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: NMarek Roszko <mark.roszko@gmail.com>
Acked-by: NLeilei Zhao <leilei.zhao@atmel.com>
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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

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

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Because the UART lack of receive timeout register, so we use a timer to trigger
data receive.
The DBGU is regarded as UART.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Distinguish usart and uart by read ip name register,
The usart read name is "USAR",
The uart and dbgu read name is "DBGU".
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We will switch to pio mode when request of dma or pdc fail.
But soon or later, when the request is success, the transfer mode can switch to them at
next open serial port action.
So in startup stage, we should get original transfer mode.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Request a cyclic dma channel for rx dma use. Use cyclic transfer is to prevent
receive data overrun.

We allocate a cycle dma cookie after request channel,
after that, enable uart timeout interrupt in startup stage, when data successful
received, the timeout callback will check the residual bytes and insert
receiving datas into the framework during the transfer interval.

When current descriptor finished, the dma callback will also check the residual
bytes and filp the receiving data.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Request a slave dma channel for tx dma use. Tx dma will setup a single transfer,
when transfer complete, it will call atmel_complete_tx_dma to do finish stuff.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

use function pointer can avoid define atmel_use_pdc_tx/rx everywhere.
(*prepare_rx/tx)() is in setup transfer stage.
(*schedule_rx/tx)() is in tasklet schedule stage.
(*release_rx/tx)() is used when shutdown the transfer.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA is available since at91sam9x5 socs, before that, we use PDC.
Signed-off-by: NElen Song <elen.song@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d063
(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: NJingoo Han <jg1.han@samsung.com>
Acked-by: NBarry Song <baohua.song@csr.com>
Acked-by: NTony Prisk <linux@prisktech.co.nz>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit ab78029e (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: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Index of atmel_ports[ATMEL_MAX_UART] should be smaller
than ATMEL_MAX_UART.
Signed-off-by: NPawel Wieczorkiewicz <wpawel@gmail.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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_string this time.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The definitions provided by serial_at91.h are only used by the
atmel_serial driver, and the function that uses it is never called
from anywhere in the kernel.  Therefore, these definitions are unused
and/or obsolete, and can be removed.
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>

Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

On our custom board, we are using RS485 in half-duplex mode on an AT91SAM9G45.
SER_RS485_RX_DURING_TX is not set as we do not want to receive the data we
transmit (our transceiver will receive transmitted data).
Although the current driver attempts to disable and enable the receiver at the
appropriate points, incoming data is still loaded into the receive register
causing our code to receive the very last byte that was sent once the receiver
is enabled.

I ran this by Atmel support and they wrote: "The issue comes from the fact
that you disable the PDC/DMA Reception and not the USART Reception channel. In
your case, the[n] you will still receive data into the USART_RHR register, and
maybe you [h]ave the overrun flag set. So please disable the USART reception
channel."

The following patch should force the driver to enable/disable the receiver via
RXEN/RXDIS fields of the USART control register. It fixed the issue I was
having.
Signed-off-by: NGabe Siftar <gabe.siftar@getingeusa.com>
[nicolas.ferre@atmel.com: slightly modify commit message]
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This variable spread on every SoC that is using the atmel_serial.c
driver can be included directly into the latter.

This will allow to compile multiple soc in the same kernel.
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: kernel@avr32linux.org

Patch to fix a spinlock lockup in the driver that sometimes happens when the
tasklet starts.
Signed-off-by: NClaudio Scordino <claudio@evidence.eu.com>
Signed-off-by: NDave Bender <codehero@gmail.com>
Tested-by: NDave Bender <codehero@gmail.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Current ldisc number is passed as a paramneter -- no need to dig it
out of the tty or ldisc. So switch PPS check to that.

No tty callback can be called with port->line higher than TTY driver
num. So remove the check.

This removes some port.tty users.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Viktar Palstsiuk <viktar.palstsiuk@promwad.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The crisv10.c and the atmel_serial.c serial drivers intepret the fields of the
serial_rs485 structure in a different way.

In particular, crisv10.c uses SER_RS485_RTS_AFTER_SEND and
SER_RS485_RTS_ON_SEND for the voltage of the RTS pin; atmel_serial.c,
instead, uses these values to know if a delay must be set before and
after sending.  This patch makes the usage of these variables consistent
across all drivers and fixes the Documentation as well.

From now on, SER_RS485_RTS_AFTER_SEND and SER_RS485_RTS_ON_SEND will be
used to set the voltage of the RTS pin (as in the crisv10.c driver); the
delay will be understood by looking only at the value of
delay_rts_before_send and delay_rts_after_send.
Signed-off-by: NClaudio Scordino <claudio@evidence.eu.com>
Signed-off-by: NDarron Black <darron@griffin.net>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Auto-enumerate mechanism conflicts with bootconsoles: remove
the usage counter for this type of consoles.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Will use aliases to enumerate ports, if available.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

If no platform data provided to enumerate ports, use a bit field
to choose port number and check if port is already initialized.
Use this mechanism for both console and plain serial ports.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Easier to follow if platform_data name is pdata.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

By default the atmel_serial driver in RS485 mode disables receiving data until
all data in the send buffer has been sent. This flag allows to receive data
even whilst sending data.
Signed-off-by: NBernhard Roth <br@pwrnet.de>
Signed-off-by: NClaudio Scordino <claudio@evidence.eu.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

reflect new static uart platform ids introduced by patch
http://article.gmane.org/gmane.linux.kernel/1126105Signed-off-by: NNikolaus Voss <n.voss@weinmann.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

the atmel_ports is link to the console number and not the device id

this was not detected on at91 as we always register the dbgu on the console
as ttyS0

tested on at91sam9263 by setting the dbgu as ttyS1 and use as console

diff --git a/arch/arm/mach-at91/board-sam9263ek.c b/arch/arm/mach-at91/board-sam9263ek.c
index 70e5646..9b8a14f 100644
- a/arch/arm/mach-at91/board-sam9263ek.c
+ b/arch/arm/mach-at91/board-sam9263ek.c
@@ -58,14 +58,14 @@ static void __init ek_init_early(void)
        /* Initialize processor: 16.367 MHz crystal */
        at91_initialize(16367660);

-       /* DBGU on ttyS0. (Rx & Tx only) */
-       at91_register_uart(0, 0, 0);
+       /* DBGU on ttyS1. (Rx & Tx only) */
+       at91_register_uart(0, 1, 0);

-       /* USART0 on ttyS1. (Rx, Tx, RTS, CTS) */
-       at91_register_uart(AT91SAM9263_ID_US0, 1, ATMEL_UART_CTS | ATMEL_UART_RTS);
+       /* USART0 on ttyS0. (Rx, Tx, RTS, CTS) */
+       at91_register_uart(AT91SAM9263_ID_US0, 0, ATMEL_UART_CTS | ATMEL_UART_RTS);

-       /* set serial console to ttyS0 (ie, DBGU) */
-       at91_set_serial_console(0);
+       /* set serial console to ttyS1 (ie, DBGU) */
+       at91_set_serial_console(1);
 }

 /*
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>

specify the port num via platform_data this will allow to match the clock
with the plaform_dev staticaly
Signed-off-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>

remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: NJovi Zhang <bookjovi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>