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path: root/drivers/spi
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2015-07-16spi: spidev: Fix typoFabio Estevam
Fix the typo in "compatible". Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-15spi: spi-pxa2xx: Remove clk.h includeStephen Boyd
Clock provider drivers generally shouldn't include clk.h because it's the consumer API. Remove the include here because this is a provider driver. Cc: Daniel Mack <daniel@zonque.org> Cc: Haojian Zhuang <haojian.zhuang@gmail.com> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-14spi: xcomm: Drop owner assignment from i2c_driverKrzysztof Kozlowski
i2c_driver does not need to set an owner because i2c_register_driver() will set it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: zynq: missing break statementDan Carpenter
There is a missing break statement here so selecting both only selects upper. Fixes: dfe11a11d523 ('spi: Add support for Zynq Ultrascale+ MPSoC GQSPI controller') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: SPI_ZYNQMP_GQSPI should depend on HAS_DMAGeert Uytterhoeven
If NO_DMA=y: ERROR: "dma_unmap_single" [drivers/spi/spi-zynqmp-gqspi.ko] undefined! ERROR: "dma_mapping_error" [drivers/spi/spi-zynqmp-gqspi.ko] undefined! ERROR: "dma_map_single" [drivers/spi/spi-zynqmp-gqspi.ko] undefined! Add a dependency on HAS_DMA to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ranjit Waghmode <ranjitw@xilinx.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: spidev: add compatible value for LTC2488Jiri Prchal
Since spidev is no more allowed to use in DT and is really loudly warned about it I'd like to add this compatible value. (Geert Uytterhoeven wrote: "Add the compatible value for your device to the spidev_dt_ids[] array in drivers/spi/spidev.c.") Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: expose spi_master and spi_device statistics via sysfsMartin Sperl
per spi-master statistics accessible as: /sys/class/spi_master/spi*/statistics/* per spi-device statistics accessible via: /sys/class/spi_master/spi*/spi*.*/statistics/* The following statistics are exposed as separate "files" inside these directories: * messages number of spi_messages * transfers number of spi_transfers * bytes number of bytes transferred * bytes_rx number of bytes transmitted * bytes_tx number of bytes received * errors number of errors encounterd * timedout number of messages that have timed out * spi_async number of spi_messages submitted using spi_async * spi_sync number of spi_messages submitted using spi_sync * spi_sync_immediate number of spi_messages submitted using spi_sync, that are handled immediately without a context switch to the spi_pump worker-thread Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: sh-msiof: Remove obsolete spi_r8a779x_msiof platform_device_id entriesGeert Uytterhoeven
Since commit a483dcbfa21f919c ("ARM: shmobile: lager: Remove legacy board support"), R-Car Gen2 SoCs are only supported in generic DT-only ARM multi-platform builds. The driver doesn't need to match platform devices by name anymore, hence remove the corresponding platform_device_id entry. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi/rockchip: remove unnecessary memset of rockchip_spiAlexey Klimov
Memory for struct rockchip_spi is allocated by spi_alloc_master() using kzalloc() so it doesn't need to be set to 0 one more time. Signed-off-by: Alexey Klimov <klimov.linux@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi/s3c24xx: remove unnecessary memset of s3c24xx_spiAlexey Klimov
Memory for this struct is allocated by spi_alloc_master() using kzalloc() so it doesn't need to be set to 0 one more time. Signed-off-by: Alexey Klimov <klimov.linux@gmail.com> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: Fix per-page mapping of unaligned vmalloc-ed bufferAndrew Gabbasov
spi_map_buf() processes mapping of vmalloc-ed buffers in a special way, making mapping of every page separately. However, if the buffer is not aligned to page boundary (e.g. sub-array in a vmalloc-ed array), it fills the scatter table with page-size unaligned pieces, that cross page boundaries. This is incorrect and can, for example, cause memory corruption and various crashes when working with ubifs on spi-nor chips (though those drivers are themselves buggy in that they should be providing DMAable memory to the SPI framework). Fix this by using proper scatter table size and intra-page buffer lengths, so that the whole buffer splits into separate scatter table entries on page boundaries. Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-07spi: img-spfi: check for max speed supported by the spfi blockSifan Naeem
