Commit 08177ece59 ("serial: asc: Adopt readl_/writel_relaxed()) is
regressing the m68k allmodconfig build. This is due to the unconditional
use of readl_relaxed() which, although documented, does not currently
exist for m68k.
This is trivially fixable for st-asc because we can just update the
asc_in() accessor to make this conditional.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The architectures supported by this driver, arm and sh, have expensive
implementations of writel(), reliant on spin locks and explicit L2 cache
management. These architectures provide a cheaper writel_relaxed() which
is much better suited to peripherals that do not perform DMA. The
situation with readl()/readl_relaxed()is similar although less acute.
This driver does not use DMA and will be more power efficient and more
robust (due to absence of spin locks during console I/O) if it uses the
relaxed variants.
The driver supports COMPILE_TEST and therefore falls back to writel()
when writel_relaxed() does not exist.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: kernel@stlinux.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the current calculation, if the required baud rate is above 262143,
we get an overflow.
This patch uses a 64bits variable to do the maths.
Also, we remove the '+1' to avoid a divide by zero if the input clock
rate is something unexpected.
Indeed, if the input clock rate is zero, it is preferable to be notified,
since the UART won't work anyway.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to prevent an asc instance to be used as early console, BUG_ON is
used on either mapbase or membase being NULL.
Problem is that this condition is also true when we set console to be a ttyASx
different to the first asc instance being probed.
Instead of calling BUG_ON, it now returns -ENXIO when either mapbase or
membase is NULL.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.
SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
"If IGNBRK is set, a break condition detected on input shall be ignored;
that is, not put on the input queue and therefore not read by any
process."
Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.
Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio
Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom
Annotated for fixes:
altera_uart
mcf
Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial
Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core
Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On my test platform (B2020/STiH416) the serial port issues bad characters
during the initial message avalanche as the console comes up. The problem
also occurs when dense(ish) I/O is done using the polled I/O interface.
The problem is fixed for me by using the FIFO half-empty bit rather than
FIFO full bit. Note that using the half-empty bit causes the FIFO to be
managed in a similar way to interrupt based I/O (i.e. where the hardware
gets best test coverage).
Running the FIFO half full will have no impact (good or bad) on console
performance. The UART will still remain fully saturated and the busy-wait
until the FIFO is empty in asc_console_write() will complete at the same
time.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver, like several others, uses the upper bits of the character
to track both real and dummy state. Unfortunately it neglects to mask
these bits properly when passing the character data around. This means
neither break detection nor sysrq character handling work correctly.
This patch adds the requires masking and has been tested to confirm
that it correctly handles magic sysrq sequences on ST's B2020 board.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use devm_ioremap_resource instead of devm_request_and_ioremap.
This was done using the semantic patch
scripts/coccinelle/api/devm_ioremap_resource.cocci
and various manual modifications to move associated calls to
platform_get_resource closer to the resulting call to devm_ioremap_resource
and to remove the associated error handling code.
The initialization of port->mapbase is also moved lower, to take advantage
of the NULL test on res performed by devm_ioremap_resource.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a below warning reported by kbuild test robot.
drivers/tty/serial/st-asc.c:727:28: warning: 'asc_match' defined but
not used [-Wunused-variable]
The code used in DT case is now ifdefed under CONFIG_OF to fix this
warning.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Reported-by: Kbuild Test Robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP is common
across all the ST parts for settop box platforms.
ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
It support all industry standard baud rates.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Stephen Gallimore <stephen.gallimore@st.com>
CC: Stuart Menefy <stuart.menefy@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
