In case of TX only with DMA, the driver assumes that the data
has been transferred once DMA callback in invoked. However,
SPI's shift register may still contain data. Thus, the driver
is supposed to verify that the register is empty and the end of
the SPI transfer has been reached.
Signed-off-by: Ilkka Koskinen <ilkka.koskinen@nokia.com>
Tested-by: Tuomas Katila <ext-tuomas.2.katila@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
In the TX_ONLY transfer, the SPI controller also receives data
simultaneously and saves them in the rx register. After the TX_ONLY
transfer, the rx register will hold the random data received during
the last tx transaction.
If the direct following transfer is RX_ONLY, this random data has the
possibility to affect this transfer like this:
When the SPI controller is changed from TX_ONLY to RX_ONLY,
the random data makes the rx register full immediately and
triggers a dummy write automatically(in SPI RX_ONLY transfers,
we need a dummy write to trigger the first transaction).
So the first data received in the RX_ONLY transfer will be that
random data instead of something meaningful.
We can avoid this by inserting a Disable/Re-enable toggle of the
channel after the TX_ONLY transfer, since it purges the rx register.
Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
There may be wakeup sources that aren't associated with any devices
and their statistics information won't be available from sysfs. Also,
for debugging purposes it is convenient to have all of the wakeup
sources statistics available from one place. For these reasons,
introduce new file "wakeup_sources" in debugfs containing those
statistics.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
In this code, 0 is returned on memory allocation failure, even though other
failures return -ENOMEM or other similar values.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression ret;
expression x,e1,e2,e3;
@@
ret = 0
... when != ret = e1
*x = \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
return ret;
}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
To: Pat Gefre <pfg@sgi.com>
Cc: kernel-janitors@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1704/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch reverts the driver to enabling/disabling the NFC interrupt
mask rather than enabling/disabling the system interrupt. This cleans
up the driver so that it doesn't rely on interrupts being disabled
within the interrupt handler.
For i.MX21 we keep the current behaviour, that is calling
enable_irq/disable_irq_nosync to enable/disable interrupts. This patch
is based on earlier work by John Ogness.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: John Ogness <john.ogness@linutronix.de>
Tested-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus/i2c/2636-rc8' of git://git.fluff.org/bjdooks/linux:
i2c-imx: do not allow interruptions when waiting for I2C to complete
i2c-davinci: Fix TX setup for more SoCs
448cd16 ("Input: evdev - rearrange ioctl handling") broke EVIOCSABS by
checking for the wrong direction bit.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-by: Sven Neumann <s.neumann@raumfeld.com>
Tested-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This patch adds UART serial port support for S5P6450 SoC.
The S5P6450 has 6 UARTs, so adds resource of UART4 and UART5.
And to fix membase which is in serial/samsung.c is from Ben Dooks.
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Some systems using this bus sometimes have very basic devices on them
such as regulators. So we need to be loaded even earlier in case the
devices are used by things such as early board init code. Therefore
register in subsys_initcall().
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Currently, if the bits_per_word when doing a transfer is not 8bits, we
always treat it as 16bits when we should actually be returning an error.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
When the hardware is controlling the CS, there are some SPI options
we are unable to support. So issue a warning in the hopes that the
user will change to a SPI mode where we can support things sanely.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Using disable_irq() on the IRQ whose handler we are currently executing in
can easily lead to a hang. So use the nosync variant here.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
While combining things, also switch to the proper SPI bit define names.
This lets us punt the rarely used SPI defines.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
During runtime, the spi setup function may be called multiple times on the
same device in order to reconfigure some settings on the fly. When this
happens, we need to reset the ctl_reg bits so that changing the mode works
as expected.
Reported-by: Andy Getzendanner <james.getzendanner@students.olin.edu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This reduces duplication between the setup/transfer functions and keeps
values cached during setup from overriding values changed on a transfer
basis (like bits_per_word).
