Add transmit DMA support for UARTDM type of controllers.

Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine
and APQ8016, which have UARTDM v1.4 and BAM DMA engine.
Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make function naming consistent across this driver.
Also rename msm_irq to msm_uart_irq. No functional changes.
Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Replaces (1 << x) with BIT(x) macro
Signed-off-by: Pramod Gurav <gpramod@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The bit masks for RFR_LEVEL1 and STALE_TIMEOUT_MSB values in MR1 and
IPR registers respectively are different for UART and UART_DM hardware
cores. We have been using UART core mask values for these. Add the same
for UART_DM core.

There is no bit setting as UART_IPR_RXSTALE_LAST for UART_DM core so do
it only for UART core.
Signed-off-by: Pramod Gurav <gpramod@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If a wrong compatible flag in specified, the of_match_device
returning null.
Implemented check and if NULL then returning -ENODEV.
Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

They're used by only if CONFIG_PM is enabled, so enclose them
with proper ifdefs. Removes these warnings:

drivers/tty/serial/omap-serial.c:202:12: warning: 'serial_omap_get_context_loss_count' defined but not used [-Wunused-function]
drivers/tty/serial/omap-serial.c:213:13: warning: 'serial_omap_enable_wakeup' defined but not used [-Wunused-function]
Signed-off-by: Guido Martínez <guido@vanguardiasur.com.ar>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This ensures the dma mask that is supported by the driver is recorded
in the device structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

RX buffer is allocated from DMA coherent memory. Thus there is no need to call
DMA sync API for it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Move h/w reinit of serial console restore-from-suspend into
standalone helper function.

No functional change.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When the UART clock is set slightly under 1.8432MHz, the 8250 driver
core doesn't permit the 115200 baud rate since it calculates the maximum
frequency to pass to uart_get_baud_rate by simply dividing the uart
clock by 16 which yields a value slightly under 115200, even though the
frequency is close enough for the UART to operate reliably.

Therefore add some tolerance in the calculation of the maximum baud
rate. 1% tolerance allows for marginally slower uart clk than nominal
without introducing transmission errors.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
[pjh: Forward-port & refactor original patch; change tolerance to 1%]
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There are three natural ways in which devices may be wired to the system:
little endian (device receives correctly ordered bits of a word written
by little-endian CPU to its register, but big-endian CPU needs to swap
bytes of a word before writing it), big endian (same, but with big-endian
CPU in more favourable position) and native endian (CPU of either
endianness may do word-sized I/O without need for byteswapping).

Adding an option for native endianness allows using single kernel command
line for boards with native-endian serial ports on bi-endian
architectures. This goes in parallel with 'native-endian' DTS attribute.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

These drivers doesn't claim the serial device to be wakeup source. Even
if it is, it needs to use enable_irq_wake or other related PM wakeup
APIs to enable it.

This patch removes yet another misuse of IRQF_NO_SUSPEND.

Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kernel@stlinux.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since the FD interrupt handler can discern spurious IRQs and it is
shared with timer interrupt, use IRQF_COND_SUSPEND instead of
IRQF_NO_SUSPEND.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function can return negative values.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Acked-by: Timur Tabi <timur@tabi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Some SoCs, including Ralink/Mediatek and Alchemy Au1xxx, have a
16550-like UART with a non-standard register layout.  These are
supported by a simple mapping table in 8250_port.c  Rather than
list every SoC type using this access mode in the ifdefs there,
allow selecting the SERIAL_8250_RT288X Kconfig option with any
system and default it to y for the known cases needing it.  The
help text is reworded accordingly.

This change simplifies adding support for other SoCs also using
the same UART.

The name of the option is a little misleading, but not knowing
the true origin of this UART, it is as good a choice as any.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows to reduce the per-driver boiler plate considerably.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is done before adding more functionality to the init function with
the existing name. As this new functionality conflicts with stuff
drivers are required to implement themselves up to I want to convert
them one by one to make reviewing and reverting more easy in case I
broke something.

