line_info() wants to work with struct uart_state. Do not pass a
driver and an index. Pass the precomputed struct directly.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-27-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The linking is done implicitly by tty_port_register_device_attr_serdev()
few lines below. So drop this explicit tty_port_link_device().

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-26-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The intent of console_start was to resume a previously suspended console,
so rename it accordingly.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-4-0b878577f2e6@suse.com
[pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c.]
Signed-off-by: Petr Mladek <pmladek@suse.com>

The intent of console_stop was in fact to suspend it, so rename the
function accordingly.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-3-0b878577f2e6@suse.com
[pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c]
Signed-off-by: Petr Mladek <pmladek@suse.com>