Maximum speed supported by spfi is limited to 1/4 of the spfi clock. But in some SoCs the maximum speed supported by the spfi block can be limited to less than 1/4 of the spfi clock. In such cases we have to define the limit in the device tree so that the driver can pick it up. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-03spi: rspi: Make qspi_set_send_trigger() return "unsigned int"Geert Uytterhoeven
qspi_set_send_trigger() returns an unsigned value, so make it return "unsigned int". Update the loop variables qspi_trigger_transfer_out_int() to match the above. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-03spi: rspi: Drop variable "error" in qspi_trigger_transfer_out_in()Geert Uytterhoeven
Just use "ret" instead, for consistency with other similar functions. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-22spi: img-spfi: fix support for speeds up to 1/4th input clockSifan Naeem
Setting the Same Edge bit indicates to the spfi block to receive and transmit data on the same edge of the spfi clock, which in turn doubles the operating frequency of spfi. The maximum supported frequency is limited to 1/4th of the spfi input clock, but without this bit set the maximum would be 1/8th of the input clock. The current driver calculates the divisor with maximum speed at 1/4th of the input clock, this would fail if the requested frequency is higher than 1/8 of the input clock. Any requests for 1/8th of the input clock would still pass. Fixes: 8543d0e72d43 ("spi: img-spfi: Limit bit clock to 1/4th of input clock") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: <stable@vger.kernel.org>
2015-06-18Merge remote-tracking branches 'spi/topic/sirf', 'spi/topic/spidev' and ↵Mark Brown
'spi/topic/zynq' into spi-next
2015-06-18Merge remote-tracking branches 'spi/topic/pxa', 'spi/topic/rb4xx', ↵Mark Brown
'spi/topic/rspi', 'spi/topic/s3c64xx' and 'spi/topic/sh-msiof' into spi-next
2015-06-18Merge remote-tracking branches 'spi/topic/fsl-dspi', 'spi/topic/gpio', ↵Mark Brown
'spi/topic/imx' and 'spi/topic/orion' into spi-next
2015-06-18Merge remote-tracking branches 'spi/topic/ath79', 'spi/topic/atmel' and ↵Mark Brown
'spi/topic/davinci' into spi-next
2015-06-18Merge remote-tracking branch 'spi/topic/omap2-mcspi' into spi-nextMark Brown
2015-06-18Merge remote-tracking branch 'spi/topic/bcm2835' into spi-nextMark Brown
2015-06-18Merge remote-tracking branches 'spi/fix/fsl-dspi', 'spi/fix/fsl-espi', ↵Mark Brown
'spi/fix/orion' and 'spi/fix/pl022' into spi-linus
2015-06-18Merge remote-tracking branch 'spi/fix/core' into spi-linusMark Brown
2015-06-17spi: zynq: Remove execute bitMark Brown
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-16spi: atmel: add support to FIFOsCyrille Pitchen
The latest SPI controllers embedded inside sama5d2x SoCs come with FIFOs. When FIFOs are enabled, they can either work in SINGLE data mode or MULTIPLE data mode. The selected mode depends on the configuration of the SPI controller (see below). In SINGLE data mode (or legacy mode), for a single I/O access, only one data can be read from the Receive Data Register (RDR) or written into the Transmit Data Register (TDR). On the other hand, in MULTIPLE data mode, up to 4 data can be read from the RDR or up 2 data can be written into the TDR in a single 32bit I/O access. So programmers should take good care of the width of the I/O access to read/write the right number of data. The exact number of read/written data depends on both the I/O access width and the data width (from 8 up to 16 bits). To enable the FIFO feature a "atmel,fifo-size" property must be set to provide the maximum number of data (not bytes) the RX and TX FIFOs can store. Hence a 32 data FIFO can always store up to 32 data unrelated with the actual data width. When FIFOs are enabled, the RX one is forced to operate in SINGLE data mode because this driver configures the spi controller as a master. In master mode only, the Received Data Register has an additionnal Peripheral Chip Select field, which prevents us