Commit graph

94 commits

Author SHA1 Message Date
Cyrille Pitchen a649943522 tty/serial: at91: fix I/O accesses on RHR and THR for AVR32
This patch fixes I/O accesses on the Receiver Holding Register and on the
Transmitter Holding Register. Indeed AVR32 can only perform 32bit I/O
accesses on registers: using 8bit I/O accesses would read or write garbage
data.

Fixes: commit b5199d4681 ("tty/serial: at91: add support to FIFOs")
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:07:22 -07:00
Cyrille Pitchen 5f258b3e3d tty/serial: at91: use 32bit writes into TX FIFO when DMA is enabled
For now this improvement is only used with TX DMA transfers. The data
width must be set properly when configuring the DMA controller. Also
the FIFO configuration must be set to match the DMA transfer data
width:
TXRDYM (Transmitter Ready Mode) and RXRDYM (Receiver Ready Mode) must
be set into the FIFO Mode Register. These values are used by the
USART to trigger the DMA controller. In single data mode they are not
used and should be reset to 0.
So the TXRDYM bits are changed to FOUR_DATA; then USART triggers the
DMA controller when at least 4 data can be written into the TX FIFO
througth the THR. On the other hand the RXRDYM bits are left unchanged
to ONE_DATA.

Atmel eXtended DMA controller allows us to set a different data width
for each part of a scatter-gather transfer. So when calling
dmaengine_slave_config() to configure the TX path, we just need to set
dst_addr_width to the maximum data width. Then DMA writes into THR are
split into up to two parts. The first part carries the first data to
be sent and has a length equal to the greatest multiple of 4 (bytes)
lower than or equal to the total length of the TX DMA transfer. The
second part carries the trailing data (up to 3 bytes). The first part
is written by the DMA into THR using 32 bit accesses, whereas 8bit
accesses are used for the second part.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23 18:00:43 -07:00
Cyrille Pitchen b5199d4681 tty/serial: at91: add support to FIFOs
Depending on the hardware, TX and RX FIFOs may be available. The RX
FIFO can avoid receive overruns, especially when DMA transfers are
not used to read data from the Receive Holding Register. For heavy
system load, The CPU is likely not be able to fetch data fast enough
from the RHR.

In addition, the RX FIFO can supersede the DMA/PDC to control the RTS
line when the Hardware Handshaking mode is enabled. Two thresholds
are to be set for that purpose:
- When the number of data in the RX FIFO crosses and becomes lower
  than or equal to the low threshold, the RTS line is set to low
  level: the remote peer is requested to send data.
- When the number of data in the RX FIFO crosses and becomes greater
  than or equal to the high threshold, the RTS line is set to high
  level: the remote peer should stop sending new data.
- low threshold <= high threshold
Once these two thresholds are set properly, this new feature is
enabled by setting the FIFO RTS Control bit of the FIFO Mode Register.

FIFOs also introduce a new multiple data mode: the USART works either
in multiple data mode or in single data (legacy) mode.

If MODE9 bit is set into the Mode Register or if USMODE is set to
either LIN_MASTER, LIN_SLAVE or LON_MODE, FIFOs operate in single
data mode. Otherwise, they operate in multiple data mode.

In this new multiple data mode, accesses to the Receive Holding
Register or Transmit Holding Register slightly change.

Since this driver implements neither the 9bit data feature (MODE9 bit
set into the Mode Register) nor LIN modes, the USART works in
multiple data mode whenever FIFOs are available and enabled. We also
assume that data are 8bit wide.

In single data mode, 32bit access CAN be used to read a single data
from RHR or write a single data into THR.
However in multiple data mode, a 32bit access to RHR now allows us to
read four consecutive data from RX FIFO. Also a 32bit access to THR
now allows to write four consecutive data into TX FIFO. So we MUST
use 8bit access whenever only one data have to be read/written at a
time.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23 18:00:42 -07:00
Cyrille Pitchen 4e7decdaaa tty/serial: at91: remove bunch of macros to access UART registers
This patch replaces the UART_PUT_*, resp. UART_GET_*, macros by
atmel_uart_writel(), resp. atmel_uart_readl(), inline function calls.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23 18:00:42 -07:00
Nicolas Ferre 8687634b79 tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send
In RS485 mode, we may want to set the delay_rts_after_send value to 0.
In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but
this is exactly the expected behavior if we want no delay...

