tty: mxser: convert to u8 and size_t

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

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231206073712.17776-19-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: Annotate struct mxser_board with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct mxser_board.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230922175245.work.196-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_operations::write()'s count size_t

Unify with the rest of the code. Use size_t for counts and ssize_t for
retval.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-30-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: propagate u8 data to tty_operations::put_char()

Data are now typed as u8. Propagate this change to
tty_operations::put_char().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Link: https://lore.kernel.org/r/20230810091510.13006-29-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: propagate u8 data to tty_operations::write()

Data are now typed as u8. Propagate this change to
tty_operations::write().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20230810091510.13006-28-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Convert hw_stopped in tty_struct to bool

hw_stopped in tty_struct is used like bool, convert the variable type
to bool.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Link: https://lore.kernel.org/r/20230309082035.14880-9-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Call ->dtr_rts() parameter active consistently

Convert various parameter names for ->dtr_rts() and related functions
from onoff, on, and raise to active.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230117090358.4796-12-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Convert ->dtr_rts() to take bool argument

Convert the raise/on parameter in ->dtr_rts() to bool through the
callchain. The parameter is used like bool. In USB serial, there
remains a few implicit bool -> larger type conversions because some
devices use u8 in their control messages.

In moxa_tiocmget(), dtr variable was reused for line status which
requires int so use a separate variable for status.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230117090358.4796-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Convert ->carrier_raised() and callchains to bool

Return boolean from ->carrier_raised() instead of 0 and 1. Make the
return type change also to tty_port_carrier_raised() that makes the
->carrier_raised() call (+ cd variable in moxa into which its return
value is stored).

Also cleans up a few unnecessary constructs related to this change:

return xx ? 1 : 0;
-> return xx;

if (xx)
return 1;
return 0;
-> return xx;

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230117090358.4796-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Cleanup tty_port_set_initialized() bool parameter

Make callers pass true/false consistently for bool val.

Reviewed-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230117090358.4796-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: remove redundant assignment to hwid

The variable hwid is assigned a value but it is never read. The
assignment is redundant and can be removed.

Cleans up clang scan build warning:
drivers/tty/mxser.c:401:7: warning: Although the value stored to 'hwid'
is used in the enclosing expression, the value is never actually read
from 'hwid' [deadcode.DeadStores]

Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220730130925.150018-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Make ->set_termios() old ktermios const

There should be no reason to adjust old ktermios which is going to get
discarded anyway.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220816115739.10928-9-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove BOTHER ifdefs

BOTHER is defined by all architectures since commit d0ffb805b729
("arch/alpha, termios: implement BOTHER, IBSHIFT and termios2").

Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220513082906.11096-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: make use of UART_LCR_WLEN() + tty_get_char_size()

Having a generic UART_LCR_WLEN() macro and the tty_get_char_size()
helper, we can remove all those repeated switch-cases in drivers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220224095558.30929-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: switch from xmit_buf to kfifo

Use kfifo for xmit buffer handling. The change is mostly
straightforward. It saves complexity both on the stuffing side
(mxser_write() and mxser_put_char()) and pulling side
(mxser_transmit_chars()). In fact, the loop in mxser_write() can be
completely deleted as the wrap of the buffer is taken care of in the
kfifo code now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use tty_port xmit_buf helpers

For the mxser driver to use kfifo, use tty_port_alloc_xmit_buf() and
tty_port_free_xmit_buf() helpers in activate/shutdown, respectively.

As these calls have to be done in a non-atomic context, we have to move
them outside spinlock and make sure irq is really stopped after we write
to the ISR register.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: fix xmit_buf leak in activate when LSR == 0xff

When LSR is 0xff in ->activate() (rather unlike), we return an error.
Provided ->shutdown() is not called when ->activate() fails, nothing
actually frees the buffer in this case.

Fix this by properly freeing the buffer in a designated label. We jump
there also from the "!info->type" if now too.

Fixes: 6769140d3047 ("tty: mxser: use the tty_port_open method")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use PCI_DEVICE_DATA

Now that we have all the PCI device IDs unified, we can use
PCI_DEVICE_DATA() macro to simplify mxser's pci_device_id list, i.e.
mxser_pcibrds.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-20-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move ids from pci_ids.h here

There is no point having MOXA PCI device IDs in include/linux/pci_ids.h.
Move them to the driver and sort them all by the ID.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: add MOXA prefix to some PCI device IDs

Some of the MOXA PCI device IDs contain _MOXA_, some don't. Add it to
the latter, so that they are all unified.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: increase buf_overrun if tty_insert_flip_char() fails

mxser doesn't increase port->icount.buf_overrun at all. Do so if overrun
happens, so that it can be read from the stats.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-17-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove tty parameter from mxser_receive_chars_new()

After the previous change (no plays with of tty->receive_room), the tty
parameter is unused.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: don't throttle manually

First, checking tty->receive_room to signalize whether there is enough space
in the tty buffers does not make much sense. Provided the tty buffers
are in tty_port and those are not checked at all.

