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path: root/drivers/spi/spi_bfin5xx.c
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* Merge branch 'spi/merge' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds2011-04-11
|\ | | | | | | | | | | | | | | | | * 'spi/merge' of git://git.secretlab.ca/git/linux-2.6: dt/fsldma: fix build warning caused by of_platform_device changes spi: Fix race condition in stop_queue() gpio/pch_gpio: Fix output value of pch_gpio_direction_output() gpio/ml_ioh_gpio: Fix output value of ioh_gpio_direction_output() gpio/pca953x: fix error handling path in probe() call
| * spi: Fix race condition in stop_queue()Vasily Khoruzhick2011-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a race condition in stop_queue() in some drivers - if drv_data->queue is empty, but drv_data->busy is still set (or opposite situation) stop_queue will return -EBUSY. So fix loop condition to check that both drv_data->queue is empty and drv_data->busy is not set. This patch affects following drivers: pxa2xx_spi spi_bfin5xx amba-pl022 dw_spi Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com> Acked-by: Eric Miao <eric.y.miao@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* | Fix common misspellingsLucas De Marchi2011-03-31
|/ | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* spi/bfin_spi: return immediately after skipping to next transferSonic Zhang2011-02-15
| | | | | | | | | | If there is an error with setting up a transfer, we need to return immediately rather than trying to continue to process things. We already set up the error states for the caller at this point. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* spi/bfin_spi: support for multiples of 8bits with hardware CSBob Liu2011-02-15
| | | | | | | | | We can do multiples of 8bit transfers when using the hardware CS and a little bit of magic, so make it work. Signed-off-by: Bob Liu <lliubbo@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* spi/bfin_spi: only request GPIO on first loadMichael Hennerich2010-10-22
| | | | | | | | | | | | 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>
* spi/bfin_spi: handle error/status changes after data interruptsMichael Hennerich2010-10-22
| | | | | | | | | | | | | | 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>
* spi/bfin_spi: namespace local structsMike Frysinger2010-10-18
| | | | Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* spi/bfin_spi: init earlyMichael Hennerich2010-10-18
| | | | | | | | | | 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>
* spi/bfin_spi: check per-transfer bits_per_wordBob Liu2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: warn when CS is driven by hardware (CPHA=0)Barry Song2010-10-18
| | | | | | | | | 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>
* spi/bfin_spi: cs should be always low when a new transfer beginsRob Maris2010-10-18
| | | | | | 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>
* spi/bfin_spi: fix typo in commentRob Maris2010-10-18
| | | | | | 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>
* spi/bfin_spi: reject unsupported SPI modesMike Frysinger2010-10-18
| | | | | | Who knows what people will try! Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* spi/bfin_spi: use dma_disable_irq_nosync() in irq handlerBarry Song2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: combine duplicate SPI_CTL read/write logicMike Frysinger2010-10-18
| | | | | | | 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>
* spi/bfin_spi: reset ctl_reg bits when setup is run again on a deviceMike Frysinger2010-10-18
| | | | | | | | | | 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>
* spi/bfin_spi: push all size checks into the transfer functionMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: use nosync when disabling the IRQ from the IRQ handlerYi Li2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: sync hardware state before reprogramming everythingBarry Song2010-10-18
| | | | | | | | | | 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>
* spi/bfin_spi: save/restore state when suspending/resumingBarry Song2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: redo GPIO CS handlingBarry Song2010-10-18
| | | | | | | | | | | | | | | | | 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>
* spi/bfin_spi: use the SPI namespaced bit namesMike Frysinger2010-10-18
| | | | | | This lets us push the short SPI MMR bit names out of the global namespace. Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* spi/bfin_spi: drop extra memory we don't needMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: convert struct names to something more logicalMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: convert read/write/duplex funcs to a dedicated ops structureMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: convert queue run state to true/falseMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: fix up some unused/misleading commentsMike Frysinger2010-10-18
| | | | | Reported-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* spi/bfin_spi: punt useless null read/write funcsMike Frysinger2010-10-18
| | | | | | | | 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>
* spi/bfin_spi: drop custom cs_change_per_word supportMike Frysinger2010-10-18
| | | | | | | | | 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>
* spi/bfin_spi: fix CS handlingBarry Song2010-10-18
| | | | | | | | | | | | | | 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>
* spi/bfin_spi: utilize the SPI interrupt in PIO modeYi Li2010-10-18
| | | | | | | | | | 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>
* spi/bfin_spi: force sane master-mode state at bootWolfgang Muees2010-10-18
| | | | | | | | | | | | | | | | | | | 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>
* spi/bfin_spi: work around anomaly 05000119Sonic Zhang2010-10-18
| | | | | | | | | 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>
* spi/bfin_spi: fix resources leakageDaniel Mack2010-10-18
| | | | | | | | | | 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>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* spi: spi_bfin5xx.c: use resource_size()hartleys2009-12-17
| | | | | | | Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Bryan Wu <cooloney@kernel.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* spi: move more spi_setup() functionality into coreDavid Brownell2009-06-18
