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path: root/drivers/spi/atmel_spi.c
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2009-03-24spi: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Cc: dbrownell@users.sourceforge.net Cc: spi-devel-general@lists.sourceforge.net Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
2009-01-15atmel_spi: allow transfer when max_speed_hz = 0Stanislaw Gruszka
For some reason I have to slowdown clock to touchscreen device. In atmel_spi_setup() there is comment that max_speed_hz == 0 means as slow as possible and divider is set to maximum value. But in atmel_spi_transfer() function is check against not zero max_speed_hz with EINVAL returned. Probably driver should setup divider for each transfer based on transfer->speed_hz value, but I think that would be not necessary overhead as all used devices have constant clock. Below patch works fine for me. Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.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>
2009-01-06spi: atmel_spi update chipselect handlingHaavard Skinnemoen
This solves several issues: * It fixes the wrong idle clock polarity issue in a cleaner and less expensive way. * It handles the AT32AP7000 errata "SPI Chip Select 0 BITS field overrides other Chip Selects". Other chips, e.g. AT91SAM9261, have similar issues. Currently, the AT91RM9200 code path is left alone. But it might be interesting to try the same technique on RM9200 using a different CSR register. [dbrownell@users.sourceforge.net: restore debug message for activation] Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> 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>
2009-01-06atmel_spi: clean up SPIv1 quirk handlingHaavard Skinnemoen
Currently, we have a flag called "new_1" which is basically equivalent to cpu_is_at91rm9200(). The latter is also called directly a few places. Clean up this mess by introducing a atmel_spi_v2() function for determining the controller version, and move all version dependent code over to use it. This allows us to remove the new_1 flag. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> 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>
2008-11-12atmel_spi: work-around required for new HW bug in AT91SAM9263 Rev.B SPI ↵Jean-Christophe Lallemand
controller We're working with an AT91SAM9263 Rev B in our design and I experienced some inconsistency in spi-based touchscreen usage between our board and the Atmel evaluation kit we have that runs on a Rev A chip. The data was apparently delayed by 1 byte and got ridiculous data out of the touchscreen driver, very strange. As everything looked normal in the spi, touchscreen and dma logs, I contacted the Atmel support and they triggered me on a new HW bug that appeared in the Rev B SPI controller. The problem is that the SPI controller on the Rev B needs that the software reset is performed two times so that it's performed correctly. Applying the patch below solves the issue on my Rev B board. I've tested it as well on my Rev A evaluation kit and it has apparently no unwanted side effect, things continue to work as expected. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.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>
2008-08-07[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/machRussell King
This just leaves include/asm-arm/plat-* to deal with. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-04atmel_spi: fix hang due to missed interruptGerard Kam
For some time my at91sam9260 board with JFFS2 on serial flash (m25p80) would hang when accessing the serial flash and SPI bus. Slowing the SPI clock down to 9 MHz reduced the occurrence of the hang from "always" during boot to a nuisance level that allowed other SW development to continue. Finally had to address this issue when an application stresses the I/O to always cause a hang. Hang seems to be caused by a missed SPI interrupt, so that the task ends up waiting forever after calling spi_sync(). The fix has 2 parts. First is to halt the DMA engine before the "current" PDC registers are loaded. This ensures that the "next" registers are loaded before the DMA operation takes off. The second part of the fix is a kludge that adds a "completion" interrupt in case the ENDRX interrupt for the last segment of the DMA chaining operation was missed. The patch allows the SPI clock for the serial flash to be increased from 9 MHz to 15 MHz (or more?). No hangs or SPI overruns were encountered. Haavard: while this patch does indeed improve things, I still see overruns and CRC errors on my NGW100 board when running the DataFlash at 10 MHz. However, I think some improvement is better than nothing, so I'm passing this on for inclusion in 2.6.27. Signed-off-by: Gerard Kam <gerardk5@verizon.net> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.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>
2008-07-26dma-mapping: add the device argument to dma_mapping_error()FUJITA Tomonori
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30atmel_spi: clean up baud rate divisor calculationHaavard Skinnemoen