Second, if the rx path is throttled, with CRTSCTS, RTS is deasserted,
but is never asserted again. This leads to port "lockup", not accepting
any more input.

So:
1) stty -F /dev/ttyMI0 crtscts # the mxser port
2) stty -F /dev/ttyS6 crtscts # the connected port
3) cat /dev/ttyMI0
4) "write in a loop" to /dev/ttyS6
5) cat from 3) produces the bytes from 4)
6) killall -STOP cat (the 3)'s one)
7) wait for RTS to drop on /dev/ttyMI0
8) killall -CONT cat (again the 3)'s one)

cat erroneously produces no more output now (i.e. no data sent from
ttyS6 to ttyMI can be seen).

Note that the step 7) is performed twice: once from n_tty by
tty_throttle_safe(), once by mxser_stoprx() from the receive path. Then
after step 7), n_tty correctly unthrottles the input, but mxser calls
mxser_stoprx() again as there is still only a little space in n_tty
buffers (tty->receive_room mentioned at the beginning), but the device's
FIFO is/can be already filled.

After this patch, the output is correctly resumed, i.e. n_tty both
throttles and unthrottles without interfering with mxser's attempts.

This allows us to get rid of the non-standard ldisc_stop_rx flag from
struct mxser_port.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: clean up timeout handling in mxser_wait_until_sent()

timeout cannot be zero at the point of use. So no need to check for
zero. Also precompute the expiration time (into expire) and use it. This
makes the code more clear.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-14-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use msleep_interruptible() in mxser_wait_until_sent()

Instead of schedule_timeout_interruptible(), because:
1) we don't have to bother with the task state, and
2) msleep* guarantees to sleep that time (if not interrupted).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract TX empty check from mxser_wait_until_sent()

And move it to new mxser_tx_empty(), because:
1) it simplifies the code (esp. the locking), and
2) serial_core needs such a hook anyway, so have it ready.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-12-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use tty_port_close() in mxser_close()

Finally, the mxser_close() code in is mostly identical to
tty_port_close(), so replace the code by a single call to the function.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-11-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: don't flush buffer from mxser_close() directly

I fail to see the point of calling mxser_flush_buffer() from
mxser_close():
1) The SW xmit buffer is freed in mxser_shutdown_port() right after the
call to mxser_flush_buffer(). And all 'cnt', 'head', and 'tail' are
properly initialized to 0 in mxser_activate().
2) The HW buffer is flushed in mxser_shutdown_port() via
mxser_disable_and_clear_FIFO() too.

So the effect of doing it by mxser_flush_buffer() in mxser_close() is
none. Hence remove it, so that when we use tty_port_close() later, the
code is 1:1 identical.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-10-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: call stop_rx from mxser_shutdown_port()

mxser_stop_rx() should be called from mxser_shutdown_port() for several
reasons:
1) info->slock is held while manipulating IER (as on other places),
2) hangup now stops rx too,
3) mxser_close() will use tty_port_close() and there is no place except
tty_port_operations::shutdown() where this can be done,
4) this is the same sequence as serial_core does. So we can map this
code 1:1 when switching the driver to it.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove tty->driver_data NULL check

Noone sets tty->driver_data to NULL in the driver, so there is no point
to check that in mxser_close(). Remove the check.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove pointless xmit_buf checks

xmit_buf is supposed to exist in all these functions. I.e. from
tty_port_operations::activate() to ::shutdown(). So remove these checks.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: clean up tx handling in mxser_transmit_chars()

The port->icount.tx is handled in a too complicated manner. Instead of
remembering the original count and subtracting the new one from it,
simply increase tx for each character in the loop. No need for cnt
variable then.

Change also the "X = X & Y" assignment to simpler "X &= Y".

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move MSR read to mxser_check_modem_status()

The MSR read is currently performed on both places where
mxser_check_modem_status() is called. So move it there to avoid code
duplication.

Rename the variable to msr while we move it, to actually see what
"status" we are testing.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: keep only !tty test in ISR

The others are superfluous with tty refcounting in place now. And they
are racy in fact:
* tty_port_initialized() reports false for a small moment after
interrupts are enabled.
* closing is 1 while the port is still alive.

The queues are flushed later during close anyway. So there is no need
for this special handling. Actually, the ISR should not flush the
queues. It should behave as every other driver, just queue the chars
into tty buffer and go on. But this will be changed later. There is
still a lot code depending on having tty in ISR (and not only tty_port).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: rename mxser_close_port() to mxser_stop_rx()

As it is the only thing it does now. This is one of the future
serial_core hooks.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove wait for sent from mxser_close_port

mxser_close() behaves like this:
-> tty_port_close_start()
-> tty_wait_until_sent()
-> mxser_wait_until_sent()
-> mxser_close_port
-> wait for TEMT

So it is already waited for TEMT through mxser_wait_until_sent() and
there is another round of waiting in mxser_close_port(). The latter one
is superfluous as nothing could be filled into the output FIFO. Remove
the call.

