Commit Graph

273 Commits

Author SHA1 Message Date
Uwe Kleine-König 694e6729bf serial: imx: remove long dead code
This if (0) exists since the driver was introduced in commit
c49bde83eb6a ([ARM PATCH] 1956/2: Re: Motorola i.MX serial driver)
back in 2004.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:26:32 +01:00
Uwe Kleine-König 91555ce901 serial: imx: Fix clearing of receiver overrun flag
The writeable bits in the USR2 register are all "write 1 to
clear" so only write the bits that actually should be cleared.

Fixes: f1f836e420 ("serial: imx: Add Rx Fifo overrun error message")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:26:32 +01:00
Fabio Estevam 4f86a95d75 serial: imx: Do not store/restore the UBRC register
UBRC is a read-only register, so we should not store and restore it inside
imx_flush_buffer().

Reported-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:13:08 +01:00
Sanjeev Sharma ad3d4fdc8e serial:imx make of_device_id array const
Make of_device_id array const.

Signed-off-by: Sanjeev Sharma <Sanjeev_Sharma@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:13:07 +01:00
Fabio Estevam 934084a9d2 serial: imx: Fix imx_flush_buffer()
When running an userspace program that does a 'tcflush(fd, TCIOFLUSH)' call
we still see the last received character in the URXD register afterwards.

Clear UCR2_SRST bit so that the UART FIFO is flushed properly.

Since UCR2_SRST also resets some UART registers, we need to save and restore
some of them.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Fugang Duan <B38611@freescale.com>
Acked-by: Jason Liu <r64343@freecale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:24 -08:00
Eric Nelson 865cea8589 serial: imx: ignore framing errors when IGNPAR is set.
When IGNPAR is set in termios->c_iflag,  characters with
framing errors should be ignored.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:28:18 -08:00
Eric Nelson 8d267fd98b serial: imx: preserve characters with parity or framing errors
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: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:28:17 -08:00
Jiada Wang 91a1a909f9 serial: imx: Support sw flow control in DMA mode
This patch adds Software flow control support in DMA mode.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:59 -08:00
Jiada Wang 7e2fb5aa8d serial: imx: Fix issue in software flow control
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:59 -08:00
Jiada Wang 6f026d6b7c serial: imx: Enable UCR4_OREN in startup interface
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:59 -08:00
Robin Gong ee5e7c1091 serial: imx: start rx_dma once RXFIFO is not empty
Start rx_dma once RXFIFO is not empty that can avoid dma request lost
and causes data delay issue.

Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:59 -08:00
Anton Bondarenko 068500e08d serial: imx: initialized DMA w/o HW flow enabled
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: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:57 -08:00
Dirk Behme a2c718ce6a serial: imx: disable TDMAEN in imx_flush_buffer()
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Jiada Wang 0bbc9b81c1 serial: imx: call imx_dma_tx() again in dma_tx_callback
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Jiada Wang d64b8607ac Revert "serial: imx: always wake up the processes in the TX callback"
This reverts commit 2ad28e3efe.

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 2ad28e3 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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Dirk Behme 42f752b3fb serial: imx: use dma_is_txing to synchronize dma_tx_callback and imx_dma_tx
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: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Dirk Behme 82e86ae941 serial: imx: unmap scatter gather list in imx_flush_buffer
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: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Dirk Behme 2464982174 serial: imx: unmap sg in case of dmaengine_prep_slave_sg() failure
In case dmaengine_prep_slave_sg() fails, add the missing dma_unmap_sg().

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Dirk Behme 7942f8577f serial: imx: TX DMA: clean up sg initialization
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: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Dirk Behme 55c3cb1358 serial: imx: remove unneeded imx_transmit_buffer() from imx_start_tx()
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: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Andy Lowe <andy_lowe@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Jiada Wang 73631813c1 serial: imx: use locking to stop concurrent access of UCR1
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:07 -08:00
Jiada Wang 55d8693acd serial: imx: add CREAD flag support
Add CREAD flag hanlding in set_termios and UART DMA mode
which ignores all received chars when CREAD flag cleared.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:23:06 -08:00
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 Version: GnuPG v2
 
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Fabio Estevam 93d94b37fd serial: imx: Fix warning when building 'allmodconfig'
When CONFIG_SERIAL_IMX_CONSOLE=n and CONFIG_CONSOLE_POLL=y we get the following
build warning:

drivers/tty/serial/imx.c:306:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:315:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]

imx_port_ucrs_save/restore are only used under CONFIG_SERIAL_IMX_CONSOLE, so
their definitions should be also be protected only by CONFIG_SERIAL_IMX_CONSOLE.

This was detected when building 'allmodconfig'.

Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:39 -08:00
Daniel Thompson 6b8bdad961 serial: imx: add imx_poll_init()
For the console poll usage, .poll_init() will perform deeper hardware
initialization to ensure the serial port is always active.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:23 -08:00
Daniel Thompson f968ef3494 serial: imx: clean up imx_poll_put_char()
imx_put_poll_char() has been simplified to remove the code to disable
interrupts. The present code can corrupt register state when re-entered
from FIQ handler.

Switch to _relaxed() MMIO functions (which are safe for polled I/O and
needed to avoid taking spin locks).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Huang Shijie <b32955@freescale.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:23 -08:00
Fabio Estevam f0fd1b73b0 serial: imx: Remove unneeded registration message
There is no real value in displaying "Serial: IMX driver" in every boot.

The uart_register_driver() can fail and even so the "Serial: IMX driver" will
be displayed, which is not really helpful.

This is particularly annoying when booting multi_v7_defconfig kernel on a SoC
that is not a i.MX and even though this message gets displayed.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:03:20 -08:00
Fabio Estevam f1f2b6e497 serial: imx: Remove unneeded OOM error message
When kzalloc() fails the core MM will already complain about it, so there is
no need to have the error message locally.

Remove the unneeded error message.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:03:20 -08:00
Fabio Estevam cb0f0a5ff4 serial: imx: Remove unneeded goto label
Instead of jumping to 'error_out1' label we can simplify the code and return the
error code directly.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:03:20 -08:00
Fabio Estevam c0d1c6b0f0 serial: imx: Fix the reporting of interrupts
On a imx system with ttymxc0, ttymxc1 and ttymxc4 registered we see the
following output from 'cat /proc/interrupts':

$ cat /proc/interrupts
           CPU0
...
 58:         39       GIC  58  2020000.serial
 67:        115       GIC  67  21f8000.i2c

The only uart irq that appears is ttymxc0, which is the console.