| | | | | | | | | | | | | | | | | | | | | | Move some common spi_setup() error checks into the SPI framework from the spi_master controller drivers: - Add a new "mode_bits" field to spi_master - Use that in spi_setup to validate the spi->mode value being requested. Setting this new field is now mandatory for any controller supporting more than vanilla SPI_MODE_0. - Update all spi_master drivers to: * Initialize that field * Remove current spi_setup() checks using that value. This is a net minor code shrink. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* spi: move common spi_setup() functionality into coreDavid Brownell2009-06-18
| | | | | | | | | | | | | | | | | | Start moving some spi_setup() functionality into the SPI core from the various spi_master controller drivers: - Make that function stop being an inline; - Move two common idioms from drivers into that new function: * Default bits_per_word to 8 if that field isn't set * Issue a standardized dev_dbg() message This is a net minor source code shrink, and supports enhancments found in some follow-up patches. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* spi_bfin5xx: limit reaches -1Roel Kluin2009-06-18
| | | | | | | | | | | bfin_spi_flush() returns limit, which reaches -1 upon timeout. but in function bfin_spi_pump_transfers() it is compared with 0. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Bryan Wu <cooloney@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin: rename bfin_addr_dcachable to bfin_addr_dcacheableJie Zhang2009-06-13
| | | | | | | The latter naming convention is much more common. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* spi_bfin5xx: remove unused IS_DMA_ALIGNED macroMike Rapoport2009-04-07
| | | | | | | | Signed-off-by: Mike Rapoport <mike@compulab.co.il> Cc: Bryan Wu <bryan.wu@analog.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: Make mmc_spi driver work on BlackfinWolfgang Muees2009-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | 1. Rewrite of the non-dma data transfer functions to use only ONE mode of TIMOD (TIMOD=0x1). With TIMOD=0, it was not possible to set the TX bit pattern. So the TDBR = 0xFFFF inside the read calls won't work. 2. Clear SPI_RDBR before reading and before duplex transfer. Otherwise the garbage data in RDBR will get read. Since mmc_spi uses a lot of duplex transfers, this is the main cause of mmc_spi failure. 3. Poll RXS for transfer completion. Polling SPIF or TXS cannot guarantee transfer completion. This may interrupt a transfer before it is finished. Also this may leave garbage data in buffer and affect next transfer. [Yi Li <yi.li@analog.com>: add a field "u16 idle_tx_val" in "struct bfin5xx_spi_chip" to specify the value to transmit if no TX value is supplied.] Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de> Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: Add GPIO controlled SPI Slave Select supportMichael Hennerich2009-04-07
| | | | | | | | | | | | | | | | | | | | | | Add support for GPIO controlled SPI Chip Selects. To make use of this feature, set chip_select = 0 and add a proper cs_gpio to your controller_data. struct spi_board_info .chip_select = 0 struct bfin5xx_spi_chip .cs_gpio = GPIO_P### There are various SPI devices that require SPI MODE_0, and need to have the Chip Selects asserted during the entire transfer. Consider using SPI_MODE_3 (SPI_CPHA | SPI_CPOL) if your device allows it. Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: fix NULL pointer crashMike Frysinger2009-04-07
| | | | | | | | | | Fix NULL pointer crash when cleaning up from invalid platform resources Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: use bfin_spi_ prefix on all functionsMike Frysinger2009-04-07
| | | | | | | | | | | | Do this because when things crash, we get simple names like "setup" and "start_queue" which is pretty difficult to trace back to the real thing: the spi driver Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: fix bug - correct usage of struct spi_transfer.cs_changeYi Li2009-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to comments in linux/spi/spi.h: * All SPI transfers start with the relevant chipselect active. Normally * it stays selected until after the last transfer in a message. Drivers * can affect the chipselect signal using cs_change. * * (i) If the transfer isn't the last one in the message, this flag is * used to make the chipselect briefly go inactive in the middle of the * message. Toggling chipselect in this way may be needed to terminate * a chip command, letting a single spi_message perform all of group of * chip transactions together. * * (ii) When the transfer is the last one in the message, the chip may * stay selected until the next transfer. On multi-device SPI busses * with nothing blocking messages going to other devices, this is just * a performance hint; starting a message to another device deselects * this one. But in other cases, this can be used to ensure correctness. * Some devices need protocol transactions to be built from a series of * spi_message submissions, where the content of one message is determined * by the results of previous messages and where the whole transaction * ends when the chipselect goes intactive. Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: fix bug - spi controller driver does not ↵Yi Li2009-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | assert/deassert CS correctly This bug can be observed when two SPI devices are sharing the spi bus: One device is set as SPI CS 7, another one is using SPI CS 4. In spi_bfin5xx.c: cs_active(), cs_deactive() are used to control SPI_FLG register. From the debug bellow: cs_active: flag: 0x7f91, chip->flag: 0x7f80, cs: 7 cs_active: flag: 0xef91, chip->flag: 0xef10, cs: 4 When device A (cs_7) activate CS 7, SPI_FLG is set as 0x7f91 (however, SPI_FLG should be set as 0x7f80, or 0x6f91 if in broadcast mode). Due to some HW bug (very possibly), if SPI_FLG is set as 0x7f91, SPISSEL7 is asserted, however SPISSEL4 will be asserted too (I can see this using the scope). This is unreasonable according to HRM. Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: tweak magic spi dma sequence to get it working on BF54xMike Frysinger2009-04-07
| | | | | | | | | | | Without this change, SPI DMA is not reliably under stress tests. Obiviously it's a hardware issue which is not addressed by any document. Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Blackfin SPI Driver: add timeout while waiting for SPIF in dma irq handlerMike Frysinger2009-04-07
| | | | | | | | | | | The "while" endless loop will cause the system hang if hardware error, so we add timeout control to make the system alive. Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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