This helps unification among drivers (so that all behave the same) and
future use of tty_port_close().

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: store FCR state in mxser_port::FCR

We force the FCR contents on many places in the code instead of writing
what was actually set in mxser_change_speed() (by ->activate() or
->set_serial_info()).

So introduce mxser_port::FCR to hold the proper contents and bitwise-OR
the value to what needs to be set on all those locations. That is,
clearing RX and/or TX FIFOs. Those flags are self-clearing, so no need
to set them to mxser_port::FCR.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: don't read from UART_FCR

The UART_FCR register is write-only. When reading it, one gets contents
of (read-only) UART_IIR instead as they are shared. This mistake was
performed in mxser_flush_buffer() to clear FIFOs.

Actually FCR handling throughout the driver is completely broken. On
many places, it respects neither mu860 settings, nor FIFO (16450 vs
16550) setting. This patch doesn't help to fix this, it actually does
the same. We will introduce a mxser_port::FCR in the next patch to fix
this issue.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move FIFO clearing to mxser_disable_and_clear_FIFO()

This code is used on two places, make a helper for disabling and
clearing FIFOs. And demangle the too complicated 'if' by using a local
variable.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: simplify FCR computation in mxser_change_speed()

Provided FIFO is always enabled for MUST chips, move its FCR setting out
of PORT_8250/PORT_16450 special case in mxser_change_speed(). Now, we
can pre-set fcr to zero and invert the condition of the 'if'.

This makes the code more readable (no functional change intended).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: make mxser_port::ldisc_stop_rx a bool

It's used only as a yes-no variable, so make it a bool and switch the
set values appropriately.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: simplify condition in mxser_receive_chars_new

mxser_receive_chars_old() is used whenever MOXA_MUST_LSR_RERR is set in
status no matter the HW ID (the last 'if'). So there is no need for
another check of MOXA_MUST_LSR_RERR _with_ hwid == MOXA_MUST_MU860_HWID
(the third 'if'). Hence remove this subcase. That allows us to check
status on a single line with both UART_LSR_BRK_ERROR_BITS (from the
second 'if') and MOXA_MUST_LSR_RERR (the last 'if').

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: restore baud rate if its setting fails

If a user tries to set a too high rate, it fails due to check in
mxser_set_baud(). But the high rate remains set in termios, so the user
might think everything went smooth. Restore the baud rate from the
old_termios if this happens, so that user knows nothing was changed in
fact.

It used to behave the correct way many years ago, but somehow the
restoration vanished with commit 1c45607ad3eb (Char: mxser, remove it)
-- the commit removed mxser's older clone.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210922075938.31390-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use semi-colons instead of commas

This code works, but it's cleaner to use semi-colons at the end of
a statement instead of a comma.

Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210825072435.GB13013@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: drop put_tty_driver

put_tty_driver() is an alias for tty_driver_kref_put(). There is no need
for two exported identical functions, therefore switch all users of
old put_tty_driver() to new tty_driver_kref_put() and remove the former
for good.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: stop using alloc_tty_driver

alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012.

I never got into eliminating alloc_tty_driver until now. So we still
have two functions for allocating drivers which might be confusing. So
get rid of alloc_tty_driver uses to eliminate it for good in the next
patch.

Note we need to switch return value checking as tty_alloc_driver uses
ERR_PTR. And flags are now a parameter of tty_alloc_driver.

Cc: Richard Henderson <rth@twiddle.net>(odd fixer:ALPHA PORT)
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: introduce mxser_16550A_or_MUST helper

This check is used in the code on many places. Either in positive or
negative form. So introduce a helper called mxser_16550A_or_MUST for
this purpose. And replace all the occurrences.

This simplifies many ifs in there.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-67-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: rename flags to old_speed in mxser_set_serial_info

Local 'flags' are used to store speed in mxser_set_serial_info, not
actual flags (by doing & ASYNC_SPD_MASK). So rename 'flags' to
'old_speed' (after what it is).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-66-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: use port variable in mxser_set_serial_info

mxser_set_serial_info already defined a local 'port' of type struct
tty_port. So use it in the code everywhere.

This eliminates some text from the code there.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-65-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: access info->MCR under info->slock

info->MCR is protected by info->slock all over the code. Extend the lock
in mxser_tiocmget around the info->MCR fetch too.

It likely doesn't change anything, but it's always good to be consistent.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-64-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: fix typos around enhanced mode

Fix spelling of "enhanced" in macros and comments around them.

While "enchance" comes from the original Moxa's driver, I don't think it
was meant to be that. From the context, they obviously mean "enhanced".

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-63-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: decrypt FCR values

Currently, some of the values written to FCR are magic constants. But
they are composed of well-defined bits. Use these named macros in place
of the constants.