from reading more than a single data at each register access. Besides, the TX FIFO operates in MULTIPLE data mode. However, even when a 8bit data size is used, only two data by access could be written into the Transmit Data Register. Indeed the first data has to be written into the lowest 16 bits whereas the second data has to be written into the highest 16 bits of the TDR. When DMA transfers are used to send data, we don't rework the transmit buffer to cope with this hardware limitation: the additional copies required to prepare a new input buffer suited to both the DMA controller and the spi controller would waste all the benefit of the DMA transfer. Instead, the DMA controller is configured to write only one data at time into the TDR. In pio mode, two data are written in the TDR in a single access. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-15spi: pxa2xx: Constify ACPI device idsMathias Krause
Constify the ACPI device ID array, it doesn't need to be writable at runtime. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-12spi: Add support for Zynq Ultrascale+ MPSoC GQSPI controllerRanjit Waghmode
This patch adds support for GQSPI controller driver used by Zynq Ultrascale+ MPSoC Signed-off-by: Ranjit Waghmode <ranjit.waghmode@xilinx.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-12spi: fsl-dspi: Use pinctrl PM helpersMirza Krak
Add support for "sleep" state of pinctrl. Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-10spi: davinci: change the lower limit of pre-scale divider to 1Murali Karicheri
SPI hardware spec for Keystone specify a lower value of 0 for pre-scale divider which determine what max value of spi clock (spi-max-frequency) the device can support. This translates to a clock divider of 2. So fix the lower limit value used for the boundary check in davinci_spi_get_prescale() function to 1 so that a maximum of spi device clock rate / 2 is possible to be set for spi-max-frequency. Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Acked-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09spi: spi-fsl-dspi: Change the way of increasing spi_message->actual_lengthHaikun Wang
In current driver, we increase actual_length in the following way: message->actual_length += dspi_xxx_transfer() It has two defects. First, transmitting maybe in process when the function call finished and we don't know the transmitting result in this moment. Secondly, the last sentence in function before returning is accessing the SPI register and trigger the data transmitting. If we enable interrupt, interrupt may be generated before function return and we also have the same sentence "message->actual_length += dspi_xxx_transfer()" in the IRQ handler. And usually dspi_xxx_transfer will trigger a new IRQ. The original dspi_xxx_transfer call may return when no new IRQ generate. This may mess the variable spi_message->actual_length. Now we increase the variable in the IRQ handler and only when we get the TCF or EOQ interrupt And we get the transmitted data length from the SPI transfer counter instead of the function return value. Signed-off-by: Haikun Wang <haikun.wang@freescale.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09spi: spi-fsl-dspi: Enable TCF interrupt mode supportHaikun Wang
DSPI module has two optional interrupts when complete data transfer. One is EOQ interrupt, the other one is TCF interrupt. EOQ indicates a queue of data frame has been transmitted. TCF indicates a frame has been transmitted. This patch enable support TCF mode. Driver binds a correct interrupt mode to every compatible string. User should use the correct compatible string in the dts node. Signed-off-by: Haikun Wang <haikun.wang@freescale.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09Merge branch 'fix/fsl-dspi' of ↵Mark Brown
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-fsl-dspi
2015-06-09spi: atmel: add support for the internal chip-select of the spi controllerCyrille Pitchen
