The Altera 16550 soft IP UART requires 2 additional registers for
TX FIFO threshold support. These 2 registers enable the TX FIFO
Low Watermark and set the TX FIFO Low Watermark.
Set the TX FIFO threshold to the FIFO size - tx_loadsz.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Initialize the tx_loadsz parameter from passed in devicetree
tx-threshold parameter.
The tx_loadsz is calculated as the number of bytes to fill FIFO
when tx-threshold is triggered.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The USR2_DCDIN bit is tested for in register usr1. As the name
suggests the usr2 register should be used instead. This fixes
reading the Carrier detect status.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Fixes: 90ebc483 ("serial: imx: repair and complete handshaking")
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: <stable@vger.kernel.org> # 4.5+
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We get 2 warnings when building kernel with W=1:
drivers/tty/serial/stm32-usart.c:63:5: warning: no previous prototype for 'stm32_pending_rx' [-Wmissing-prototypes]
drivers/tty/serial/stm32-usart.c:88:15: warning: no previous prototype for 'stm32_get_char' [-Wmissing-prototypes]

In fact, these two functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.

So this patch marks these functions with 'static'.
Signed-off-by: NBaoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add initialisation of control register and baud rate to
cdns_early_console_setup(), required when running kernel standalone
without a boot loader. Baud rate is only initialised when specified in
earlycon command-line option, otherwise it is assumed this has been
set by a boot loader. Updated Documentation/kernel-parameters.txt
accordingly.
Signed-off-by: NScott Telford <stelford@cadence.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch Remove the unwated checks while reading the parity,framing,
overrun and Break detection errors.
Signed-off-by: NNava kishore Manne <navam@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
[stelford@cadence.com: cherry picked from
https://github.com/Xilinx/linux-xlnx commit
b1cf74970df5470ffbc8e7876a9edf5e3498ef94]
Signed-off-by: NScott Telford <stelford@cadence.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The existing interrupt handling logic has following issues.
- Upon a parity error with default configuration, the control
  never comes out of the ISR thereby hanging Linux.
- The error handling logic around framing and parity error are buggy.
  There are chances that the errors will never be captured.
This patch ensures that the status registers are cleared on all cases so
that a hang situation never arises.
Signed-off-by: NAnirudha Sarangi <anirudh@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
[stelford@cadence.com: cherry picked from
https://github.com/Xilinx/linux-xlnx commit
ac297e20d399850d7a8e373b6eccf2e183c15165 with manual conflict resolution]
Signed-off-by: NScott Telford <stelford@cadence.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Building this driver with a 64-bit dma_addr_t type results in
a compiler warning:

drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_rx_probe':
drivers/tty/serial/stm32-usart.c:746:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_tx_probe':
drivers/tty/serial/stm32-usart.c:818:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]

While the type conversion here is harmless, this hints at a different
problem: we pass an __iomem pointer into a DMA engine, which expects
a phys_addr_t. This happens to work because stm32 has no MMU and
ioremap() is an identity mapping here, but it's still an incorrect
API use. Using dma_addr_t is doubly wrong here, because that would
be the result of dma_map_single() rather than the physical address.

Using the mapbase instead fixes multiple issues:

- the warning is gone
- we don't go through ioremap in error
- the cast is gone, making it use the correct resource_size_t/phys_addr_t
  type in the process.

Fixes: 34891872 ("serial: stm32: adding dma support")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The problem with previous code was it rounded values in wrong
place and produced wrong baud rate in some cases.
Signed-off-by: NAlexey Starikovskiy <aystarik@gmail.com>
[nicolas.ferre@atmel.com: port to newer kernel and add commit log]
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch makes changes not to enable parity error interrupt.
With the current implementation, each parity error results in
two distinct interrupts (almost always). The first one is normal
parity error interrupt with no data in the fifo and the second one
is a proper Rx interrupt with the received data in the fifo. By
disabling parity error interrupt we still ensure handling of
parity errors as for the Rx fifo interrupt the parity error still
shows up in the interrupt status register. Considering the fact
that the by default INPCK and IGNPAR are not set, this is the
optimal implementation for parity error handling.
Signed-off-by: NAnirudha Sarangi <anirudh@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
[stelford@cadence.com: cherry picked from
https://github.com/Xilinx/linux-xlnx commit
bf9f610b445e2c9ed33c41e1e0e30b43be4e1f97 with manual conflict
resolution]
Signed-off-by: NScott Telford <stelford@cadence.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds dma mode support for rx and tx
with pio mode as fallback in case of dma error.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keep the clock enabled at the end of stm32_init_port
but disable it in stm32_serial_remove.
Note that stm32_pm function is there to manage the
clock at runtime.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