No changes in objdump -d.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-62-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove xmit_cnt < 0 tests

mxser_port::xmit_cnt is unsigned, it cannot be negative. Therefore
remove all the xmit_cnt < 0 tests.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-61-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: introduce and use start/stop_tx helpers

Starting and stopping TX is performed on many places in the driver. It
is repeated outb and info->IER modification. Create few helpers
(__mxser_start_tx, mxser_start_tx, __mxser_stop_tx) and use them in the
code instead of open coding.

This should be a base for an uart driver for this device in the future.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-60-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract and dedup CTS handling

CTS is handled on two locations in mxser. Extract the code into
separation function mxser_handle_cts. And call it from the two
locations.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-59-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: don't start TX from tty_operations::put_char

TX is not supposed to be started from tty_operations::put_char. Line
disciplines ought to call tty_operations::put_char several times and
then do a single tty_operations::flush_chars to start TX.

Fix this in mxser by removing TX startup from mxser_put_char.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-58-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup mxser_dtr_rts

mxser_dtr_rts now does all inb, outb, & or | in a single statement. The
code is hard to follow, so make it more readable by doing one-line =
one-statement.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-57-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup mxser_rs_break

mxser_rs_break now does all inb, outb, & or | in a single statement. The
code is hard to follow, so make it more readable by doing one-line =
one-statement.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-56-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove pointless ioaddr checks

struct mxser_port::ioaddr can never be NULL once set in ->probe. Hence
the checks for it are pointless. Remove them.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-55-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: alloc only needed # of ports

Many boards have only 2 ports. But we always allocate 8 ports (struct
mxser_port) in each struct mxser_board.

Switch this to an empty/variable sized array ([]) and allocate the
needed number of ports using struct_size helper in ->probe.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-54-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: alloc struct mxser_board dynamically

There is no need to preallocate an array of four struct mxser_board's.
In most cases a single board or two will be present in a machine. So
allocate struct mxser_board as needed in ->probe.

This makes mxser_boards a bit array. There we store which indexes are
free (unallocated).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-53-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: make mxser_board::idx really an index

mxser_board::idx is named as index, but actually contain a base. So
assign index there. And for base, introduce a local variable.

This is needed for the next patch (use index as a bit index).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-52-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: rework and simplify mxser_open

In mxser_open, tty->port is already set thanks to
tty_port_register_device in ->probe. So we can simply use container_of
to deduce the struct mxser_port's pointer. Thus avoiding divisions and
complex computations.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-51-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup mxser_process_txrx_fifo

Rename process_txrx_fifo to mxser_process_txrx_fifo and:
* remove useless parentheses
* return from the 'if's true branch and process the rest in normal code
flow (shift the code one level left)

All this to make the code more readable.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-50-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove mxser_cardinfo

Now that mxser_cards array (of struct mxser_cardinfo) contains only port
count and a quirk, we can encode these two directly into
pci_device_id::driver_data. And we can remove this struct completely.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-49-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove info message from probe

There is a dev_info in ->probe which prints device's name, bus and slot
numbers. All these can be fetched from the lspci output. So remove this
useless print.

This eliminates the whole mxser_cardinfo::name field.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-48-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move request irq to probe and switch to managed

Move request_irq from mxser_initbrd to mxser_probe so that we can switch
it to managed request. It simplifies the cleanup code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-47-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: pci, switch to managed resources

Switch to managed resources for PCI using pcim_enable_device.
Regions and device disabling is now taken care of by the core and we
need not unwind. Neither in ->probe, nor in ->remove. That simplifies
the code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-46-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: inline mxser_board_remove into mxser_remove

The only user of mxser_board_remove is mxser_remove. Move there those
few lines.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-45-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move board init into mxser_initbrd

What's done in ->probe for board is actually its initialization. So move
it to mxser_initbrd where it belongs.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-44-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: clean up the rest of MUST helpers

Clean up the rest of MUST helpers. They all can use the newly added
mxser_must_set_EFR. And passing a bool instead of having two functions
(_enable+_disable) simplifies the code a lot too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-43-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: introduce mxser_must_select_bank and use it

Again, selecting a bank in the EFR register is duplicated many times.
Extract it to a separate function (mxser_must_select_bank) and use it on
all the places.