This patch relies on the CSAAT (Chip Select Active After Transfer) feature introduced by the version 2 of the spi controller. This new mode allows to use properly the internal chip-select output pin of the spi controller instead of using external gpios. Consequently, the "cs-gpios" device-tree property becomes optional. When the new CSAAT bit is set into the Chip Select Register, the internal chip-select output pin remains asserted till both the following conditions become true: - the LASTXFER bit is set into the Control Register (or the Transmit Data Register) - the Transmit Data Register and its shift register are empty. WARNING: if the LASTXFER bit is set into the Control Register then new data are written into the Transmit Data Register fast enough to keep its shifter not empty, the chip-select output pin remains asserted. Only when the shifter becomes empty, the chip-select output pin is unasserted. When the CSAAT bit is clear in the Chip Select Register, the LASTXFER bit is ignored in both the Control Register and the Transmit Data Register. The internal chip-select output pin remains active as long as the Transmit Data Register or its shift register are not empty. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-09spi: spi-pxa2xx: remove legacy PXA DMA bitsDaniel Mack
Generic DMA support was already implemented by commit cd7bed003404 ("spi/pxa2xx: break out the private DMA API usage into a separate file") which moved all the legacy PXA DMA implementation code into its own file. With generic DMA available for PXA, we can now just trash this file. Signed-off-by: Daniel Mack <zonque@gmail.com> Acked-by: Mark Brown <broonie@linaro.org> [respin after pxa dmaengine support upstream] Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-05spi: pxa2xx: Make LPSS SPI general register optionalJarkko Nikula
General register located in LPSS SPI private register space is not found in upcoming Intel LPSS platforms. Access it conditionally depending is it defined in configuration. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-05spi: pxa2xx: Prepare for new Intel LPSS SPI typeJarkko Nikula
Some of the Intel LPSS SPI properties will be different in upcoming platforms compared to existing Lynxpoint and BayTrail/Braswell. LPSS SPI private registers will be at different offset and there will be changes in individual registers and default FIFO thresholds too. Add configuration for these differences and use them in runtime based on LPSS SSP type. With this change private registers offset autodetection becomes needless. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-05spi: pxa2xx: Differentiate Intel LPSS typesJarkko Nikula
Intel LPSS SPI properties differ between between platforms. Now private registers offset 0x400 or 0x800 is autodetected but there is need to support also other offset and handle a few other differences. Prepare for that by splitting the LPSS_SSP type into compatible hardware types and set it now based on PCI or ACPI ID. That type will be used to set properties that differ between current and upcoming platforms. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-02spi: restore rx/tx_buf in case of unset CONFIG_HAS_DMAMartin Sperl
The case where spi_master sets the flags SPI_MASTER_MUST_RX/TX while CONFIG_HAS_DMA is unset (which is unlikley) together with a driver that reuses spi_messages with rx/tx_buff set to NULL, can result in: * data disclosure over the SPI (for tx_buf == NULL) * memory corruption (for rx_buf == NULL) This happenes when dummy_rx/dummy_tx are changing address due to krealloc or free and an allocation of the memory by a different part of the kernel. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-02spi: rspi: Re-do the returning value of qspi_transfer_out_inHiep Cao Minh
To reduce complexity of code, drop "ret" then qspi_transfer_out_in function should return the value of "qspi_trigger_transfer_out_in" directly. Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-06-02spi: rspi: modify the name of "qspi_trigger_transfer_out_int" functionHiep Cao Minh
The name of "qspi_trigger_transfer_out_int" function should be "qspi_trigger_transfer_out_in" without "t". Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-27spi: orion: Fix extended baud rates for each Armada SoCsGregory CLEMENT
The commit df59fa7f4bca "spi: orion: support armada extended baud rates" made the assumptions that all the Armada SoCs supported the same maximum frequency. However, according the hardware datasheet, the maximum frequency supported by the Armada 370 SoC is tclk/4, for the Armada XP, Armada 38x and Armada 39x SoCs the limitation is 50MHz and for the Armada 375 it is tclk/15. This patch introduces new compatible strings to handle all these case. In order to be future proof a compatible was created for each SoC even if currently some SoCs seem using the same IP. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-26spi: sirf: add the reset for USP-based SPIQipan Li