"st,hw-flow-ctrl" property is documented in device tree
binding whereas "auto-flow-control" was used in the code.
The driver is now aligned with the binding name
"st,hw-flow-ctrl".
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Register offset management rework to support both
stm32f4 (default) and stm32f7. Driver rework to
ensure same functional level on both stm32f4 and
stm32f7: no new feature in this version yet.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After issuing the reset, driver is not checking the rx and tx reset
done status. So, modified driver to wait for the reset done status.
Signed-off-by: NNava kishore Manne <navam@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds RXBS register access support for zynqmp.
To avoid the corner error conditions it will consider only
RXBS[2:0] bits while checking the error conditions
(Parity,Framing and BRAK).
Signed-off-by: NNava kishore Manne <navam@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

First loop in wait_for_xmitr could also trigger NMI
watchdog in case reading from the port is slow:

  PID: 0      TASK: ffffffff819c1460  CPU: 0   COMMAND: "swapper/0"
   #0 [ffff88019f405e58] crash_nmi_callback at ffffffff8104d382
   #1 [ffff88019f405e68] nmi_handle at ffffffff8168ead9
   #2 [ffff88019f405eb0] do_nmi at ffffffff8168ec53
   #3 [ffff88019f405ef0] end_repeat_nmi at ffffffff8168df13
      [exception RIP: delay_tsc+50]
      RIP: ffffffff81325642  RSP: ffff88019f403bb0  RFLAGS: 00000083
      RAX: 00000000000005c8  RBX: ffffffff81f83000  RCX: 0000024e4fb88a8b
      RDX: 0000024e4fb89053  RSI: 0000000000000000  RDI: 00000000000007d1
      RBP: ffff88019f403bb0   R8: 000000000000000a   R9: 0000000000000000
      R10: 0000000000000000  R11: ffff88019f403ad6  R12: 000000000000250f
      R13: 0000000000000020  R14: ffffffff81d360c7  R15: 0000000000000047
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  --- <NMI exception stack> ---
   #4 [ffff88019f403bb0] delay_tsc at ffffffff81325642
   #5 [ffff88019f403bb8] __const_udelay at ffffffff813255a8
   #6 [ffff88019f403bc8] wait_for_xmitr at ffffffff81404390
   #7 [ffff88019f403bf0] serial8250_console_putchar at ffffffff8140455c
   #8 [ffff88019f403c10] uart_console_write at ffffffff813ff00a
   #9 [ffff88019f403c40] serial8250_console_write at ffffffff814044ae
  #10 [ffff88019f403c88] call_console_drivers.constprop.15 at ffffffff81086b01
  #11 [ffff88019f403cb0] console_unlock at ffffffff8108842f
  #12 [ffff88019f403ce8] vprintk_emit at ffffffff81088834
  #13 [ffff88019f403d58] vprintk_default at ffffffff81088ba9
  #14 [ffff88019f403d68] printk at ffffffff8167f034

Adding touch_nmi_watchdog call to the first loop as well.
Reported-by: NChunyu Hu <chuhu@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Less magic that only requires comments.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE
device") changes earlycon function pl011_putc() to use a pointer to
uart_amba_port.  This causes a regression when earlycon is enabled,
because uart_amba_port is not available yet at earlycon time.  Let's
revert the change on pl011_putc() to fix the regression.

The earlycon support for ZTE device can probably be added later by
declaring a new earlycon setup function with a vendor specific
compatible.
Reported-by: NSudeep Holla <sudeep.holla@arm.com>
Fixes: 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 5d7519df ("serial: mxs-auart: Disable clock on error path")
try to disable clock on error path, but still missing the clk_set_rate()
error handling path.
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine_terminate_all() is deprecated and should be replaced by
dmaengine_terminate_sync() in non-atomic context or dmaengine_terminate_async()
with dmaengine_synchronize().

See commit b36f09c3 ("dmaengine: Add transfer termination synchronization support")
Signed-off-by: NFabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit 761ed4a9 ("tty: serial_core: convert uart_close to use
tty_port_close") refactored uart_close() to use tty_port_close().  At the same
time it introduced a potential NULL pointer dereference. Rearrange the code to
avoid kernel crash.

Fixes: 761ed4a9 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 18dfef9c ("serial: atmel: convert to irq handling
provided mctrl-gpio"), interrupts from GPIOs are not disabled any more
when the serial port is closed, leading to an oops when the one of the
input pin is toggled (CTS/DSR/DCD/RNG).