Once mctrl_gpio_init is there and all drivers are converted
mctrl_gpio_init_noauto can be removed again.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit also fixes compiler warnings and errors seen when building
on x86_64.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The RX bytecount was only updated in the PIO path and thus
the device erroneously reported a value of 0 if DMA is in
use.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit enabling DMA support even if no flow control is present
was reverted on the grounds that it uncovered a number of bugs in
the code that lead to hanging tty devices and/or missing characters.

After tracking down the issues it is clear that those were generic
bugs and had nothing to do with flow control being present or not,
only that allowing DMA without hardware flow control increased
the exposure of that code a lot.

Now that those bugs are fixed, it should be safe to re-enable DMA
support.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The reference manual states that idle condition detect should not be used
with DMA transfers, as the ROM SDMA scripts don't check those conditions.

The RAM SDMA scripts worked around this, but the change broke compatibility
with the ROM scripts.

The previous commits fixed the DMA burst sizes, so that the aging timer is
now working as described in the reference manual. With this fixed we can
remove the hack of using the idle condition detect to stop the DMA transfer
if there are no new characters incoming.

This should work with both the ROM and RAM SDMA scripts.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Triggering the DMA engine for every byte is horribly inefficient.
Also it doesn't allow to use the aging timer for the RX FIFO as this
requires the DMA engine to leave one byte remaining in the FIFO when
doing a normal burst transfer.

Adjust watermark levels so that the DMA engine can do at least 8 byte
burst transfers. This is a conservative value, as the both TX and RX
FIFOs are able to contain 32 bytes.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify the DMA restart logic to always queue up the next transfer
immediately if there is at least one more byte available in the FIFO,
so that the transfer will finish in a limited time.

This way the driver stops to rely on zero length transfers to signal
transfers ends. Those will go away when the idle detect DMA requests
are disabled.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA transfer is only started once we are sure it will finish
in a limited time, i.e. only after we received a RRDY interrupt.

In order to allow the watermark level to be raised the aging
timer and the corresponding interrupt need to be set up as an
additional trigger, so that the transfer is also started if the
incoming amount of bytes never reach the watermark.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This function currently doesn't use its parameter.

Change prototype to pass in watermark levels, so we can reuse this
function in the DMA setup paths. Also relocate to be near the calling
functions.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial8250_register_8250_port adds it to all ports it
registers. No need to set it separately.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using the same style of declaring variables as used in the
other functions of the driver. Passing uart_port to the
function instead of uart_8250_port, as it is the one mostly
needed.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the extra return.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Adding comment where the purpose of the function is
explained.

The dma parameters are not used, so removing them, and also
moving the assignment of the function to the same place
where the other dw8250_data structures members are being set
in dw8250_probe.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the DW_apb_uart is configured with UART_16550_COMPATIBLE
configuration parameter set, then the Busy Functionality is
not available. These UARTs will never generate the Busy
detect indication interrupt, and therefore don't need
handling for it.

This creates a small optimization for the DW_apb_uarts
configured without the busy functionality, but more
importantly, it removes the small but real risk of hitting
potential issues caused by busy functionality handling when
no busy functionality exist.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merging the DT and ACPI specific probe functions into
dw8250_quirks. Those functions did not have that much code
any more and some of the quirks need to be shared. This
will also allow platforms without DT or ACPI to use the
driver.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds a flag "skip_autocfg" that the platforms that do
not have the ADDITIONAL_FEATURES implemented can use to skip
the port setup. It's then enough to call dw8250_setup_port
just from dw8250_probe based on that flag.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of assigning the dma member in dw8250_probe_of and
dw8250_probe_acpi separately, assigning it in dw8250_probe.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This makes the properties available for all types of
platforms instead of just the ones using DT.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For convenience, adding separate pointer for the "port"
member of struct uart_8250_port that is being filled in the
probe function.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>