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>

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>

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>

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>

Use an unified new dev variable instead of &pdev->dev and p->dev
in probe function.
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Added devices ids for acces i/o products quad and octal serial cards
that make use of existing Pericom PI7C9X7954 and PI7C9X7958
configurations .
Signed-off-by: NJimi Damon <jdamon@accesio.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

DMA on Intel Quark SoC is a part of UART IP block. Enable it.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel Quark SoC supports MSI for LPSS, in particular for UART. Enable MSI for
Intel Quark.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel Quark has DesignWare UART. Move the code from 8250_pci to 8250_lpss.
Reviewed-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The SoCs, such as Intel Braswell, have DesignWare UART IP. Split out the
support of such chips to a separate module which also will be used for Intel
Quark later.

The rationale to have the separate driver to be existing:
- Do not contaminate 8250_pci.c anymore with LPSS related quirks
- All of them are using same DMA engine and they are Designware IP which means
  that in the future we might share the code between 8250_dw.c and 8250_lpss.c
- It reduces the kernel memory footprint on non-X86 machines where 8250_pci.c
  is in use

Besides the split the driver also has been refactored, in particular a) the DMA
and port setup are separate functions, b) the two new structures lpss8250 and
lpss8250_board are introduced to keep necessary data instead of
pciserial_board, c) DMA parameters are passed to the DMA setup via mentioned
custom structure. Most of the changes are done due to the future support of
UART DMA on Intel Quark.

The Intel Quark UART DMA support is based on bits taking from BSP code
published by Intel earlier.

The driver does not use any specific power management. PCI core takes care of
the default behaviour during suspend and resume.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel Quark has 16550A compatible UART with autoflow feature enabled. It has
only 16 bytes of FIFO. Currently serial8250_do_set_termios() prevents to enable
autoflow since the minimum requirement of 32 bytes of FIFO size.

Drop a FIFO size limitation to allow autoflow control be enabled on such UARTs.

While here, comment out UART_CAP_AFE for PORT_AR7 since it wasn't working and
it will be not a good idea to use it in conjunction with trigger level of 1
byte.
Suggested-by: NPeter Hurley <peter@hurleysoftware.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some UARTs, e.g. one is used in Intel Quark, have a different address base for
DMA operations. Introduce an additional field (per RX and TX DMA channels) in
struct uart_8250_dma to cover those cases.
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert dmaengine_terminate_all() calls to synchronous and asynchronous
versions where appropriate.
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mediatek can support baud rate up to 4M.
the 'uart_get_baud_rate' function will limit the max baud rate.
Modify max baud to remove the limit.
Signed-off-by: NLong Cheng <long.cheng@mediatek.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since the commit c1a67b48 ("serial: 8250_pci: replace switch-case by
formula for Intel MID"), the 8250 driver crashes in the byt_set_termios()
function with a divide error. This is caused by the fact that a baud rate of 0
(B0) is not handled properly. Fix it by falling back to B9600 in this case.
Reported-by: N"Mendez Salinas, Fernando" <fernando.mendez.salinas@intel.com>
Fixes: c1a67b48 ("serial: 8250_pci: replace switch-case by formula for Intel MID")
Cc: stable@vger.kernel.org
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It should check the data->pclk, not data->clk when get apb_pclk.

Fixes: c8ed99d4("serial: 8250_dw: Add support for deferred probing")
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Serial console is broken in v4.8-rcX. Mika and I independently bisected down to
commit 4ef03d32 ("tty/serial/8250: use mctrl_gpio helpers").

Since neither author nor anyone else didn't propose a solution we better revert
it for now.

This reverts commit 4ef03d32.

Link: https://lkml.kernel.org/r/20160809130229.GN1729@lahna.fi.intel.comSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A bugfix for the fintek driver required defining some macros, but
one of them clashes with a system header on ARM:

drivers/tty/serial/8250/8250_fintek.c:34:0: error: "IRQ_MODE" redefined [-Werror]
 #define IRQ_MODE 0x70

In file included from /git/arm-soc/arch/arm/include/asm/ptrace.h:13:0,
                 from /git/arm-soc/arch/arm/include/asm/irqflags.h:6,
                 from /git/arm-soc/include/linux/irqflags.h:15,
                 from /git/arm-soc/arch/arm/include/asm/bitops.h:27,
                 from /git/arm-soc/include/linux/bitops.h:36,
                 from /git/arm-soc/include/linux/kernel.h:10,
                 from /git/arm-soc/include/linux/list.h:8,
                 from /git/arm-soc/include/linux/module.h:9,
                 from /git/arm-soc/drivers/tty/serial/8250/8250_fintek.c:11:
arch/arm/include/uapi/asm/ptrace.h:55:0: note: this is the location of the previous definition

This renames the newly introduced 'IRQ_MODE' macro to FINTEK_IRQ_MODE.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 4da22f14 ("serial: 8250_fintek: fix the mismatched IRQ mode")
Link: https://patchwork.kernel.org/patch/9200119/Acked-by: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Acked-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
conditional has been added to the OF_EARLYCON_DECLARE() define.

