This is required in case the interrupt line is shared with other
devices.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
passing argument 2 of 'dma_map_single' discards qualifiers from pointer target type
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
use platform_driver_register instead of platform_driver_probe. The
latter only checks available devices at the time of calling. So if a
device gets inserter at a later point in time then the driver will never
play with it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Add manufacturer name to the Kconfig prompt string and move
the controller name to the begining of the prompt.
This helps locate the driver easily among the list of existing
drivers.
While at it, also add information about being able to build
the driver as module.
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Shorten names of local variables and structure members where
possible.
Local variables:
* 'davinci_spi' is being renamed 'dspi'
* 'davinci_spi_dma' is being renamed 'dma'
Structure members:
* 'dma_{tx|rx}_channel' is being renamed '{tx|rx}_channel'
since the structure containing them is already called
'davinci_spi_dma'
* 'davinci_spi_dma' in 'davinci_spi' structure is being
renamed 'dma'
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Remove unnecesary private data member 'region_size'
being used to store the size of SPI memory region.
Instead, get the memory resource size directly from
the platform data.
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Add copyright for EF Johnson Technologies since the driver
has been majorly overhauled by Brian.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Add comments describing the platform data members
and per-chip-select SPI configuration structure.
Also, add some comments describing the what happens
during the driver 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>
Setup the owner member of the platform driver to THIS_MODULE
instead of leaving it NULL.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Enable SPI only when active transfers are in progress. Keep
it in local low power when not in use.
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 "clk_internal" platform data member which contols the
CLKMOD bit in Global Control Register 1 is not useful
since CLKMOD needs be set to 1 *always* to ensure master
mode operation.
Remove this 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>
Let DMA operation be specified on a per-device basis instead
of selecting it once during probe.
A side effect of this is the need to combine the PIO and DMA buffer
txrx_bufs routine. This is good since they anyway share some common
functionality.
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 DMA code does not use the existing completion variable 'done'
which is being used for interrupt mode transfers. Instead it uses
two different completion variables specific to DMA mode transfers.
Eliminate the usage of new completion variables for DMA mode and
use the existing completion variable.
[nsekhar@ti.com: To make this process easy, eliminate the two
different DMA completion callback functions for tx and rx and
use a single callback function instead]
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 simply clean the DMA channel on a DMA completion
error. Instead, use wcount and rcount members of davinci_spi
to detecion non-completion of DMA and signal EIO to the
application.
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 a dummy param slot linked to itself to take care of the
extra "sync event" that gets sent to EDMA controller after
the last byte has been transferred.
The dummy PaRAM slot that is linked to the actual DMA PaRAM
slot "absorbs" this event and prevents a EDMA CC error to
be asserted.
Without this provision, the EDMA CC error would be asserted
because the channel PaRAM would be empty after the transfer
and EDMA would not know what to make out of the extra sync
event.
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 allocate (and de-allocate) SPI DMA channels during setup
(and cleanup) for each SPI device. Instead, allocate the DMA
channels once duing probe and use them for the life time of
the driver.
This makes sense since there are dedicated DMA channels meant
for SPI use.
This also helps remove the unnecessary DMA "sync_dev" variables
being used to store DMA channel information.
Also, the "use_dma" platform variable is now eliminated since
it is possible to check if the platform supports DMA or not
based upon whether DMA resources can be found or not.
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Tested-By: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Do not stop SPI DMA event generation in either transmit or
receive DMA event call back because the single setting affects
both transmit and receive event generation.
Depending on the order in which the callbacks happen, transmit
or receive events can get unintentionally stalled.
Instead, disable event generation once after both the transmit
and receive DMA completes.
While at it, remove the largely under-used function to set or
clear DMA event generation.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Currently a series of EDMA API calls are being made to setup
various aspects of EDMA PaRAM slots for receive and transmit.
Instead setup the PaRAM using a local structure and write once
to the hardware using edma_write_slot()
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 keeping with the full duplex nature of the SPI bus. Always
start receive DMA along with transmit DMA.
If there is no receive buffer provided with the transfer, use
a temporary buffer to receive the data to be thrown away.
