Currently dw8250_set_termios sets the input clock to the nearest
achievable rate to baudx16.  If necessary, the input clock is then
divided down to baudx16 using an integer divider within the UART
device, with the divisor calculated in the 8250 core driver.

However, the clock rate set by dw8250_set_termios and subsequently
divided down could be considerably different to the target baudx16
rate, resulting in incorrect operation.  This patch fixes this by
iteratively searching for an input clock rate that is within +/-1.6%
of an integer multiple of the target baudx16 rate.
Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a define for the maximum baud rate divisor, to improve code
readability.
Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If a port has no dma channel defined in the device tree, then
don't attempt to allocate a dma channel for the port.
Also suppress the warning message concerning the failure to allocate
a dma channel.  Continue to emit the warning message if a dma
channel is defined but cannot be allocated.
Signed-off-by: Andy Lowe <andy_lowe@mentor.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel Cedar Fork PCH has similar HSU as has been used on Intel Denverton.
Add PCI ID to get it enumerated.

While here, remove DNV part form INTEL_MID_UART_DNV_FISR to show that is
used not only on Intel Denverton from now on.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove
* pdev from mxser_initbrd
* old_termios from mxser_change_speed
as they are unused and update the callers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

move to arch_initcall to get the console up really early, it is
quite helpful for spotting early boot problems.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch remove the extra compatibility string "st,stm32-usart" from
driver & device tree.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes the extra compatibility string "st,stm32-usart" to
avoid confusion, save some time & space.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The atmel serial port driver reported the following warning on suspend:
atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter

As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared
when the transmitter is disabled, we need to know the transmitter's
state to return the real fifo state. And as ATMEL_US_CR is write-only,
it is necessary to save the state of the transmitter in a local
variable, and update the variable when TXEN and TXDIS is written in
ATMEL_US_CR.

After those changes, atmel_tx_empty can return "empty" on suspend, the
warning in uart_suspend_port disappears, and suspending is 20ms shorter
for each enabled Atmel serial port.
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

HSCIF has facilities that allow changing the timeout after which an RX
interrupt is triggered even if the FIFO is not filled. This patch allows
changing the default (15 bits of silence) using the existing sysfs
attribute "rx_fifo_timeout".
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the checkpatch.pl error complain:

ERROR: space required before the open brace '{'
Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is fix the warning reported by smatch as following:

drivers/tty/serial/8250/8250_fintek.c:294 fintek_8250_goto_highspeed()
warn: inconsistent indenting
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The F81216H had 4 clocksource 1.8432/18.432/14.769/24MHzand  baud rates can
be up to 1.5Mbits with 24MHz. The register value and mask is the same with
F81866. But F81866 register address is F2h, F81216H is F0h.

We'll implements the dynamic clocksource in fintek_8250_set_termios().
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The F81866 had 4 clocksource 1.8432/18.432/14.769/24MHz and baud rates can
be up to 1.5Mbits with 24MHz. We'll implements the dynamic clocksource in
fintek_8250_set_termios().
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

        Use setup_timer function instead of initializing timer with the
        function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

        Use setup_timer function instead of initializing timer with the
        function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

        Use setup_timer function instead of initializing timer with the
        function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable "dma_is_txing" is an unsigned int, set as either "0" or "1"
in all but one location, where it is instead set to "false". For
consistency, set dma_is_txing to "0" in this location too.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The imx serial driver uses PAGE_SIZE when allocating rx_buf, but then
uses RX_BUF_SIZE (which is currently defined as PAGE_SIZE) to describe
the length of the buffer when initialising the scatter gather list.

In order to ensure that this stays consistent, use RX_BUF_SIZE in both
locations.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Uwe Kleine-König <u.kleine-könig@pengtronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable dma_is_rxing is currently set to 1 in imx_disable_rx_int().
This is problematic as:

- whilst imx_disable_rx_int() is currently always called before
  start_rx_dma() this dependency isn't obvious.
- start_rx_dma() does error checking and might exit without
  enabling DMA. Currently this will result in dma_is_rxing suggesting
  that DMA is being used for recieving.

To avoid these issues, move the setting of dma_is_rxing to
start_rx_dma() when appropriate.
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

UART core function uart_update_mctrl relies on a cached value of
modem control lines. This was used but not updated by local RTS
control functions within imx.c. These are used for RS485 line
driver enable signalling. Having an out-of-date value in the cached
mctrl can result in the transmitter being enabled when it shouldn't
be.

Fix this by updating the mctrl value before applying it.
Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Origin: id:8195c96e674517b82a6ff7fe914c7ba0f86e702b.1505375165.git.ian.dev@arkver.com
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds support for the rs485 specific properties defined in
Documentation/devicetree/bindings/serial/rs485.txt.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Forwarded: id:20170913081833.2740-7-u.kleine-koenig@pengutronix.de (v5)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The i.MX driver defaulted to full duplex rs485 which is rather
unusual and doesn't match the default implemented in other drivers.

So change the default to half duplex.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We just got a common helper for parsing the rs485 specific
device tree properties. Use it and drop the open coded parser.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We just got a common helper for parsing the rs485 specific
device tree properties. Use it and drop the open coded parser.

As a side effect this adds support for parsing rs485-rts-delay and
rs485-rx-during-tx. As the driver doesn't support this though, probing
fails if these are defined.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We just got a common helper for parsing the rs485 specific
device tree properties. Use it and drop the open coded parser.

Note that there is a small difference between the removed and the now
used implementation: The former cleared flags to 0 if rs485-rts-delay
was given, the common helper clears SER_RS485_RX_DURING_TX and
SER_RS485_ENABLED only but always which makes more sense.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[ukleinek: point out semantic change in commit log]
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Several drivers have the same device tree parsing code. Create
a common helper function for it.

This patch bases on work done by Sascha Hauer.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit a6d7514b ("tty: serial: lpuart: add a more accurate baud
rate calculation method") the baud rate is now calculated inside the
lpuart32_serial_setbrg() function, so we no longer need to read the
UARTBAUD register inside lpuart32_set_termios().

The 'bd' variable can be simply removed.

This fixes the following build warning with W=1:

drivers/tty/serial/fsl_lpuart.c: In function 'lpuart32_set_termios':
drivers/tty/serial/fsl_lpuart.c:1652:32: warning: variable 'bd' set but not used [-Wunused-but-set-variable]

Fixes: a6d7514b ("tty: serial: lpuart: add a more accurate baud rate calculation method")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In order to avoid code duplication and to be more consistent with the
other error handling paths in this function, we should 'goto errout'.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use bsearch library function instead of duplicated functionality.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make this const as it is only stored in the const field 'ops' of an
uart_port structure. It is not referenced in any other file and therefore
make it static too.

Done using Coccinelle.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix some minor typo spotted in comments:
- s/wit ha/with a/
- s/doestroyed/destroyed/
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This dirver try to implement the Magic SysRq support[1] for
Amlogic Inc's meson platfo
>From the hardware perspective, the UART IP can't detect the 'BREAK' command
clearly via the status register. Instead, we rely on the combination of
'FRAME_ERR bit && ch == 0', and it works fine.

[1] Documentation/admin-guide/sysrq.rst
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>