Moreover, if the value was set to non-zero value by device-tree or earlier
ioctl command, it was impossible to change it back to zero.

Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable@vger.kernel.org  # 3.2+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:49:16 -07:00
Leilei Zhao d033e82db9 tty/serial: at91: handle IRQ status more safely
Handle the changed flag of IRQ status in interruption
instead of handling it in tasklet due to the tasklet
may be scheduled more than once in one interruption.
Otherwise, the changed status may be processed more
than once which will lead to unexpected result. And
seriously, kernel will crash.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06 22:26:58 +02:00
Ludovic Desroches a8d4e01637 tty/serial: at91: maxburst was missing for dma transfers
Maxburst was not set when doing the dma slave configuration. This value
is checked by the recently introduced xdmac. It causes an error when
doing the slave configuration and so prevents from using dma.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12 and later
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-28 14:27:38 +02:00
Greg Kroah-Hartman becba85f0e Merge 4.0-rc3 into tty-testing
This resolves a merge issue in drivers/tty/serial/8250/8250_pci.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-09 07:08:37 +01:00
Leilei Zhao 1e1257860f tty/serial: at91: correct the usage of tasklet
The tasklet may be scheduled and executed after serial port
was shutdown, for example, DMA rx callback will schedule the
tasklet while serial port is shutting down, especially serial
port is sending and receiving data in a higher baud rate and
it's killed by external program. In this case, tasklet_kill
can only clear the current scheduling out, so tasklet should
be disabled to prevent being executed in later scheduling.
Otherwise, the tasklet executed after serial port was shutdown
can lead to kernel crash.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:51:47 +01:00
Leilei Zhao 4d9628a148 tty/serial: at91: set ops in property init each time
The property in device tree will be reading each time when tty is opened,
so the ops of serial port should be set after that instead of setting once
in probe. Otherwise, the ops of serial port is inconsistent with the state
of serial work manner. For example, the atmel serial driver can't work when
switching to PIO mode due to DMA channel is not available.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:51:47 +01:00
Leilei Zhao 4a1e888867 tty/serial: at91: revise the return type of atmel_init_property
The function of atmel_init_property is to set the work manner of
atmel serial ports according to the property in device trees.
If DMA or PDC is not set or something goes wrong in getting property,
the work manner will switch to general PIO mode, thus there will
not be any failure case in this function. It's actually a procedure.
So changing the return type from int to void.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:51:47 +01:00
Leilei Zhao a510880f6e tty/serial: at91: correct buffer size used in DMA
The buffer size set in DMA is inconsistent with its allocation.
So keep them consistent here. The structure atmel_uart_char is
used in PIO mode with its meaning. But here in DMA, all of the
buffer is treated as general char.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:51:47 +01:00
Leilei Zhao 2c27705410 tty/serial: at91: correct check of buf used in DMA
We only use buf of ring In DMA rx function while using buf of xmit
in DMA tx function. So in DMA rx we need definitively to check the
buf of ring which is corresponding to DMA rx function. And use macro
PAGE_ALIGNED to simplify the expression.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:51:47 +01:00
Uwe Kleine-König 722ccf416a serial: atmel: fix error handling when mctrl_gpio_init fails
mctrl_gpio_init at present doesn't return NULL. (It might be used in the
future when no gpios are to be used indicating success.) Properly pass
error returned and also make driver probing fail on error.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07 03:15:03 +01:00
Boris BREZILLON 2c7af5ba65 tty: serial: atmel: rework interrupt and wakeup handling
The IRQ line connected to the DBGU UART is often shared with a timer device
which request the IRQ with IRQF_NO_SUSPEND.

