The driver provides different rs485_supported for the case where RTS is
not available making it unnecessary to handle it in
imx_uart_rs485_config.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-32-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Serial core handles serial_rs485 sanitization. Remove custom
sanitization from lpuart_config_rs485.
This change loses dev_err when SER_RS485_RX_DURING_TX is set due to
incorrect configuration. Other drivers do not do similar prinout for
full-duplex case and it should be done in serial core if it is
desirable to notify on this condition. Personally, I doesn't see it
important because the kernel gracefully downgrades to half-duplex.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-31-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Serial core handles serial_rs485 sanitization and rs485 struct
assignment. As serial_rs485 is already clear for the non-RS485 case by
serial core, there no need to clear flags in the driver.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-26-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to be add new flags more cleanly and safely, return -EINVAL
from TIOCSRS485 ioctl for the flags bits which are not among the
current legacy ones.
This might cause a regression for userspace as those non-flag bits do
not currently trigger -EINVAL. However, it would only occur if the
userspace is sending garbage bits so perhaps we'll get away with this
change.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-25-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When SER_RS485_ENABLED is not set, having any other flag/field set in
serial_rs485 struct does not have an effect different from not having
them set. Thus, make the serial_rs485 struct also match the behavior
for all flags, not just SER_RS485_ENABLED.
Some drivers do similar clearing of rs485 struct in their
rs485_config() already, but not all. This change makes the behavior
consistent across drivers.
Don't try to validate rs485 struct further when no RS485 is requested,
this silences some bogus warnings.
This change has (minor) userspace visible impact.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-24-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sanitize serial_rs485 struct before calling into rs485_setup. The
drivers provide supported_rs485 to help sanitization of the fields.
If neither of SER_RS485_RTS_ON_SEND or SER_RS485_RTS_AFTER_SEND
supported, don't pretend they can be set to sane settings but clear
them both instead. If only one of them is supported it may look
tempting to use the one driver supports to set the other, however, the
userspace does not have that information readily available so it
wouldn't be helpful.
While adjusting the documentation, remove also the claim that
TIOCGRS485 would call driver specific code. In reality, it does nothing
else than copies the stored serial_rs485 structure from uart_port to
userspace.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-23-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add information on supported serial_rs485 features.
This driver does not support delay_rts_after_send but the pre-existing
behavior is to return -EINVAL if delay_rts_after_send is non-zero. In
contrast, other drivers that do not support delay_rts_after_send either
zero delay_rts_after_send or do not care (leave the inaccurate value).
As changing this would cause userspace visible impact, the change is
not attempted here. But perhaps it should be still tried (maybe nobody
finds that kind of API oddity significant)?
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-21-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add information on supported serial_rs485 features.
In the case where RTS is lacking, RS485 cannot be enabled so provide
zero rs485_supported for that case. Perhaps it would make sense to not
provide rs485_config() at all in that case but such a change would have
userspace visible impact/change in behavior so this patch does not
attempt it.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-17-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add information on supported serial_rs485 features.
In the case where RTS is lacking, RS485 cannot be enabled so provide
zero rs485_supported for that case. Perhaps it would make sense to not
provide rs485_config() at all in that case but such a change would have
userspace visible impact/change in behavior so this patch does not
attempt it.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-14-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add information on supported serial_rs485 features. When the driver is
using em485, take advantage of serial8250_em485_supported.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Preparing to move serial_rs485 struct sanitization into serial core,
each driver has to provide what fields/flags it supports. This
information is pointed into by rs485_supported.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A few serial drivers make a call to rs485_config() themselves (all
these seem to relate to init). Convert them all to use a common helper
which makes it easy to make adjustments on tasks related to it as
serial_rs485 struct sanitization is going to be added.
In pci_fintek_setup() (in 8250_pci.c), the rs485_config() call was made
with NULL, however, it can be changed to pass uart_port's rs485 struct.
No other callers should pass NULL into rs485_config() so the NULL check
can now be eliminated.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure LSR flags are preserved in dw8250_tx_wait_empty(). This
function is called from a low-level out function and therefore cannot
call serial_lsr_in() as it would lead to infinite recursion.
It is borderline if the flags need to be saved here at all since this
code relates to writing LCR register which usually implies no important
characters should be arriving.
Fixes: 914eaf935e ("serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() reads LSR under a few conditions, convert both to
use serial_lsr_in() in order to preserve LSR flags properly across
reads.
Fixes: 424d79183a ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
Fixes: aa63d786ce ("serial: 8250: dw: Add support for DMA flow controlling devices")
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_rx_chars() has max_count based character limit. If it
triggers, the function returns the old LSR value (and it has never
returned only flags which were not handled). Adjust the comment to
match behavior and warn about which flags can be depended on.
I'd have moved LSR read before LSR read and used serial_lsr_in() also
here but I came across an old discussion about the topic. That
discussion generated commit d22f8f1068 ("serial: 8250: Fix lost rx
state") so I left the code as it is (it works as long as the callers
only use a subset of the LSR flags which holds true today) and changed
the comment instead.
Link: https://www.spinics.net/lists/linux-serial/msg16220.html
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_handle_irq() assumes it's the first to read LSR register.
However, there are 8250 drivers which perform LSR read in their own irq
handler prior to calling serial8250_handle_irq(). As not all flags are
preserved across LSR reads, use serial_lsr_in() helper to get all the
preserved flags.
This commit might fix other commits too besides the ones for DW UART
mentioned below. It's just not clear to me which of the other devices
clear some of the LSR flags on read. AFAIK, nobody has complained about
this problem (either against DW or other devices) so it might not have
that bad impact in the end.
