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path: root/drivers/spi/spi-pxa2xx-dma.c
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2014-06-06spi/pxa2xx: change default supported DMA burst size to 1Chew, Chiau Ee
This is to fix the SPI DMA transfer failure for speed less than 1M. If using current DMA burst size setting (16), the Rx data bytes are invalid due to each data byte is multiplied according to the burst size setting. Let's said supposedly we shall receive the following 18 bytes of data: 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Instead, the data bytes received consist of "16 bytes of '01' + 2 bytes of '02'" : 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 02 02 Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-05-12spi/pxa2xx: Prevent DMA from transferring too many bytesMika Westerberg
In case we are doing DMA transfer and the size of the buffer is not multiple of 4 bytes the driver truncates that to 4-byte boundary and tries to handle remaining bytes using PIO. Or that is what it tried to do. What actually happens is that it calls ALIGN() to the buffer size which aligns it to the next 4-byte boundary (doesn't truncate). Doing this results 1-3 bytes extra to be transferred. Furthermore we handle remaining bytes using PIO which results one extra byte to be transferred. In worst case the driver transfers 4 extra bytes. While investigating this it turned out that the DMA hardware doesn't even have such limitation so we can solve this by dropping the code that tries to handle unaligned bytes. Reported-by: Chiau Ee Chew <chiau.ee.chew@intel.com> Reported-by: Hock Leong Kweh <hock.leong.kweh@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-03spi: delete non-required instances of include <linux/init.h>Paul Gortmaker
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-06-26Merge remote-tracking branch 'spi/topic/pxa' into spi-nextMark Brown
2013-06-18spi/pxa2xx: use GFP_ATOMIC in sg table allocationMika Westerberg
pxa2xx_spi_map_dma_buffer() gets called in tasklet context so we can't sleep when we allocate a new sg table. Use GFP_ATOMIC here instead. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@linaro.org> Cc: stable@vger.kernel.org
2013-05-13spi/pxa2xx: convert to dma_request_slave_channel_compat()Mika Westerberg
Now that we have these nice DMA API helper functions we can take advantage of those instead of open-coding the channel/request line extraction from ACPI. Use the _compat version which still allows passing the channel/request line from platform data. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2013-02-08spi/pxa2xx: add support for DMA engineMika Westerberg
To be able to use DMA with this driver on non-PXA platforms we implement support for the generic DMA engine API. This lets user to use different DMA engines with little or no modification to the driver. Request lines and channel numbers can be passed to the driver from the platform specific data. The DMA engine implementation will be selected by default even on PXA platform. User can select the legacy DMA API by enabling Kconfig option CONFIG_SPI_PXA2XX_PXADMA. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Lu Cao <lucao@marvell.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>