Since the UART driver is correctly disabling IRQs when entering suspend
we can safely request the IRQ with IRQF_COND_SUSPEND so that irq core
will not complain about mixing IRQF_NO_SUSPEND and !IRQF_NO_SUSPEND.

Rework the interrupt handler to wake the system up when an interrupt
happens on the DEBUG_UART while the system is suspended.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-06 00:46:44 +01:00
Cyrille Pitchen 1842dc2e29 tty/serial: at91: fix typo and indentation
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:20:49 -08:00
Cyrille Pitchen 1cf6e8fc83 tty/serial: at91: fix RTS line management when hardware handshake is enabled
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: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:20:49 -08:00
Cyrille Pitchen 6fbb9bdf0f tty/serial: at91: fix error handling in atmel_serial_probe()
-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: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:20:49 -08:00
Cyrille Pitchen d4f641876a tty/serial: at91: enable peripheral clock before accessing I/O registers
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: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:20:49 -08:00
Cyrille Pitchen 485819b5b9 tty/serial: at91: use correct type for dma_sync_*_for_cpu() and dma_sync_*_for_device()
dma_sync_*_for_cpu() and dma_sync_*_for_device() use 'enum dma_data_direction',
not 'enum dma_transfer_direction'

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 14:20:49 -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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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
Ricardo Ribalda Delgado bd737f8738 tty/serial_core: Introduce lock mechanism for RS485
Introduce an homogeneous lock system between setting and using the rs485
data of the uart_port.

This patch should not be split into multiple ones in order to avoid
leaving the tree in an unstable state.

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Suggested-by: Alan Cox <alan@linux.intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 15:00:44 -08:00
Ricardo Ribalda Delgado 13bd3e6fa1 serial/atmel: Use the rs485 functions on serial_core
In order to unify all the rs485 ioctl handling.
Use the implementation of TIOC[GS]RS485 ioctl handling on serial_core.

Reviewed-by: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:59:22 -08:00
Peter Hurley cab68f8954 serial: Test/disable MSIs if switching from N_PPS
Switching to the N_PPS line discipline may require enabling
modem status interrupts; conversely switching from N_PPS may
require disabling modem status interrupts.

Affected drivers:
8250
amba-pl010
atmel

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:27 -08:00
Peter Hurley d41510ce2f serial: Take uart port lock for direct *_enable_ms()
Three UART drivers (8250, atmel & amba-pl010) directly call their
enable_ms() method; the uart port lock must be acquired before
any h/w programming.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:27 -08:00
Peter Hurley 732a84a037 serial: core: Pass termios to set_ldisc() notifications
UART drivers which enable modem status interrupts when switching
to N_PPS line discipline need to determine if modem status
interrupts should be disabled when switching from N_PPS.
Specifically, the set_ldisc() notification needs to evaluate
UART_ENABLE_MS() which requires termios->c_cflag.

Convert in-tree UART drivers to new interface.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:27 -08:00
Maxime Ripard 5483c10e03 serial: at91: Use dmaengine_slave_config API
We are removing the dmaengine_device_control API, that shouldn't even have been
exposed in the first place. Change the callers to use the proper API.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:25 -08:00
Cyrille Pitchen 66f37aafd6 tty/serial: at91: fix rx ring buffer management
This patch swaps the use "tail" and "head" to fit the semantic of the linux
circular buffer documentation:
- head: the point at which the producer (the DMA controller) inserts items.
- tail: the point at which the consumer (the serial framework) finds the next
        item.

Besides the former code of the rx ring buffer didn't manage the case where
head < tail, which might lead to loss of data. To fix this bug the data are now
sent from the DMA buffer to the serial framework in two steps:
1 - First, we test if head < tail. If so, we copy the data from tail to the end
    of the DMA buffer then reset tail to zero.
2 - Finally, we copy data from tail to head then set tail to head.

