Use wait_event_interruptible in lpuart_dma_shutdown isn't a reasonable
behavior, since it may cause the system hang here if the condition
!sport->dma_tx_in_progress never to be true in some corner case, such as
when enable the flow control, the dma tx request may never be completed
due to the peer's CTS setting when run .shutdown().
So here change to use wait_event_interruptible_timeout instead of
wait_event_interruptible, the tx dma will be forcibly terminated if the
tx dma request cannot be completed within 300ms.
Considering the worst tx dma case is to have a 4K bytes tx buffer, which
would require about 300ms to complete when the baudrate is 115200.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20211203030441.22873-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert commit b4b844930f ("tty: serial: fsl_lpuart: drop earlycon entry
for i.MX8QXP"), because this breaks earlycon support on imx8qm/imx8qxp.
While it is true that for earlycon there is no difference between
i.MX8QXP and i.MX7ULP (for now at least), there are differences
regarding clocks and fixups for wakeup support. For that reason it was
deemed unacceptable to add the imx7ulp compatible to device tree in
order to get earlycon working again.
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211124073109.805088-1-alexander.stein@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Do software reset for communication port on imx7ulp and imx8qxp after
the port is registered if the UART controller support the feature.
Do partition reset with LPUART's power on, LPUART registers will
keep the previous status, like on i.MX8QXP platform, which is not
expected action, so need to set the RST bit of GLOBAL register to reset
all uart internal logic and registers.
Currently, only i.MX7ULP and i.MX8QXP LPUART controllers include
global register that support the software reset.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210823091801.17447-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch e60c2991f1 make the lpuart32_get_mctrl always return 0, actually
this will break the functions of device which use flow control such as
Bluetooth.
For lpuart32 plaform, the hardware can handle the CTS automatically.
So we should set TIOCM_CTS active. Also need to set CAR and DSR active.
Patch has been tested on lpuart32 platforms such as imx8qm and imx8ulp.
Fixes: e60c2991f1 ("serial: fsl_lpuart: remove RTSCTS handling from get_mctrl()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210729083109.31541-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SYSRQ doesn't work with DMA. This is because there is no error
indication whether a symbol had a framing error or not. Actually,
this is not completely correct, there is a bit in the data register
which is set in this case, but we'd have to read change the DMA access
to 16 bit and we'd need to post process the data, thus make the DMA
pointless in the first place.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The LPUART doesn't have the ability to control the RTS or CTS line
manually. Instead it will set it automatically when data is send or
handle it when data is received. Thus drop the wrong code in set_mctrl.
For the 32 bit version this was already done in the commit 2b30efe2e8
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"). Keep
the 8-bit version in sync and remove it there, too.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-8-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wrong code in set_mctrl() was already removed in commit 2b30efe2e8
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"), but the
code in get_mctrl() wasn't removed. It will not return the state of the
RTS or CTS line but whether automatic flow control is enabled, which is
wrong for the get_mctrl(). Thus remove it.
Fixes: 2b30efe2e8 ("tty: serial: lpuart: Remove unnecessary code from set_mctrl")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-7-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>From commit 75f4e830fa ("serial: do not restore interrupt state in
sysrq helper"):
Since commit 81e2073c17 ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly
requested as threaded are always called with interrupts disabled and
there is no need to save the interrupt state when taking the port
lock.
Apply this also to fsl_lpuart in prepartion for sysrq handling with
uart_unlock_and_check_sysrq().
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-4-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should be very careful about the register values that will be used
for division or modulo operations, althrough the possibility that the
UARTBAUD register value is zero is very low, but we had better to deal
with the "bad data" of hardware in advance to avoid division or modulo
by zero leading to undefined kernel behavior.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prior to the commit that this one fixes, the FIFO size was derived from
the read-only register LPUARTx_FIFO[TXFIFOSIZE] using the following
formula:
TX FIFO size = 2 ^ (LPUARTx_FIFO[TXFIFOSIZE] - 1)
The documentation for LS1021A is a mess. Under chapter 26.1.3 LS1021A
LPUART module special consideration, it mentions TXFIFO_SZ and RXFIFO_SZ
being equal to 4, and in the register description for LPUARTx_FIFO, it
shows the out-of-reset value of TXFIFOSIZE and RXFIFOSIZE fields as "011",
even though these registers read as "101" in reality.
And when LPUART on LS1021A was working, the "101" value did correspond
to "16 datawords", by applying the formula above, even though the
documentation is wrong again (!!!!) and says that "101" means 64 datawords
(hint: it doesn't).
So the "new" formula created by commit f77ebb241c has all the premises
of being wrong for LS1021A, because it relied only on false data and no
actual experimentation.
Interestingly, in commit c2f448cff2 ("tty: serial: fsl_lpuart: add
LS1028A support"), Michael Walle applied a workaround to this by manually
setting the FIFO widths for LS1028A. It looks like the same values are
used by LS1021A as well, in fact.
When the driver thinks that it has a deeper FIFO than it really has,
getty (user space) output gets truncated.
