Commit Graph

748 Commits

Author SHA1 Message Date
Sekhar Nori 23ce17adb7 spi: davinci: kconfig: add manufacturer name to prompt string
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>
2010-11-18 18:38:38 +05:30
Sekhar Nori 212d4b6965 spi: davinci: shorten variable names
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>
2010-11-18 18:38:38 +05:30
Sekhar Nori 0e0eae4d1c spi: davinci: remove unnecessary private data member 'region_size'
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>
2010-11-18 18:38:37 +05:30
Brian Niebuhr 43abb11ba5 spi: davinci: add EF Johnson Technologies copyright
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>
2010-11-18 18:38:37 +05:30
Brian Niebuhr 035540f6ea spi: davinci: add additional comments
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>
2010-11-18 18:38:37 +05:30
Brian Niebuhr d8c174cdeb spi: davinci: setup the driver owner
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>
2010-11-18 18:38:37 +05:30
Brian Niebuhr 3f27b57c16 spi: davinci: enable and power-up SPI only when required
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>
2010-11-18 18:38:36 +05:30
Brian Niebuhr 3409e408ab spi: davinci: remove non-useful "clk_internal" platform data
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>
2010-11-18 18:38:36 +05:30
Brian Niebuhr 87467bd905 spi: davinci: let DMA operation be specified on per-device basis
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>
2010-11-18 18:38:36 +05:30
Brian Niebuhr 6dbd29b27b spi: davinci: remove usage of additional completion variables for DMA
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>
2010-11-18 18:38:35 +05:30
Brian Niebuhr 9b189fd758 spi: davinci: handle DMA completion errors correctly
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>
2010-11-18 18:38:35 +05:30
Brian Niebuhr 523c37e700 spi: davinci: fix EDMA CC errors at end of transfers
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>
2010-11-18 18:38:35 +05:30
Sekhar Nori 903ca25b21 spi: davinci: do not allocate DMA channels during SPI device setup
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>
2010-11-18 18:38:34 +05:30
Brian Niebuhr a4f4497b86 spi: davinci: fix DMA event generation stoppage
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>
2010-11-18 18:38:34 +05:30
Brian Niebuhr 49fc3f497d spi: davinci: use edma_write_slot() to setup EDMA PaRAM slot
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>
2010-11-18 18:38:34 +05:30
Brian Niebuhr e91c659bbc spi: davinci: always start receive DMA
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>
2010-11-18 18:38:34 +05:30
Brian Niebuhr d3f7141cbf spi: davinci: do not use temporary buffer if no transmit data provided
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>
2010-11-18 18:38:33 +05:30
Brian Niebuhr c29e3c60e7 spi: davinci: always start transmit DMA
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>
2010-11-18 18:38:33 +05:30
Brian Niebuhr 96fd881f22 spi: davinci: do not store DMA channel information per chip select
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>
2010-11-18 18:38:33 +05:30
Brian Niebuhr b23a5d4691 spi: davinci: remove unnecessary call to davinci_spi_setup_transfer()
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>
2010-11-18 18:38:33 +05:30
Brian Niebuhr be88471b96 spi: davinci: remove unnecessary function davinci_spi_bufs_prep()
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>
2010-11-18 18:38:32 +05:30
Brian Niebuhr f34bd4cc68 spi: davinci: configure the invariable bits in spipc0 only once
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>
2010-11-18 18:38:31 +05:30
Brian Niebuhr e0d205e991 spi: davinci: add support for interrupt mode
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>
2010-11-18 18:38:30 +05:30
Brian Niebuhr 839c996ca8 spi: davinci: simplify poll mode transfers
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>
2010-11-18 18:38:30 +05:30
Brian Niebuhr cf90fe7350 spi: davinci: remove non-useful interrupt mode support
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>
2010-11-18 18:38:29 +05:30
Brian Niebuhr 47f44671c0 spi: davinci: remove unnecessary completion variable initialization
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>
2010-11-18 18:38:29 +05:30
Sekhar Nori 134e32b979 spi: davinci: do not treat Tx interrupt being set as error
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>
2010-11-18 18:38:29 +05:30
Brian Niebuhr f2bf4e8493 spi: davinci: remove unnecessary 'count' variable in driver private data
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>
2010-11-18 18:38:29 +05:30
Brian Niebuhr fab89ea330 spi: davinci: remove unnecessary disable of SPI
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>
2010-11-18 18:38:28 +05:30
Brian Niebuhr 53d454a170 spi: davinci: check for NULL buffer pointer before using it
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>