In addition, since tty_insert_flip_string() may now be called twice,
atmel_flip_buffer_rx_dma() becomes less efficient than moving the calls
dma_sync_sg_for_cpu(), dma_sync_sg_for_device(), tty_insert_flip_string() and
tty_flip_buffer_push() directly into atmel_rx_from_dma().

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 14:57:18 -08:00
Peter Hurley 479e9b94fd serial: Refactor uart_flush_buffer() from uart_close()
In the context of the final tty & port close, flushing the tx
ring buffer after the hardware has already been shutdown and
the ring buffer freed is neither required nor desirable.

uart_flush_buffer() performs 3 operations:
1. Resets tx ring buffer indices, but the tx ring buffer has
   already been freed and the indices are reset if the port is
   re-opened.
2. Calls uart driver's flush_buffer() method
   5 in-tree uart drivers define flush_buffer() methods:
     amba-pl011, atmel-serial, imx, serial-tegra, timbuart
   These have been refactored into the shutdown() method, if
   required.
3. Kicks the ldisc for more writing, but this is undesirable.
   The file handle is being released; any waiting writer will
   will be kicked out by tty_release() with a warning. Further,
   the N_TTY ldisc may generate SIGIO for a file handle which
   is no longer valid.

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 18:53:54 -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
Linus Torvalds 52d589a01d Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine updates from Vinod Koul:
 "For dmaengine contributions we have:
   - designware cleanup by Andy
   - my series moving device_control users to dmanegine_xxx APIs for
     later removal of device_control API
   - minor fixes spread over drivers mainly mv_xor, pl330, mmp, imx-sdma
     etc"

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (60 commits)
  serial: atmel: add missing dmaengine header
  dmaengine: remove FSLDMA_EXTERNAL_START
  dmaengine: freescale: remove FSLDMA_EXTERNAL_START control method
  carma-fpga: move to fsl_dma_external_start()
  carma-fpga: use dmaengine_xxx() API
  dmaengine: freescale: add and export fsl_dma_external_start()
  dmaengine: add dmaengine_prep_dma_sg() helper
  video: mx3fb: use dmaengine_terminate_all() API
  serial: sh-sci: use dmaengine_terminate_all() API
  net: ks8842: use dmaengine_terminate_all() API
  mtd: sh_flctl: use dmaengine_terminate_all() API
  mtd: fsmc_nand: use dmaengine_terminate_all() API
  V4L2: mx3_camer: use dmaengine_pause() API
  dmaengine: coh901318: use dmaengine_terminate_all() API
  pata_arasan_cf: use dmaengine_terminate_all() API
  dmaengine: edma: check for echan->edesc => NULL in edma_dma_pause()
  dmaengine: dw: export probe()/remove() and Co to users
  dmaengine: dw: enable and disable controller when needed
  dmaengine: dw: always export dw_dma_{en,dis}able
  dmaengine: dw: introduce dw_dma_on() helper
  ...
2014-10-18 18:11:04 -07:00
Vinod Koul 6b997bab20 serial: atmel: add missing dmaengine header
The atmel serial driver uses dmaengine APIs but never included the dmaengine
header as it was getting inculded thru one of driver headers.

commit 3d588f83e4 - "dmaengine: dw: split
dma-dw.h to platform and private parts" broke this as it moved headers
around.  Fix this by doing the right thing to include the dmaengine header

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 08f738be88 (serial: at91: add tx dma support)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-16 14:08:05 +05:30
Richard Genoud 35b675b910 tty/serial: at91: BUG: disable interrupts when !UART_ENABLE_MS()
In set_termios(), interrupts where not disabled if UART_ENABLE_MS() was
false.

