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path: root/drivers/spi
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2018-09-18spi/bcm63xx-hsspi: keep pll clk enabledJonas Gorski
If the pll clock needs to be enabled to get its rate, it will also need to be enabled to provide it. So ensure it is kept enabled through the lifetime of the device. Fixes: 0d7412ed1f5dc ("spi/bcm63xx-hspi: Enable the clock before calling clk_get_rate().") Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-17spi: pxa2xx: Remove the shutdown callbackLubomir Rintel
It makes no sense to remove the device on shutdown. And it break things when the hardware crucial for shutdown (such as the embedded controller) is attached to the SPI bus. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-17spi: spi-davinci: Add support for SPI_CS_WORDDavid Lechner
This adds support for the SPI_CS_WORD flag to the TI DaVinci SPI driver. This mode can be used as long as we are using the hardware chip select and not a GPIO chip select. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-17Merge tag 'spi-cs-word' into spi-4.20Mark Brown
spi: Provide SPI_CS_WORD This provides a SPI operation mode which changes chip select after every word, used by some devices such as ADCs and DACs.
2018-09-17spi: add software implementation for SPI_CS_WORDDavid Lechner
This adds a default software implementation for the SPI_CS_WORD flag for controllers that don't have such a feature. The SPI_CS_WORD flag indicates that the CS line should be toggled between each word sent, not just between each transfer. The implementation works by using existing functions to split transfers into one-word-sized transfers and sets the cs_change bit for each of the new transfers. Signed-off-by: David Lechner <david@lechnology.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-17Merge tag 'spi-fix-v4.19-rc4' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi Mark writes: "spi: Fixes for v4.19 As well as one driver fix there's a couple of fixes here which address issues with the use of IDRs for allocation of dynamic bus numbers, ensuring that dynamic bus numbers interact well with static bus numbers assigned via DT and otherwise." * tag 'spi-fix-v4.19-rc4' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: spi: spi-fsl-dspi: fix broken DSPI_EOQ_MODE spi: Fix double IDR allocation with DT aliases spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers
2018-09-17spi: pic32-sqi: remove unnecessary of_node_get()Alexey Khoroshilov
Almost all spi drivers assign spi master->dev.of_node from its parent platform device without additional refcounting. It seems of_node_get() in pic32_sqi_probe() is unnecessary and there is no corresponding of_node_put(). Found by Linux Driver Verification project (linuxtesting.org) Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-13spi: davinci: remove set but not used variable 'pdata'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/spi/spi-davinci.c: In function 'davinci_spi_setup': drivers/spi/spi-davinci.c:422:36: warning: variable 'pdata' set but not used [-Wunused-but-set-variable] Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-11spi: davinci: Remove chip select GPIO pdataLinus Walleij
The DaVinci SPI can use either: - Internal chip selects (inside the SPI host) - External chip selects (using GPIO) - External chip selects passed in pdata The last way of passing external chip selects through platform data is not used in the kernel. Delete it to make the code simpler when refactoring GPIO. Cc: Sekhar Nori <nsekhar@ti.com> Cc: Kevin Hilman <khilman@kernel.org> Cc: Michele Dionisio <michele.dionisio@gmail.com> Cc: Frode Isaksen <fisaksen@baylibre.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-11spi: at91-usart: Make local functions staticLee Jones
Suggested-by: Radu Nicolae Pirea <pirea.radu@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-09-10spi: spi-mem: Adjust op len based on message/transfer size limitationsChuanhua Han
We need that to adjust the len of the 2nd transfer (called data in spi-mem) if it's too long to fit in a SPI message or SPI transfer. Fixes: c36ff266dc82 ("spi: Extend the core to ease integration of SPI memory controllers") Cc: <stable@vger.kernel.org> Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com> Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-10spi: at91-usart: Add driver for at91-usart as SPIRadu Pirea
This is the driver for at91-usart in spi mode. The USART IP can be configured to work in many modes and one of them is SPI. The driver was tested on sama5d3-xplained and sama5d4-xplained boards with enc28j60 ethernet controller as slave. Signed-off-by: Radu Pirea <radu.pirea@microchip.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviwed-by: Mark Brown <broonie@kernel.org> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-09-10spi: gpio: No MISO does not imply no RXLinus Walleij
