If RS-485 is enabled, make the OMAP UART fire THR interrupts when both
TX FIFO and TX shift register are empty instead of polling the
equivalent status bit. This removes the burst of interrupt requests
seen at every end of transmission.

Also: the comment said that the TX FIFO trigger level was set at 16
characters when it's 32 in reality.
Signed-off-by: NPhilippe Proulx <philippe.proulx@savoirfairelinux.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

During resume, a startup will request_irq again, meantime resume function's
enable_irq will cause unbalanced IRQ issue.
Fix this issue by moving request_irq to probe function.
Signed-off-by: NDavid Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: NChen, Jie <jie.d.chen@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the recent pinctrl-single changes, omaps can treat
wake-up events from deeper idle states as interrupts.

There's a separate "io chain" controller on most omaps
that stays enabled when the device hits off-idle and the
regular interrupt controller is powered off.

Let's add support for the optional second interrupt for
wake-up events. And then serial-omap can manage the
wake-up interrupt from it's runtime PM calls to avoid
spurious interrupts during runtime.

Note that the wake interrupt is board specific as it
uses the UART RX pin, and for omap3, there are six pin
options for UART3 RX pin.

Also Note that the legacy platform based booting handles
the wake-ups in the legacy mux driver and does not need to
pass the wake-up interrupt to the driver.

And finally, to pass the wake-up interrupt in the dts file,
either interrupt-map or the pending interrupts-extended
property needs to be passed. It's probably best to use
interrupts-extended when it's available.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Reviewed-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes duplicate defines in drivers/tty/serial/sirfsoc_uart.h
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Clock notifiers are only available when CONFIG_COMMON_CLK is enabled.
Hence all notifier related code has to be protected by corresponsing
ifdefs.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If CONFIG_PM_SLEEP is enabled and CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
is not, a forward declaration of the uart_driver struct is not
included, leading to a build error due to an undeclared variable.
Fixing this by moving the definition of the struct uart_driver before
the definition of the suspend/resume callbacks.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Initialize varibles for which a 'may be used uninitalized' warning is
issued.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAngelo Butti <buttiangelo@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Implement suspend and resume callbacks in order to support system
suspend/hibernation.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a clock notifier to dynamically handle frequency changes of the
input clock by reprogramming the UART in order to keep the baud rate
constant.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original algorithm to find the best baud rate dividers does not necessarily
find the best set of dividers. And in the worst case may even write illegal
values to the hardware.
The new function should make better use of the hardware capabilities and be able
to provide valid settings for a wider range of baud rates and also input clocks.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is possible that under certain circumstances xuartps_console_write is entered
while the UART disabled. When this happens the code will busy loop in
xuartps_console_putchar, since the character is never written and the TXEMPTY
flag is never set. The result is a system lockup. This patch force enables the
UART for the duration of xuartps_console_write to avoid this.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJohn Linn <john.linn@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Changes to use the 64 byte FIFO depth and fix the issue
by clearing the txempty interrupt in isr status for tx
after filling in data in start_tx function
Signed-off-by: NSuneel Garapati <suneelg@xilinx.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows KDB/KGDB to run.
Signed-off-by: NVlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Cadence UART does not do break detection, even if the
datasheet says it does. This patch adds break detection in
software (tested in 8N1 mode only) and enables SYSRQ,
allowing for Break-g to enter KDB and all the other goodies.
Signed-off-by: NVlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the device managed interface for memory allocation, simplifying
error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the device managed interface for clocks, simplifying error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On older SoC, the "name" field is not filled in the register map.
Fix the way to figure out if the serial port is an uart or an usart for these
older products (with corresponding properties).
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 055560b0 (serial: at91:
distinguish usart and uart) the older products which do not have a
name field in their register map are unable to use their serial output.
As the main console output is usually the serial interface (aka DBGU) it
is pretty unfortunate.
So, instead of failing during probe() we just silently configure the serial
peripheral as an uart. It allows us to use these serial outputs.
The proper solution is proposed in another patch.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds support for Fintek's 4, 8, and 12 port PCIE serial cards.