As ttymxc1 and ttymxc4 will only have their irq registered at imx_startup(),
they are not shown right after probe.

Transmitting to ttymxc1 and ttymxc4 will cause their irqs to be registered, but
the output shows:

$ echo "111111" > /dev/ttymxc1
$ echo "444444" > /dev/ttymxc4
$ cat /proc/interrupts
           CPU0
...
 58:        150       GIC  58  2020000.serial
 59:          1       GIC  59
 62:          1       GIC  62
 67:        115       GIC  67  21f8000.i2c

,which misses printing the associated device address.

In order to fix this, register all the irqs inside the probe function via
devm_request_irq(), which will correctly report the serial interrupts associated
with their correspondent serial device and also helps simplyfing the code by
avoiding the calls to free_irq().

$ echo "111111" > /dev/ttymxc1
$ echo "444444" > /dev/ttymxc4
$ cat /proc/interrupts

	   CPU0
....
 58:        202       GIC  58  2020000.serial
 59:          1       GIC  59  21e8000.serial
 62:          1       GIC  62  21f4000.serial
 67:        115       GIC  67  21f8000.i2c

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 20:03:20 -08:00
Wolfram Sang 9144b3cded tty: serial: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:45 +02:00
Huang Shijie a4688bcd34 serial: imx: change the wait even to interruptiable
The wait_event() makes the application hang for ever in the following case:
 [1] the hardware flow control is enabled.
 [2] the other end (or the remote end) is terminated, and the TX is still
     waiting for the hardware flow control signal to become asserted.

This patch fixes it by changing the wait_event to wait_event_interruptible.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Huang Shijie 45564a6656 serial: imx: terminate the RX DMA when the UART is suspending
When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Fugang Duan bb2f861ad0 serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
when the 'CTSC' bit is negated. 'CTS' has no function when 'CTSC' is asserted.
0: The CTS pin is high (inactive)
1: The CTS pin is low (active)

For throttle, it needs to clear 'CTS' and 'CTSC' bits.
For unthrottle, it needs to enable 'CTS' and 'CTSC' bits.

The patch just fix the issue.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-28 21:26:38 -04:00
Dirk Behme 26c474128b serial: imx: clean up imx_poll_get_char()
Looking at the get_poll_char() function of the 8250.c serial driver,
we learn:

* poll_get_char() doesn't have to save/disable/restore the interrupt
  registers. No interrupt handling is needed in this function at all.
  Remove it.

* Don't block in case there is no data available. So instead blocking
  in the do {} while loop, just return with NO_POLL_CHAR, immediately .

Additionally, while the i.MX6 register URXD[7-0] contain the RX_DATA,
the upper bits of this register (URXD[15-10]) might contain some
control flags. To ensure that these are not returned with the data
read, just mask out URXD[7-0].

These changes fix the 'hang' working with kdb:

$ echo ttymxc3 > /sys/module/kgdboc/parameters/kgdboc
$ echo g >/proc/sysrq-trigger
[0]kdb> help
...
<hang>

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08 16:26:07 -07:00
Peter Hurley 5e42e9a30c serial: imx: Fix x_char handling and tx flow control
The serial core expects the UART driver to transmit x_char
(START/STOP chars) even if tx is stopped and before data already
in the tx ring buffer if possible. Also, sending x_char must
not cause additional data in the tx ring buffer to transmit
if tx is stopped.

Cause x_char to be transmitted before any other data is sent.
Auto-stop tx if the tx ring buffer is empty or tx should be stopped.
Only perform one write wakeup if tx ring buffer space is below
threshold.

x_char handling in DMA mode is still broken; add FIXME.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08 16:21:35 -07:00
Peter Hurley 8bec751bd6 serial: imx: Fix build breakage
Fix breakage introduced by
commit c557d392fb,
'serial: Test for no tx data on tx restart'.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-11 17:43:13 -07:00
Peter Hurley c557d392fb serial: Test for no tx data on tx restart
Commit 717f3bbab3,
'serial_core: Fix conditional start_tx on ring buffer not empty'
exposes an incorrect assumption in several drivers' start_tx methods;
the tx ring buffer can, in fact, be empty when restarting tx while
performing flow control.

Affected drivers:
sunsab.c
ip22zilog.c
pmac_zilog.c
sunzilog.c
m32r_sio.c
imx.c

Other in-tree serial drivers either are not affected or already
test for empty tx ring buffer before transmitting.

Test for empty tx ring buffer in start_tx() method, after transmitting
x_char (if applicable).

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Seth Bollinger <sethb@digi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:31:34 -07:00
Greg Kroah-Hartman 9ce4f8f3f4 Revert "serial: imx: remove the DMA wait queue"
This reverts commit e2f2786606.

Huang reports that this patch is broken and should be reverted.

Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-29 19:30:54 -07:00
Huang Shijie 85878399e7 serial: imx: disable the receiver ready interrupt for imx_stop_rx
This patch disables the receiver ready interrupt for imx_stop_rx.
It reduces the interrupt numbers when the uart is going to close
or suspend.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:41:32 -07:00
Huang Shijie e2f2786606 serial: imx: remove the DMA wait queue
The DMA wait queue makes the code very complicated:
  For RX, the @->stop_rx hook does not really stop the RX;
  For TX, the @->stop_tx hook does not really stop the TX.

The above make the imx_shutdown has to wait the RX/TX DMA to be finished.

In order to make code more simple, this patch removes the DMA wait queue.
By calling the dmaengine_terminate_all, this patch makes the RX stops
immediately after we call the @->stop_rx hook, so does the TX.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:41:32 -07:00
Huang Shijie 8eccd0cd21 serial: imx: remove the redundant code
In the imx_startup(), we will reset the uart port which will reset all
the FIFOs, including the URXD.

So the code to clear the RX FIFO is redundant. Just remove it.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:40:43 -07:00
Huang Shijie 772f89910a serial: imx: reset the uart port all the time
Current code resets the uart port only when it supports the irda mode.
In actually, we also need to reset the uart port in the non-irda mode.
A hang was caught in the following case:

    UART A transmits data to the other end. But the transmission maybe
    terminated. In some corner case, the TX FIFO maybe not empty.

The kernel will hang at the imx_set_termios():
	............................................................
	while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
		barrier();
	............................................................