2010-11-18 18:38:28 +05:30
Brian Niebuhr b7ab24a0da spi: davinci: simplify calculation of edma acount value
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>
2010-11-18 18:38:28 +05:30
Brian Niebuhr 6321be60ed spi: davinci: eliminate unnecessary update of davinci_spi->count
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>
2010-11-18 18:38:27 +05:30
Brian Niebuhr cda987ebb8 spi: davinci: eliminate the single member structure davinci_spi_slave
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>
2010-11-18 18:38:27 +05:30
Brian Niebuhr b6c4eeac5b spi: davinci: remove unused members of davinci_spi_slave
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>
2010-11-18 18:38:27 +05:30
Brian Niebuhr 7abbf23c59 spi: davinci: add support for wait enable timeouts
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>
2010-11-18 18:38:27 +05:30
Brian Niebuhr fd764463fe spi: davinci: setup chip-select timers values only if timer enabled
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>
2010-11-18 18:38:26 +05:30
Brian Niebuhr 25f33512f6 spi: davinci: consolidate setup of SPIFMTn in one function
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>
2010-11-18 18:38:26 +05:30
Brian Niebuhr 53a31b07c5 spi: davinci: make chip-slect specific parameters really chip-select specific
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>
2010-11-18 18:38:26 +05:30
Brian Niebuhr 472880c73d spi: davinci: remove 'wait_enable' platform data member
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>
2010-11-18 18:38:25 +05:30
Brian Niebuhr 7fe0092b1f spi: davinci: simplify prescalar calculation
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>
2010-11-18 18:38:25 +05:30
Brian Niebuhr 23853973d9 spi: davinci: enable GPIO lines to be used as chip selects
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>
2010-11-18 18:38:25 +05:30
Brian Niebuhr cfbc5d1d8f spi: davinci: remove unnecessary data transmit on CS disable
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>
2010-11-18 18:38:24 +05:30
Brian Niebuhr 7978b8c385 spi: davinci: enable both activation and deactivation of chip-selects
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>
2010-11-18 18:38:24 +05:30
Brian Niebuhr 843a713bc5 spi: davinci: set chip-select mode in SPIDEF only once
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>
2010-11-18 18:38:24 +05:30
Sekhar Nori 50356dd7c1 spi: davinci: remove unnecessary typecast
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>
2010-11-18 18:38:24 +05:30
Sekhar Nori 8e206f1cbd spi: davinci: removed unused #defines
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>
2010-11-18 18:38:23 +05:30
Brian Niebuhr c3c475c235 spi: davinci: remove unused variable 'pdata'
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>
2010-11-18 18:38:23 +05:30
Brian Niebuhr 778e261ed6 spi: davinci: whitespace cleanup
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>
2010-11-18 18:38:23 +05:30
Brian Niebuhr 3b740b10e9 spi: davinci: fix checkpatch errors
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>
2010-11-18 18:38:23 +05:30
Joe Perches bc3f67a3e1 drivers/spi: Remove unnecessary semicolons
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-11-14 20:57:20 -07:00
Grant Likely eae6cb31d8 spi/xilinx: merge OF support code into main driver
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>
2010-11-09 21:41:28 -07:00
Grant Likely 8fd8821b62 spi/xilinx: fold platform_driver support into main body
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>
2010-11-09 21:41:27 -07:00
Grant Likely 91565c4068 spi/xilinx: Eliminate pdata references from common code.
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>
2010-11-09 21:41:27 -07:00
Uwe Kleine-König b595076a18 tree-wide: fix comment/printk typos
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Linus Torvalds 90ae83f7fc Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6
* '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
2010-11-01 07:50:43 -04:00
Linus Torvalds b18cae4224 Merge branch 'for-next' of git://android.git.kernel.org/kernel/tegra
* 'for-next' of git://android.git.kernel.org/kernel/tegra:
  spi: tegra: fix error setting on timeout
  spi: add spi_tegra driver
  tegra: harmony: enable PCI Express
  tegra: add PCI Express support
  tegra: add PCI Express clocks
  [ARM] tegra: Add APB DMA support
  [ARM] tegra: Add cpufreq support
  [ARM] tegra: common: Update common clock init table
  [ARM] tegra: clock: Add dvfs support, bug fixes, and cleanups
  [ARM] tegra: Add support for reading fuses
  [ARM] tegra: gpio: Add suspend and wake support
  [ARM] tegra: pinmux: add safe values, move tegra2, add suspend
  [ARM] tegra: add suspend and mirror irqs to legacy controller
  [ARM] tegra: Add legacy irq support
  [ARM] tegra: update iomap
2010-10-25 18:42:06 -07:00
Erik Gilling f41649e040 spi: tegra: fix error setting on timeout
avoids derefencing an uninitialized pointer

