- 29 May, 2020 9 commits
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Serge Semin authored
Generic DMA support is going to be part of the DW APB SSI core object. In order to preserve the kernel loadable module name as spi-dw.ko, let's add the "-core" suffix to the object with generic DW APB SSI code and build it into the target spi-dw.ko driver. Suggested-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by:
Mark Brown <broonie@kernel.org>
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Serge Semin authored
Tx-only DMA transfers are working perfectly fine since in this case the code just ignores the Rx FIFO overflow interrupts. But it turns out the SPI Rx-only transfers are broken since nothing pushing any data to the shift registers, so the Rx FIFO is left empty and the SPI core subsystems just returns a timeout error. Since DW DMAC driver doesn't support something like cyclic write operations of a single byte to a device register, the only way to support the Rx-only SPI transfers is to fake it by using a dummy Tx-buffer. This is what we intend to fix in this commit by setting the SPI_CONTROLLER_MUST_TX flag for DMA-capable platform. Signed-off-by:
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Serge Semin authored
Each channel of DMA controller may have a limited length of burst transaction (number of IO operations performed at ones in a single DMA client request). This parameter can be used to setup the most optimal DMA Tx/Rx data level values. In order to avoid the Tx buffer overrun we can set the DMA Tx level to be of FIFO depth minus the maximum burst transactions length. To prevent the Rx buffer underflow the DMA Rx level should be set to the maximum burst transactions length. This commit setups the DMA channels and the DW SPI DMA Tx/Rx levels in accordance with these rules. Signed-off-by:
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Serge Semin authored
It isn't good to have numeric literals in the code especially if there are multiple of them and they are related. Let's replace the Tx and Rx burst level literals with the corresponding constants. Co-developed-by:
Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru> Co-developed-by:
Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru> Signed-off-by:
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Serge Semin authored
Having any data left in the Rx FIFO after the DMA engine claimed it has finished all DMA transactions is an abnormal situation, since the DW SPI controller driver expects to have all the data being fetched and placed into the SPI Rx buffer at that moment. In case if that has happened we hopefully assume that the DMA engine may still be doing the data fetching, thus we give it sometime to finish. If after a short period of time the data is still left in the Rx FIFO, the driver will give up waiting and return an error indicating that the SPI controller/DMA engine must have hung up or failed at some point of doing their duties. Fixes: 7063c0d9 ("spi/dw_spi: add DMA support") Co-developed-by:
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Serge Semin authored
Since DMA transfers are performed asynchronously with actual SPI bus transfers, then even if DMA transactions are finished it doesn't mean all data is actually pushed to the SPI bus. Some data might still be in the controller FIFO. This is specifically true for Tx-only transfers. In this case if the next SPI transfer is recharged while a tail of the previous one is still in FIFO, we'll loose that tail data. In order to fix that problem let's add the wait procedure of the Tx SPI transfer completion after the DMA transactions are finished. Fixes: 7063c0d9 ("spi/dw_spi: add DMA support") Co-developed-by:
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Serge Semin authored
In general each DMA-based SPI transfer can be split up into two stages: DMA data transmission/reception and SPI-bus transmission/reception. DMA asynchronous transactions completion can be tracked by means of the DMA async Tx-descriptor completion callback. But that callback being called indicates that the DMA transfer has been finished, it doesn't mean that SPI data transmission is also done. Moreover in fact it isn't for at least Tx-only SPI transfers. Upon DMA transfer completion some data is left in the Tx FIFO and being pushed out by the SPI controller. So in order to make sure that an SPI transfer is completely pushed to the SPI-bus, the driver has to wait for both DMA transaction and the SPI-bus transmission/reception are finished. Note if there is a way to asynchronously track the former event by