Tested on at91sam9g35.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # >= 3.16
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08 16:33:56 -07:00
Wolfram Sang 48479148a2 drivers/tty/serial: use correct type for dma_map/unmap
dma_{un}map_* uses 'enum dma_data_direction' not 'enum dma_transfer_direction'.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-22 16:34:33 -07:00
Peter Hurley ef8b9ddcb4 serial: Fix IGNBRK handling
If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19 13:04:52 -07:00
Richard Genoud ab5e4e4108 tty/serial: at91: add interrupts for modem control lines
Handle CTS/DSR/RI/DCD GPIO interrupts in atmel_serial.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:51:18 -07:00
Richard Genoud e0b0baadb7 tty/serial: at91: use mctrl_gpio helpers
On sam9x5, dedicated CTS (and RTS) pins are unusable together with the
LCDC, the EMAC, or the MMC because they share the same line.

Moreover, the USART controller doesn't handle DTR/DSR/DCD/RI signals,
so we have to control them via GPIO.

This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
signals.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:49:44 -07:00
Linus Torvalds dfc25e4503 ARM: SoC: cleanups for 3.15
These cleanup patches are mainly move stuff around and should all
 be harmless. They are mainly split out so that other branches can
 be based on top to avoid conflicts.
 
 Notable changes are:
 
 * We finally remove all mach/timex.h, after CLOCK_TICK_RATE is no
   longer used. (Uwe Kleine-König)
 * The Qualcomm MSM platform is split out into legacy mach-msm and
   new-style mach-qcom, to allow easier maintainance of the new
   hardware support without regressions. (Kumar Gala)
 * A rework of some of the Kconfig logic to simplify multiplatform
   support (Rob Herring)
 * Samsung Exynos gets closer to supporting multiplatform (Sachin
   Kamat and others)
 * mach-bcm3528 gets merged into mach-bcm (Stephen Warren)
 * at91 gains some common clock framework support (Alexandre Belloni,
   Jean-Jacques Hiblot and other French people).
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Merge tag 'cleanup-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC cleanups from Arnd Bergmann:
 "These cleanup patches are mainly move stuff around and should all be
  harmless.  They are mainly split out so that other branches can be
  based on top to avoid conflicts.

  Notable changes are:

   - We finally remove all mach/timex.h, after CLOCK_TICK_RATE is no
     longer used (Uwe Kleine-König)
   - The Qualcomm MSM platform is split out into legacy mach-msm and
     new-style mach-qcom, to allow easier maintainance of the new
     hardware support without regressions (Kumar Gala)
   - A rework of some of the Kconfig logic to simplify multiplatform
     support (Rob Herring)
   - Samsung Exynos gets closer to supporting multiplatform (Sachin
     Kamat and others)
   - mach-bcm3528 gets merged into mach-bcm (Stephen Warren)
   - at91 gains some common clock framework support (Alexandre Belloni,
     Jean-Jacques Hiblot and other French people)"

* tag 'cleanup-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (89 commits)
  ARM: hisi: select HAVE_ARM_SCU only for SMP
  ARM: efm32: allow uncompress debug output
  ARM: prima2: build reset code standalone
  ARM: at91: add PWM clock
  ARM: at91: move sam9261 SoC to common clk
  ARM: at91: prepare common clk transition for sam9261 SoC
  ARM: at91: updated the at91_dt_defconfig with support for the ADS7846
  ARM: at91: dt: sam9261: Device Tree support for the at91sam9261ek
  ARM: at91: dt: defconfig: Added the sam9261 to the list of DT-enabled SOCs
  ARM: at91: dt: Add at91sam9261 dt SoC support
  ARM: at91: switch sam9rl to common clock framework
  ARM: at91/dt: define main clk frequency of at91sam9rlek
  ARM: at91/dt: define at91sam9rl clocks
  ARM: at91: prepare common clk transition for sam9rl SoCs
  ARM: at91: prepare sam9 dt boards transition to common clk
  ARM: at91: dt: sam9rl: Device Tree for the at91sam9rlek
  ARM: at91/defconfig: Add the sam9rl to the list of DT-enabled SOCs
  ARM: at91: Add at91sam9rl DT SoC support
  ARM: at91: prepare at91sam9rl DT transition
  ARM: at91/defconfig: refresh at91sam9260_9g20_defconfig
  ...
2014-04-05 13:51:19 -07:00
Richard Genoud a3c1fa99f4 tty/serial: at91: remove unused open/close hooks
commit 95e629b761 removed the use of board
specific hooks in serial_at91.h, so now, the open/close hook are just
dead code.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:38:39 -08:00
Richard Genoud ddaa603739 tty/serial: at91: use dev_err instead of printk
For better consistency.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:38:39 -08:00
Olof Johansson 11d73c56b9 This cleanup series gets rid of <mach/timex.h> for platforms not using
ARCH_MULTIPLATFORM. (For multi-platform code it's already unused since
 387798b (ARM: initial multiplatform support).)
 