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Using disable_irq() on the IRQ whose handler we are currently executing in
can easily lead to a hang. So use the nosync variant here.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Sometimes under load, the Blackfin core is able to send SPI register
updates out before the controller is actually disabled. So when we
go to reprogram the entire state (to switch to a different slave),
make sure we sync after disabling the controller.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We can't rely on the SPI_CTL/SPI_FLG registers retaining their state when
suspending, so save/restore their entire values.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The common SPI layers take care of detecting CS conflicts and preventing
two devices from claiming the same CS. This causes problems for the GPIO
CS support we currently have as we are using CS0 to mean "GPIO CS". But
if we have multiple devices using a GPIO CS, the common SPI layers see
multiple devices using the virtual "CS0" and reject any such attempts.
To make both work, we introduce an offset define. This represents the
max number of hardware CS values that the SPI peripheral supports. If
the CS is below this limit, we know we can use the hardware CS. If it's
above, we treat it as a GPIO CS. This keeps the CS unique as seen by
the common code and prevents conflicts.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The driver that we based ours on uses a little extra memory behind the
normal driver state, but we don't. So drop this useless bit of memory.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The current structure names are a bit confusing as to what they represent,
so use better names.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Rather than having to look up the same 3 sets of functions at the same
time, just use an ops structure so we only need to set one pointer.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
No point in creating our own version of true/false defines when there is
already a standard stdbool available to us.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The chip ops should always be initialized, so having null fallback
functions are useless.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
As David points out, the cs_change_per_word option isn't standard, nor is
anyone actually using it. So punt all of the dead code considering it
makes up ~10% of the code size.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The CS helper functions were toggling both the Flag Enable and the Flag
Value bits, but the Flag Value bit is ignored if the corresponding Flag
Enable bit is cleared. So under high speed transactions, the CS sometimes
would not toggle properly.
Since it makes no sense to toggle the Flag Enable bit dynamically when we
actually want to control the Flag Value, do this when setting up the device
and then only handle toggling of the CS value during runtime.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The current behavior in PIO mode is to poll the SPI status registers which
can obviously lead to higher latencies when doing a lot of SPI traffic.
There is a SPI interrupt which can be used instead to signal individual
completion of transactions.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We should make sure the SPI controller is in a sane state in case the
boot loader left it in a crappy state. Such as DMA pending which causes
interrupts to fire on us.
When setting a sane initial state, do not default to slave mode. If we
do, then the SPI peripheral may implicitly take over the SPISS pin which
other things might be using.
For example, the BF533-STAMP uses this pin as a GPIO to control switching
between ethernet and flash. If the SPI peripheral controls the output
state instead, the ethernet is no longer accessible.
URL: http://blackfin.uclinux.org/gf/tracker/5630
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Anomaly 05000119 states that the DMA_RUN bit with peripherals isn't
reliable. However, the way the driver is currently written (DMA IRQ
callback), we don't need the polling in the first place, so drop it.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Re-order setup() a bit so we don't leak memory/dma/gpio resources upon
errors. Also make sure we don't call kfree() twice on the same object.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The i2c_imx_trx_complete() function is using
wait_event_interruptible_timeout() to wait for the I2C controller to
signal that it has completed an I2C bus operation. If the process that
causes the I2C operation receives a signal, the wait will be
interrupted, returning an error. It is better to let the I2C operation
finished before handling the signal (i.e. returning into userspace).
It is safe to use wait_event_timeout() instead, because the timeout
will allow the process to exit if the I2C bus hangs. It's also better
to allow the I2C operation to finish, because unacknowledged I2C
operations can cause the I2C bus to hang.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This patch is an improvement to 4bba0fd8d1
which got to mainline a little early.
Sudhakar Rajashekhara explains that at least OMAP-L138 requires MDR mode
settings before DXR for correct behaviour, so load MDR first with
STT cleared and later load again with STT set.
Tested on DM355 connected to Techwell TW2836 and Wolfson WM8985
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Acked-by: Troy Kisky <troy.kisky@boundarydevices.com>
Tested-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Fixes cursor corruption in certain cases.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