There is a logical problem in spi-gpio with host just assigning a MOSI line and no MISO: this is interpreted as the host cannot do RX and the host is flagged with SPI_MASTER_NO_RX. This is wrong: since GPIO lines can switch direction, in 3WIRE operation the host will simply reverse the direction of the GPIO line and start reading from it, there is even code for doing this in the driver, but it went unnoticed because it was tested by using a master with 4 wires but a device using just 3 wires. Remove the offending flag. Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-07spi: pic32: remove unnecessary of_node_get()Alexey Khoroshilov
Almost all spi drivers assign spi master->dev.of_node from its parent platform device without additional refcounting. It seems of_node_get() in pic32_spi_probe() is unnecessary and there is no corresponding of_node_put(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-07spi: pl022: Remove set but not used variable 'chip'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/spi/spi-pl022.c: In function 'do_polling_transfer': drivers/spi/spi-pl022.c:1493:20: warning: variable 'chip' set but not used [-Wunused-but-set-variable] Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-06spi: dw: support 4-16 bits per wordSimon Goldschmidt
The spi-dw driver currently only supports 8 or 16 bits per word. Since the hardware supports 4-16 bits per word, adapt the driver to also support this. Tested on socfpga cyclone5 with a 9-bit SPI display. Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-06spi: spi-gpio: Remove set but not used variable 'pdata'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/spi/spi-gpio.c: In function 'spi_gpio_remove': drivers/spi/spi-gpio.c:450:33: warning: variable 'pdata' set but not used [-Wunused-but-set-variable] Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-05spi: rspi: Fix interrupted DMA transfersGeert Uytterhoeven
When interrupted, wait_event_interruptible_timeout() returns -ERESTARTSYS, and the SPI transfer in progress will fail, as expected: m25p80 spi0.0: SPI transfer failed: -512 spi_master spi0: failed to transfer one message from queue However, as the underlying DMA transfers may not have completed, all subsequent SPI transfers may start to fail: spi_master spi0: receive timeout qspi_transfer_out_in() returned -110 m25p80 spi0.0: SPI transfer failed: -110 spi_master spi0: failed to transfer one message from queue Fix this by calling dmaengine_terminate_all() not only for timeouts, but also for errors. This can be reproduced on r8a7991/koelsch, using "hd /dev/mtd0" followed by CTRL-C. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-09-05spi: rspi: Fix invalid SPI use during system suspendGeert Uytterhoeven
If the SPI queue is running during system suspend, the system may lock up. Fix this by stopping/restarting the queue during system suspend/resume, by calling spi_master_suspend()/spi_master_resume() from the PM callbacks. In-kernel users will receive an -ESHUTDOWN error while system suspend/resume is in progress. Based on a patch for sh-msiof by Gaku Inami. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-09-05spi: sh-msiof: Fix handling of write value for SISTR registerHiromitsu Yamasaki
This patch changes writing to the SISTR register according to the H/W user's manual. The TDREQ bit and RDREQ bits of SISTR are read-only, and must be written their initial values of zero. Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> [geert: reword] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-09-05spi: sh-msiof: Fix invalid SPI use during system suspendGaku Inami
If the SPI queue is running during system suspend, the system may lock up. Fix this by stopping/restarting the queue during system suspend/resume by calling spi_master_suspend()/spi_master_resume() from the PM callbacks. In-kernel users will receive an -ESHUTDOWN error while system suspend/resume is in progress. Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com> Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> [geert: Cleanup, reword] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-09-05spi: Do not print a message if spi_controller_{suspend,resume}() failsGeert Uytterhoeven
spi_controller_{suspend,resume}() already prints an error message on failure, so there is no need to repeat this in individual drivers. Note: spi_master_{suspend,resume}() is an alias for spi_controller_{suspend,resume}(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Daniel Mack <daniel@zonque.org> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-04spi: gpio: Fix copy-and-paste errorLinus Walleij
This fixes an embarrassing copy-and-paste error in the errorpath of spi_gpio_request(): we were checking the wrong struct member for error code right after retrieveing the sck GPIO. Fixes: 9b00bc7b901ff672 ("spi: spi-gpio: Rewrite to use GPIO descriptors") Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-03spi: orion: cosmetics - alias long direct_access variablesKosta Zertsekel
This change increases the source code readability. Instead of using `spi->child[cs].direct_access.XXX` use `dir_acc->XXX`. Instead of using `orion_spi->child[cs].direct_access.vaddr` use `vaddr`. Signed-off-by: Kosta Zertsekel <zertsekel@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Stefan Roese <sr@denx.de> Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-03spi: tegra20-slink: explicitly enable/disable clockMarcel Ziswiler