This patch resets the uart port all the time in the imx_startup().
And fix the hang.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:39:46 -07:00
Fabio Estevam b38cb7d257 serial: imx: Disable new features of autobaud detection
Bit 7 of UCR3 is described in the i.MX reference manuals (with the exception
of i.MX1) as follows:

ADNIMP: Autobaud Detection Not Improved-. Disables new features of
	autobaud detection (See Baud Rate Automatic Detection
	Protocol, for more details).

	0 Autobaud detection new features selected
	1 Keep old autobaud detection mechanism

The "new features" mechanism occasionally cause the receiver to get out of sync
and continuously produce received characters of '\xff'.

In order to reproduce the problem:

$ stty -F /dev/ttymxc0 19200

- Change the terminal baudrate to 19200

- Type in the console and it should look good

- Change the terminal baudrate back to 115200

- Type 'b' in the console, then a stream of garbage characters is seen.

Also rename the bit definition as per the reference manual.

Tested on mx6q, mx6dl, mx6solo and mx53.

Based on a patch from Eric Nelson for U-boot.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:36:21 -07:00
Alexander Shiyan 45af780a0f serial: imx: Remove init() and exit() platform callbacks
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Alexander Shiyan 436e4ab5fc serial: imx: Use dev_name() for request_irq() to distinguish UARTs
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Alexander Shiyan da82f99724 serial: imx: Use devm_ioremap_resource()
Use devm_ioremap_resource() in order to make the code simpler and
it gives proper codes on errors.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Huang Shijie 2ad28e3efe serial: imx: always wake up the processes in the TX callback
The current code only wakes up the processes when the circle
buffer has less data then the WAKEUP_CHARS.

But sometimes, the circle buffer may has data more then the WAKEUP_CHARS,
in such case, the processes will hang.

This patch makes it always wakes up the processes in the TX callback.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:48 -08:00
Huang Shijie 6b471a9840 serial: imx: add support for loopback mode.
Add the loopback mode support for imx uart driver.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08 17:09:07 -08:00
Linus Torvalds 56edff7529 TTY/Serial driver updates for 3.13-rc1
Here's the big tty/serial driver update for 3.13-rc1.
 
 There's some more minor n_tty work here, but nothing like previous
 kernel releases.  Also some new driver ids, driver updates for new
 hardware, and other small things.
 
 All of this has been in linux-next for a while with no issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver update for 3.13-rc1.

  There's some more minor n_tty work here, but nothing like previous
  kernel releases.  Also some new driver ids, driver updates for new
  hardware, and other small things.

  All of this has been in linux-next for a while with no issues"

* tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
  serial: omap: fix missing comma
  serial: sh-sci: Enable the driver on all ARM platforms
  serial: mfd: Staticize local symbols
  serial: omap: fix a few checkpatch warnings
  serial: omap: improve RS-485 performance
  mrst_max3110: fix unbalanced IRQ issue during resume
  serial: omap: Add support for optional wake-up
  serial: sirf: remove duplicate defines
  tty: xuartps: Fix build error when COMMON_CLK is not set
  tty: xuartps: Fix build error due to missing forward declaration
  tty: xuartps: Fix "may be used uninitialized" build warning
  serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8
  tty: xuartps: Update copyright information
  tty: xuartps: Implement suspend/resume callbacks
  tty: xuartps: Dynamically adjust to input frequency changes
  tty: xuartps: Updating set_baud_rate()
  tty: xuartps: Force enable the UART in xuartps_console_write
  tty: xuartps: support 64 byte FIFO size
  tty: xuartps: Add polled mode support for xuartps
  tty: xuartps: Implement BREAK detection, add SYSRQ support
  ...
2013-11-07 12:17:06 +09:00
Huang Shijie 7cb92fd2a0 serial: imx: optimization: remove the workqueues for DMA
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: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 18:25:30 -07:00
Huang Shijie f0ef8834b2 serial: imx: use the dmaengine_tx_status
Use the dmaengine_tx_status to simplify the code, do not change any logic.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:55 -07:00
Huang Shijie 947c74eba8 serial: imx: fix the wrong number of scatterlist entries when xmit->head is 0
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: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Huang Shijie 1ce43e58d4 serial: imx: check the DMA for imx_tx_empty
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: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Huang Shijie eb56b7edae serial: imx: implement the flush_buffer hook
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: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-16 13:19:54 -07:00
Greg Kroah-Hartman b4e788df8d Revert "serial: i.MX: evaluate linux,stdout-path property"
This reverts commit f7d2c0bbdb, as it
causes build errors when the driver is built as a module.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07 19:06:59 -07:00
Olof Johansson a50c44ce24 serial: imx: Change cast to handle 64-bit resource_size_t
This resolves a warning where resource_size_t is larger than void *:

  drivers/tty/serial/imx.c:1542:6: warning: cast to pointer from integer
  	of different size [-Wint-to-pointer-cast]

Since iomem_base is a void *, casting to unsigned long is safe.

It's unclear to me that this comparison is truly needed, but it's there
on several other drivers as well.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 15:41:38 -07:00
Fabio Estevam e2c2725338 serial: imx: Use NULL as the last argument of add_preferred_console()
Commit f7d2c0bbd (serial: i.MX: evaluate linux,stdout-path property) introduced
the following sparse warning:

drivers/tty/serial/imx.c:1916:77: warning: Using plain integer as NULL pointer

Pass NULL as the last argument of add_preferred_console() instead of zero.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 14:25:26 -07:00
Huang Shijie b09c74ae12 serial: imx: initialize the local variable
The slave_config is not initialized, so some of its fields may
be set with random data which may causes the failure in the following
dmaengine_prep_slave_sg().

This patch fixes this issue.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-30 14:11:28 -07:00
Sascha Hauer f7d2c0bbdb serial: i.MX: evaluate linux,stdout-path property
devicetrees may have the linux,stdout-path property to specify the
console. This patch adds support to the i.MX serial driver for this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 11:23:53 -07:00
Jingoo Han 574de559c1 serial: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-31 17:56:15 -07:00
Huang Shijie b4cdc8f61b serial: imx: add DMA support for imx6q
We only enable the DMA support when the following are meet:

  [1] The uart port supports the hardware flow control(CTS/RTS).
      (Some uart port does not support the CTS/RTS.)

  [2] The application enables the CTS/RTS.

  [3] The Soc is imx6q.
      For the sdma's firmware limit, we do not support the DMA except
      the imx6q platform.

  [4] The uart is not used as a console.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 15:44:11 -07:00
Hubert Feurstein 09bd00f6e9 serial/imx: fix custom-baudrate handling
It was not possible to set custom-baudrates like 62500.

Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 15:43:37 -07:00
Huang Shijie a496e6284c serial: imx: distinguish the imx6q uart from the others
We will add the DMA support for the imx uart. For the firmware's limit,
only the imx6 serial chips (including the imx6q, imx6dl, imx6sl) can
support the DMA.

This patch adds the necessary macro and helper to distinguish the
imx6q uart from the other imx uart. Other chips can use the "fsl,imx6q-uart"
to enable the DMA support.

This patch also replaces the check "is_imx21_uart()" with "!is_imx1_uart()".

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 15:43:16 -07:00
Huang Shijie 1cf93e0d54 serial: imx: remove the uart_console() check
The uart_console() check makes the clocks(clk_per and clk_ipg) opened
even when we close the console uart.

This patch enable/disable the clocks in imx_console_write(),
so we can keep the clocks closed when the console uart is closed.

Also remove the clock enable/disable oprations in the probe, we do not
need them any more.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 15:42:46 -07:00
Jingoo Han 43b829b3c1 serial: remove unnecessary platform_set_drvdata()
The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d06310
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Barry Song <baohua.song@csr.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26 15:39:36 -07:00
Wolfram Sang e84f54fc58 drivers/tty/serial: don't use devm_pinctrl_get_select_default() in probe
Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for setting the default pins. Compile tested only.

Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24 15:21:13 -07:00
Fabio Estevam 80c48497f2 serial: imx: Fix serial clock unbalance
Since commit 0c375501 (serial: imx: enable the clocks for console), the
imx_startup() function calls clk_prepare_enable conditionally, so we
need to call clk_disable_unprepare inside imx_shutdown() under the same
condition to avoid unbalanced clock calls.

This avoids the following warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 70 at drivers/clk/clk.c:780 __clk_disable+0x68/0x84()
Modules linked in:
CPU: 0 PID: 70 Comm: mountall Not tainted 3.10.0-rc4-next-20130607+ #435
Backtrace:
[<800116a4>] (dump_backtrace+0x0/0x10c) from [<80011844>] (show_stack+0x18/0x1c)
 r6:8069f4e8 r5:0000030c r4:00000000 r3:00000000
[<8001182c>] (show_stack+0x0/0x1c) from [<8053bce0>] (dump_stack+0x78/0x94)
[<8053bc68>] (dump_stack+0x0/0x94) from [<80023df8>] (warn_slowpath_common+0x6c/0x8c)
 r4:00000000 r3:00000000
[<80023d8c>] (warn_slowpath_common+0x0/0x8c) from [<80023e3c>] (warn_slowpath_null+0x24/0x2c)
 r8:bf2ed008 r7:bfaa9810 r6:000f0013 r5:bf824b80 r4:bf824b80
[<80023e18>] (warn_slowpath_null+0x0/0x2c) from [<8041af84>] (__clk_disable+0x68/0x84)
[<8041af1c>] (__clk_disable+0x0/0x84) from [<8041b098>] (clk_disable+0x20/0x2c)
 r4:600f0013 r3:00000001
[<8041b078>] (clk_disable+0x0/0x2c) from [<802c93e8>] (imx_shutdown+0xbc/0xec)
 r5:bf824b80 r4:bfaa9810
[<802c932c>] (imx_shutdown+0x0/0xec) from [<802c63a0>] (uart_port_shutdown+0x34/0x40)
 r5:bf86f860 r4:bfaa9810
[<802c636c>] (uart_port_shutdown+0x0/0x40) from [<802c68c0>] (uart_shutdown+0x98/0xc4)
 r4:bf86f800 r3:00000000
[<802c6828>] (uart_shutdown+0x0/0xc4) from [<802c7514>] (uart_close+0x5c/0x198)
 r7:bfaa9810 r6:bf274400 r5:bf86f86c r4:bf86f800
[<802c74b8>] (uart_close+0x0/0x198) from [<802ac648>] (tty_release+0xf8/0x500)
[<802ac550>] (tty_release+0x0/0x500) from [<800c5a30>] (__fput+0x9c/0x208)
[<800c5994>] (__fput+0x0/0x208) from [<800c5bac>] (____fput+0x10/0x14)
[<800c5b9c>] (____fput+0x0/0x14) from [<80040234>] (task_work_run+0xb4/0xec)
[<80040180>] (task_work_run+0x0/0xec) from [<80029238>] (do_exit+0x2b0/0x920)
 r8:8000e144 r7:000000f8 r6:bf306300 r5:00000000 r4:bfac1180
[<80028f88>] (do_exit+0x0/0x920) from [<80029a4c>] (do_group_exit+0x50/0xd4)
 r7:000000f8
[<800299fc>] (do_group_exit+0x0/0xd4) from [<80029ae8>] (__wake_up_parent+0x0/0x28)
 r7:000000f8 r6:00000001 r5:0006f7ae r4:0006f79a
[<80029ad0>] (SyS_exit_group+0x0/0x18) from [<8000dfc0>] (ret_fast_syscall+0x0/0x30)
---[ end trace 16d080eb7efea4e9 ]---

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-17 12:49:43 -07:00
Huang Shijie 0c375501be serial: imx: enable the clocks for console
The console's clocks are disabled after the uart driver is probed.
It makes that we can see less log from the console now
(though we still can get all the log by the `dmesg`).

So enable the clocks for console, and we can see all the log again.

This patch also disables the sport->clk_per when we fail to enable
the sport->clk_ipg;

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-08 22:31:47 -07:00
Greg Kroah-Hartman 1ba7055af2 Merge 3.10-rc5 into tty-next 2013-06-08 21:23:33 -07:00
Fabio Estevam e8bfa76073 serial: imx: Fix warning when !CONFIG_SERIAL_IMX_CONSOLE
When CONFIG_SERIAL_IMX_CONSOLE is not selected the following build warnings
appear:

drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]

imx_port_ucrs_save() and imx_port_ucrs_restore() are only used when
CONFIG_CONSOLE_POLL or CONFIG_SERIAL_IMX_CONSOLE are selected, so protect these
functions declaration with a proper ifdef.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-06 13:09:55 -07:00
Huang Shijie 28eb4274e7 serial: imx: enable the clocks only when the uart is used
Current code opens the clocks when the uart driver is probed.
This will wastes some power if several uarts are enabled, but not really
used.

