Remove usage of temporary buffer when no transmit data is provided.
Instead, use the transmit register itself as the source of data.
By choosing the transmit register itself as the source of data, this
patch helps remove unnecessary accesses to memory when no real data
is being transmitted.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Due to the full duplex nature of the SPI bus, the SPI master
on DaVinci needs transmit to be active even if the tranfer is
only meant to collect receive data.
The current code achieves this by using a temporary zeroed buffer
to provide DMA data in case the transfer does not have a transmit
buffer provided.
However, the transmit DMA is started only if transmit buffer is
provided rendering the temporary buffer unused. Instead the code
relies on a write to SPIDAT1 register to trigger transmit operation.
This however only sends two bytes of data.
Fix this by starting transmit DMA always.
This changes exposes a bug on DM355 where the CSHOLD bit in
SPIDAT1 needs to be written to in between transfers. Handle
that by introducing a "cshold_bug" platform data which is
set to true for DM355.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Do not store DMA channel related information per chip-select since
that information does not depend on the chip select.
The same DMA channels can be used for transfers on all chip-selects
since the transfer happens one-at-a-time.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Remove unnecessary call to davinci_spi_setup_transfer() at the end
of davinci_spi_setup().
davinci_spi_setup_transfer() is registered as the setup_transfer
callback for the bitbang layer and is called independently by
the bitbang layer to setup the transfer before it begins.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The function davinci_spi_bufs_prep() is doing stuff that
davinci_spi_setup() is doing. Eliminate it and move the work
to davinci_spi_setup()
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Configure the data-in, data-out and clock functionality pins
in SPIPC0 register only once during probe. No need to set these
bits for each transfer.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Add support for SPI interrupt mode operation.
Define a per chip-select "io type" variable which
specifies if the transfers on this chip-select should
happen in interrupt mode or polled mode.
Introduce a new function davinci_spi_process_events()
to help consolidate the code between interrupt mode
processing and polled mode processing.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Use the fact that the get_tx and get_rx can now cope with
NULL buffer pointers to simplify the poll mode transfer
code.
While at it, check for SPI errors every transfer rather than
at the end of the whole transfer.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The interrupt mode support as it stands is another version
of poll mode. Even when interrupt mode is selected, the code
tight loops on interrupt status register, rendering it totally
useless. A completion variable is initialized, but never used.
Remove this fake interrupt mode since users can anyway use
poll mode with no functional difference. A usefully implemented
interrupt mode support can be added later.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The completion variable 'done' is unnecessarly initialized by
the function davinci_spi_bufs_dma() where as it is not used
for DMA transfers at all.
Remove the unnecessary initialization.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
In davinci_spi_check_error(), Tx interrupt being set is
treated as error. This function is only meant to flag
bus error conditions and Tx interrupt being set at that
point is not a bus error but rather a driver bug.
Stop checking for Tx interrupt and flagging that as an
IO error.
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The variable count in DaVinci SPI driver's private data is
largely unused and its minor use can easily be eliminated.
Remove the variable.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
In the davinci_spi_bufs_dma() function, SPI is briefly disabled
before enabling it immediately back again.
Remove this unnecessary disable.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
In the davinci_spi_{tx|rx}_u{8|16}() functions, check for
buffer pointer being valid before using it. While providing
for better error checking, this change will help simplify
code in the caller.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The EDMA acount (called data_type in davinci_spi_bufs_dma())
is simply the bytes_per_word obtained in the transfer setup
function. The current code calculates the acount value from
bytes_per_word in a convoluted manner. Simplify the code.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The count member of davinci_spi is internal to the driver and
is not shared with framework. Eliminate its unnecessary update.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The struct davinci_spi_slave has a single member. Eliminate it
and store the per-chipselect data in struct davinci_spi directly.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Several members of struct davinci_spi_slave are unused in code.
Remove such members.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Just enabling WAITENA in SPIFMTn register waits for the
enable signal from the slave indefinitely. Allow support
for finite waiting by adding support for c2e delay
(maximum time for addressed slave to respond) and t2e
delay (maximum time for slave to respond after transmit
data finished).
While at it, modify the T2C and C2T defines by prepending
the register name as is the convention followed for other
register field elsewhere in the driver.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Setup chip-select timers values only if timer is enabled
(timer_disbled in spi configuration is false).