Depending on the SPI instance one may get an interrupt storm upon requesting resp. interrupt unless the clock is explicitly enabled beforehand. This has been observed trying to bring up instance 4 on T20. Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-08-31spi: dw-mmio: avoid hardcoded field maskAlexandre Belloni
Define a mask for the IF_SI_OWNER field. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-30spi: davinci: remove set but not used variable 'pdata'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/spi/spi-davinci.c: In function 'davinci_spi_chipselect': drivers/spi/spi-davinci.c:211:36: warning: variable 'pdata' set but not used [-Wunused-but-set-variable] Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-29spi: dw-mmio: add MSCC Jaguar2 supportAlexandre Belloni
Unfortunately, the Jaguar2 CPU_SYSTEM_CTRL register set has a different layout than the Ocelot one. Handle that while keeping most of the code common. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-28spi: sprd: Add SPI driver for Spreadtrum SC9860Lanqing Liu
This patch adds the SPI controller driver for Spreadtrum SC9860 platform. Signed-off-by: Lanqing Liu <lanqing.liu@spreadtrum.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-28spi: spi-fsl-dspi: fix broken DSPI_EOQ_MODEAngelo Dureghello
This patch fixes the dspi_eoq_write function used by the ColdFire mcf5441x family. The 16 bit cmd part must be re-set at each data transfer. Also, now that fifo_size variables are used for eoq_read/write, a proper fifo size must be set (16 slots for the ColdFire dspi module version). Signed-off-by: Angelo Dureghello <angelo@sysam.it> Acked-by: Esben Haabendal <esben@haabendal.dk> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-08-28spi: Fix double IDR allocation with DT aliasesGeert Uytterhoeven
If the SPI bus number is provided by a DT alias, idr_alloc() is called twice, leading to: WARNING: CPU: 1 PID: 1 at drivers/spi/spi.c:2179 spi_register_controller+0x11c/0x5d8 couldn't get idr Fix this by moving the handling of fixed SPI bus numbers up, before the DT handling code fills in ctlr->bus_num. Fixes: 1a4327fbf4554d5b ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-28spi: use SPDX identifier for Renesas driversWolfram Sang
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-18Merge tag 'hwlock-v4.19' of git://github.com/andersson/remoteprocLinus Torvalds
Pull hwspinlock updates from Bjorn Andersson: "This introduces devres helpers and an API to request a lock by name, then migrates the sprd SPI driver to use these" * tag 'hwlock-v4.19' of git://github.com/andersson/remoteproc: hwspinlock: Fix incorrect return pointers spi: sprd: Change to use devm_hwspin_lock_request_specific() spi: sprd: Replace of_hwspin_lock_get_id() with of_hwspin_lock_get_id_byname() hwspinlock: Fix one comment mistake hwspinlock: Remove redundant config hwspinlock: Add devm_xxx() APIs to register/unregister one hwlock controller hwspinlock: Add devm_xxx() APIs to request/free hwlock hwspinlock: Add one new API to support getting a specific hwlock by the name
2018-08-15spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbersKirill Kapranov
On systems where some controllers get a dynamic ID assigned and some have a fixed number (e.g. from ACPI tables), the current implementation might run into an IDR collision: in case of a fixed bus number is gotten by a driver (but not marked busy in IDR tree) and a driver with dynamic bus number gets the same ID and predictably fails. Fix this by means of checking-in fixed IDsin IDR as far as dynamic ones at the moment of the controller registration. Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-08-10Merge branch 'spi-4.19' into spi-nextMark Brown
2018-08-10Merge branch 'spi-4.18' into spi-linusMark Brown
2018-08-10spi: davinci: fix a NULL pointer dereferenceBartosz Golaszewski
On non-OF systems spi->controlled_data may be NULL. This causes a NULL pointer derefence on dm365-evm. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2018-08-02spi: spi-mem: Extend the SPI mem interface to set a custom memory nameFrieder Schrempf
When porting (Q)SPI controller drivers from the MTD layer to the SPI layer, the naming scheme for the memory devices changes. To be able to keep compatibility with the old drivers naming scheme, a name field is added to struct spi_mem and a hook is added to let controller drivers set a custom name for the memory device. Example for the FSL QSPI driver: Name with the old driver: 21e0000.qspi, or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ... Name with the new driver without spi_mem_get_name: spi4.0 Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de> Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-02spi: uniphier: remove unnecessary include headersKeiji Hayashibara
This commit removed include headers of linux/of.h and linux/of_platform.h, because they are not used. Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-01spi: spi-gpio: add SPI_3WIRE supportLorenzo Bianconi