So close these clocks for uart, and enable the clocks only when
the uart is used.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-06 13:05:38 -07:00
Huang Shijie 20ff2fe60a serial: imx: add support for DTE mode
The uart works in the DCE mode by default, but sometime we need it
works at the DTE mode.

This patch adds the support for the DTE mode.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 14:31:39 -07:00
Lucas Stach bff09b099b serial/imx: disable hardware flow control at startup
We only want to enable hardware flow control if RTS/CTS pins
are connected.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 10:08:28 -07:00
Alexander Stein f1f836e420 serial: imx: Add Rx Fifo overrun error message
This patch enables the overrun error (ORE) interrupt and increases the
counter in case of overrun.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-20 11:53:46 -07:00
Shawn Guo f30e826069 serial: imx: fix uninitialized variable warning
Commit 677fe55 (serial: imx: Fix recursive locking bug) introduces an
uninitialized variable warning as below.

  CC      drivers/tty/serial/imx.o
drivers/tty/serial/imx.c: In function ‘imx_console_write’:
include/linux/spinlock.h:340:2: warning: ‘flags’ may be used uninitialized in this function [-Wuninitialized]
drivers/tty/serial/imx.c:1214:16: note: ‘flags’ was declared here

Initialize the variable to suppress the warning.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-18 11:05:14 -08:00
Thomas Gleixner 677fe555cb serial: imx: Fix recursive locking bug
commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe
on SMP) introduced a recursive locking bug in imx_console_write().

The callchain is:

imx_rxint()
  spin_lock_irqsave(&sport->port.lock,flags);
  ...
  uart_handle_sysrq_char();
    sysrq_function();
      printk();
        imx_console_write();
          spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD

The bad news is that the kernel debugging facilities can dectect the
problem, but the printks never surface on the serial console for
obvious reasons.

There is a similar issue with oops_in_progress. If the kernel crashes
we really don't want to be stuck on the lock and unable to tell what
happened.

In general most UP originated drivers miss these checks and nobody
ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by
a large number of developers.

The solution is to avoid locking in the sysrq case and trylock in the
oops_in_progress case.

This scheme is used in other drivers as well and it would be nice if
we could move this to a common place, so the usual copy/paste/modify
bugs can be avoided.

Now there is another issue with this scheme:

CPU0 	    	     	 CPU1
printk()
			 rxint()
			   sysrq_detection() -> sets port->sysrq
			 return from interrupt
  console_write()
     if (port->sysrq)
     	avoid locking

port->sysrq is reset with the next receive character. So as long as
the port->sysrq is not reset and this can take an endless amount of
time if after the break no futher receive character follows, all
console writes happen unlocked.

While the current writer is protected against other console writers by
the console sem, it's unprotected against open/close or other
operations which fiddle with the port. That's what the above mentioned
commit tried to solve.

That's an issue in all drivers which use that scheme and unfortunately
there is no easy workaround. The only solution is to have a separate
indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to
smp_processor_id() before calling into handle_sysrq() and resets it to
-1 after that. Then change the locking check to:

     if (port->sysrq_cpu == smp_processor_id())
     	 locked = 0;
     else if (oops_in_progress)
         locked = spin_trylock_irqsave(port->lock, flags);
     else
  	 spin_lock_irqsave(port->lock, flags);

That would force all other cpus into the spin_lock path. Problem
solved, but that's way beyond the scope of this fix and really wants
to be implemented in a common function which calls the uart specific
write function to avoid another gazillion of hard to debug
copy/paste/modify bugs.

Reported-and-tested-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org>  # 3.6+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14 12:17:20 -08:00
fabio.estevam@freescale.com 44a754117a Revert "serial: imx: Move imx_port_ucrs_save/restore under CONFIG_CONSOLE_POLL"
This reverts commit cdc8da3998.

In my attempt to fix a build warning on arm randconfig a build error on
imx_v6_v7_defconfig was introduced, so revert it for now.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-06 13:36:54 -08:00
Fabio Estevam cdc8da3998 serial: imx: Move imx_port_ucrs_save/restore under CONFIG_CONSOLE_POLL
If CONFIG_CONSOLE_POLL is not defined, the following build warning happens:

drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]

Move imx_port_ucrs_saver/restore under CONFIG_CONSOLE_POLL ifdef block to fix it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-05 11:13:51 -08:00
Fabio Estevam 45e786a6ba serial: imx: Remove unused 'tty' variable
Commit 2e124b4a39 (TTY: switch tty_flip_buffer_push) introduced the following
build warning:

drivers/tty/serial/imx.c:519:21: warning: unused variable 'tty' [-Wunused-variable]

Remove the unused 'tty' variable.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 17:31:24 -08:00
Jiri Slaby 2e124b4a39 TTY: switch tty_flip_buffer_push
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:30:15 -08:00
Jiri Slaby 92a19f9cec TTY: switch tty_insert_flip_char
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_char is the next one to proceed. This one is used all
over the code, so the patch is huge.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:21:36 -08:00
Sachin Kamat 42d3419154 serial: imx: Use devm_* APIs
devm_* APIs are device managed and make cleanup and exit code simpler
and easier.

Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:02:52 -08:00
Sachin Kamat 50bbdba3dd serial: imx: Use pr_info instead of printk
Silences checkpatch warnings.

Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:02:52 -08:00
Sachin Kamat 699cbd6726 serial: imx: Fix coding style issue
Silences the following checkpatch error:
ERROR: that open brace { should be on the previous line

Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:02:51 -08:00
Sachin Kamat e32a9f8f34 serial: imx: Use <linux/io.h> instead of <asm/io.h>
Silences the following checkpatch warning:
WARNING: Use #include <linux/io.h> instead of <asm/io.h>

Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:02:51 -08:00
Sachin Kamat 82313e66b1 serial: imx: Fix checkpatch errors related to spacing
Fixed checkpatch errors and warnings related to incorrect spacing.

Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:02:51 -08:00
Linus Torvalds 9cd11c0c47 ARM: soc: multiplatform enablement
This is a pretty significant branch. It's the introduction of the
 first multiplatform support on ARM, and with this (and the later
 branch) merged, it is now possible to build one kernel that contains
 support for highbank, vexpress, mvebu, socfpga, and picoxcell. More
 platforms will be convered over in the next few releases.
 
 Two critical last things had to be done for this to be practical and
 possible:
 * Today each platform has its own include directory under
   mach-<mach>/include/mach/*, and traditionally that is where a lot of
   driver/platform shared definitions have gone, such as platform data
   structures. They now need to move out to a common location instead,
   and this branch moves a large number of those out to
   include/linux/platform_data.
 * Each platform used to list the device trees to compile for its
   boards in mach-<mach>/Makefile.boot.
 