The same conditional can be dropped from 8250_ingenic.c because
the unused symbols will be marked as __maybe_unsed.
Also, the Kconfig dependency can become much simpler.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The !defined(MODULE) conditional has been added to the
OF_EARLYCON_DECLARE() define.

This commit partially reverts commit 3f5921a6 ("serial:
8250/mediatek: fix building with SERIAL_8250=m").
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The !defined(MODULE) conditional has been added to the
OF_EARLYCON_DECLARE() define.

Now we can revert commit a2d3ea2f ("serial: 8250/uniphier:
fix modular build").
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch permits the usage for GPIOs to control
the CTS/RTS/DTR/DSR/DCD/RI signals.
Signed-off-by: NYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce serial8250_out_MCR() and serial8250_in_MCR() routines, that
replace following calls:

serial_out(port, UART_MCR, val)
serial_port_out(up, UART_MCR, val)
serial_in(port, UART_MCR)

This patch is needed in order to integrate reading/writing of MCR
signals via SERIAL_MCTRL_GPIO infrastructure later.
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NYegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In DNV, when RX DMA is used and number of bytes received is less than
transfer size, only RX DMA timeout interrupt is sent. When this happens,
read the RX buffer.
Signed-off-by: NChuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Export serial8250_rx_dma_flush() for use by SOC UART drivers.
Signed-off-by: NChuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To allow other code to safely read DMA Channel Status Register (where
the register attribute for Channel Error, Descriptor Time Out &
Descriptor Done fields are read-clear), export hsu_dma_get_status().
hsu_dma_irq() is renamed to hsu_dma_do_irq() and requires Status
Register value to be passed in.
Signed-off-by: NChuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When using the 8250 as a boot console and the main console results in
messages being printed twice.  The console framework will only
unregister boot consoles if a new console is registered with the
CON_CONSDEV flag set.

Set this flag for the univ8250 console to prevent double-registration.
Signed-off-by: NMatthew Leach <matthew.leach@codethink.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add COMPILE_TEST for the compilation test coverage.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Adds support for the WCH CH355 4S card in the 8250 serial driver.
Signed-off-by: NAlexandr Petrenko <petrenkoas83@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some BIOS only use _OSI("Linux") to distinguish between Linux & Windows.
Apply Level/Low to UART trigger mode if Windows, Edge/High mode otherwise.
But since 2.6.23 the mainline kernel no longer returns true for
_OSI(“Linux”).

The default IRQ0~15 trigger mode in Linux is Edge/High mode without
ACPI MADT override. It mismatches IRQ mode and makes UART malfunctional on
such motherboard.

This patch will check the current IRQ mode and apply correct mode to UART.

The following link is F81216AD spec PDF:
http://html.alldatasheet.com/html-pdf/257956/FINTEK/F81216AD/5569/
25/F81216AD.html

LDN0~3
	70h: IRQ channel & Mode register
		Bit 6~5	:
			00	: Active low level mode
			01	: Active high edge mode
		Bit 4	: Sharing Flag (0: not share/1: share)
		Bit 3~0 : IRQ channel
Signed-off-by: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some board like Hisilicon D02 uses Synopsys DesignWare ABP UART, declare an
OF early console for it, so early console device can be enabled with comand
line "earlycon"(without option) via the "stdout-path" property in device-tree.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: NJon Mason <jon.mason@broadcom.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The compiler complains about variables that are set, but never used:
* intX variables in exar_handle_irq
  drivers/tty/serial/8250/8250_port.c:1864:34: warning: variable ‘int3’ set but not used [-Wunused-but-set-variable]
* val variable in pci_quatech_wqopr
  drivers/tty/serial/8250/8250_pci.c:1139:10: warning: variable ‘val’ set but not used [-Wunused-but-set-variable]

And about a shadow variable:
* tmout in wait_for_xmitr is defined twice with the same type. Both of
  them are also initialized before use.

Remove all of them.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Matt Schulte <matts@commtech-fastcom.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert DEBUG_INTR to pr_debug:
* defined semantics (DEBUG, DYNAMIC_DEBUG)
* KERN_DEBUG level instead of KERN_DEFAULT
* emit __func__ and \n
* verified 'fmt' even when !DEBUG

I wonder if anybody ever used that or whether we should just drop the
lines.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hub6 and irqflags from struct old_serial_port are nowhere set. Drop
them from the structure and replace the reads by zeros.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit cdcea058 ("serial: 8250_dw: Avoid serial_outx code duplicate
with new dw8250_check_lcr()") introduce a wrong logic when write val to
LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally.

The __raw_readq/__raw_writeq is introduced by commit bca2092d ("serial:
8250_dw: Use 64-bit access for OCTEON.") for OCTEON.

So for 64BIT && !PORT_OCTEON, we better to use coincident write function.

Fixes: cdcea058("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()")
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>