The comment in imx_flush_buffer() states that the state of 4 registers
are to be saved/restored, then only saves and restores 3 registers. The
missing register (UBRC) is read only and thus can't be restored.

Update the comment to reflect reality.
Signed-off-by: NMartyn Welch <martyn.welch@collabora.co.uk>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

vt has a mixture of pr_<level> and printk.
Convert to using only pr_<level>.

Miscellanea:

o Coalesce formats
o Realign arguments
o Add missing braces around an if/else with the printk conversion
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When kernel configuration SMP,PREEMPT and DEBUG_PREEMPT are enabled,
echo 1 >/proc/sys/kernel/sysrq
echo p >/proc/sysrq-trigger
kernel will print call trace as below:

sysrq: SysRq : Show Regs
BUG: using __this_cpu_read() in preemptible [00000000] code: sh/435
caller is __this_cpu_preempt_check+0x18/0x20
Call trace:
[<ffffff8008088e80>] dump_backtrace+0x0/0x1d0
[<ffffff8008089074>] show_stack+0x24/0x30
[<ffffff8008447970>] dump_stack+0x90/0xb0
[<ffffff8008463950>] check_preemption_disabled+0x100/0x108
[<ffffff8008463998>] __this_cpu_preempt_check+0x18/0x20
[<ffffff80084c9194>] sysrq_handle_showregs+0x1c/0x40
[<ffffff80084c9c7c>] __handle_sysrq+0x12c/0x1a0
[<ffffff80084ca140>] write_sysrq_trigger+0x60/0x70
[<ffffff8008251e00>] proc_reg_write+0x90/0xd0
[<ffffff80081f1788>] __vfs_write+0x48/0x90
[<ffffff80081f241c>] vfs_write+0xa4/0x190
[<ffffff80081f3354>] SyS_write+0x54/0xb0
[<ffffff80080833f0>] el0_svc_naked+0x24/0x28

This can be seen on a common board like an r-pi3.
This happens because when echo p >/proc/sysrq-trigger,
get_irq_regs() is called outside of IRQ context,
if preemption is enabled in this situation,kernel will
print the call trace. Since many prior discussions on
the mailing lists have made it clear that get_irq_regs
either just returns NULL or stale data when used outside
of IRQ context,we simply avoid calling it outside of
IRQ context.
Signed-off-by: NJibin Xu <jibin.xu@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NEd Blake <ed.blake@sondrel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a define for the maximum baud rate divisor, to improve code
readability.
Signed-off-by: NEd Blake <ed.blake@sondrel.com>
Signed-off-by: NGreg 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: NAndy Lowe <andy_lowe@mentor.com>
Signed-off-by: NEugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: NGreg 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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg 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: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg 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: NShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Tested-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch remove the extra compatibility string "st,stm32-usart" from
driver & device tree.
Signed-off-by: NVikas Manocha <vikas.manocha@st.com>
Reviewed-by: NPatrice Chotard <patrice.chotard@st.com>
Signed-off-by: NGreg 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: NRomain Izard <romain.izard.pro@gmail.com>
Tested-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg 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: NUlrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the checkpatch.pl error complain:

ERROR: space required before the open brace '{'
Signed-off-by: NGimcuan Hui <gimcuan@gmail.com>
Signed-off-by: NGreg 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: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: NGreg 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: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: NGreg 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: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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

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

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

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

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

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

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

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: NAllen Pais <allen.lkml@gmail.com>
Signed-off-by: NGreg 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: NMartyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: NGreg 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: NMartyn Welch <martyn.welch@collabora.co.uk>
Acked-by: NUwe Kleine-König <u.kleine-könig@pengtronix.de>
Signed-off-by: NGreg 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: NRomain Perier <romain.perier@collabora.com>
Signed-off-by: NMartyn Welch <martyn.welch@collabora.co.uk>
Reviewed-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

    Use setup_timer function instead of initializing timer with the
    function and data fields.
Signed-off-by: NAllen Pais <allen.lkml@gmail.com>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NIan Jamison <ian.dev@arkver.com>
Origin: id:8195c96e674517b82a6ff7fe914c7ba0f86e702b.1505375165.git.ian.dev@arkver.com
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds support for the rs485 specific properties defined in
Documentation/devicetree/bindings/serial/rs485.txt.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Forwarded: id:20170913081833.2740-7-u.kleine-koenig@pengutronix.de (v5)
Signed-off-by: NGreg 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: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NSascha Hauer <s.hauer@pengutronix.de>
[ukleinek: point out semantic change in commit log]
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg 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: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NGreg 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: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use bsearch library function instead of duplicated functionality.
Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NGreg 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: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>