 Both of the above changes will mean that there are some merge
 conflicts to come (and some to resolve here). It's a one-time move and
 once it settles in, we should be good for quite a while. Sorry for the
 overhead.
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Merge tag 'multiplatform' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM soc multiplatform enablement from Olof Johansson:
 "This is a pretty significant branch.  It's the introduction of the
  first multiplatform support on ARM, and with this (and the later
  branch) merged, it is now possible to build one kernel that contains
  support for highbank, vexpress, mvebu, socfpga, and picoxcell.  More
  platforms will be convered over in the next few releases.

  Two critical last things had to be done for this to be practical and
  possible:
   * Today each platform has its own include directory under
     mach-<mach>/include/mach/*, and traditionally that is where a lot
     of driver/platform shared definitions have gone, such as platform
     data structures.  They now need to move out to a common location
     instead, and this branch moves a large number of those out to
     include/linux/platform_data.
   * Each platform used to list the device trees to compile for its
     boards in mach-<mach>/Makefile.boot.

  Both of the above changes will mean that there are some merge
  conflicts to come (and some to resolve here).  It's a one-time move
  and once it settles in, we should be good for quite a while.  Sorry
  for the overhead."

Fix conflicts as per Olof.

* tag 'multiplatform' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (51 commits)
  ARM: add v7 multi-platform defconfig
  ARM: msm: Move core.h contents into common.h
  ARM: highbank: call highbank_pm_init from .init_machine
  ARM: dtb: move all dtb targets to common Makefile
  ARM: spear: move platform_data definitions
  ARM: samsung: move platform_data definitions
  ARM: orion: move platform_data definitions
  ARM: vexpress: convert to multi-platform
  ARM: initial multiplatform support
  ARM: mvebu: move armada-370-xp.h in mach dir
  ARM: vexpress: remove dependency on mach/* headers
  ARM: picoxcell: remove dependency on mach/* headers
  ARM: move all dtb targets out of Makefile.boot
  ARM: picoxcell: move debug macros to include/debug
  ARM: socfpga: move debug macros to include/debug
  ARM: mvebu: move debug macros to include/debug
  ARM: vexpress: move debug macros to include/debug
  ARM: highbank: move debug macros to include/debug
  ARM: move debug macros to common location
  ARM: make mach/gpio.h headers optional
  ...
2012-10-01 19:11:38 -07:00
Olof Johansson e3a66aa33a Merge branch 'multiplatform/platform-data' into next/multiplatform
* multiplatform/platform-data:
  ARM: spear: move platform_data definitions
  ARM: samsung: move platform_data definitions
  ARM: orion: move platform_data definitions
  ARM: nomadik: move platform_data definitions
  ARM: w90x900: move platform_data definitions
  ARM: vt8500: move platform_data definitions
  ARM: tegra: move sdhci platform_data definition
  ARM: sa1100: move platform_data definitions
  ARM: pxa: move platform_data definitions
  ARM: netx: move platform_data definitions
  ARM: msm: move platform_data definitions
  ARM: imx: move platform_data definitions
  ARM: ep93xx: move platform_data definitions
  ARM: davinci: move platform_data definitions
  ARM: at91: move platform_data definitions

Conflicts due to removed files:
	arch/arm/mach-tegra/board-harmony.c
	arch/arm/mach-tegra/board-trimslice.c

Conflicts due to code removal:
	arch/arm/mach-tegra/board-paz00.c

Context conflicts in:
	drivers/mmc/host/sdhci-tegra.c
	drivers/net/irda/pxaficp_ir.c

Signed-off-by: Olof Johansson <olof@lixom.net>
2012-09-22 01:07:21 -07:00
Richard Zhao 034dc4db6f serial: imx: remove null check of sport in suspend/resume function
platform_get_drvdata always retrun a valid value after probe succeed.

It also fixed smatch warnings:
drivers/tty/serial/imx.c:1376 serial_imx_suspend() warn: variable dereferenced before check 'sport' (see line 1372)
drivers/tty/serial/imx.c:1392 serial_imx_resume() warn: variable dereferenced before check 'sport' (see line 1388)

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-21 09:53:16 -07:00
Richard Zhao 0a86a86b92 serial: imx: set sport as drvdata, like it's used elsewhere
Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-21 09:53:15 -07:00
Olof Johansson 32dec75349 ARM: tegra: switch to dmaengine
The Tegra code-base has contained both a legacy DMA and a dmaengine
 driver since v3.6-rcX. This series flips Tegra's defconfig to enable
 dmaengine rather than the legacy driver, and removes the legacy driver
 and all client code.
 
 The branch is based on v3.6-rc6 in order to pick up a bug-fix to the
 ASoC Tegra PCM driver that's required for audio to work correctly when
 using dmaengine.
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Merge tag 'tegra-for-3.7-dmaengine' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into next/cleanup

ARM: tegra: switch to dmaengine

The Tegra code-base has contained both a legacy DMA and a dmaengine
driver since v3.6-rcX. This series flips Tegra's defconfig to enable
dmaengine rather than the legacy driver, and removes the legacy driver
and all client code.

* tag 'tegra-for-3.7-dmaengine' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra:
  ASoC: tegra: remove support of legacy DMA driver based access
  spi: tegra: remove support of legacy DMA driver based access
  ARM: tegra: apbio: remove support of legacy DMA driver based access
  ARM: tegra: dma: remove legacy APB DMA driver
  ARM: tegra: config: enable dmaengine based APB DMA driver
  + sync to 3.6-rc6
2012-09-20 19:57:38 -07:00
Greg Kroah-Hartman 7ac3c93e5d Merge 3.6-rc6 into tty-next
This pulls in the fixes in 3.6-rc6

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-16 17:31:36 -07:00
Arnd Bergmann 82906b13a6 ARM: imx: move platform_data definitions
Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the imx include directories

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Sascha Hauer <kernel@pengutronix.de>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Dan Williams <djbw@fb.com>
Cc: "Ben Dooks (embedded platforms)" <ben-linux@fluff.org>
Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
2012-09-14 11:17:21 +02:00
Uwe Kleine-König 833462e94c serial/imx: improve error diagnosics for clock and pinctrl failures
These error paths are used more often now after deep changes to the
clock code and pinctrl is still new for imx. So help debugging and give
clues in the boot log.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05 13:15:07 -07:00
Dirk Behme 7be0670f7b tty: serial: imx: don't reinit clock in imx_setup_ufcr()
Remove the clock configuration from imx_setup_ufcr(). This
isn't needed here and will cause garbage output if done.