 To make this work some code out of arch/arm needed to be adapted. The
 respective changes got acks by their maintainers to be taken via armsoc
 (with Andrew Morton substituting for Alessandro Zummo as rtc maintainer).
 
 Compared to the previous pull request there was another patch added that
 fixes a (non-critical) regression on ixp4xx. Olof Johansson asked to not
 squash this fix into the original commit to save him from the need to
 reverify the series.
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Merge tag 'dropmachtimexh-v2' of git://git.pengutronix.de/git/ukl/linux into next/cleanup

This cleanup series gets rid of <mach/timex.h> for platforms not using
ARCH_MULTIPLATFORM. (For multi-platform code it's already unused since
387798b (ARM: initial multiplatform support).)

To make this work some code out of arch/arm needed to be adapted. The
respective changes got acks by their maintainers to be taken via armsoc
(with Andrew Morton substituting for Alessandro Zummo as rtc maintainer).

Compared to the previous pull request there was another patch added that
fixes a (non-critical) regression on ixp4xx. Olof Johansson asked to not
squash this fix into the original commit to save him from the need to
reverify the series.

* tag 'dropmachtimexh-v2' of git://git.pengutronix.de/git/ukl/linux:
  ARM: ixp4xx: fix timer latch calculation
  ARM: drop <mach/timex.h> for !ARCH_MULTIPLATFORM, too
  ARM: rpc: stop using <mach/timex.h>
  ARM: ixp4xx: stop using <mach/timex.h>
  input: ixp4xx-beeper: don't use symbols from <mach/timex.h>
  ARM: at91: don't use <mach/timex.h>
  ARM: ep93xx: stop using mach/timex.h
  ARM: mmp: stop using mach/timex.h
  ARM: netx: stop using mach/timex.h
  ARM: sa1100: stop using mach/timex.h
  clocksource: sirf/marco+prima2: drop usage of CLOCK_TICK_RATE
  rtc: pxa: drop unused #define TIMER_FREQ
  rtc: at91sam9: include <mach/hardware.h> explicitly
  ARM/serial: at91: switch atmel serial to use gpiolib

Signed-off-by: Olof Johansson <olof@lixom.net>
2014-02-18 22:19:33 -08:00
Nicolas Ferre c972d806fd tty/serial: atmel_serial: remove dev_dbg in atmel_set_termios
This fixes a driver bug which stopped the whole system (in case
of serial console).
This log message is not useful anyway as this information is
printed elsewhere.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:48 -08:00
Marek Roszko 8bc661bfc0 tty/serial: at91: disable uart timer at start of shutdown
The uart timer will schedule a tasklet when it fires. It is possible that it
can fire inside _shutdown before it is killed in the dma and pdc cleanup
routines. This causes a tasklet that exists after the port is shutdown, so when
the kernel finally executes it, it panics as the tty port is NULL.

This is a somewhat rare condition but its possible if a program keeps on
opening/closing the port. It has been observed in particular with systemd
boot messages that were causing a kernel panic because of this behavior.

Moving the timer deletion to the beginning of the function stops a tasklet from
being scheduled unexpectedly.

Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Cc: stable <stable@vger.kernel.org> # v3.12
[nicolas.ferre@atmel.com: modify commit message, call setup_timer() in any case]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13 15:55:59 -08:00
Mark Deneen bb7e73c598 tty/serial: at91: reset rx_ring when port is shutdown
When using RX DMA, the driver won't pass any data to the uart layer
until the buffer is flipped. When the port is shutdown, the dma buffers
are unmapped, but the head and tail of the ring buffer are not reseted.
Since the serial console will keep the port open, this will only
present itself when the uart is not shared.