This is only the case if those pins are used as GPIOs, i.e. declared
like that:
usart1: serial@f8020000 {
        /* CTS and DTS will be handled by GPIO */
        status = "okay";
        rts-gpios = <&pioB 17 GPIO_ACTIVE_LOW>;
        cts-gpios = <&pioB 16 GPIO_ACTIVE_LOW>;
        dtr-gpios = <&pioB 14 GPIO_ACTIVE_LOW>;
        dsr-gpios = <&pioC 31 GPIO_ACTIVE_LOW>;
        rng-gpios = <&pioB 12 GPIO_ACTIVE_LOW>;
        dcd-gpios = <&pioB 15 GPIO_ACTIVE_LOW>;
};

That's because modem interrupts used to be freed in atmel_shutdown().
After commit 18dfef9c ("serial: atmel: convert to irq handling
provided mctrl-gpio"), this code was just removed.
Calling atmel_disable_ms() disables the interrupts and everything works
fine again.

Tested on at91sam9g35-cm

(This patch doesn't apply on -stable kernels, fixes for 4.4 and 4.7 will
be sent after this one is applied.)
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Fixes: 18dfef9c ("serial: atmel: convert to irq handling provided mctrl-gpio")
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function lpuart_start_rx_dma() is called from several
places, in some of which, such as lpuart_startup(), a lock
be held here, so we should use GFP_ATOMIC when a lock is held.

Fixes: 5887ad43 ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When dev.of_node is not NULL, we also need to set IRQF_TRIGGER_FALLING
flag, otherwise it may cause uncertain interrupts.
Signed-off-by: NLiu Xiang <liu.xiang6@zte.com.cn>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR.

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should disable the previously acquired clock when enabling s->clk
fails.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Guenter Roeck reported a regression caused by commit "serial: earlycon:
Extend earlycon command line option to support 64-bit addresses":

console= and earlycon= options have the following format:
...,<addr>,<options>

Historically used here simple_strtoul() had no problems with comma, but the
new and recommended kstrtoull() requires null-terminated string and returns
-EINVAL in case there are "options" at the end. There is no recommended to
use function currently that will support it, so stick to obsolete
simple_strtoull() variant.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some functions called by serial_imx_probe emit an error message themself
(like kmalloc() and friends). clk_prepare_enable() and
devm_request_irq() however don't which might make the driver silently
fail to probe. So add an error message for these.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since we have nice macro IRQ_RETVAL() we would use it to convert a flag of
handled interrupt from int to irqreturn_t.

The rationale of doing this is:
a) hence we implicitly mark hsu_dma_do_irq() as an auxiliary function that
   can't be used as interrupt handler directly, and
b) to be in align with serial driver which is using serial8250_handle_irq()
   that returns plain int by design.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

earlycon implementation used "unsigned long" internally, but there are systems
(ARM with LPAE) where sizeof(unsigned long) == 4 and uart is mapped beyond 4GiB
address range.

Switch to resource_size_t internally and replace obsoleted simple_strtoul() with
kstrtoull().
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We get 1 warning when building kernel with W=1:
drivers/tty/serial/earlycon-arm-semihost.c:56:12: warning: no previous prototype for 'early_smh_setup' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.
Signed-off-by: NBaoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add ACPI identifier for UART on Hisilicon Hip05 SoC, be careful that
it is not 16550 compatible, and "reg-io-width" and "reg-shift" need
be set properly by _DSD method in DSDT.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Unify the check of em485 variable to be either (em485) or (!em485) instead of
the explicit comparison to NULL.

While here, remove redundant check in __do_stop_tx_rs485() and
__stop_tx_rs485() since the functions ain't called with NULL value of em485
variable.

Cc: "Matwey V. Kornilov" <matwey@sai.msu.ru>
Tested-by: NYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are calls to serial8250_rpm_{get|put}() in __do_stop_tx_rs485() that are
certainly placed in a wrong location. I dunno how it had been tested with
runtime PM enabled because it is obvious "sleep in atomic context" error.

Besides that serial8250_rpm_get() is called immediately after an IO just
happened. It implies that the device is already powered on, see implementation
of serial8250_em485_rts_after_send() and serial8250_clear_fifos() for the
details.

There is no bug have been seen due to, as I can guess, use of auto suspend mode
when scheduled transaction to suspend is invoked quite lately than it's needed
for a few writes to the port. It might be possible to trigger a warning if
stop_tx_timer fires when device is suspended.

Refactor the code to use runtime PM only in case of timer function.

Fixes: 0c66940d ("tty/serial/8250: fix RS485 half-duplex RX")
Cc: "Matwey V. Kornilov" <matwey@sai.msu.ru>
Tested-by: NYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The UART DMA was only being configured on i.MX6Q compatible devices. We
know that the DMA also works for i.MX53 devices, so enable uart DMA for
imx53 and let the device tree to configure if DMA should be used or not.
Signed-off-by: NMartyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: NFabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>