This cleans up most of the helpers. And mxser_get_must_hardware_id now
returns the HW ID directly, not via a by-reference parameter.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-42-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: dedup mxser_must_set_enhance_mode

There are multiple copies of setting the EFR register. Separate it to a
new universal function called __mxser_must_set_EFR. And use it in the
code by introducing mxser_must_set_enhance_mode instead of
mxser_disable_must_enchance_mode and mxser_enable_must_enchance_mode.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-41-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: simplify mxser_ioctl_op_mode

* ModeMask local array is just inverted OP_MODE_MASK shifted by shiftbit.
Drop this array and use the value directly.
* return from the if's true branch and drop 'else' branch by moving the
code completely outside the if.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-40-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract mxser_ioctl_op_mode

This ioctl code sets RS232, RS422 or RS485 mode. Move the code to a
separate function (mxser_ioctl_op_mode) with a note that these
mxser-special ioctls should be likely replaced eventually by TIOCGRS485
and TIOCSRS485.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-39-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup mxser_change_speed

* use UART macros instead of magic constants
* let the default case reuse already existing code (CS5 case)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-38-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop mxser_port::custom_divisor

It's an once-set constant, so define a macro for the constant
(MXSER_CUSTOM_DIVISOR) and use it in the code instead.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-37-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop mxser_port::baud_base

It's an once-set constant, so define a macro for the constant
(MXSER_BAUD_BASE) and use it in the code instead.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-36-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove unused mxser_port::stop_rx

It's been a long time since mxser_port::stop_rx was abandoned. Remove it.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-35-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop unused mxser_port::normal_termios

After the previous patches, mxser_port::normal_termios is unused, so
time to wave bye-bye.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-34-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: don't allocate MXSER_PORTS + 1

The MXSER_PORTS's tty_device is never registered and neither its
tty_port instance exists. Hence, it's quite pointless to allocate it.

It used to be used for global information fetches via ioctls. We have
just removed these as non-existent tty_device+tty_port was exactly the
reason to remove the ioctls.

It would be peculiar to add this "virtual" port as we require a backing
tty_port since commit ecbbfd44a08f (TTY: move tty buffers to tty_port)
in 2012.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-33-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove cnt from mxser_receive_chars

After the previous ioctls removal, cnt is needed only in
mxser_receive_chars_old now. So remove it from mxser_receive_chars and
mxser_receive_chars_new and account only in mxser_receive_chars_old.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-32-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_HighSpeedOn ioctl

1) The semantics are defined exactly nowhere.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.
3) It's not even mentioned in any of the mxser utilities.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-31-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_ASPP_OQUEUE ioctl

1) The semantics are defined exactly nowhere.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.
3) It's not even mentioned in any of the mxser utilities.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-30-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_GETMSTATUS ioctl

1) MOXA_GETMSTATUS is broken at least since commit ecbbfd44a08f (TTY:
move tty buffers to tty_port) in 2012.
Even though it's mentioned in the mon_pa moxa utility, obviously
noone ever tried that in that timeframe.
2) The ioctl definition was never exposed to userspace, so noone
should actually be reliably using this.

Provided the above, remove this mxser-special ioctl.

And remove the whole concept of mxser_ioctl_special as this was the last
ioctl in there.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-29-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_GETDATACOUNT ioctl

1) MOXA_GETDATACOUNT is broken at least since commit ecbbfd44a08f (TTY:
move tty buffers to tty_port) in 2012.
Even though it's mentioned in the mon_p moxa utility, obviously noone
ever tried that in that timeframe.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-28-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_CHKPORTENABLE ioctl

1) MOXA_CHKPORTENABLE is broken at least since commit ecbbfd44a08f (TTY:
move tty buffers to tty_port) in 2012.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.
3) It's not even mentioned in any of the mxser utilities.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_ASPP_LSTATUS ioctl

1) The semantics are defined exactly nowhere.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.
3) It's not even mentioned in any of the mxser utilities.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-26-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_ASPP_MON and friends

1) MOXA_ASPP_MON_EXT is broken at least since commit ecbbfd44a08f (TTY:
move tty buffers to tty_port) in 2012.
2) The ioctl definitions were never exposed to userspace, so noone should
actually be reliably using them.
3) They're not even mentioned in any of the mxser utilities.

So remove all these mxser-special ioctls: MOXA_ASPP_MON,
MOXA_ASPP_MON_EXT, and MOXA_SDS_RSTICOUNTER.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-25-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_SET_BAUD_METHOD ioctl

1) The semantics are defined exactly nowhere.
2) The ioctl definition was never exposed to userspace, so noone should
actually be reliably using this.
3) It's not even mentioned in any of the mxser utilities.

Provided the above, remove this mxser-special ioctl.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-24-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove MOXA_GET_MAJOR deprecated ioctl

MOXA_GET_MAJOR was deprecated in commit 41aee9a121fd (Char: mxser, ioctl
cleanup) in 2008. Remove this ioctl finally.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop unused MOXA_DIAGNOSE macro

It's unused.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-22-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop UART_MCR_AFE and UART_LSR_SPECIAL defines

* UART_MCR_AFE is a redefinition of serial_reg.h's one.
* UART_LSR_SPECIAL is a redefinition of serial_reg.h's
UART_LSR_BRK_ERROR_BITS.

So remove both and replace the latter uses by already defined
UART_LSR_BRK_ERROR_BITS.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-21-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: make xmit ring buffer variables unsigned

Make the xmit ring buffer pointers and counter (xmit_head, xmit_tail,
xmit_cnt) unsigned. Now, the assumptions for the compiler are clear --
they cannot be negative.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-20-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: correct types for uart variables

In struct mxser_port, all the UART registers and masks, and the xon/xoff
character are stored into int. Let's re-type all these as UART registers
are 8bit (u8) and xon/xoff character is an unsigned char (cc_t in
ktermios).

