Currently vt_bind and vt_unbind access at least the con_driver object
and registered_con_driver array without holding the console lock. Fix
this by locking around the whole function in each case.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The default console driver (conswitchp) and busy drivers bound to a
console (as reported by con_is_bound()) shouldn't be unregistered.
System console drivers (without the CON_DRIVER_FLAG_MODULE flag) can be
unregistered, provided they are neither default nor busy. The current
code checks for the CON_DRIVER_FLAG_INIT flag but this doesn't make
sense: this flag is set for a driver whenever its associated console's
con_startup() function is called, which first happens when the console
driver is registered (so before the console gets bound) and gets cleared
when the console gets unbound. The purpose of this flag is to show if we
need to call con_startup() on a console before we use it.

Based on the above, do_unregister_con_driver() in its current form will
allow unregistering a console driver only if it was never bound, but
will refuse to unregister one that was bound and later unbound.

Fix this by dropping the CON_DRIVER_FLAG_INIT check, allowing
unregistering of any console driver provided that it's not the default
one and it's not busy.

v2:
- reword the third paragraph to clarify how the fix works (Peter Hurley)
v3:
- unchanged
v4:
- Allow unregistering a system console driver too, needed by i915 to
  unregister vgacon. Update commit description accordingly. (Daniel)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace a misspelled function name by %s and then __func__.

This was done using Coccinelle, including the use of Levenshtein distance,
as proposed by Rasmus Villemoes.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace the last argument of serial_paranoia_check by the actual function
name.

This was done using Coccinelle, including the use of Levenshtein distance,
as proposed by Rasmus Villemoes.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In early 8250, IER is already zero so no point in writing this - twice
per line

This helped improve the SystemC model based ARC OSCI platform

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some of FSL SoCs like T1040 has new version of UART controller which
can support 64byte FiFo.
To enable 64 byte support, following needs to be done:
-FCR[EN64] needs to be programmed to 1 to enable it.
-Also, when FCR[EN64]==1, RTL bits to be used as below
to define various Receive Trigger Levels:
        -FCR[RTL] = 00  1 byte
        -FCR[RTL] = 01  16 bytes
        -FCR[RTL] = 10  32 bytes
        -FCR[RTL] = 11  56 bytes
-tx_loadsz is set to 63-bytes instead of 64-bytes to implement
 workaround of errata A-008006 which states that tx_loadsz should
 be configured less than Maximum supported fifo bytes
Signed-off-by: NVijay Rai <vijay.rai@freescale.com>
Signed-off-by: NPriyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: NPoonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use "cnxt" since it once was the stock ticker of Conexant.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When IGNPAR is set in termios->c_iflag,  characters with
framing errors should be ignored.
Signed-off-by: NEric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If IGNPAR/INPCK are clear in termios->c_iflag,  characters
received with parity or framing errors should be preserved
and passed to the upper layers of the tty stack.

Specifically, the decision of whether to set the character
value to zero should be made by n_tty.c/n_tty_receive_parity_error().
Signed-off-by: NEric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add device pointer to port->dev.

Before:

"(NULL device *): ttyAL0 at MMIO 0x2020 (irq = 6, base_baud = 3125000)
is a Altera UART"

After:
"altera_uart 2020.serial: ttyAL0 at MMIO 0x2020 (irq = 6, base_baud = 3125000)
is a Altera UART"
Signed-off-by: NLey Foon Tan <lftan@altera.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add device pointer to port->dev.

Before:

"(NULL device *): ttyJ0 at MMIO 0x1008 (irq = 2, base_baud = 0) is a
Altera JTAG UART"

After:
"altera_jtaguart 1008.serial: ttyJ0 at MMIO 0x1008 (irq = 2, base_baud = 0) is a
Altera JTAG UART"
Signed-off-by: NLey Foon Tan <lftan@altera.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add RX DMA transfers support for samsung serial driver. It's enabled
when DMA controller for RX channel is specified in device-tree.

DMA transactions are started when number of bytes in RX FIFO reaches
trigger level, otherwise PIO mode is used. DMA transfer size is always
PAGE_SIZE which can cause large latency when smaller data amount is
transferred, so we always terminate DMA transaction on RX timeout
interrupt. Timeout interval is set to 64 frame times.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add TX DMA transfers support for samsung serial driver. It's enabled
when "dmas" property is defined in serial device-tree node, otherwise
TX transfers are prerformed using PIO.

TX DMA is used for data segments larger than fifosize to reduce number
of interrupts during data transmission. For buffers shorter than fifosize
PIO mode is selected.

Data blocks for DMA transfers are aligned to cache line size to avoid
problems with coherency (some areas of TX circ buffer can be used by
CPU during DMA transaction, so we have to ensure that our data is always
consistent).

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add functions requesting and releasing RX and TX DMA channels. This
function are called only when "dmas" property in serial device-tree
node is defined.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This macro definitions are necessary to implement DMA transfers
is samsung serial driver.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When we have "dmas" property in serial node in device-tree, we do
memory alocation for dma structure which will be used in DMA handling
code.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This struct contains DMA configuration for each serial port.
It will be used in next commits adding DMA support in driver.

Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds Software flow control support in DMA mode.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After send out x_char in UART driver, x_char needs to be cleared
by UART driver itself, otherwise data in TXFIFO can no longer be
sent out.
Also tx counter needs to be increased to keep track of correct
number of transmitted data.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Other than enable Receiver Overrun Interrupt Enable (UCR4_OREN)
in start_tx interface, UCR4_OREN should be enabled before enable
of Receiver.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Start rx_dma once RXFIFO is not empty that can avoid dma request lost
and causes data delay issue.
Signed-off-by: NRobin Gong <b38343@freescale.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

DMA mode for UART can be used even w/o HW flow control with RTS/CTS.
So it need to be initialized and enabled earlier.
Signed-off-by: NAnton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Terminating the DMA, make sure the interrupt is disabled, too.
This fixes random kernel Oops due to dma_tx_call() called for
invalid transmissions.

If we disable the TDMAEN, make sure it's enabled again if a TX
DMA is started.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently in dma_tx_callback(), no matter if there is still
remaining data pending in circle buffer or not, DMA transmit
will be terminated.

This will result in some data never get transmitted.
In order to fix this issue, call imx_dma_tx() again in
dma_tx_callback, when there is pending data and uart hasn't
been stopped.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 2ad28e3e.

Instead of always wake up write_wait process in TX callback,
TX callback should call imx_dma_tx() again, and let imx_dma_tx
transfer the remaining data in circle buffer.

The issue with commit 2ad28e3e is, in case there is remaining
data in circle buffer, but no process is waiting on write_wait
queue, then as no following uart_write() will be called after
uart_write_wakeup(), thus cause data loss.

Moreover according to Documentation/serial/driver, uart_write_wakeup()
should be called in case the transmit buffer have dropped below
a threshold.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To synchronize between dma_tx_callback() and imx_dma_tx() use the same
variable, dma_is_txing. This prevents any race between these two functions
and ensures that a new DMA can start only after the first has been
finished.

Before the new DMA can be set up, update the circular buffer logic, first.
Therefore, change dma_is_txing after that update, instead of before.

While doing this, in dma_tx_callback() extend the locking to dma_unmap_sg()
and the update of dma_is_txing.
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

First, reformat the code to exit immediately. This allows us to add
more code in more readable format.

In case the TX DMA was still running, remove and disable it's resources.
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In case dmaengine_prep_slave_sg() fails, add the missing dma_unmap_sg().
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NAnton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Inverting the logic of the if statement for the sg initialization
makes the if statement easier and better to read.

No functional change.
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use imx_start_tx() just to enable the TX interrupt. It's the job of the
TX interrupt ISR to fill the transmit buffer, then. If the transmit buffer
is empty, the TX interrupt should be executed as soon as the start_tx()
enables the interrupt, so there is no reason for the extra
imx_transmit_buffer() call, here. Remove it.
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: NAndy Lowe <andy_lowe@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Several places are accessing the UCR1 register without locking.
This probably will cause a race issue when another thread
is accessing the same register.
Add locking to preventing concurrent access of the UCR1 register.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add CREAD flag hanlding in set_termios and UART DMA mode
which ignores all received chars when CREAD flag cleared.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NAnton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes many bugs in the code dealing with the hardware handshake.

As an example, in atmel_set_termios(), we used to test whether the CRTSCTS
c_cflag was set. If so, we selected the "Hardware Handshake" mode through the
Mode Register. However, few lines below the mode was reset to "Normal" (0).
So there was no way to select the "Hardware Handshake" mode. To fix this issue,
we moved the CRTSCRTS c_cflag test AFTER the mode has been reset to "Normal".

Also setting the RTSEN and RTSDIS bits in the Control Register has different
results whether the USART is set in "Normal" or "Hardware Handshake" mode:

1) "Normal" mode
- the RTSEN bit forces the RTS line to low level, which tells the remote peer
  that we are ready to received new data.
- the RTSDIS bit forces the RTS line to high level, which tells the remote peer
  to stop sending new data.

2) "Hardware Handshake" mode
- the RTSEN bit forces the RTS line to high level.
- the RTSDIS bit lets the hardware control the RTS line.

WARNING:
when FIFOs are not available or not enabled, the RTS line is controlled by the
PDC. This is why using the Hardware Handshake mode requires using the PDC
channel for reception. However the Hardware Handshake mode DOES NOT work with
DMA controller since it cannot control the RTS line.
Future designs with FIFOs will introduce a new feature: the RTS line will be
controlled by the RX FIFO using thresholds. This patch was tested with this new
design.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

-EDEFER error wasn't handle properly by atmel_serial_probe().
As an example, when atmel_serial_probe() is called for the first time, we pass
the test_and_set_bit() test to check whether the port has already been
initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly
returned before by clk_get(). Consequently atmel_serial_probe() used to return
this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask.
When atmel_serial_probe() was called for the second time, it used to fail on
the test_and_set_bit() function then returning -EBUSY.

When atmel_serial_probe() fails, this patch make it clear the port bit in the
"atmel_ports_in_use" mask, if needed, before returning the error code.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls
clk_disable_unprepare() to disable the peripheral clock before returning.

Later atmel_serial_probe() accesses some I/O registers such as the Mode and
Control registers for RS485 support then the Name and Version registers, through a call to
atmel_get_ip_name(), but at that moment the peripheral clock was still
disabled.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dma_sync_*_for_cpu() and dma_sync_*_for_device() use 'enum dma_data_direction',
not 'enum dma_transfer_direction'
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MARCO will not be supported any more and the project was dropped.
it has been replaced by CSR atlas7.
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>