To be be sure that we only touch the bits we want (TXTL and RXTL)
we have to mask out all other bits of the UFCR register. Add
one non-existing bit macro for this, too (bit 6, DCEDTE on i.MX6).

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
CC: Shawn Guo <shawn.guo@linaro.org>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Troy Kisky <troy.kisky@boundarydevices.com>
CC: Xinyu Chen <xinyu.chen@freescale.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05 12:44:44 -07:00
Xinyu Chen 9ec1882df2 tty: serial: imx: console write routing is unsafe on SMP
The console feature's write routing is unsafe on SMP with
the startup/shutdown call.

There could be several consumers of the console
* the kernel printk
* the init process using /dev/kmsg to call printk to show log
* shell, which open /dev/console and write with sys_write()

The shell goes into the normal uart open/write routing,
but the other two go into the console operations.
The open routing calls imx serial startup, which will write USR1/2
register without any lock and critical with imx_console_write call.

Add a spin_lock for startup/shutdown/console_write routing.

This patch is a port from Freescale's Android kernel.

Signed-off-by: Xinyu Chen <xinyu.chen@freescale.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05 12:44:44 -07:00
Greg Kroah-Hartman c87985a3ce Merge tty-next into 3.6-rc1
This handles the merge issue in:
	arch/um/drivers/line.c
	arch/um/drivers/line.h
And resolves the duplicate patches that were in both trees do to the
tty-next branch not getting merged into 3.6-rc1.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-06 09:48:31 -07:00
Shawn Guo 1ee8f65b56 tty: serial: imx: remove the use of MXC_INTERNAL_IRQS
As the part of the effort to enable SPARE_IRQ for imx platform,
the macro MXC_INTERNAL_IRQS will be removed.  The imx serial driver
has a references to it for a decision on flags of request_irq call
based on rtsirq is beyond MXC_INTERNAL_IRQS.  However the searching
on imx platform code tells that rtsirq will never be beyond
MXC_INTERNAL_IRQS.  That said, the check, consequently the reference
to MXC_INTERNAL_IRQS are not needed, so remove them.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: linux-serial@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
2012-07-01 21:59:07 +08:00
Uwe Kleine-König 7d0b066fbb serial/imx: make devdata member point to const data
This is only cosmetic for now. In case that

	http://mid.gmane.org/1335171381-24869-1-git-send-email-u.kleine-koenig@pengutronix.de

will be applied, it fixes a warning

	drivers/tty/serial/imx.c: In function 'serial_imx_probe_dt':
	drivers/tty/serial/imx.c:1430:17: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]

though.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-12 15:40:08 -07:00
Arnd Bergmann 4f5a9fd341 Merge branch 'imx/pinctrl' into imx/clock
Conflicts:
	drivers/mmc/host/sdhci-esdhc-imx.c
	drivers/net/ethernet/freescale/fec.c
	drivers/spi/spi-imx.c
	drivers/tty/serial/imx.c

This resolves dependencies between the pinctrl and clock changes
in imx.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-05-14 15:30:52 +02:00
Shawn Guo fed78ce4c6 tty: serial: imx: adopt pinctrl support
Cc: linux-serial@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
2012-05-11 15:01:57 +08:00
Sascha Hauer 3a9465fa2d serial i.MX: do not depend on grouped clocks
the current i.MX clock support groups together unrelated clocks
to a single clock which is then used by the driver. This can't
be accomplished with the generic clock framework so we instead
request the individual clocks in the driver. For i.MX there are
generally three different clocks:

ipg: bus clock (needed to access registers)
ahb: dma relevant clock, sometimes referred to as hclk in the datasheet
per: bit clock, pixel clock

This patch changes the driver to request the individual clocks.
Currently all clk_get will get the same clock until the SoCs
are converted to the generic clock framework

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-04-25 17:03:39 +02:00
Richard Zhao ef5ca193ca serial: imx: add clk_prepare/clk_unprepare
It's for migrating to generic clk framework API.

Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-02-01 14:29:31 +01:00
Eric Miao 995234da19 tty: serial: imx: move del_timer_sync() to avoid potential deadlock
del_timer_sync() acquires its own lock and doesn't have to be nested
within the spinlock of sport->port.lock in imx_set_termios(),  which
will cause potential deadlock.  Fix this by moving it outside.

Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Eric Miao <eric.miao@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:36 -08:00
Saleem Abdulrasool 01f56abd08 imx: add polled io uart methods
These methods are invoked if the iMX uart is used in conjuction with kgdb during
early boot.  In order to access the UART without the interrupts, the kernel uses
the basic polling methods for IO with the device.  With these methods
implemented, it is now possible to enable kgdb during early boot over serial.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Fabio Estevam <festevam@gmail.com>
CC: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
CC: linux-serial@vger.kernel.org
CC: Alan Cox <alan@linux.intel.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:35 -08:00
Dirk Behme 0ad5a81472 imx: Add save/restore functions for UART control regs
Factor out the uart save/restore functionality instead of
having the same code several times in the driver.

Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
CC: Saleem Abdulrasool <compnerd@compnerd.org>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Fabio Estevam <festevam@gmail.com>
CC: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
CC: linux-serial@vger.kernel.org
CC: Alan Cox <alan@linux.intel.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:35 -08:00
Uwe Kleine-König 20bb8095a4 serial/imx: let probing fail for the dt case without a valid alias
When the uart device is instantiated by dt but dt doesn't provide an
alias then better let probing fail instead of falling back to an
unrelated device id used for the line number and no platform data.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:34 -08:00
Uwe Kleine-König a197a191f7 serial/imx: propagate error from of_alias_get_id instead of using -ENODEV
A quick look at of_alias_get_id shows that in the error case it returns
-ENODEV, too, but still it's better style to propagate the value as is.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Jason Liu <jason.hui@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:34 -08:00
Fabio Estevam db1a9b5500 tty: serial: imx: Allow UART to be a source for wakeup
Allow UART to be a source for wakeup from low power mode.

Tested on a MX27PDK by doing:

echo enabled > /sys/devices/platform/imx21-uart.0/tty/ttymxc0/power/wakeup

echo mem > /sys/power/state

and then pressing a key in the console will wakeup the sytem.