This save some bytes in memory, but more importantly the change makes it
what it really is.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove else from LSR bits checks

UART_LSR_SPECIAL is composed of UART_LSR_BI, UART_LSR_PE, UART_LSR_FE,
UART_LSR_OE. So status cannot be anything else. Remove the unused else
branch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract mxser_receive_chars_old

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-17-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract mxser_receive_chars_new

Extract the new handling of receive chars (using the MUST chip
enhancements) into a separate function. This eliminates the need for the
intr_old label and makes the code of mxser_receive_chars more compact.
In the next step, we will extract the old handling too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: simplify mxser_interrupt and drop mxser_board::vector_mask

mxser_board::vector_mask is just a bitfield with bits set for all
available ports. We can obtain this value simply by
"BIT(brd->info->nports) - 1" directly in the ISR. So remove vector_mask
and simplify the code a bit.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: extract port ISR

The ISR is terrible mix of letters. Let's extract the proper per-port
handling to a separate function called mxser_port_isr. This way, we can
actually see what both mxser_interrupt and mxser_port_isr do now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-14-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup LSR handling in mxser_receive_chars

mxser_interrupt is a bit confusing as it passes a pointer to LSR
variable ("status") to mxser_receive_chars. That function can indeed
update the LCR variable. Make this clear by not passing a variable by
reference, instead, return updated status. And change its type
accordingly -- to u8.

Note that the next patches will rework ISR so that even the definition
of status will be u8 soon too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove nonsense from ISR

request_irq was passed a board. There is no need to check dev_id and/or
find the appropriate board in the ISR. Neither check if board is NULL.
Remove this nonsense.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-12-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: move max_baud from port to board

mxser_port::max_baud is actually a board property, not port's. So move
it to mxser_board.

While at it, drop the printk informing about max baud rate during probe.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-11-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop constant board::uart_type

board::uart_type is always set to PORT_16550A. So, use this constant in
the code instead. And drop the mxser_board member.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-10-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: introduce enum mxser_must_hwid

Provided the MUST HW ID is an enumeration, define one (enum
mxser_must_hwid) and use it in the code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: rename mxser_board::chip_flag to must_hwid

It is named IsMoxaMustChipFlag in the original Moxa's driver. Over the
time, it was reduced to chip_flag which doesn't make much sense. So dub
it again by what it is: must_hwid (mxser_must_get_hwid assigns to it).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: rename CheckIsMoxaMust to mxser_get_must_hwid

CheckIsMoxaMust actually finds out what the card is. So rename it to
mxser_must_get_hwid, so that the name conforms to the semantics of the
function.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: cleanup Gpci_uart_info struct

The Gpci_uart_info structure contains up to tripled information and
chose weird types for the members. Deduplicate the members and choose
proper types for the data -- everything can be u8 except baud rate.
There, we use speed_t, which is used in this context.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: integrate mxser.h into .c

As mxser.h serves only mxser.c, integrate the definitions into .c and
drop .h. There are some "semi-public" ioctl definitions, but they are
mostly go away in the next patches. If something, they would need to
live in an uapi header anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove info printout from init

There is no reason/desire to print module information upon module load.
Drop this printk (and a version define).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: renumber mxser_cards

After the ISA cards removal in the previous patch, the mxser_cards array
has holes in it. So renumber the array while updating PCI device's
driver_data.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: drop ISA support

While mxser PCI cards are still around and produced (Moxa provided me
with two recently), ISA cards are obsolete for a long time. I haven't
seen anyone using the cards and the ISA code paths are barely tested.

Hence, remove ISA support from mxser driver so that we can clean the
driver up.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_operations::chars_in_buffer return uint

tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_operations::write_room return uint

Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Acked-by: David Sterba <dsterba@suse.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: cumulate and document tty_struct::flow* members

Group the flow flags under a single struct called flow. The new struct
contains 'stopped' and 'tco_stopped' bools which used to be bits in a
bitfield. The struct also contains the lock protecting them to
potentially share the same cache line.

Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::unused) is aligned to a 8B boundary too and occupies some
bytes from the next word.

So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
pads the end.

This is also the perfect time to start the documentation of tty_struct
where all this lives. So we start by documenting what these bools
actually serve for. And why we do all the alignment dances. Only the few
up-to-date information from the Theodore's comment made it into this new
Kerneldoc comment.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: drop low-latency workaround

Commit 67d2bc58afdd ("Char: mxser_new, fix recursive locking") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
simply dropping and reacquiring the port lock in the interrupt handler.

Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Link: https://lore.kernel.org/lkml/3018694794025219@wsc.cz/T/#m06b04c640a7b6f41afb3d34a4cf29b1df4935d3a
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: fix TIOCSSERIAL permission check

Changing the port type and closing_wait parameter are privileged
operations so make sure to return -EPERM if a regular user tries to
change them.