As a nice side effect, this patch removes code duplicated in
davinci_spi_bufs_pio() and davinci_spi_bufs_dma().
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Consolidate the setup of SPIFMTn register under
davinci_spi_setup_transfer() simplifying the code
and avoiding unnecessary reads and writes to the
register.
The two inline functions {set|clear}_fmt_bits() can
be eliminated because of this.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Some chip-select specific paramterers like wdelay, parity, usage of
chip-select timers (and the actual timer values) are included in
platform data forcing the same behaviour across all chip-selects.
Create a new davinci_spi_config data structure which can be passed
along using controller_data member of spi_device data structure
on a per-device basis.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The SPI_READY bit of struct spi_device:mode serves the purpose
of letting the SPI master know if the slave can signal if it is
ready for transfer or not.
The 'wait_enable' platform data was duplicating this functionality.
Use the framework provided method of indicating this capability.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Simplify pre-scalar calculation and move it into a seprate
function.
Refuse to correct invalid pre-scalar values silently as this
might lead to unexpected bugs and lower performance. Instead
an error will force users to dig into the root-cause of the
issue.
While at it, remove some device specific checks on the maximum
SPI frequency. As the driver supports the SPI interface
implemented on various devices, it should only take care of core
SPI limitations and leave the device specific handling to platform
code.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Sometimes, the chip selects provided by SPI module are
muxed with other functionality and cannot be used in
some designs. In such cases, it becomes convenient to use
an available GPIO line as chip select.
This patch enables the DaVinci SPI driver to treat specific
GPIO lines as chip selects based on information provided in
platform data.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
On TI DaVinci's SPI controller, the SPIDAT1 register which
controls the chip slect status, also has data transmit register
in the lower 16 bits. Writing to the whole 32-bits triggers
an additional data transmit every time the chip select is disabled.
While most SPI slaves cope-up with this, some cannot. This
patch fixes this by doing a 16-bit write on the upper half
of the SPIDAT1 register
While at it, group the SPIGCR1 register related defines seperately
from SPIDAT1 register defines.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Let davinci_spi_chipselect() perform both activation and
deactivation of chip selects. This lets spi_bitbang fully
control chip select activation, as intended by the SPI API.
With this change, the chip select activation code need not
be duplicated in davinci_spi_bufs_{pio|dma}().
Also, keeping chip select active control is removed as a
platform data and simply controlled using information from
spi_bitbang on whether chip slect should be activated or
de-activated.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Quit writing the same constant value determining the chip-select
mode when no transmissions are in progress in davinci_spi_chipelect().
Instead just setup the SPIDEF register once during probe.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The typecasting of SPI base address to davinci_spi_reg is
unused.
Remove it.
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Remove unused defines from code which should help
in easy reading of code.
Also, use the opportuinity to keep the SPIGCR1
register defines together.
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The 'pdata' variable is unused in couple of routines.
Remove such occurences.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cleanup unnecessary white space from various
parts of the file.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Fix the following checkpatch error:
WARNING: unnecessary whitespace before a quoted newline
+ dev_info(&pdev->dev, "Controller at 0x%p \n", davinci_spi->base);
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The stradis driver is on its way out, but it should still be marked
correctly as depending on the big kernel lock. It could easily be
changed to not require it if someone decides to revive the driver and
port it to v4l2 in the process.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Sedat Dilek <sedat.dilek@googlemail.com>
Cc: Nathan Laredo <laredo@gnu.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / PM QoS: Fix reversed min and max
PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
PM: Allow devices to be removed during late suspend and early resume
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.
The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.
Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)
Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.
Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] kprobes: Fix the return address of multiple kretprobes
[S390] kprobes: disable interrupts throughout
[S390] ftrace: build without frame pointers on s390
[S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking
[S390] vmlogrdr: purge after recording is switched off
[S390] cio: fix incorrect ccw_device_init_count
[S390] tape: add medium state notifications
[S390] fix get_user_pages_fast
I just loaded 2.6.37-rc2 on my machines, and I noticed that X no longer starts.