Thanks to Fintek for the sample devices, and the spec needed in order to
implement this.

Cc: Amanda Ying <amanda_ying@fintek.com.tw>
Cc: Felix Shih <felix_shih@fintek.com.tw>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I worried that the delay of the sdma_run_channel0() maybe too long for
interrupt context, so I added the workqueues for RX/TX DMA.

But tested with bluetooth device, I find that the delay of sdma_run_channel0()
is about 8us (tested in imx6dl sabreauto board). I think the delay
is acceptable.

This patch removes the RX/TX workqueues for DMA, it makes the
code more clear.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the dmaengine_tx_status to simplify the code, do not change any logic.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the (xmit->tail > xmit->head) is true and the xmit->head is 0,
we only need one DMA scatterlist in actually. Current code uses two DMA
scatterlists in this case, this is obviously wrong.

This patch fixes it.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Assume the following situation:

  If the DMA is enabled, and the a TX DMA operation is working,
But we have not issued the TX DMA operation (or we have issued the
TX DMA operation with dma_async_issue_pending(), but the DMA has not
started to move the data from the memory to the TXFIFO).

At this time, we may get the wrong status of the transmitter when we
call the imx_tx_empty. In such situation, only check the USR2_TXDC
does not enough for us.

This patch checks the DMA's situation, and return 0 when the TX DMA is
working.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current driver does not implement the flush_buffer hook for
uart_ops. When we enable the DMA for the driver, and test it with Bluetooth,
we may meet the following bug for TX:

    [1] User application may call the flush operation at any time.
        The uart_flush_buffer() calls the uart_circ_clear() to set
        the xmit->head and xmit->tail with 0.

    [2] The TX DMA callback can be called at any time too.
        The dma_tx_call() will update the xmit->tail.

    If [2] occurs just after the [1], we will get the wrong xmit->tail.

This patch implements the flush_buffer hook to fix this issue.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This deletes the .set_wake() callback in the struct uart_ops.
Apparently this has been unused since pre-git times. In the
old-2.6-bkcvs it is deleted as part of a changeset removing
the PM_SET_WAKEUP from pm_request_t which is since also deleted
from the kernel.

The apropriate way to set wakeups in the kernel is to have a
code snippet like this in .suspend() or .runtime_suspend()
callbacks:

static int foo_suspend(struct device *dev)
{
	if (device_may_wakeup(dev)) {
		/* Enable wakeups, set internal states */
	}
}

This specific callback is not coming back.

Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Dmitry Artamonow <mad_soft@inbox.ru>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is gone and not coming back, so will not be
supported later.

Cc: Johan Hovold <jhovold@gmail.com>
Acked-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is gone and not coming back, so will not be
supported later.

Cc: Gerhard Sittig <gsi@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
SA1100 platforms should be done in the suspend() callback
so the platform hook is left in the serial port struct for
later enablement.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
OMAP serial driver is done through other runpaths these days.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

test echo_buf() result for ECHO_OP_START
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These aren't necessary after switch and while blocks.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a race between termios configuration and xmit that can cause the
intel_mid_ssp_spi driver to stall.

Serializing spi transactions fixes the problem.
Signed-off-by: NBin Gao <bin.gao@intel.com>
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should check the validity of the irq number before calling
disable_irq() and enable_irq() in the suspend/resume function,
as "max->irq == 0" means the irq is not enabled for max3110
device, otherwise it will hurt device whose irq number is really 0.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add calls to clk_prepare and unprepare so that EMMA Mobile EV2 can
migrate to the common clock framework.
Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[takashi.yoshii.ze@renesas.com: edited for conflicts]
Signed-off-by: NTakashi Yoshii <takashi.yoshii.zj@renesas.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE)
into a Kconfig variable.

Original version by Bastian Blank <waldi@debian.org>.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It makes more sense to enter a bitmask in hexadecimal rather than
decimal.  Sadly we can't make it read back as hexadecimal.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>