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path: root/drivers/spi/spi-bcm2835.c
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2015-04-10spi: bcm2835: transform native-cs to gpio-cs on first spi_setupMartin Sperl1-5/+44
Transforms the bcm-2835 native SPI-chip select to their gpio-cs equivalent. This allows for some support of some optimizations that are not possible due to HW-gliches on the CS line - especially filling the FIFO before enabling SPI interrupts (by writing to CS register) while the transfer is already in progress (See commit: e3a2be3030e2) This patch also works arround some issues in bcm2835-pinctrl which does not set the value when setting the GPIO as output - it just sets up output and (typically) leaves the GPIO as low. When a fix for this is merged then this gpio_set_value can get removed from bcm2835_spi_setup. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-29spi: bcm2835: fill FIFO before enabling interrupts to reduce interrupts/messageMartin Sperl1-0/+16
To reduce the number of interrupts/message we fill the FIFO before enabling interrupts - for short messages this reduces the interrupt count from 2 to 1 interrupt. There have been rare cases where short (<200ns) chip-select switches with native CS have been observed during such operation, this is why this optimization is only enabled for GPIO-CS. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Tested-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-29spi: bcm2835: fix code formatting issueMartin Sperl1-2/+1
Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Tested-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-27spi: bcm2835: move to the transfer_one driver modelMartin Sperl1-88/+124
This also allows for GPIO-CS to get used removing the limitation of 2/3 SPI devises on the SPI bus. Fixes: spi-cs-high with native CS with multiple devices on the spi-bus resetting the chip selects to "normal" polarity after a finished transfer. No other functionality/improvements added. Tested with the following 4 devices on the spi-bus: * mcp2515 with native CS * mcp2515 with gpio CS * fb_st7735r with native CS (plus spi-cs-high via transistor inverting polarity) * enc28j60 with gpio-CS Tested-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-23spi: bcm2835: enable support of 3-wire modeMartin Sperl1-1/+5
Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-23spi: bcm2835: clock divider can be a multiple of 2Martin Sperl1-2/+3
The official documentation is wrong in this respect. Has been tested empirically for dividers 2-1024 Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-23spi: bcm2835: fill/drain SPI-fifo as much as possible during interruptMartin Sperl1-61/+17
Implement the recommendation from the BCM2835 data-sheet with regards to polling drivers to fill/drain the FIFO as much data as possible also for the interrupt-driven case (which this driver is making use of). This means that for long transfers (>64bytes) we need one interrupt every 64 bytes instead of every 12 bytes, as the FIFO is 16 words (not bytes) wide. Tested with mcp251x (can bus), fb_st7735 (TFT framebuffer device) and enc28j60 (ethernet) drivers. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-20spi: bcm2835: fix all checkpath --strict messagesMartin Sperl1-7/+11
The following errors/warnings issued by checkpatch.pl --strict have been fixed: drivers/spi/spi-bcm2835.c:182: CHECK: Alignment should match open parenthesis drivers/spi/spi-bcm2835.c:191: CHECK: braces {} should be used on all arms of this statement drivers/spi/spi-bcm2835.c:234: CHECK: Alignment should match open parenthesis drivers/spi/spi-bcm2835.c:256: CHECK: Alignment should match open parenthesis drivers/spi/spi-bcm2835.c:271: CHECK: Alignment should match open parenthesis drivers/spi/spi-bcm2835.c:346: CHECK: Alignment should match open parenthesis total: 0 errors, 0 warnings, 6 checks, 403 lines checked In 2 locations the arguments had to get split/moved to the next line so that the line width stays below 80 chars. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2014-12-22spi: Remove FSF mailing addressesJarkko Nikula1-4/+0
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-20spi: drop owner assignment from platform_driversWolfram Sang1-1/+0
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-02-16spi: Remove explictly set bus_num and num_chipselect to default settingAxel Lin1-1/+0
The purpose of commit 1e8a52e18cfb "spi: By default setup spi_masters with 1 chipselect and dynamics bus number" is to avoid setting default value for bus_num and num_chipselect in spi master drivers. So let's remove the duplicate code. Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-By: David Daney <david.daney@cavium.com> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-18spi: bcm2835: Use devm_request_irq()Jingoo Han1-7/+3
