tty: serdev: drop serdev_controller_ops::write_room()

In particular, serdev_device_write_room() is not called, so the whole
serdev's write_room() can go.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby

tty: serdev: drop serdev_controller_ops::write_room()

In particular, serdev_device_write_room() is not called, so the whole
serdev's write_room() can go.

Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
Cc: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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treewide, serdev: change receive_buf() return type to size_t

receive_buf() is called from ttyport_receive_buf() that expects values
">= 0" from serdev_controller_receive_buf(), change its return typ

treewide, serdev: change receive_buf() return type to size_t

receive_buf() is called from ttyport_receive_buf() that expects values
">= 0" from serdev_controller_receive_buf(), change its return type from
ssize_t to size_t.

The need for this clean-up was noticed while fixing a warning, see
commit 94d053942544 ("Bluetooth: btnxpuart: fix recv_buf() return value").
Changing the callback prototype to return an unsigned seems the best way
to document the API and ensure that is properly used.

GNSS drivers implementation of serdev receive_buf() callback return
directly the return value of gnss_insert_raw(). gnss_insert_raw()
returns a signed int, however this is not an issue since the value
returned is always positive, because of the kfifo_in() implementation.
gnss_insert_raw() could be changed to return also an unsigned, however
this is not implemented here as request by the GNSS maintainer Johan
Hovold.

Suggested-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Francesco Dolcini <[email protected]>
Acked-by: Jonathan Cameron <[email protected]> #for-iio
Reviewed-by: Johan Hovold <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Alex Elder <[email protected]>
Acked-by: Maximilian Luz <[email protected]> # for platform/surface
Acked-by: Lee Jones <[email protected]>
Acked-by: Ilpo Järvinen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: serdev: convert to u8 and size_t in serdev_controller_ops

Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.

In this patch, only str

tty: serdev: convert to u8 and size_t in serdev_controller_ops

Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.

In this patch, only struct serdev_controller_ops hooks. The rest will
follow.

Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]>
Cc: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serial: core: Move tty and serdev to be children of serial core port device

Let's move tty and serdev controller to be children of the serial core port
device. This way the runtime PM usage count of

serial: core: Move tty and serdev to be children of serial core port device

Let's move tty and serdev controller to be children of the serial core port
device. This way the runtime PM usage count of a child device propagates
to the serial hardware device.

The tty and serdev devices are associated with a specific serial port of
a serial hardware controller device, and we now have serial core hierarchy
of controllers and ports.

The tty device moves happily with just a change of the parent device and
update of device_find_child() handling. The serdev device init needs some
changes to separate the serial hardware controller device from the parent
device.

With this change the tty devices move under sysfs similar to this x86_64
qemu example of a diff of "find /sys -name ttyS*":

/sys/class/tty/ttyS0
/sys/class/tty/ttyS3
/sys/class/tty/ttyS1
-/sys/devices/pnp0/00:04/tty/ttyS0
-/sys/devices/platform/serial8250/tty/ttyS2
-/sys/devices/platform/serial8250/tty/ttyS3
-/sys/devices/platform/serial8250/tty/ttyS1
+/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty/ttyS0
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty/ttyS3
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty/ttyS1
+/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty/ttyS2

If a serdev device is used instead of a tty, it moves in a similar way.

Suggested-by: Johan Hovold <[email protected]>
Cc: Maximilian Luz <[email protected]>
Cc: Rob Herring <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: make counts in tty_port_client_operations hooks size_t

The counts in tty_port_client_operations hooks' are currently
represented by all 'int', 'unsigned int', and 'size_t'. Unify them all
to un

tty: make counts in tty_port_client_operations hooks size_t

The counts in tty_port_client_operations hooks' are currently
represented by all 'int', 'unsigned int', and 'size_t'. Unify them all
to unsigned 'size_t' for clarity. Note that size_t is used already in
tty_buffer.c. So, eventually, it is spread for counts everywhere and
this is the beginning.