Running an strace of the X server shows that it's doing this:
open("/sys/bus/pci/devices/0000:07:00.0/resource0", O_RDWR) = 10
mmap(NULL, 16777216, PROT_READ|PROT_WRITE, MAP_SHARED, 10, 0) = -1 EINVAL (Invalid argument)
This code seems to be asking for a shared read/write mapping of 16MB worth of
BAR0 starting at file offset 0, and letting the kernel assign a starting
address. Unfortunately, this -EINVAL causes X not to start. Looking into
dmesg, there's a complaint like so:
process "Xorg" tried to map 0x01000000 bytes at page 0x00000000 on 0000:07:00.0 BAR 0 (start 0x 96000000, size 0x 1000000)
...with the following code in pci_mmap_fits:
pci_start = (mmap_api == PCI_MMAP_SYSFS) ?
pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
if (start >= pci_start && start < pci_start + size &&
start + nr <= pci_start + size)
It looks like the logic here is set up such that when the mmap call comes via
sysfs, the check in pci_mmap_fits wants vma->vm_pgoff to be between the
resource's start and end address, and the end of the vma to be no farther than
the end. However, the sysfs PCI resource files always start at offset zero,
which means that this test always fails for programs that mmap the sysfs files.
Given the comment in the original commit
3b519e4ea6, I _think_ the old procfs files
require that the file offset be equal to the resource's base address when
mmapping.
I think what we want here is for pci_start to be 0 when mmap_api ==
PCI_MMAP_PROCFS. The following patch makes that change, after which the Matrox
and Mach64 X drivers work again.
Acked-by: Martin Wilck <martin.wilck@ts.fujitsu.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
hwmon: (w83795) Check for BEEP pin availability
hwmon: (w83795) Clear intrusion alarm immediately
hwmon: (w83795) Read the intrusion state properly
hwmon: (w83795) Print the actual temperature channels as sources
hwmon: (w83795) List all usable temperature sources
hwmon: (w83795) Expose fan control method
hwmon: (w83795) Fix fan control mode attributes
hwmon: (lm95241) Check validity of input values
hwmon: Change mail address of Hans J. Koch
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: sysfs: fix printk warnings
PCI: fix pci_bus_alloc_resource() hang, prefer positive decode
PCI: read current power state at enable time
PCI: fix size checks for mmap() on /proc/bus/pci files
x86/PCI: coalesce overlapping host bridge windows
PCI hotplug: ibmphp: Add check to prevent reading beyond mapped area
Make sure I2C adapters being registered have the required struct
fields set. If they don't, problems will happen later.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
It's about time to make it clear that i2c_adapter.id is deprecated.
Hopefully this will remind the last user to move over to a different
strategy.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Drivers don't need to include <linux/i2c-id.h>, especially not when
they don't use anything that header file provides.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Hunold <michael@mihu.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Delete unused I2C adapter IDs. Special cases are:
* I2C_HW_B_RIVA was still set in driver rivafb, however no other
driver is ever looking for this value, so we can safely remove it.
* I2C_HW_B_HDPVR is used in staging driver lirc_zilog, however no
adapter ID is ever set to this value, so the code in question never
runs. As the code additionally expects that I2C_HW_B_HDPVR may not
be defined, we can delete it now and let the lirc_zilog driver
maintainer rewrite this piece of code.
Big thanks for Hans Verkuil for doing all the hard work :)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
A few new i2c-drivers came into the kernel which clear the clientdata-pointer
on exit. This is obsolete meanwhile, so fix it and hope the word will spread.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The fix in commit 6b4e81db25 ("i8k: Tell gcc that *regs gets
clobbered") to work around the gcc miscompiling i8k.c to add "+m
(*regs)" caused register pressure problems and a build failure.
Changing the 'asm' statement to 'asm volatile' instead should prevent
that and works around the gcc bug as well, so we can remove the "+m".
[ Background on the gcc bug: a memory clobber fails to mark the function
the asm resides in as non-pure (aka "__attribute__((const))"), so if
the function does nothing else that triggers the non-pure logic, gcc
will think that that function has no side effects at all. As a result,
callers will be mis-compiled.
Adding the "+m" made gcc see that it's not a pure function, and so
does "asm volatile". The problem was never really the need to mark
"*regs" as changed, since the memory clobber did that part - the
problem was just a bug in the gcc "pure" function analysis - Linus ]
Signed-off-by: Jim Bos <jim876@xs4all.nl>
Acked-by: Jakub Jelinek <jakub@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On the W83795ADG, there's a single pin for BEEP and OVT#, so you
can't have both. Check the configuration and don't create beep
attributes when BEEP pin is not available.
The W83795G has a dedicated BEEP pin so the functionality is always
available there.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