Use devm_request_irq() to make cleanup paths simpler. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-11-28Merge remote-tracking branches 'spi/fix/bcm2835', 'spi/fix/bcm63xx', ↵Mark Brown1-1/+1
'spi/fix/mpc512x-psc', 'spi/fix/mxs', 'spi/fix/pxa2xx', 'spi/fix/qspi', 'spi/fix/rspi' and 'spi/fix/txx9' into spi-linus
2013-11-15spi: bcm2835: fix reference leak to master in bcm2835_spi_remove()Wei Yongjun1-1/+1
Once a spi_master_get() call succeeds, we need an additional spi_master_put() call to free the memory, otherwise we will leak a reference to master. Fix by removing the unnecessary spi_master_get() call. Fixes: 247263dba208 ('spi: bcm2835: use devm_spi_register_master()') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-11-15tree-wide: use reinit_completion instead of INIT_COMPLETIONWolfram Sang1-1/+1
Use this new function to make code more comprehensible, since we are reinitialzing the completion, not initializing. [akpm@linux-foundation.org: linux-next resyncs] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-26spi: bcm2835: use devm_spi_register_master()Jingoo Han1-3/+1
Use devm_spi_register_master() to make cleanup paths simpler, and remove a duplicate put. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-08-22spi: bcm2835: Add spi_master_get() call to prevent use after freeAxel Lin1-1/+1
The call to spi_unregister_master results in device memory being freed, it must no longer be accessed afterwards. Thus call spi_master_get() to get an extra reference to the device and call spi_master_put() only after the last access to device data. Note, current code has an extra spi_master_put() call in bcm2835_spi_remove(). Thus this patch just adds an spi_master_get() to balance the reference count. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-08-05spi: bcm2835: Use SPI_BPW_MASK macro for bits_per_word_mask settingAxel Lin1-1/+1
We have a SPI_BPW_MASK macro defined in spi.h, use it instead of open-coded. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-24spi: bcm2835: don't check resource with devm_ioremap_resourceWolfram Sang1-6/+0
devm_ioremap_resource does sanity checks on the given resource. No need to duplicate this in the driver. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-05-13spi: bmc2835: use devm_ioremap_resource()Laurent Navet1-4/+3
Replace a call to deprecated devm_request_and_ioremap by devm_ioremap_resource. Found with coccicheck and this semantic patch: scripts/coccinelle/api/devm_request_and_ioremap.cocci. Signed-off-by: Laurent Navet <laurent.navet@gmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2013-04-01spi: bcm2835: make use of new bits_per_word_mask core featureStephen Warren1-35/+1
This driver only supports bits_per_word==8, so inform the SPI core of this. Remove all the open-coded validation that's no longer needed. Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2013-03-12spi: add driver for BCM2835Chris Boot1-0/+456
The BCM2835 contains two forms of SPI master controller (one known simply as SPI0, and the other known as the "Universal SPI Master", in the auxilliary block) and one form of SPI slave controller. This patch adds support for the SPI0 controller. This driver is taken from Chris Boot's repository at git://github.com/bootc/linux.git rpi-linear as of commit 6de2905 "spi-bcm2708: fix printf with spurious %s". In the first SPI-related commit there, Chris wrote: Thanks to csoutreach / A Robinson for his driver which I used as an inspiration. You can find his version here: http://piface.openlx.org.uk/raspberry-pi-spi-kernel-driver-available-for Changes made during upstreaming: * Renamed bcm2708 to bcm2835 as per upstream naming for this SoC. * Removed support for brcm,realtime property. * Increased transfer timeout to 30 seconds. * Return IRQ_NONE from the IRQ handler if no interrupt was handled. * Disable TA (Transfer Active) and clear FIFOs on a transfer timeout. * Wrote device tree binding documentation. * Request unnamed clock rather than "sys_pclk"; the DT will provide the correct clock. * Assume that tfr->speed_hz and tfr->bits_per_word are always set in bcm2835_spi_start_transfer(), bcm2835_spi_transfer_one(), so no need to check spi->speed_hz or tft->bits_per_word. * Re-ordered probe() to remove the need for temporary variables. * Call clk_disable_unprepare() rather than just clk_unprepare() on probe() failure. * Don't use devm_request_irq(), to ensure that the IRQ doesn't fire after we've torn down the device, but not unhooked the IRQ. * Moved probe()'s call to clk_prepare_enable() so we can be sure the clock is enabled if the IRQ handler fires immediately. * Remove redundant checks from bcm2835_spi_check_transfer() and bcm2835_spi_setup(). * Re-ordered IRQ handler to check for RXR before DONE. Added comments to ISR. * Removed empty prepare/unprepare implementations. * Removed use of devinit/devexit. * Added BCM2835_ prefix to defines. Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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