So the two changes namely:
* ::receive_buf() is called from tty_ldisc_receive_buf(). And that
expects values ">= 0" from ::receive_buf(), so switch its rettype to
size_t is fine. tty_ldisc_receive_buf() types will be changed
separately.
* ::lookahead_buf()'s count comes from lookahead_bufs() and is already
'unsigned int'.

Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]>
Cc: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: make tty_port_client_operations operate with u8

The parameters are already unsigned chars. So make them explicitly u8s,
as the rest is going to be unified to u8 eventually too.

Signed-off-by:

tty: make tty_port_client_operations operate with u8

The parameters are already unsigned chars. So make them explicitly u8s,
as the rest is going to be unified to u8 eventually too.

Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]>
Cc: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: Add method to assert break signal over tty UART port

Adds serdev_device_break_ctl() and an implementation for ttyport.
This function simply calls the break_ctl in tty layer, which can
assert

serdev: Add method to assert break signal over tty UART port

Adds serdev_device_break_ctl() and an implementation for ttyport.
This function simply calls the break_ctl in tty layer, which can
assert a break signal over UART-TX line, if the tty and the
underlying platform and UART peripheral supports this operation.

Signed-off-by: Neeraj Sanjay Kale <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

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serdev: Replace all instances of ENOTSUPP with EOPNOTSUPP

This replaces all instances of ENOTSUPP with EOPNOTSUPP since ENOTSUPP
is not a standard error code. This will help maintain consistency in

serdev: Replace all instances of ENOTSUPP with EOPNOTSUPP

This replaces all instances of ENOTSUPP with EOPNOTSUPP since ENOTSUPP
is not a standard error code. This will help maintain consistency in
error codes when new serdev API's are added.

Signed-off-by: Neeraj Sanjay Kale <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

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Revert "serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2"

This reverts commit d8e9a406a931f687945703a4bac45042eb81ce92.

It needs some future changes as pointed out by Johan and is not r

Revert "serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2"

This reverts commit d8e9a406a931f687945703a4bac45042eb81ce92.

It needs some future changes as pointed out by Johan and is not ready to
be merged just yet.

Reported-by: Johan Hovold <[email protected]>
Cc: Magnus Damm <[email protected]>
Link: https://lore.kernel.org/r/Yc7oZ/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2

Allow serdev device drivers get notified by hardware errors such as BREAK,
FRAME, PARITY and OVERRUN.

With this patch, in the event of a

serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2

Allow serdev device drivers get notified by hardware errors such as BREAK,
FRAME, PARITY and OVERRUN.

With this patch, in the event of an error detected in the UART device driver
the serdev_device_driver will get the newly introduced ->error() callback
invoked if serdev_device_set_error_mask() has previously been used to enable
the type of error. The errors are taken straight from the TTY layer and fed
into the serdev_device_driver after filtering out only enabled errors.

Without this patch the hardware errors never reach the serdev_device_driver.

Signed-off-by: Magnus Damm <[email protected]>
Link: https://lore.kernel.org/r/163931528842.27756.3665040315954968747.sendpatchset@octo
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: restore client ops on deregistration

The serdev tty-port controller driver should reset the tty-port client
operations also on deregistration to avoid a NULL-pointer dereference in

serdev: ttyport: restore client ops on deregistration

The serdev tty-port controller driver should reset the tty-port client
operations also on deregistration to avoid a NULL-pointer dereference in
case the port is later re-registered as a normal tty device.

Note that this can only happen with tty drivers such as 8250 which have
statically allocated port structures that can end up being reused and
where a later registration would not register a serdev controller (e.g.
due to registration errors or if the devicetree has been changed in
between).

Specifically, this can be an issue for any statically defined ports that
would be registered by 8250 core when an 8250 driver is being unbound.

Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver")
Cc: stable <[email protected]> # 4.11
Reported-by: Loic Poulain <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: call tiocmget and tiocmset ops directly

The tty struct holds a pointer to the driver's tty operations so drop
the unnecessary driver dereference when calling tiocmget and tiocmset.

serdev: ttyport: call tiocmget and tiocmset ops directly

The tty struct holds a pointer to the driver's tty operations so drop
the unnecessary driver dereference when calling tiocmget and tiocmset.

Note that this also makes the calls match the preceding sanity checks as
expected.

Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: add method to set parity

Adds serdev_device_set_parity() and an implementation for ttyport.
The interface uses an enum with the values SERIAL_PARITY_NONE,
SERIAL_PARITY_EVEN and SERIAL_PARIT

serdev: add method to set parity

Adds serdev_device_set_parity() and an implementation for ttyport.
The interface uses an enum with the values SERIAL_PARITY_NONE,
SERIAL_PARITY_EVEN and SERIAL_PARITY_ODD.

Signed-off-by: Ulrich Hecht <[email protected]>
Reviewed-by: Sebastian Reichel <[email protected]>
Reviewed-by: Johan Hovold <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>

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serdev: ttyport: do not used keyed wakeup in write_wakeup

Serdev does not use the file abstraction and specifically there will
never be anyone polling a file descriptor for POLLOUT events.

Just use

serdev: ttyport: do not used keyed wakeup in write_wakeup

Serdev does not use the file abstraction and specifically there will
never be anyone polling a file descriptor for POLLOUT events.

Just use plain wake_up_interruptible() in the write_wakeup callback and
document why it's there.

Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: ignore carrier detect to avoid hangups

Serdev currently does not support hangups so make sure to set CLOCAL to
prevent loss of carrier from triggering one.

Note however that not al

serdev: ttyport: ignore carrier detect to avoid hangups

Serdev currently does not support hangups so make sure to set CLOCAL to
prevent loss of carrier from triggering one.

Note however that not all tty drivers honour CLOCAL.

Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: release tty lock sooner on open

Release the tty lock once tty-driver open returns to make it clear that
it does not protect neither tty->termios or the serport flags.

Signed-off-by

serdev: ttyport: release tty lock sooner on open

Release the tty lock once tty-driver open returns to make it clear that
it does not protect neither tty->termios or the serport flags.

Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: fix tty locking in close

Make sure to hold the tty lock as required when calling tty-driver
close() (e.g. to avoid racing with hangup()).

Note that the serport active flag is curre

serdev: ttyport: fix tty locking in close

Make sure to hold the tty lock as required when calling tty-driver
close() (e.g. to avoid racing with hangup()).

Note that the serport active flag is currently set under the lock at
controller open, but really isn't protected by it.

Fixes: cd6484e1830b ("serdev: Introduce new bus for serial attached devices")
Signed-off-by: Johan Hovold <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: fix NULL-deref on hangup

Make sure to use a properly refcounted tty_struct in write_wake up to
avoid dereferencing a NULL-pointer when a port is being hung up.

Fixes: bed35c6dfa6a

serdev: ttyport: fix NULL-deref on hangup

Make sure to use a properly refcounted tty_struct in write_wake up to
avoid dereferencing a NULL-pointer when a port is being hung up.

Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver")
Cc: stable <[email protected]> # 4.11
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: add missing receive_buf sanity checks

The receive_buf tty-port callback should return the number of bytes
accepted and must specifically never return a negative errno (or a value
la

serdev: ttyport: add missing receive_buf sanity checks

The receive_buf tty-port callback should return the number of bytes
accepted and must specifically never return a negative errno (or a value
larger than the buffer size) to the tty layer.

A serdev driver not providing a receive_buf callback would currently
cause the flush_to_ldisc() worker to spin in a tight loop when the tty
buffer pointers are incremented with -EINVAL (-22) after data has been
received.

A serdev driver occasionally returning a negative errno (or a too large
byte count) could cause information leaks or crashes when accessing
memory outside the tty buffers in consecutive callbacks.