means of the DMA async Tx callback, there isn't easy one for the later (IRQ-based solution won't work since SPI controller doesn't notify about Rx FIFO being empty). The DMA transfer completion callback isn't suitable to wait for the SPI controller activity finish either. The callback might (in case of DW DMAC it will) be called in the tasklet context. Waiting for the SPI controller to complete the transfer might take a considerable amount of time since SPI-bus might be pretty slow. In this case delaying the execution in the tasklet atomic context might cause significant system performance drop. So to speak the best option we've got to solve the problem is to consequently wait for both stages being finished in the locally implemented SPI transfer execution procedure even if it costs us of the local wait-function re-implementation. In this case we don't need to use the SPI-core transfer-wait functionality, but we'll make sure that all DMA and SPI-bus transactions are completely finished before the SPI-core transfer_one callback returns. In this commit we provide an implementation of the DMA-transfers completion wait functionality. The DW APB SSI DMA-specific SPI transfer_one function waits for both Tx and Rx DMA transfers being finished, and only then exits with zero returned signalling to the SPI core that the SPI transfer is finished. This implementation is fully equivalent to the currently used DMA-execution-SPI-core-wait algorithm. The SPI-bus transmission/reception wait methods will be added in the follow-up commits. Signed-off-by:
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Serge Semin authored
DW APB SSI DMA-part of the driver may need to perform the requested SPI-transfer synchronously. In that case the dma_transfer() callback will return 0 as a marker of the SPI transfer being finished so the SPI core doesn't need to wait and may proceed with the SPI message trasnfers pumping procedure. This will be needed to fix the problem when DMA transactions are finished, but there is still data left in the SPI Tx/Rx FIFOs being sent/received. But for now make dma_transfer to return 1 as the normal dw_spi_transfer_one() method. Signed-off-by:
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Serge Semin authored
Seeing DW APB SSI controller doesn't support setting the exactly requested SPI bus frequency, but only a rounded frequency determined by means of the odd-numbered half-worded reference clock divider, it would be good to tune the SPI core up and initialize the current transfer effective_speed_hz. By doing so the core will be able to execute the xfer-related delays with better accuracy. Signed-off-by:
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- 28 May, 2020 5 commits
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Mark Brown authored
There is ecspi ERR009165 on i.mx6/7 soc family, which cause FIFO transfer to be send twice in DMA mode. Please get more information from: https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf. The workaround is adding new sdma ram script which works in XCH mode as PIO inside sdma instead of SMC mode, meanwhile, 'TX_THRESHOLD' should be 0. The issue should be exist on all legacy i.mx6/7 soc family before i.mx6ul. NXP fix this design issue from i.mx6ul, so newer chips including i.mx6ul/ 6ull/6sll do not need this workaroud anymore. All other i.mx6/7/8 chips still need this workaroud. This patch set add new 'fsl,imx6ul-ecspi' for ecspi driver and 'ecspi_fixed' in sdma driver to choose if need errata or not. The first two reverted patches should be the same issue, though, it seems 'fixed' by changing to other shp script. Hope Sean or Sascha could have the chance to test this patch set if could fix their issues. Besides, enable sdma support for i.mx8mm/8mq and fix ecspi1 not work on i.mx8mm because the event id is zero. PS: Please get sdma firmware from below linux-firmware and copy it to your local rootfs /lib/firmware/imx/sdma. https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/imx/sdma v2: 1.Add commit log for reverted patches. 2.Add comment for 'ecspi_fixed' in sdma driver. 3.Add 'fsl,imx6sll-ecspi' compatible instead of 'fsl,imx6ul-ecspi' rather than remove. v3: 1.Confirm with design team make sure ERR009165 fixed on i.mx6ul/i.mx6ull /i.mx6sll, not fixed on i.mx8m/8mm and other i.mx6/7 legacy chips. Correct dts related dts patch in v2. 