Make the baud rate divisor calculation code a bit more readable and add a few comments. Also fix wrong debug information being displayed when !new_1 and max_speed_hz == 0. [david-b@pacbell.net: fix it] Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: "Janesh Ramakrishnan" <jramakrishnan@neuropace.com> Acked-by David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28atmel_spi: support zero length transferAtsushi Nemoto
A spi transfer with zero length is not invalid. For example, such transfer (len == 0 && delay_usecs != 0) can be used to achieve delay before first CLK edge after chipselect assertion. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Haavard Skinnemoen <hskinnemoen@atmel.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>
2008-04-11spi: fix platform driver hotplug/coldplugKay Sievers
Since 43cc71eed1250755986da4c0f9898f9a635cb3bf, the platform modalias is prefixed with "platform:". Add MODULE_ALIAS() to the hotpluggable SPI platform drivers, to allow module auto loading. [dbrownell@users.sourceforge.net: more drivers: registration fixes] Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> 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>
2008-02-23atmel_spi: fix clock polarityAtsushi Nemoto
The atmel_spi driver does not initialize clock polarity correctly (except for at91rm9200 CS0 channel) in some case. The atmel_spi driver uses gpio-controlled chipselect. OTOH spi clock signal is controlled by CSRn.CPOL bit, but this register controls clock signal correctly only in 'real transfer' duration. At the time of cs_activate() call, CSRn.CPOL will be initialized correctly, but the controller do not know which channel is to be used next, so clock signal will stay at the inactive state of last transfer. If clock polarity of new transfer and last transfer was differ, new transfer will start with wrong clock signal state. For example, if you started SPI MODE 2 or 3 transfer after SPI MODE 0 or 1 transfer, the clock signal state at the assertion of chipselect will be low. Of course this will violates SPI transfer. This patch is short term solution for this problem. It makes all CSRn.CPOL match for the transfer before activating chipselect. For longer term, the best fix might be to let NPCS0 stay selected permanently in MR and overwrite CSR0 with to the new slave's settings before asserting CS. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.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>
2008-02-06atmel_spi: fix dmachain oops with DEBUG enabledHaavard Skinnemoen
In atmel_spi_next_xfer, xfer can be NULL because the next transfer may already have been submitted to the PDC (using DMA chaining). This can cause an oops, since the debug message assumed it was never null. The fix changes how those debug messages are issued, ensuring that one is issued each time a transfer is started instead of once per call. Also, properly indent the "can this transfer be chained" test so it's not hidden as if it were non-conditional code. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> 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>
2008-02-06atmel_spi: chain DMA transfersSilvester Erdeg
Add support for chained transfers in the atmel_spi driver, letting the DMA controller switch to the next buffer pair without CPU intervention. This reduced I/O latencies by about 2% in one bulk I/O test. It should also help work around several interrelated errata affecting chipselect 0 on at91rm9200 chips. Almost all of the changes are in the reworked atmel_spi_next_xfer() function. That's now called with the driver in one of three states: 1. It isn't transferring anything (in which case the first transfer of the current message is going to be sent) 2. It has finished transfering a non-chainable transfer (in which case it will go to the next transfer in the message) 3. It has finished transfering a chained transfer (in which case the next transfer is already queued) After that it will queue the next transfer if it can be chained. Signed-off-by: Szilveszter Ordog <slipszi@gmail.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> 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>
2008-02-06atmel_spi throughput improvementHaavard Skinnemoen
Don't insert (undesirable) delays between consecutive words (DLYBCT) or when activating chipselects (DLYBS). Removing the between-word delays improves the performance of bulk transfers (such as mtd_dataflash, m25p80, mmc_spi) significantly. In one test, the improvement was a factor of more than eight! (The large DLYBCT value came from the legacy at91 SPI driver, and it's not clear why it used such a huge value.) Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> 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>
2007-12-10atmel_spi: reload RCR before TCRRini van Zetten
We have a wifi module connected to the spi bus and got sometimes FIFO overrun errors on the spi bus. After some investigation i found that the driver loads the TCR (transmit count) register before the RCR (receive count). When the transfer list is not empty the atmel_spi_next_message is called while tx and rx are enabled. As soon as the TCR is loaded, hardware starts transfer and causes a rx fifo overrun because the RCR is not loaded yet. Load the RCR before the TCR. After this patch the fifo overrun disapears at out setup. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Rini van Zetten <rini@arvoo.nl> 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>