Note that the closing_wait parameter would not actually have been
changed but the return value did not indicate that.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-15-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: fix TIOCSSERIAL jiffies conversions

The port close_delay and closing wait parameters set by TIOCSSERIAL are
specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.

Add the missing conversions so that TIOCSSERIAL works as expected also
when HZ is not 100.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-14-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty_port: drop last traces of low_latency

The main purpose of tty_port::low_latency was removed in commit
a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in
place for drivers as an optional tune knob. But only one driver has been
using it until the previous commit. So remove this misconcept
completely, given there are no users.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210105120239.28031-11-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: make mxser_change_speed() return void

No other functions use the return value of mxser_change_speed() and the
return value is always 0 now. Make it return void. This fixes the
following coccicheck warning:

drivers/tty/mxser.c:645:5-8: Unneeded variable: "ret". Return "0" on
line 650

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200506061735.19369-1-yanaijie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: switch to ->[sg]et_serial()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

tty: 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: Jiri Slaby <jslaby@suse.com>
Cc: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 <jslaby@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: "Uwe Kleine-König" <kernel@pengutronix.de>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: remove unused parameters

Remove
* pdev from mxser_initbrd
* old_termios from mxser_change_speed
as they are unused and update the callers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: fix timeout calculation for low rates

Paul reported, that low rates like B300 make the driver to hang in
mxser_wait_until_sent. His debugging tackled the issue down to the
info->timeout computation in mxser_set_baud. Obviously, ints are used
there and they easily overflow with these low rates: B300 makes
info->timeout to be -373.

So switch all these types to unsigned as it ought to be. And use the u64
domain to perform the computation as in the worst case, we need 35 bits
to store the computed value (before division).

And use do_div not to break 32 bit kernels.

[v2] make it actually build

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paul <Paul@abelian.netcom.co.uk>
Tested-by: <Paul@abelian.netcom.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: constify pci_device_id.

pci_device_id are not supposed to change at runtime. All functions
working with pci_device_id provided by <linux/pci.h> work with
const pci_device_id. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
20253 1184 19904 41341 a17d drivers/tty/mxser.o

File size After adding 'const':
text data bss dec hex filename
21117 300 19904 41341 a17d drivers/tty/mxser.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Annotate hardware config module parameters in drivers/tty/

When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image. Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify. The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in drivers/tty/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jiri Slaby <jslaby@suse.com>
cc: linux-serial@vger.kernel.org

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tty: cyclades+mxser, do not initialize to zero

Do not initialize members of initialized structures to zero. They are
zeroed automatically.

Part of hub6 cleanup series.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: Remove unused ASYNC_SHARE_IRQ flag

ASYNC*_SHARE_IRQ is no longer used; remove.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Replace ASYNC_INITIALIZED bit and update atomically

Replace ASYNC_INITIALIZED bit in the tty_port::flags field with
TTY_PORT_INITIALIZED bit in the tty_port::iflags field. Introduce helpers
tty_port_set_initialized() and tty_port_initialized() to abstract
atomic bit ops.

Note: the transforms for test_and_set_bit() and test_and_clear_bit()
are unnecessary as the state transitions are already mutually exclusive;
the tty lock prevents concurrent open/close/hangup.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Replace ASYNC_CHECK_CD and update atomically

Replace ASYNC_CHECK_CD bit in the tty_port::flags field with
TTY_PORT_CHECK_CD bit in the tty_port::iflags field. Introduce helpers
tty_port_set_check_carrier() and tty_port_check_carrier() to abstract
the atomic bit ops.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Replace ASYNC_CTS_FLOW bit and update atomically

Replace ASYNC_CTS_FLOW bit in the tty_port::flags field with
TTY_PORT_CTS_FLOW bit in the tty_port::iflags field. Add
tty_port_set_cts_flow() helper to abstract the atomic bit ops.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Replace TTY_IO_ERROR bit tests with tty_io_error()

Abstract TTY_IO_ERROR status test treewide with tty_io_error().
NB: tty->flags uses atomic bit ops; replace non-atomic bit test
with test_bit().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: constify tty_port_operations structs

Constifies tty_port_operations structures in
the tty driver since they are not modified
after their initialization.

Detected and found using Coccinelle.

Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: Remove ASYNC_CLOSING

The tty core no longer provides ASYNC_CLOSING. Use private flag for
same purpose, which is to clear the fifos at each and every interrupt
during driver close(). The driver uses this sledgehammer approach because
its close/shutdown sequence is hopelessly borked.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: Use termios c_*flag macros

Expressions of the form "tty->termios.c_*flag & FLAG"
are more clearly expressed with the termios flags macros,
I_FLAG(), C_FLAG(), O_FLAG(), and L_FLAG().