To reproduce the issue, with an unpatched driver, run a getty on /dev/ttyS0
with no serial console and exit. Getty will exit, and when the new one returns
you will be unable to log in.  If you hold down a key long enough to fill the
DMA buffer and flip it, you can then log in.

Signed-off-by: Mark Deneen <mdeneen@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
[nicolas.ferre@atmel.com: adapt to mainline kernel, handle !DMA case]
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07 17:11:48 -08:00
Marek Roszko f50c995f9e tty/serial: at91: fix race condition in atmel_serial_remove
The _remove callback could be called when a tasklet is scheduled. tasklet_kill
was called inside the function in order to free up any scheduled tasklets.
However it was called after uart_remove_one_port which destroys tty references
needed in the port for atmel_tasklet_func.
Simply putting the tasklet_kill at the start of the function will prevent this
conflict.

Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07 17:10:24 -08:00
Marek Roszko 0cc7c6c791 tty/serial: at91: Handle shutdown more safely
Interrupts were being cleaned up late in the shutdown handler, it is possible
that an interrupt can occur and schedule a tasklet that runs after the port is
cleaned up. There is a null dereference due to this race condition with the
following stacktrace:

[<c02092b0>] (atmel_tasklet_func+0x514/0x814) from [<c001fd34>] (tasklet_action+0x70/0xa8)
[<c001fd34>] (tasklet_action+0x70/0xa8) from [<c001f60c>] (__do_softirq+0x90/0x144)
[<c001f60c>] (__do_softirq+0x90/0x144) from [<c001fa18>] (irq_exit+0x40/0x4c)
[<c001fa18>] (irq_exit+0x40/0x4c) from [<c000e298>] (handle_IRQ+0x64/0x84)
[<c000e298>] (handle_IRQ+0x64/0x84) from [<c000d6c0>] (__irq_svc+0x40/0x50)
[<c000d6c0>] (__irq_svc+0x40/0x50) from [<c0208060>] (atmel_rx_dma_release+0x88/0xb8)
[<c0208060>] (atmel_rx_dma_release+0x88/0xb8) from [<c0209740>] (atmel_shutdown+0x104/0x160)
[<c0209740>] (atmel_shutdown+0x104/0x160) from [<c0205e8c>] (uart_port_shutdown+0x2c/0x38)

Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07 17:10:24 -08:00
Linus Walleij 354e57f3a0 ARM/serial: at91: switch atmel serial to use gpiolib
This passes the errata fix using a GPIO to control the RTS pin
on one of the AT91 chips to use gpiolib instead of the
AT91-specific interfaces. Also remove the reliance on
compile-time #defines and the cpu_* check and rely on the
platform passing down the proper GPIO pin through platform
data.

This is a prerequisite for getting rid of the local GPIO
implementation in the AT91 platform and move toward
multiplatform.

The patch also adds device tree support for getting the
RTS GPIO pin from the device tree on DT boot paths.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2013-12-20 11:41:30 +01:00
Nicolas Ferre 731d9cae02 tty/serial: at91: add a fallback option to determine uart/usart property
On older SoC, the "name" field is not filled in the register map.
Fix the way to figure out if the serial port is an uart or an usart for these
older products (with corresponding properties).

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:31:19 -07:00
Nicolas Ferre 892db58bd1 tty/serial: at91: fix uart/usart selection for older products
Since commit 055560b04a (serial: at91:
distinguish usart and uart) the older products which do not have a
name field in their register map are unable to use their serial output.
As the main console output is usually the serial interface (aka DBGU) it
is pretty unfortunate.
So, instead of failing during probe() we just silently configure the serial
peripheral as an uart. It allows us to use these serial outputs.
The proper solution is proposed in another patch.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-17 13:30:14 -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