Commit Graph

711 Commits

Author SHA1 Message Date
Grant Likely
496a2e360a Merge branch 'for-grant' of git://arago-project.org/git/projects/linux-davinci into spi/next
* 'for-grant' of git://arago-project.org/git/projects/linux-davinci into spi/next
   spi: davinci: fix checkpatch errors
   spi: davinci: whitespace cleanup
   spi: davinci: remove unused variable 'pdata'
   spi: davinci: set chip-select mode in SPIDEF only once
   spi: davinci: enable both activation and deactivation of chip-selects
   spi: davinci: remove unnecessary data transmit on CS disable
   spi: davinci: enable GPIO lines to be used as chip selects
   spi: davinci: simplify prescalar calculation
   spi: davinci: remove 'wait_enable' platform data member
   spi: davinci: make chip-slect specific parameters really chip-select specific
   spi: davinci: consolidate setup of SPIFMTn in one function
   spi: davinci: setup chip-select timers values only if timer enabled
   spi: davinci: add support for wait enable timeouts
   spi: davinci: remove unused members of davinci_spi_slave
   spi: davinci: eliminate the single member structure davinci_spi_slave
   spi: davinci: eliminate unnecessary update of davinci_spi->count
   spi: davinci: simplify calculation of edma acount value
   spi: davinci: check for NULL buffer pointer before using it
   spi: davinci: remove unnecessary disable of SPI
   spi: davinci: remove unnecessary 'count' variable in driver private data
   spi: davinci: remove unnecessary completion variable initialization
   spi: davinci: remove non-useful interrupt mode support
   spi: davinci: simplify poll mode transfers
   spi: davinci: add support for interrupt mode
   spi: davinci: configure the invariable bits in spipc0 only once
   spi: davinci: remove unnecessary function davinci_spi_bufs_prep()
   spi: davinci: remove unnecessary call to davinci_spi_setup_transfer()
   spi: davinci: do not store DMA channel information per chip select
   spi: davinci: always start transmit DMA
   spi: davinci: do not use temporary buffer if no transmit data provided
   spi: davinci: always start receive DMA
   spi: davinci: use edma_write_slot() to setup EDMA PaRAM slot
   spi: davinci: fix DMA event generation stoppage
   spi: davinci: fix EDMA CC errors at end of transfers
   spi: davinci: handle DMA completion errors correctly
   spi: davinci: remove usage of additional completion variables for DMA
   spi: davinci: let DMA operation be specified on per-device basis
   spi: davinci: remove non-useful "clk_internal" platform data
   spi: davinci: enable and power-up SPI only when required
   spi: davinci: setup the driver owner
   spi: davinci: add additional comments
   spi: davinci: add EF Johnson Technologies copyright
   spi: davinci: removed unused #defines
   spi: davinci: remove unnecessary typecast
   spi: davinci: do not treat Tx interrupt being set as error
   spi: davinci: do not allocate DMA channels during SPI device setup
   spi: davinci: remove unnecessary private data member 'region_size'
   spi: davinci: shorten variable names
   spi: davinci: kconfig: add manufacturer name to prompt string
2010-12-29 00:47:38 -07:00
Wolfram Sang
5aa68b8595 spi/mpc52xx-psc-spi: move probe/remove to proper sections
Probe/remove should be in __devinit/__devexit. Found by a section-mismatch
warning. Also, copy do_remove() over to remove().

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 11:18:34 -07:00
Feng Tang
7063c0d942 spi/dw_spi: add DMA support
dw_spi driver in upstream only supports PIO mode, and this patch
will support it to cowork with the Designware dma controller used
on Intel Moorestown platform, at the same time it provides a general
framework to support dw_spi core to cowork with dma controllers on
other platforms

It has been tested with a Option GTM501L 3G modem and Infenion 60x60
modem. To use DMA mode, DMA controller 2 of Moorestown has to be enabled

Also change the dma interface suggested by Linus Walleij.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
[Typo fix and renames to match intel_mid_dma renaming]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 01:23:25 -07:00
Feng Tang
79290a2aa2 spi/dw_spi: change to EXPORT_SYMBOL_GPL for exported APIs
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 01:09:21 -07:00
Feng Tang
ebf45b7d02 spi/dw_spi: Fix too short timeout in spi polling loop
The SPI polling loop timeout only works with HZ=100 as the loop was
actually too short.

Also add appropriate cpu_relax() in the busy wait loops...

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 01:08:42 -07:00
Linus Walleij
5e8b821de3 spi/pl022: convert running variable
This variable is a bool but defined an int and defined completely
backwards. This makes the code more readable.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 21:06:47 -07:00
Linus Walleij
dec5a581eb spi/pl022: convert busy flag to a bool
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 21:06:47 -07:00
Linus Walleij
082086f2ce spi/pl022: pass the returned sglen to the DMA engine
The sglen return by the dma_map_sg() should be passed to the DMA
engine, not the one passed in. If we one day have a DMA mapper
that can coalesce entries, this will bug due to a too large
number of entries being passed in.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 21:06:46 -07:00
Linus Walleij
b729889686 spi/pl022: map the buffers on the DMA engine
The struct device for the DMA engine is the apropriate one to use
when mapping/unmapping buffers. This is because the memory which
is addressable by DMA is determined by the DMA engine rather than
the device.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 21:06:43 -07:00
Tomoya MORINAGA
9d32af66aa spi/topcliff_pch: Fix data transfer issue
It seems spi_topcliff_pch of linux-2.6.37-rc6 degraded by previous patch.
In fact, data transfer fails on evaluation board testing.
I found like the following register miss-setting line.
Using this patch, I have confirmed data transfer can work well.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 20:30:11 -07:00
Uwe Kleine-König
893421745a spi/imx: remove autodetection
There are no machines in-tree that still use the driver
name as device name.  So save a few bytes and remove it.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Jason Wang <jason77.wang@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-23 19:18:36 -07:00
Grant Likely
752a4a95e3 Merge commit 'v2.6.37-rc7' into spi/next 2010-12-22 00:10:01 -07:00
Major Lee
3d0b6087f3 dw_spi: Fix missing final read in some polling situations
There is a possibility that the last word of a transaction will be lost
if data is not ready.  Re-read in poll_transfer() to solve this issue
when poll_mode is enabled.

Verified on SPI touch screen device.

Signed-off-by: Major Lee <major_lee@wistron.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-14 18:48:59 -08:00
Jean-Christophe PLAGNIOL-VILLARD
214b574ab8 atmel_spi: fix warning In function 'atmel_spi_dma_map_xfer'
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>
2010-11-30 17:23:24 +01:00
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