Add SPI_3WIRE support to spi-gpio controller introducing set_line_direction function pointer in spi_bitbang data structure. Spi-gpio controller has been tested using hts221 temp/rh iio sensor running in 3wire mode and lsm6dsm running in 4wire mode Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-01spi: add flags parameter to txrx_word function pointersLorenzo Bianconi
Add the capability to specify the flag parameter used in bitbang_txrx_be_cpha{0,1} through the txrx_word function pointers of spi_bitbang data structure. That feature will be used to add spi-3wire support to the spi-gpio controller Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-01spi: add SPI controller driver for UniPhier SoCKeiji Hayashibara
Add SPI controller driver implemented in Socionext UniPhier SoCs. UniPhier SoCs have two types SPI controllers; SCSSI supports a single channel, and MCSSI supports multiple channels. This driver supports SCSSI only. This controller has 32bit TX/RX FIFO with depth of eight entry, and supports the SPI master mode only. This commit is implemented in PIO transfer mode, not DMA transfer. Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-30spi: img-spfi: Set device select bits for SPFI port stateIonela Voinescu
Even if the chip select line is not controlled by the SPFI hardware, the device select bits need to be set to specify the chip select line in use for the hardware to know what parameters to use for the current transfer. Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com> Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-30spi: omap2-mcspi: remove several redundant variablesColin Ian King
Variable count, l, mcspi and spi_cntrl are being assigned but are never used hence they are redundant and can be removed. Cleans up clang warnings: warning: variable 'count' set but not used [-Wunused-but-set-variable] warning: variable 'l' set but not used [-Wunused-but-set-variable] warning: variable 'mcspi' set but not used [-Wunused-but-set-variable] warning: variable 'spi_cntrl' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-30spi: dw-mmio: add MSCC Ocelot supportAlexandre Belloni
Because the SPI controller deasserts the chip select when the TX fifo is empty (which may happen in the middle of a transfer), the CS should be handled by linux. Unfortunately, some or all of the first four chip selects are not muxable as GPIOs, depending on the SoC. There is a way to bitbang those pins by using the SPI boot controller so use it to set the chip selects. At init time, it is also necessary to give control of the SPI interface to the Designware IP. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-30spi: dw: export dw_spi_set_csAlexandre Belloni
Export dw_spi_set_cs so it can be used from the various IP integration modules. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-26spi: spi-fsl-espi: Log fifo counters on errorTiago Brusamarello
Log RX and TX fifo counters when a transfer is done and these are not zero. Signed-off-by: Tiago Brusamarello <tiago.brusamarello@datacom.ind.br> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-24spi: imx: Use the longuest possible burst size when in dynamic_burstMaxime Chevallier
Dynamic burst mode allows to group together multiple words and send them in one continuous burst. When the number of bytes to be sent is not a strict multiple of the FIFO entry size (32 bits), the controller expects the non aligned bits to be sent first. This commit adds support for this particular constraint, avoiding the need to send the non-aligned bytes one by one at the end of the transfer, speeding-up transfer speed in that case. With this method, a transfer is divided into multiple bursts, limited in size by the maximum amount of data that the controller can transfer in one continuous burst (which is 512 bytes). The non-512 byte part of the transfer is sent first. The remaining bytes to be transferred in the current burst is stored in the 'remainder' field. With this method, the read_u32 field is no longer necessary, and is removed. This was tested on imx6 solo and imx6 quad. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-24spi: imx: remove unnecessary check in spi_imx_can_dmaMaxime Chevallier
The spi_imx_can_dma function computes the watermark level so that the transfer will fit in exactly N bursts (without a remainder). The smallest watermark level possible being one FIFO entry per burst, we can't never have a case where the transfer size isn't divsiible by 1. Remove the extra check for the wml being different than 0. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-24spi: imx: Use correct number of bytes per wordsMaxime Chevallier
The SPI core enforces that we always use the next power-of-two number of bytes to store words. As a result, a 24 bits word will be stored in 4 bytes. This commit fixes the spi_imx_bytes_per_word function to return the correct number of bytes. This also allows to get rid of unnecessary checks in the can_dma function, since the SPI core validates that we always have a transfer length that is a multiple of the number of bytes per word. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>