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path: root/drivers/spi/davinci_spi.c
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* spi: reorganize driversGrant Likely2011-06-061-1030/+0
| | | | | | | | | | | | | | | | Sort the SPI makefile and enforce the naming convention spi_*.c for spi drivers. This change also rolls the contents of atmel_spi.h into the .c file since there is only one user of that particular include file. v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be be the predominant pattern for subsystem prefixes. - Clean up filenames in Kconfig and header comment blocks Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Linus Walleij <linus.walleij@linaro.org>
* Merge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds2011-03-181-13/+30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'spi/next' of git://git.secretlab.ca/git/linux-2.6: (34 commits) spi/dw_spi: move dw_spi.h into drivers/spi spi/dw_spi: Fix missing header gpio/langwell: Clear edge bit before handling gpio/langwell: Simplify demux loop gpio/langwell: Convert irq name space gpio/langwell: Fix broken irq_eoi change. gpio; Make Intel chipset gpio drivers depend on x86 gpio/cs5535-gpio: Fix section mismatch spi/rtc-{ds1390,ds3234,m41t94}: Use spi_get_drvdata() for SPI devices spi/davinci: Support DMA transfers larger than 65535 words spi/davinci: Use correct length parameter to dma_map_single calls gpio: Use __devexit at necessary places gpio: add MODULE_DEVICE_TABLE to pch_gpio and ml_ioh_gpio gpio/mcp23s08: support mcp23s17 variant of_mmc_spi: add card detect irq support spi/omap_mcspi: catch xfers of non-multiple SPI word size spi/omap_mcspi: Off-by-one error in finding the right divisor gpio/pca953x: Fix wrong pointer type spi/pl022: rid dangling labels spi: add support for SuperH SPI ...
| * spi/davinci: Support DMA transfers larger than 65535 wordsMichael Williamson2011-03-141-8/+25
| | | | | | | | | | | | | | | | | | | | | | The current davinci SPI driver, in DMA mode, is limited to 65535 words for a single transfer. Modify the driver by configuring a 3 dimensional EDMA transfer to support up to 65535x65535 words. Signed-off-by: Michael Williamson <michael.williamson@criticallink.com> Tested-by: Stefano Babic <sbabic@denx.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| * spi/davinci: Use correct length parameter to dma_map_single callsMichael Williamson2011-03-141-5/+5
| | | | | | | | | | | | | | | | | | | | The davinci spi driver provides an option to use DMA transfers for data. In the dma_map_single() call, the driver is passing the number of words to be transfered for the mapping size. It should be the number of bytes. Signed-off-by: Michael Williamson <michael.williamson@criticallink.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* | davinci: spi: move event queue parameter to platform dataMichael Williamson2011-02-281-8/+3
|/ | | | | | | | | | | | | | | For DMA operation, the davinci spi driver needs an event queue number. Currently, this number is passed as a IORESOURCE_DMA. This is not correct, as the event queue is not a DMA channel. Pass the event queue via the platform data structure instead. On dm355 and dm365, move the eventq assignment for spi0 out of resources array and into platform data. Signed-off-by: Michael Williamson <michael.williamson@criticallink.com> Acked-by: Sekhar Nori <nsekhar@ti.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Kevin Hilman <khilman@ti.com>
* spi: davinci: shorten variable namesSekhar Nori2010-11-181-211/+198
| | | | | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary private data member 'region_size'Sekhar Nori2010-11-181-7/+6
| | | | | | | | | | | 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>
* spi: davinci: add EF Johnson Technologies copyrightBrian Niebuhr2010-11-181-0/+1
| | | | | | | | 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>
* spi: davinci: add additional commentsBrian Niebuhr2010-11-181-0/+7
| | | | | | | | | | | | 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>
* spi: davinci: setup the driver ownerBrian Niebuhr2010-11-181-1/+4
| | | | | | | | | 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>
* spi: davinci: enable and power-up SPI only when requiredBrian Niebuhr2010-11-181-2/+6
| | | | | | | | | 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>
* spi: davinci: remove non-useful "clk_internal" platform dataBrian Niebuhr2010-11-181-8/+1
| | | | | | | | | | | | | 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>
* spi: davinci: let DMA operation be specified on per-device basisBrian Niebuhr2010-11-181-187/+155
| | | | | | | | | | | | | 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>
* spi: davinci: remove usage of additional completion variables for DMABrian Niebuhr2010-11-181-35/+23
| | | | | | | | | | | | | | | | | 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>
* spi: davinci: handle DMA completion errors correctlyBrian Niebuhr2010-11-181-27/+36
| | | | | | | | | | | 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>
* spi: davinci: fix EDMA CC errors at end of transfersBrian Niebuhr2010-11-181-3/+25
| | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: do not allocate DMA channels during SPI device setupSekhar Nori2010-11-181-102/+51
| | | | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: fix DMA event generation stoppageBrian Niebuhr2010-11-181-15/+3
| | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: use edma_write_slot() to setup EDMA PaRAM slotBrian Niebuhr2010-11-181-15/+19
| | | | | | | | | | | | 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>
* spi: davinci: always start receive DMABrian Niebuhr2010-11-181-28/+42
| | | | | | | | | | | | | | | | 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>
* spi: davinci: do not use temporary buffer if no transmit data providedBrian Niebuhr2010-11-181-31/+21
| | | | | | | | | | | | | 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>
* spi: davinci: always start transmit DMABrian Niebuhr2010-11-181-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: do not store DMA channel information per chip selectBrian Niebuhr2010-11-181-29/+18
| | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary call to davinci_spi_setup_transfer()Brian Niebuhr2010-11-181-8/+3
| | | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary function davinci_spi_bufs_prep()Brian Niebuhr2010-11-181-43/+21
| | | | | | | | | | 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>
* spi: davinci: configure the invariable bits in spipc0 only onceBrian Niebuhr2010-11-181-3/+5
| | | | | | | | | | 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>
* spi: davinci: add support for interrupt modeBrian Niebuhr2010-11-181-30/+115
| | | | | | | | | | | | | | | | 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>
* spi: davinci: simplify poll mode transfersBrian Niebuhr2010-11-181-55/+41
| | | | | | | | | | | | | 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>
* spi: davinci: remove non-useful interrupt mode supportBrian Niebuhr2010-11-181-107/+19
| | | | | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary completion variable initializationBrian Niebuhr2010-11-181-2/+0
| | | | | | | | | | | | 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>
* spi: davinci: do not treat Tx interrupt being set as errorSekhar Nori2010-11-181-4/+0
| | | | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary 'count' variable in driver private dataBrian Niebuhr2010-11-181-7/+3
| | | | | | | | | | | 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>
* spi: davinci: remove unnecessary disable of SPIBrian Niebuhr2010-11-181-2/+0
| | | | | | | | | | | 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>
* spi: davinci: check for NULL buffer pointer before using itBrian Niebuhr2010-11-181-18/+22
| | | | | | | | | | | 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>
* spi: davinci: simplify calculation of edma acount valueBrian Niebuhr2010-11-181-22/+3
| | | | | | | | | | | 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>
* spi: davinci: eliminate unnecessary update of davinci_spi->countBrian Niebuhr2010-11-181-6/+0
| | | | | | | | | 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>
* spi: davinci: eliminate the single member structure davinci_spi_slaveBrian Niebuhr2010-11-181-9/+5
| | | | | | | | | 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>
* spi: davinci: remove unused members of davinci_spi_slaveBrian Niebuhr2010-11-181-5/+0
| | | | | | | | | 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>
* spi: davinci: add support for wait enable timeoutsBrian Niebuhr2010-11-181-9/+27
| | | | | | | | | | | | | | | | | 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>
* spi: davinci: setup chip-select timers values only if timer enabledBrian Niebuhr2010-11-181-17/+4
| | | | | | | | | | | | 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>
* spi: davinci: consolidate setup of SPIFMTn in one functionBrian Niebuhr2010-11-181-105/+49
| | | | | | | | | | | | | | 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>
* spi: davinci: make chip-slect specific parameters really chip-select specificBrian Niebuhr2010-11-181-30/+37
| | | | | | | | | | | | | | 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>
* spi: davinci: remove 'wait_enable' platform data memberBrian Niebuhr2010-11-181-1/+1
| | | | | | | | | | | | | 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>
* spi: davinci: simplify prescalar calculationBrian Niebuhr2010-11-181-22/+31
| | | | | | | | | | | | | | | | | | | | 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>
* spi: davinci: enable GPIO lines to be used as chip selectsBrian Niebuhr2010-11-181-7/+32
| | | | | | | | | | | | | | | 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>
* spi: davinci: remove unnecessary data transmit on CS disableBrian Niebuhr2010-11-181-12/+8
| | | | | | | | | | | | | | | | | | 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>
* spi: davinci: enable both activation and deactivation of chip-selectsBrian Niebuhr2010-11-181-35/+18
| | | | | | | | | | | | | | | | | | 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>
* spi: davinci: set chip-select mode in SPIDEF only onceBrian Niebuhr2010-11-181-2/+2
| | | | | | | | | | | 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>
* spi: davinci: remove unnecessary typecastSekhar Nori2010-11-181-2/+1
| | | | | | | | | | | 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>
* spi: davinci: removed unused #definesSekhar Nori2010-11-181-31/+2
| | | | | | | | | | | | 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>
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