Fixes: 424d79183a ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
Fixes: aa63d786ce ("serial: 8250: dw: Add support for DMA flow controlling devices")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LSR register readers need to be careful in order to not lose bits that
are not preserved across reads. Create a helper that takes care of
storing the non-preserved bits into lsr_save_flags.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Not all LSR register flags are preserved across reads. Therefore, LSR
readers must store the non-preserved bits into lsr_save_flags.
This fix was initially mixed into feature commit f6f586102a ("serial:
8250: Handle UART without interrupt on TEMT using em485"). However,
that feature change had a flaw and it was reverted to make room for
simpler approach providing the same feature. The embedded fix got
reverted with the feature change.
Re-add the lsr_save_flags fix and properly mark it's a fix.
Link: https://lore.kernel.org/all/1d6c31d-d194-9e6a-ddf9-5f29af829f3@linux.intel.com/T/#m1737eef986bd20cf19593e344cebd7b0244945fc
Fixes: e490c9144c ("tty: Add software emulated RS485 support for 8250")
Co-developed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As either start_tx_rs485() or start_tx() calls __start_tx() as the last
line of their logic, it makes sense to just move that call into
start_tx(). When start_tx_rs485() wants to defer tx using timer, return
false so start_tx() can return based on it.
Reorganize em485 code in serial8250_start_tx() so that the return can be
shared for the cases where tx start is deferred.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220607084154.8172-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There seems to be little reason for __do_stop_tx() to exits on its own.
It is rather simple and is only called from __stop_tx(). Thus, move its
logic into __stop_tx().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220607084154.8172-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following coccicheck warnings:
drivers/tty/vt/vt.c:3942:8-16:
WARNING: use scnprintf or sprintf
drivers/tty/vt/vt.c:3950:8-16:
WARNING: use scnprintf or sprintf
Signed-off-by: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Link: https://lore.kernel.org/r/20220531072814.34999-1-zhangxuezhi1@coolpad.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I2C implementation on this chip has a few key differences
compared to SPI, as described in previous patches.
* extended register space access needs no extra logic
* slave address is used to select which UART to communicate
with
To accommodate these differences, add an I2C interface config,
set the RevID register address and implement an empty method
for setting the GlobalCommand register, since no special handling
is needed for the extended register space.
To handle the port-specific slave address, create an I2C dummy
device for each port, except the base one (UART0), which is
expected to be the one specified in firmware, and create a
regmap for each I2C device.
Add minimum and maximum slave addresses to each devtype for
sanity checking.
Also, use a separate regmap config with no write_flag_mask,
since I2C has a R/W bit in its slave address, and set the
max register to the address of the RevID register, since the
extended register space needs no extra logic.
Finally, add the I2C driver.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-5-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SPI can only use 5 address bits, since one bit is reserved for
specifying R/W and 2 bits are used to specify the UART port.
To access registers that have addresses past 0x1F, an extended
register space can be enabled by writing to the GlobalCommand
register (address 0x1F).
I2C uses 8 address bits. The R/W bit is placed in the slave
address, and so is the UART port. Because of this, registers
that have addresses higher than 0x1F can be accessed normally.
To access the RevID register, on SPI, 0xCE must be written to
the 0x1F address to enable the extended register space, after
which the RevID register is accessible at address 0x5. 0xCD
must be written to the 0x1F address to disable the extended
register space.
On I2C, the RevID register is accessible at address 0x25.
Create an interface config struct, and add a method for
toggling the extended register space and a member for the RevId
register address. Implement these for SPI.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-4-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver currently does manual register manipulation in
multiple places to talk to a specific UART port.
In order to talk to a specific UART port over SPI, the bits U1
and U0 of the register address can be set, as explained in the
Command byte configuration section of the datasheet.
Make this more elegant by creating regmaps for each UART port
and setting the read_flag_mask and write_flag_mask
accordingly.
All communcations regarding global registers are done on UART
port 0, so replace the global regmap entirely with the port 0
regmap.
Also, remove the 0x1f masks from reg_writeable(), reg_volatile()
and reg_precious() methods, since setting the U1 and U0 bits of
the register address happens inside the regmap core now.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-3-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SPI batch read/write operations can be implemented as simple
regmap raw read and write, which will also try to do a gather
write just as it is done here.
Use the regmap raw read and write methods.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220605144659.4169853-2-demonsingur@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fetch the user data one by one (by get_user()) and fill in the local
buffer simultaneously. I.e. we no longer require to walk two buffers and
save thus 256 B from stack (whole ubuf).
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-36-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The old->refcount is guaranteed to be > 1, so we can directly call
con_allocate_new() to make the code more obvious.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-35-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The first part of con_do_clear_unimap() is needed on another place, so
extract it to a separate function called con_allocate_new(). It will be
used once more in the next patch.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-34-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
con_do_clear_unimap() currently decreases and increases refcount of old
dictionary in a back and forth fashion. This makes the code really hard
to follow. Decrease the refcount only if everything went well and we
really allocated a new one and decoupled from the old dictionary.
I sincerelly hope I did not make a mistake in this (ill) logic.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-33-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are still some remaining tabs/spaces at EOLs or spaces before
tabs. Remove them all now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-32-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1) Fetch *conp->vc_uni_pagedir_loc first and do the NULL check on the local
variable.
2) Decouple the large "if" into few smaller "if"s.
3) Remove a \n from the definition line.
This makes the code more readable.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-31-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ilpo Järvinen