Many thanks to Michael for pointing out where to look.
Fixes: f77ebb241c ("tty: serial: fsl_lpuart: correct the FIFO depth size")
Suggested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20201023013429.3551026-1-vladimir.oltean@nxp.com
Reviewed-by：Fugang Duan <fugang.duan@nxp.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're about to amend uart_get_rs485_mode() to support a GPIO pin for
rs485 bus termination. Retrieving the GPIO descriptor may fail, so
allow uart_get_rs485_mode() to return an errno and change all callers
to check for failure.
The GPIO descriptor is going to be stored in struct uart_port. Pass
that struct to uart_get_rs485_mode() in lieu of a struct device and
struct serial_rs485, both of which are directly accessible from struct
uart_port.
A few drivers call uart_get_rs485_mode() before setting the struct
device pointer in struct uart_port. Shuffle those calls around where
necessary.
[Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the following messages are seen when booting i.MX8QXP:
fsl-lpuart 5a060000.serial: DMA tx channel request failed, operating without tx DMA (-19)
fsl-lpuart 5a060000.serial: DMA rx channel request failed, operating without rx DMA (-19)
It is not really useful to have such messages on every boot, so change
them to debug level instead.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20200416153453.18825-1-festevam@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coverity reports the following:
var_compare_op: Comparing chan to null implies that chan might be null.
1234 if (chan)
1235 dmaengine_terminate_all(chan);
1236
Dereference after null check (FORWARD_NULL)
var_deref_op: Dereferencing null pointer chan.
1237 dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
Technically, this is correct. But lpuart_dma_rx_free() is guarded by
lpuart_dma_rx_use which is only true if there is a dma channel, see
lpuart_rx_dma_startup(). In any way, this looks bogus. So remove
the superfluous "if (chan)" check and make coverity happy.
Fixes: a092ab25fd ("tty: serial: fsl_lpuart: fix DMA mapping")
Signed-off-by: Michael Walle <michael@walle.cc>
Reported-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20200403174942.9594-1-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the correct device to request the DMA mapping. Otherwise the IOMMU
doesn't get the mapping and it will generate a page fault.
The error messages look like:
[ 19.012140] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9
[ 19.023593] arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xbbfff800, fsynr=0x3e0021, cbfrsynra=0x828, cb=9
This was tested on a custom board with a LS1028A SoC.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200306214433.23215-3-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DMA channel might not be available at probe time. This is esp. the
case if the DMA controller has an IOMMU mapping.
There is also another caveat. If there is no DMA controller at all,
dma_request_chan() will also return -EPROBE_DEFER. Thus we cannot test
for -EPROBE_DEFER in probe(). Otherwise the lpuart driver will fail to
probe if, for example, the DMA driver is not enabled in the kernel
configuration.
To workaround this, we request the DMA channel in _startup(). Other
serial drivers do it the same way.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200306214433.23215-2-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 3bc3206e1c ("serial: fsl_lpuart: Remove the alias node
dependence") the port line number can also be allocated by IDA, but in
case of an error the ID will no be removed again. More importantly, any
ID will be freed in remove(), even if it wasn't allocated but instead
fetched by of_alias_get_id(). If it was not allocated by IDA there will
be a warning:
WARN(1, "ida_free called for id=%d which is not allocated.\n", id);
Move the ID allocation more to the end of the probe() so that we still
can use plain return in the first error cases.
Fixes: 3bc3206e1c ("serial: fsl_lpuart: Remove the alias node dependence")
Signed-off-by: Michael Walle <michael@walle.cc>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200303174306.6015-3-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a659652f61.
This broke the earlycon on LS1021A processors because the order of the
earlycon_setup() functions were changed. Before the commit the normal
lpuart32_early_console_setup() was called. After the commit the
lpuart32_imx_early_console_setup() is called instead.
Fixes: a659652f61 ("tty: serial: fsl_lpuart: drop EARLYCON_DECLARE")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200303174306.6015-2-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"earlycon" no need to specify the value string since it uses
stdout-path parameters. However when earlycon and normal console
are not using the same uart port, we need specify value string
to earlycon, this is what we need to do when support dual linux
using jailhouse hypervisor. The 2nd linux will use the uart
of the 1st linux as earlycon.
earlycon=lpuart32,mmio32,0x5a060010,115200 not work for i.MX8QXP.
It is because lpuart32_early_console_setup not support little endian.
Since the original code is to support UPIO_MEM32BE, so if not
UPIO_MEM32, we still take it as UPIO_MEM32BE
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1576822230-23125-3-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)
In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-19-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently flow control is not working due to lpuart32_set_mctrl that is
clearing TXCTSE bit in all cases. This bit gets earlier setup by
lpuart32_set_termios.
As I read in Documentation set_mctrl is also not meant for hardware
flow control rather than gpio setting and clearing a RTS signal.
Therefore I guess it is safe to remove the whole code in
lpuart32_set_mctrl.
This was tested with console on a i.MX8QXP SoC.
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20191017141428.10330-1-philippe.schenker@toradex.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