Suggested-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04 16:30:33 -08:00
Uwe Kleine-König f227824e84 serial/imx: propagate error of platform_driver_register in init routine
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-26 20:10:13 -08:00
Linus Torvalds 5fffb9513c Merge branch 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6
* 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6:
  of_mdio: Don't phy_scan_fixups() twice
  Devicetree: Expand on ARM Primecell binding documentation
  dt: Add empty of_match_node() macro
  dt: add empty dt helpers for non-dt build
  devicetree: fix build error on drivers/tty/serial/altera_jtaguart.c
  devicetree: Add ARM pl022 spi controller binding doc
  devicetree: Add ARM pl061 gpio controller binding doc
  of/irq: of_irq_find_parent: check for parent equal to child
  MAINTAINERS: update devicetree maintainers
  dt: add helper to read 64-bit integers
  tty: use of_match_ptr() for of_match_table entry
  OF: Add of_match_ptr() macro
  dt: add empty for_each_child_of_node, of_find_property
  devicetree: Document Qualcomm and Atmel prefixes
  serial/imx: add of_alias_get_id() reference back
  dt: add of_alias_scan and of_alias_get_id
  devicetree: Add a registry of vendor prefixes
2011-10-27 08:35:41 +02:00
Shawn Guo ff05967a07 serial/imx: add of_alias_get_id() reference back
As of_alias_get_id() gets fixed and ready for use, the patch adds the
of_alias_get_id() reference back to imx serial driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
[grant.likely: changed pr_err() to dev_err(), dropped unnecessary else]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-09-22 11:19:42 -06:00
Hui Wang 019dc9ea8d serial/imx: support to handle break character
The imx UART hardware controller can identify BREAK character and the
imx_set_termios() can accept BRKINT set by users, but current existing
imx_rxint() can't pass BREAK character and TTY_BREAK to the tty layer
as other serial drivers do (8250.c omap_serial.c).

Here add code to handle BREAK character and pass it to tty layer.

To detect error occurrence, i use URXD_ERR to replace (URXD_OVRRUN |
URXD_FRMERR | ...) because any kind of error occurs, URXD_ERR will
always be set to 1.

I put the URXD_BRK to the first place to check since when BREAK error
occurs, not only URXD_BRK is set to 1, but also URXD_PRERR and
URXD_FRMERR are all set to 1. This arrangement can filter out fake
parity and frame errors when BREAK error occurs.

Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-24 15:27:59 -07:00
Grant Likely 9e191b22c9 dt: remove of_alias_get_id() reference
of_alias_get_id() is broken and being reverted.  Remove the reference
to it and replace with a single incrementing id number.

There is no risk of regression here on the imx driver since the imx
change to use of_alias_get_id() is commit 22698aa2, "serial/imx: add
device tree probe support" which is new for v3.1, and it won't get
used unless CONFIG_OF is enabled and the board is booted using a
device tree.  A single incrementing integer is sufficient for now.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
2011-08-04 11:16:04 +01:00
Shawn Guo 22698aa252 serial/imx: add device tree probe support
It adds device tree probe support for imx tty/serial driver.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-27 09:30:43 +08:00
Shawn Guo fe6b540ac0 serial/imx: get rid of the uses of cpu_is_mx1()
The patch removes all the uses of cpu_is_mx1().  Instead, it uses
the .id_table of platform_driver to distinguish the uart device type,
IMX1_UART and IMX21_UART.  The IMX21_UART type runs on all i.mx
except i.mx1.

A couple of !cpu_is_mx1 logic gets turned into is_imx21_uart,
as the codes wrapped there are really IMX21 type uart specific.

It also removes macro MX1_UCR3_REF25 and MX1_UCR3_REF30 which are
not used anywhere.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-27 09:30:38 +08:00
Joe Perches 28f65c11f2 treewide: Convert uses of struct resource to resource_size(ptr)
Several fixes as well where the +1 was missing.

Done via coccinelle scripts like:

@@
struct resource *ptr;
@@

- ptr->end - ptr->start + 1
+ resource_size(ptr)

and some grep and typing.

Mostly uncompiled, no cross-compilers.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-06-10 14:55:36 +02:00
Linus Torvalds 99dff58562 Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (48 commits)
  serial: 8250_pci: add support for Cronyx Omega PCI multiserial board.
  tty/serial: Fix break handling for PORT_TEGRA
  tty/serial: Add explicit PORT_TEGRA type
  n_tracerouter and n_tracesink ldisc additions.
  Intel PTI implementaiton of MIPI 1149.7.
  Kernel documentation for the PTI feature.
  export kernel call get_task_comm().
  tty: Remove to support serial for S5P6442
  pch_phub: Support new device ML7223
  8250_pci: Add support for the Digi/IBM PCIe 2-port Adapter
  ASoC: Update cx20442 for TTY API change
  pch_uart: Support new device ML7223 IOH
  parport: Use request_muxed_region for IT87 probe and lock
  tty/serial: add support for Xilinx PS UART
  n_gsm: Use print_hex_dump_bytes
  drivers/tty/moxa.c: Put correct tty value
  TTY: tty_io, annotate locking functions
  TTY: serial_core, remove superfluous set_task_state
  TTY: serial_core, remove invalid test
  Char: moxa, fix locking in moxa_write
  ...

Fix up trivial conflicts in drivers/bluetooth/hci_ldisc.c and
drivers/tty/serial/Makefile.

I did the hci_ldisc thing as an evil merge, cleaning things up.
2011-05-23 12:23:20 -07:00
Uwe Kleine-König 5680e94148 serial/imx: read cts state only after acking cts change irq
If cts changes between reading the level at the cts input (USR1_RTSS)
and acking the irq (USR1_RTSD) the last edge doesn't generate an irq and
uart_handle_cts_change is called with a outdated value for cts.

The race was introduced by commit

	ceca629 ([ARM] 2971/1: i.MX uart handle rts irq)

Reported-by: Arwed Springer <Arwed.Springer@de.trumpf.com>
Tested-by: Arwed Springer <Arwed.Springer@de.trumpf.com>
Cc: stable@kernel.org # 2.6.14+
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:36:25 -07:00
Jovi Zhang 99edb3d10a tty: remove invalid location line in file header
remove invalid location line in each file header after location
moved from driver/char to driver/tty

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19 16:33:36 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Greg Kroah-Hartman ab4382d274 tty: move drivers/serial/ to drivers/tty/serial/
The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-13 12:10:18 -08:00