[michael.williamson@criticallink.com: receive DMA size should
be same as transfer length to avoid hang-up when transfer length
is smaller than temporary rx buffer size (rx buffer not provided)]
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 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>
Now that the of_platform_bus_type has been merged with the platform
bus type, a single platform driver can handle both OF and non-OF use
cases. This patch merges the OF support into the platform driver.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
This patch merges the platform driver support into the main body of
xilinx_spi.c in preparation for merging the OF and non-OF support
code.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
The current code has the OF binding modifying the platform_data
pointer which it must not do, and the common code doesn't really need
to use a pdata pointer. This patch eliminates the platform_data
references from the common part of the driver in preparation for
merging the OF and non-OF versions.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6:
spi/pl022: fix erroneous platform data in U300
spi: fixed odd static string conventions in core code
spi/bfin_spi: only request GPIO on first load
spi/bfin_spi: handle error/status changes after data interrupts
spi: enable spi_board_info to be registered after spi_master
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
This patch removes convention of passing a static string as a
parameter to another static string. The convention is intended to
reduce text usage by sharing the common bits of the string, but the
implementation is inherently fragile (a change to one format string
but not the other will nullify any possible advantage), it isn't
necessarily a net win depending on what this compiler does, and it
it reduces code readability.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
[grant.likely@secretlab.ca: removed dev_dbg->dev_err hunk]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The gpiolib code does not allow people to do gpio_request() on a GPIO
once it has already been requested. So make sure we only request the
pin on the first setup of a SPI device. Otherwise, if you attempts to
reconfigure a SPI device on the fly (like change bit sizes), the setup
function incorrectly fails.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The error interrupt on the BF537 SIC cannot be enabled on a
per-peripheral basis. Once the error interrupt is enabled
for one peripheral, it is automatically enabled for all.
So in the Blackfin on-chip SPI driver, we need to clear out
these known errors in the data interrupt once we've successfully
finished processing all of the pending data.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Currently spi_register_board_info() has to be called before its related
spi_master be registered, otherwise these board info will be just ignored.
This patch will remove this order limit, it adds a global spi master list
like the existing global board info listr. Whenever a board info or a
spi_master is registered, the spi master list or board info list
will be scanned, and a new spi device will be created if there is a
master-board info match.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
v2 changes:
from Thierry Reding:
* add "select TEGRA_SYSTEM_DMA" to Kconfig
from Grant Likely:
* add oneline description to header
* inline references to DRIVER_NAME
* inline references to BUSY_TIMEOUT
* open coded bytes_per_word()
* spi_readl/writel -> spi_tegra_readl/writel
* move transfer validation to spi_tegra_transfer
* don't request_mem_region iomem as platform bus does that for us
* __exit -> __devexit
v3 changes:
from Russell King:
* put request_mem_region back int
from Grant Likely:
* remove #undef DEBUG
* add SLINK_ to register bit defines
* remove unused bytes_per_word
* make spi_tegra_readl/writel static linine
* various refactoring for clarity
* mark err if BSY bit is not cleared after 1000 retries
* move spinlock to protect setting of RDY bit
* subsys_initcall -> module_init
v3 changes:
from Grant Likely:
* update spi_tegra to use PTR_ERRless dma API
v4 changes:
from Grant Likely:
* remove empty spi_tegra_cleanup fucntion
* allow device ids of -1
Signed-off-by: Erik Gilling <konkers@android.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Russell King <linux@arm.linux.org.uk>
spi: tegra: cleanups from upstream review
Change-Id: Icecf7e64efcb39de072a15234ba1faa4bad40d25
Signed-off-by: Erik Gilling <konkers@android.com>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits)
arm: remove machine_desc.io_pg_offst and .phys_io
arm: use addruart macro to establish debug mappings
arm: return both physical and virtual addresses from addruart
arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC
ARM: make struct machine_desc definition coherent with its comment
eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free
cpuimx27: fix compile when ULPI is selected
mach-pcm037_eet: fix compile errors
Fixing ethernet driver compilation error for i.MX31 ADS board
cpuimx51: update board support
mx5: add cpuimx51sd module and its baseboard
iomux-mx51: fix GPIO_1_xx 's IOMUX configuration
imx-esdhc: update devices registration
mx51: add resources for SD/MMC on i.MX51
iomux-mx51: fix SD1 and SD2's iomux configuration
clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability
clock-mx51: factorize clk_set_parent and clk_get_rate
eukrea_mbimxsd: add support for DVI displays
cpuimx25 & cpuimx35: fix OTG port registration in host mode
i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
...
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>
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>
This patches a typo in the debug message.
Signed-off-by: Matthias Brugger <mensch0815@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