2007-11-29atmel_spi: label GPIOs betterDavid Brownell
Make the atmel_spi driver label GPIOs according to the device for which they're acting as a chipselect. This way the debugfs dump of gpio state is more informative. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16spi doesn't need class_deviceTony Jones
Make the SPI framework and drivers stop using class_device. Update docs accordingly ... highlighting just which sysfs paths should be "safe"/stable. Signed-off-by: Tony Jones <tonyj@suse.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31Fix typo in atmel_spi.cAndrew Victor
Fix cut 'n paste bug in Atmel SPI driver. Signed-off-by: Andrew Victor <andrew@sanpeople.com> Acked-by: David Brownell <david-b@pacbell.net> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17atmel_spi: don't always deselect chip between messagesDavid Brownell
Update chipselect handling for atmel_spi: * Teach it how to leave chipselect active between messages; this helps various drivers work better. * Cope with at91rm0200 errata: nCS0 can't be managed with GPIOs. The MR.PCS value is now updated whenever a chipselect changes. (This requires SPI pinmux init for that controller to change, and also testing on rm9200; doesn't break at91sam9 or avr32.) * Fix minor glitches: spi_setup() must leave chipselects inactive, as must removal of the spi_device. Also tweak diagnostic messaging to be a bit more useful. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17atmel_spi: minor updatesDavid Brownell
Minor updates to atmel_spi: - DMA: * Comments to explain the DMA policies * Report any mapping errors from spi_transfer() * Remove extra loop for DMA mapping - Diagnostics: report minimum clock rate, if we need to reject a spi_setup() request because that rate is too low. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17SPI controller drivers: check for unsupported modesDavid Brownell
Minor SPI controller driver updates: make the setup() methods reject spi->mode bits they don't support, by masking aginst the inverse of bits they *do* support. This insures against misbehavior later when new mode bits get added. Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH. Support for all four SPI clock/transfer modes is routine. 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>
2007-06-01atmel_spi dma address bugfixHaavard Skinnemoen
When either rx_buf or tx_buf is not being used, i.e. for plain read- or write operations, the atmel_spi uses a fixed-size DMA buffer instead. If the transfer is longer than the size of this buffer, it is split into multiple DMA transfers. When the transfer is split like this, the atmel_spi driver ends up using the same DMA address again and again even for the buffer that came from the user, which is of course wrong. Fix this by adding the number of bytes already transferred to the DMA address so that the data ends up in the right place. Thanks to Wu Xuan for discovering this bug. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> 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>
2007-05-09atmel_spi: remove unnecessary (and wrong) #ifdefsHaavard Skinnemoen
Now that the cpu_is_xxx() macros are available both on AVR32 and AT91, we can remove a couple of #ifdefs from this driver. One of them is actually wrong -- new_1 should be set on AVR32 but isn't. This causes the bus clock to run at twice the speed it is configured to. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-16[PATCH] gpio_direction_output() needs an initial valueDavid Brownell
It's been pointed out that output GPIOs should have an initial value, to avoid signal glitching ... among other things, it can be some time before a driver is ready. This patch corrects that oversight, fixing - documentation - platforms supporting the GPIO interface - users of that call (just one for now, others are pending) There's only one user of this call for now since most platforms are still using non-generic GPIO setup code, which in most cases already couples the initial value with its "set output mode" request. Note that most platforms are clear about the hardware letting the output value be set before the pin direction is changed, but the s3c241x docs are vague on that topic ... so those chips might not avoid the glitches. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Acked-by: Milan Svoboda <msvoboda@ra.rockwell.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] SPI controller build/warning fixesDavid Brownell
The signature of the per-device cleanup() routine changed to remove its const-ness. Three new SPI controller drivers now need that change, to eliminate build warnings. This also fixes a build bug with atmel_spi on AT91 systems. 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>
2007-02-14[PATCH] SPI: atmel_spi driverHaavard Skinnemoen
Driver for the Atmel on-chip SPI master controller. Tested primarily on AVR32/AT32AP7000/ATSTK1000 using mtd_dataflash and the jffs2 filesystem. Should also work fine on various AT91 ARM-based chips like AT91SAM926x and AT91RM9200. Hardware documentation can be found in the AT32AP7000 data sheet, or its AT91 siblings, which can be downloaded from http://www.atmel.com/dyn/products/datasheets.asp?family_id=682 Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> 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>