Add the missing unlock before return from function serial8250_register_8250_port()
in the error handling case.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20190703055908.141294-1-weiyongjun1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 2e9fe539108320820016f78ca7704a7342788380.

Reading LSR unconditionally but processing the error flags only if
UART_IIR_RDI bit was set before in IIR may lead to a loss of transmission
error information on UARTs where the transmission error flags are cleared
by a read of LSR. Information are lost in case an error is detected right
before the read of LSR while processing e.g. an UART_IIR_THRI interrupt.

Signed-off-by: Oliver Barta <o.barta89@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 2e9fe5391083 ("serial: 8250: Don't service RX FIFO if interrupts are disabled")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch permits the usage for GPIOs to control
the CTS/RTS/DTR/DSR/DCD/RI signals.

Changed by Stefan:
Only call mctrl_gpio_init(), if the device has no ACPI companion device
to not break existing ACPI based systems. Also only use the mctrl_gpio_
functions when "gpios" is available.

Use MSR / MCR <-> TIOCM wrapper functions.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Giulio Benetti <giulio.benetti@micronovasrl.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes: 6bf4e42f1d19 ("serial: 8250: Add support for higher baud rates to Pericom chips")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds wrapper functions to convert MSR <-> TIOCM and also
MCR <-> TIOCM. These functions are used now in serial8250_do_set_mctrl()
and serial8250_do_get_mctrl().

Signed-off-by: Stefan Roese <sr@denx.de>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Giulio Benetti <giulio.benetti@micronovasrl.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Factor out similar code pieces that set or clear UART_IER_THRI bit to
serial8250_{set,clear}_THRI() helpers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The Pericom chips can achieve additional baud rates by programming the
sample clock register. The baud rates can be described as
921600 * 16 / (16 - scr) for scr values 5 to 15. The divisor is set to 1
for these baud rates.

Adds new quirk for Pericom chips other than the four port chips to use
the

Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Interrupt handler checked THRE bit (transmitter holding register
empty) in LSR to detect if TX fifo is empty.
In case when there is only receive interrupts the TX handling
got called because THRE bit in LSR is set when there is no
transmission (FIFO empty). TX handling caused TX stop, which in
RS-485 half-duplex mode actually resets receiver FIFO. This is not
desired during reception because of possible data loss.

The fix is to check if THRI is set in IER in addition of the TX
fifo status. THRI in IER is set when TX is started and cleared
when TX is stopped.
This ensures that TX handling is only called when there is really
transmission on going and an interrupt for THRE and not when there
are only RX interrupts.

Signed-off-by: Kimmo Rautkoski <ext-kimmo.rautkoski@vaisala.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Deferred probe is an expected return value for clk_get() on many
platforms. The driver deals with it properly, so there's no need
to output a warning that may potentially confuse users.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In order to support Rx in-band wakeup, we need to enable irq wake on an
edge sensitive interrupt of Rx pin before suspend and disable it when
resuming.

This interrupt is used only as wake source to resume the system when
suspended. Note that the sent character will be lost as the controller is
actually suspended.

We use this to support wakeup on bluetooth. Bluetooth will repeatedly send
0xFD to wakeup host. Once host detects Rx falling, an interrupt is
triggered, and the system leaves sleep state. Then, the bluetooth driver
will send 0xFC to bluetooth and bluetooth can start to send normal HCI
packets.

Signed-off-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>