The patch titled
SPI: add dma_alignment field to spi_master
has been added to the -mm tree. Its filename is
spi-add-dma_alignment-field-to-spi_master.patch
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------------------------------------------------------
Subject: SPI: add dma_alignment field to spi_master
From: Mike Rapoport <mike@xxxxxxxxxxxxxx>
Some SPI controllers have restrictions on DMAable buffers alignemt.
Currently if the buffer supplied by protocol driver is not properly
aligned, the controller silently performs transfer in PIO mode. Addition
of dma_alignment field to spi_master allows protocol drivers to perform
proper alignment.
Signed-off-by: Mike Rapoport <mike@xxxxxxxxxxxxxx>
Cc: Bryan Wu <bryan.wu@xxxxxxxxxx>
Cc: David Brownell <david-b@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/spi/spi.h | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN include/linux/spi/spi.h~spi-add-dma_alignment-field-to-spi_master include/linux/spi/spi.h
--- a/include/linux/spi/spi.h~spi-add-dma_alignment-field-to-spi_master
+++ a/include/linux/spi/spi.h
@@ -204,6 +204,7 @@ static inline void spi_unregister_driver
* SPI slaves, and are numbered from zero to num_chipselects.
* each slave has a chipselect signal, but it's common that not
* every chipselect is connected to a slave.
+ * @dma_alignment: SPI controller constraint on DMA buffers alignment.
* @setup: updates the device mode and clocking records used by a
* device's SPI controller; protocol code may call this. This
* must fail if an unrecognized or unsupported mode is requested.
@@ -239,6 +240,11 @@ struct spi_master {
*/
u16 num_chipselect;
+ /* some SPI controllers pose alignment requirements on DMAable
+ * buffers; let protocol drivers know about these requirements.
+ */
+ u16 dma_alignment;
+
/* setup mode and clock, etc (spi driver may call many times) */
int (*setup)(struct spi_device *spi);
_
Patches currently in -mm which might be from mike@xxxxxxxxxxxxxx are
linux-next.patch
spi_bfin5xx-remove-unused-is_dma_aligned-macro.patch
spi-add-dma_alignment-field-to-spi_master.patch
pxa2xx_spi-set-spi_masterdma_alignment-=-8.patch
spi_imx-set-spi_masterdma_alignment-=-4.patch
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