Change-Id: Icf528441ae481e9f6f5ddc0be32c7c217fa49701
Signed-off-by: Erik Gilling <konkers@android.com>
2010-10-25 16:57:46 -07:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* '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
2010-10-22 10:52:56 -07:00
Linus Walleij eb288a1f45 spi: fixed odd static string conventions in core code
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>
2010-10-22 09:51:05 -06:00
Michael Hennerich 73e1ac1625 spi/bfin_spi: only request GPIO on first load
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>
2010-10-22 01:26:46 -06:00
Michael Hennerich 782a895693 spi/bfin_spi: handle error/status changes after data interrupts
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>
2010-10-22 01:26:46 -06:00
Feng Tang 2b9603a0d7 spi: enable spi_board_info to be registered after spi_master
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>
2010-10-21 23:52:16 -06:00
Erik Gilling 0c03a1dd5b spi: add spi_tegra driver
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>
2010-10-21 18:15:05 -07:00
Linus Torvalds b5153163ed Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* '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
  ...
2010-10-21 16:42:32 -07:00
Ilkka Koskinen 2764c500be spi/omap2_mcspi: Verify TX reg is empty after TX only xfer with DMA
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>
2010-10-20 10:43:24 -06:00
Jason Wang e1993ed642 spi/omap2_mcspi: disable channel after TX_ONLY transfer in PIO mode
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>
2010-10-20 10:30:53 -06:00
Grant Likely db181a8ee1 Merge branch 'for-spi' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin into spi/next 2010-10-18 09:25:09 -06:00
Mike Frysinger 9c0a788b43 spi/bfin_spi: namespace local structs
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:44 -04:00
Michael Hennerich 6f7c17f4f9 spi/bfin_spi: init early
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>
2010-10-18 02:49:44 -04:00
Bob Liu 2e768659df spi/bfin_spi: check per-transfer bits_per_word
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>
2010-10-18 02:49:43 -04:00
Barry Song 4190f6a51f spi/bfin_spi: warn when CS is driven by hardware (CPHA=0)
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>
2010-10-18 02:49:43 -04:00
Rob Maris e72dcde72c spi/bfin_spi: cs should be always low when a new transfer begins
Signed-off-by: Rob Maris <maris.rob@vdi.de>
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:42 -04:00
Rob Maris e35954053c spi/bfin_spi: fix typo in comment
Signed-off-by: Rob Maris <maris.rob@vdi.de>
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:41 -04:00
Mike Frysinger 7715aad4ef spi/bfin_spi: reject unsupported SPI modes
Who knows what people will try!