Fixes: cd6484e1830b ("serdev: Introduce new bus for serial attached devices")
Cc: stable <[email protected]> # 4.11
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: serdev: Remove redundant license text

Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be remo

tty: serdev: Remove redundant license text

Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Rob Herring <[email protected]>
Cc: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: add SPDX identifiers to all remaining files in drivers/tty/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/

tty: add SPDX identifiers to all remaining files in drivers/tty/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Jiri Slaby <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: David Sterba <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Eric Anholt <[email protected]>
Cc: Stefan Wahren <[email protected]>
Cc: Florian Fainelli <[email protected]>
Cc: Ray Jui <[email protected]>
Cc: Scott Branden <[email protected]>
Cc: [email protected]
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Joachim Eastwood <[email protected]>
Cc: Matthias Brugger <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Tobias Klauser <[email protected]>
Cc: Russell King <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Richard Genoud <[email protected]>
Cc: Alexander Shiyan <[email protected]>
Cc: Baruch Siach <[email protected]>
Cc: "Maciej W. Rozycki" <[email protected]>
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Pat Gefre <[email protected]>
Cc: "Guilherme G. Piccoli" <[email protected]>
Cc: Jason Wessel <[email protected]>
Cc: Vladimir Zapolskiy <[email protected]>
Cc: Sylvain Lemieux <[email protected]>
Cc: Carlo Caione <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Liviu Dudau <[email protected]>
Cc: Sudeep Holla <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Andy Gross <[email protected]>
Cc: David Brown <[email protected]>
Cc: "Andreas Färber" <[email protected]>
Cc: Kevin Cernekee <[email protected]>
Cc: Laxman Dewangan <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Jonathan Hunter <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Patrice Chotard <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Peter Korsgaard <[email protected]>
Cc: Timur Tabi <[email protected]>
Cc: Tony Prisk <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: "Sören Brinkmann" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Jiri Slaby <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: add missing open() error handling

Add missing error handling for tty-driver open() which may fail (e.g. if
resource allocation fails or if a port is being disconnected).

Note that

serdev: ttyport: add missing open() error handling

Add missing error handling for tty-driver open() which may fail (e.g. if
resource allocation fails or if a port is being disconnected).

Note that close() must be called also in case of failed open() and that
the operation sanity check is amended to catch buggy drivers.

Signed-off-by: Johan Hovold <[email protected]>
Acked-by: Rob Herring <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: ttyport: enforce tty-driver open() requirement

The tty-driver open routine is mandatory, but the serdev
tty-port-controller implementation did not treat it as such and would
instead fall bac

serdev: ttyport: enforce tty-driver open() requirement

The tty-driver open routine is mandatory, but the serdev
tty-port-controller implementation did not treat it as such and would
instead fall back to calling tty_port_open() directly.

Signed-off-by: Johan Hovold <[email protected]>
Acked-by: Rob Herring <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty/serdev: add serdev registration interface

Add a new interface for registering a serdev controller and clients, and
a helper function to deregister serdev devices (or a tty device) that
were prev

tty/serdev: add serdev registration interface

Add a new interface for registering a serdev controller and clients, and
a helper function to deregister serdev devices (or a tty device) that
were previously registered using the new interface.

Once every driver currently using the tty_port_register_device() helpers
have been vetted and converted to use the new serdev registration
interface (at least for deregistration), we can move serdev registration
to the current helpers and get rid of the serdev-specific functions.

Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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serdev: fix tty-port client deregistration

The port client data must be set when registering the serdev controller
or client deregistration will fail (and the serdev devices are left
registered and

serdev: fix tty-port client deregistration

The port client data must be set when registering the serdev controller
or client deregistration will fail (and the serdev devices are left
registered and allocated) if the port was never opened in between.

Make sure to clear the port client data on any probe errors to avoid a
use-after-free when the client is later deregistered unconditionally
(e.g. in a tty-port deregistration helper).

Also move port client operation initialisation to registration. Note
that the client ops must be restored on failed probe.

Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver")
Signed-off-by: Johan Hovold <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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