Convert treewide.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: Fix build warning introduced by dfc7b837c7f9 (Re: linux-next: build warning after merge of the tty.current tree)

Fix build warning at mxser.c introduced by dfc7b837c7f9 (tty: mxser: fix
usage of opmode_ioaddr)

Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: fix usage of opmode_ioaddr

mxser_port->opmode_ioaddr is initialized only for MOXA_MUST_MU860_HWID
chips, but no precautions have been undertaken to prevent reading and
writing to undefined port number.

Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: fix cycle termination condition in mxser_probe() and mxser_module_init()

There is a bug in resources deallocation code in mxser_probe() and
mxser_module_init(). As soon as variable 'i' is unsigned int, cycle
termination condition i >= 0 is always true. The patch fixes the issue.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: fix DTR not being dropped on hang up

Move HUPCL handling to port shutdown so that DTR is dropped also on hang
up (tty_port_close is a noop for hung-up ports).

Also do not try to drop DTR for uninitialised ports where it has never
been raised (e.g. after a failed open).

Note that this is also the current behaviour of serial-core.

Nine drivers currently call tty_port_close_start directly (rather than
through tty_port_close) and seven of them lower DTR as part of their
close (if the port has been initialised). Fixup the remaining two
drivers so that it continues to be lowered also on normal (non-HUP)
close. [ Note that most of those other seven drivers did not expect DTR
to have been dropped by tty_port_close_start in the first place. ]

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: improve error handling in mxser_probe() and mxser_module_init()

1. Currently mxser_probe() and mxser_module_init() ignore errors
that can happen in tty_port_register_device().
2. mxser_module_init() does not deallocate resources allocated in mxser_get_ISA_conf()
if mxser_initbrd() failed.

The patch adds proper error handling in all the cases.
Also it moves free_irq() from mxser_release_ISA_res() to mxser_board_remove(),
since it makes mxser_release_ISA_res() a counterpart for mxser_get_ISA_conf(),
while free_irq() is relevant to both ISA and PCI boards.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: move low_latency to tty_port

One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So it makes sense to move low_latency to
tty_port too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: switch tty_insert_flip_char

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_char is the next one to proceed. This one is used all
over the code, so the patch is huge.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove use of __devexit

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove use of __devinit

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: call tty_port_destroy in the rest of drivers

After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.

To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: add a new helper function

In most of the time, the driver needs to check if the cts flow control
is enabled. But now, the driver checks the ASYNC_CTS_FLOW flag manually,
which is not a grace way. So add a new wraper function to make the code
tidy and clean.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: mxser, fix invalid module_parm permissions

444 means 0674 and we do not definitely want that. Use S_IRUGO which
is much more safer.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Rusty Russell <rusty@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: use tty_port_register_device

Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty_port_install from tty->ops->install or
tty_port_register_device called instead of tty_register_device when
the device is being set up after connected.

In this patch we modify most of the drivers to do the latter. When the
drivers use tty_register_device and we have tty_port already, we
switch to tty_port_register_device. So we have the tty_struct =>
tty_port link for free for those.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mxser: allow overlapping vector

For many cards, this saves some IO space because interrupt status port
has precedence over the rest of ports on the card. Hence it can be
mapped to a hole in I/O ports.

Here we add a kernel parameter which allows that if a user wants to.
But they need to explicitly enable it by a module parameter.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: move the termios object into the tty

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: mxser: local variables should not be exposed globally

The variable 'mxser_port_ops' is only referenced in this file and
should be marked static to prevent it from being exposed globally.

Quites the sparse warning:

warning: symbol 'mxser_port_ops' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove all #inclusions of asm/system.h

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>

TTY: remove unneeded tty->index checks

Checking if tty->index is in bounds is not needed. The tty has the
index set in the initial open. This is done in get_tty_driver. And it
can be only in interval <0,driver->num).

So remove the tests which check exactly this interval. Some are
left untouched as they check against the current backing device count.
(Leaving apart that the check is racy in most of the cases.)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: remove re-assignments to tty_driver members

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TTY: mxser+cyclades remove wait_until_sent debug code

It makes the code really ugly. And since it can be enabled only before
building and only in the source files, it can be barely used by users.
That said, I've not seen anybody to use it in the past few years.

This crap is copied to some more drivers over the tty tree. Since I'm
not their maintainer, I'm not sure if I should remove them too?

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/tty: use printk_ratelimited() instead of printk_ratelimit()

Since the printk_ratelimit() shouldn't be used anymore (see comment in
include/linux/printk.h), replace it with printk_ratelimited().

Signed-off-by: Manuel Zerpies <manuel.f.zerpies@ww.stud.uni-erlangen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

tty: move a number of tty drivers from drivers/char/ to drivers/tty/

As planned by Arnd Bergmann, this moves the following drivers from
drivers/char/ to drivers/tty/ as that's where they really belong:
amiserial
nozomi
synclink
rocket
cyclades
moxa
mxser
isicom
bfin_jtag_comm

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>