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:41 -04:00
Barry Song a75bd65b21 spi/bfin_spi: use dma_disable_irq_nosync() in irq handler
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>
2010-10-18 02:49:40 -04:00
Mike Frysinger 5e8592dca3 spi/bfin_spi: combine duplicate SPI_CTL read/write logic
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>
2010-10-18 02:49:39 -04:00
Mike Frysinger 5b47bcd48b spi/bfin_spi: reset ctl_reg bits when setup is run again on a device
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>
2010-10-18 02:49:39 -04:00
Mike Frysinger 033f44bd0e spi/bfin_spi: push all size checks into the transfer function
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>
2010-10-18 02:49:38 -04:00
Yi Li 7370ed6b91 spi/bfin_spi: use nosync when disabling the IRQ from the IRQ handler
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>
2010-10-18 02:49:38 -04:00
Barry Song 9677b0de10 spi/bfin_spi: sync hardware state before reprogramming everything
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>
2010-10-18 02:49:37 -04:00
Barry Song b052fd0a44 spi/bfin_spi: save/restore state when suspending/resuming
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>
2010-10-18 02:49:37 -04:00
Barry Song d3cc71f71a spi/bfin_spi: redo GPIO CS handling
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>
2010-10-18 02:49:36 -04:00
Mike Frysinger 90008a641d spi/bfin_spi: use the SPI namespaced bit names
This lets us push the short SPI MMR bit names out of the global namespace.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:35 -04:00
Mike Frysinger 2a045131db spi/bfin_spi: drop extra memory we don't need
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>
2010-10-18 02:49:34 -04:00
Mike Frysinger b9f139a7a6 spi/bfin_spi: convert struct names to something more logical
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>
2010-10-18 02:49:34 -04:00
Mike Frysinger 9c4542c7a3 spi/bfin_spi: convert read/write/duplex funcs to a dedicated ops structure
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>
2010-10-18 02:49:33 -04:00
Mike Frysinger f4f50c3ff7 spi/bfin_spi: convert queue run state to true/false
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>
2010-10-18 02:49:32 -04:00
Mike Frysinger ab09e0406f spi/bfin_spi: fix up some unused/misleading comments
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-10-18 02:49:32 -04:00
Mike Frysinger 5cc0159a57 spi/bfin_spi: punt useless null read/write funcs
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>
2010-10-18 02:49:31 -04:00
Mike Frysinger 201bbc6fd8 spi/bfin_spi: drop custom cs_change_per_word support
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>
2010-10-18 02:49:30 -04:00
Barry Song 8221610e99 spi/bfin_spi: fix CS handling
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>
2010-10-18 02:49:30 -04:00
Yi Li f6a6d96685 spi/bfin_spi: utilize the SPI interrupt in PIO mode
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>
2010-10-18 02:49:29 -04:00
Wolfgang Muees bb8beecd98 spi/bfin_spi: force sane master-mode state at boot
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>
2010-10-18 02:49:29 -04:00
Sonic Zhang 60d0071b60 spi/bfin_spi: work around anomaly 05000119
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>
2010-10-18 02:49:28 -04:00
Daniel Mack ac01e97d64 spi/bfin_spi: fix resources leakage
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>
2010-10-18 02:49:28 -04:00
Matthias Brugger ee2007d299 spi/atmel: typo in debug message
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>
2010-10-15 21:56:00 -06:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Kumar Gala ef6510babf spi/fsl_spi: Fix compile errors when building on ppc64
We get the following when building on ppc64 due to lack of include of
<asm/io.h>:

In file included from drivers/spi/spi_fsl_espi.c:25:0:
drivers/spi/spi_fsl_lib.h: In function 'mpc8xxx_spi_write_reg':
drivers/spi/spi_fsl_lib.h:88:2: error: implicit declaration of function 'out_be32'
drivers/spi/spi_fsl_lib.h: In function 'mpc8xxx_spi_read_reg':
drivers/spi/spi_fsl_lib.h:93:2: error: implicit declaration of function 'in_be32'
drivers/spi/spi_fsl_espi.c: In function 'fsl_espi_remove':
drivers/spi/spi_fsl_espi.c:571:2: error: implicit declaration of function 'iounmap'
drivers/spi/spi_fsl_espi.c: In function 'fsl_espi_probe':
drivers/spi/spi_fsl_espi.c:602:2: error: implicit declaration of function 'ioremap'
drivers/spi/spi_fsl_espi.c:602:24: warning: assignment makes pointer from integer without a cast

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-14 08:30:12 -06:00
Matthias Brugger b9d228f9e8 spi/atmel: let transfers through if not changing bits_per_word
bits_per_word option in spi_transfer are allowed if it does not change
the csr register.

This is necessary for the driver in
drivers/staging/iio/adis16260_core.c, as it uses this option.

Signed-off-by: Matthias Brugger <mensch0815@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-13 23:07:37 -06:00
Grant Likely 8e41b527ff spi/topcliff: Fix uninitialized variable defect
This patch fixes the following build error introduced by commit
65308c46, "spi/topcliff: cleanup for style and conciseness".

drivers/spi/spi_topcliff_pch.c: In function 'pch_spi_process_messages':
drivers/spi/spi_topcliff_pch.c:752: warning: 'data' is used uninitialized in
+this function

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-13 23:03:15 -06:00