USP-based SPI need a disable and enable, otherwise it doesn't work. this patch adds it as HW initialization. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-26spi: sirf: remove the allocation of dummypageQipan Li
this job has been done by spi core. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-26spi: orion: Fix maximum baud rates for Armada 370/XPGregory CLEMENT
The commit df59fa7f4bca "spi: orion: support armada extended baud rates" was too optimistic for the maximum baud rate that the Armada SoCs can support. According to the hardware datasheet the maximum frequency supported by the Armada 370 SoC is tclk/4. But for the Armada XP, Armada 38x and Armada 39x SoCs the limitation is 50MHz and for the Armada 375 it is tclk/15. Currently the armada-370-spi compatible is only used by the Armada 370 and the Armada XP device tree. On Armada 370, tclk cannot be higher than 200MHz. In order to be able to handle both SoCs, we can take the minimum of 50MHz and tclk/4. A proper solution is adding a compatible string for each SoC, but it can't be done as a fix for compatibility reason (we can't modify device tree that have been already released) and it will be part of a separate patch. Fixes: df59fa7f4bca (spi: orion: support armada extended baud rates) Reported-by: Kostya Porotchkin <kostap@marvell.com> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: <stable@vger.kernel.org>
2015-05-25spi: omap2-mcspi: Handle error on gpio_requestMichael Welling
If a valid GPIO is specified but cannot be requested by the driver, print a message and error out of omap2_mcspi_setup. Signed-off-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-25spi: omap2-mcspi: Fix GPIO chip select supportMichael Welling
The OMAP2_MCSPI_CHCONF_FORCE must be toggled even when using GPIO chip selects. This patch conditionally calls the omap2_mcspi_set_cs function to do so when using GPIO chip selects. Signed-off-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-25spi: omap2-mcspi: Fix set_cs function for active highMichael Welling
The core spi driver swaps the polarity of the enable based on SPI_CS_HIGH. The omap2 controller has an internal configuration register bit called OMAP2_MCSPI_CHCONF_EPOL to handle active high chip selects as well. So we have to revert swap the polarity back for the correct setting of the OMAP2_MCSPI_CHCONF_FORCE bit in omap2_mcspi_set_cs. Signed-off-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-25spi: omap2-mcspi: Remove unnecessary delayMichael Welling
The core spi driver handles the delay between transactions. This is a remanant from the transfer_one conversion. Signed-off-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-21spi: fsl-espi: Fix an error that can cause fsl espi task blockedJane Wan
Incorrect condition is used in spin_event_timeout(). When the TX is done, the SPIE_NF bit in ESPI_SPIE register is set to 1 to indicate the Tx FIFO is not full. If the bit is 0, it indicates the Tx FIFO is full. Due to this error, if the Tx FIFO is full at the beginning, but becomes not full after handling the Rx FIFO (the SPIE_NF bit is set), the spin_event_timeout() returns with timeout occurred. It causes the interrupt handler not to send completion notification to the thread that called wait_for_complete() waiting for the notification. Signed-off-by: Jane Wan <Jane.Wan@gainspeed.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-21spi: spi-fsl-dspi: Bug fix incorrect CS de-assertHaikun Wang
SPI chip select signal need to keep asserted between several spi_transfer in the same spi_message usually. But the driver will de-assert CS signal and the assert it between serval spi_transfer in the same spi_message under some condiations. This patch fix the bug. Here is an example: Assume you have two variables like the following, struct spi_transfer a; struct spi_transfer b; if you send a spi_message only includes 'a' first, and then you send a spi_message includes 'a' and 'b' but without resetting 'a'. Driver will de-assert CS and then assert CS between 'a' and 'b'. Signed-off-by: Haikun Wang <haikun.wang@freescale.com> Signed-off-by: Mark Brown <broonie@kernel.org>