2.Clean eratta information in binding doc and new 'tx_glitch_fixed' flag in spi-imx driver to state ERR009165 fixed or not. 3.Enlarge burst size to fifo size for tx since tx_wml set to 0 in the errata workaroud, thus improve performance as possible. v4: 1.Add Ack tag from Mark and Vinod 2.Remove checking 'event_id1' zero as 'event_id0'. v5: 1.Add the last patch for compatible with the current uart driver which using rom script, so both uart ram script and rom script supported in latest firmware, by default uart rom script used. UART driver will be broken without this patch. v6: 1.Resend after rebase the latest next branch. 2.Remove below No.13~No.15 patches of v5 because they were mergered. ARM: dts: imx6ul: add dma support on ecspi ARM: dts: imx6sll: correct sdma compatible arm64: defconfig: Enable SDMA on i.mx8mq/8mm 3.Revert "dmaengine: imx-sdma: fix context cache" since 'context_loaded' removed. v7: 1.Put the last patch 13/13 'Revert "dmaengine: imx-sdma: fix context cache"' to the ahead of 03/13 'Revert "dmaengine: imx-sdma: refine to load context only once" so that no building waring during comes out during bisect. 2.Address Sascha's comments, including eliminating any i.mx6sx in this series, adding new 'is_imx6ul_ecspi()' instead imx in imx51 and taking care SMC bit for PIO. 3.Add back missing 'Reviewed-by' tag on 08/15(v5):09/13(v7) 'spi: imx: add new i.mx6ul compatible name in binding doc' v8: 1.remove 0003-Revert-dmaengine-imx-sdma-fix-context-cache.patch and merge it into 04/13 of v7 2.add 0005-spi-imx-fallback-to-PIO-if-dma-setup-failure.patch for no any ecspi function broken even if sdma firmware not updated. 3.merge 'tx.dst_maxburst' changes in the two continous patches into one patch to avoid confusion. 4.fix typo 'duplicated'. Robin Gong (13): Revert "ARM: dts: imx6q: Use correct SDMA script for SPI5 core" Revert "ARM: dts: imx6: Use correct SDMA script for SPI cores" Revert "dmaengine: imx-sdma: refine to load context only once" dmaengine: imx-sdma: remove duplicated sdma_load_context spi: imx: fallback to PIO if dma setup failure dmaengine: imx-sdma: add mcu_2_ecspi script spi: imx: fix ERR009165 spi: imx: remove ERR009165 workaround on i.mx6ul spi: imx: add new i.mx6ul compatible name in binding doc dmaengine: imx-sdma: remove ERR009165 on i.mx6ul dma: imx-sdma: add i.mx6ul compatible name dmaengine: imx-sdma: fix ecspi1 rx dma not work on i.mx8mm dmaengine: imx-sdma: add uart rom script .../devicetree/bindings/dma/fsl-imx-sdma.txt | 1 + .../devicetree/bindings/spi/fsl-imx-cspi.txt | 1 + arch/arm/boot/dts/imx6q.dtsi | 2 +- arch/arm/boot/dts/imx6qdl.dtsi | 8 +- drivers/dma/imx-sdma.c | 67 ++++++++++------ drivers/spi/spi-imx.c | 92 +++++++++++++++++++--- include/linux/platform_data/dma-imx-sdma.h | 8 +- 7 files changed, 135 insertions(+), 44 deletions(-) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Dinghao Liu authored
pm_runtime_get_sync() increments the runtime PM usage counter even when it returns an error code. Thus a pairing decrement is needed on the error handling path to keep the counter balanced. Signed-off-by:
Dinghao Liu <dinghao.liu@zju.edu.cn> Link: https://lore.kernel.org/r/20200523124758.28604-1-dinghao.liu@zju.edu.cnSigned-off-by:
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Dinghao Liu authored
pm_runtime_get_sync() increments the runtime PM usage counter even when it returns an error code. Thus a pairing decrement is needed on the error handling path to keep the counter balanced. Signed-off-by:
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Dinghao Liu authored
pm_runtime_get_sync() increments the runtime PM usage counter even when it returns an error code. Thus a pairing decrement is needed on the error handling path to keep the counter balanced. Signed-off-by:
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Robin Gong authored
Fallback to PIO in case dma setup failed. For example, sdma firmware not updated but ERR009165 workaroud added in kernel. Signed-off-by:
Robin Gong <yibin.gong@nxp.com> Acked-by:
Sascha Hauer <s.hauer@pengutronix.de> Link: https://lore.kernel.org/r/1590006865-20900-6-git-send-email-yibin.gong@nxp.comSigned-off-by:
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- 26 May, 2020 2 commits
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Dinghao Liu authored
pm_runtime_get_sync() increments the runtime PM usage counter even when it returns an error code. Thus a pairing decrement is needed on the error handling path to keep the counter balanced. Signed-off-by:
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Mark Brown authored
Originally spi_write_then_read() used a fixed statically allocated buffer which limited the maximum message size it could handle. This restriction was removed a while ago so that we could dynamically allocate a buffer if required but the kerneldoc was not updated to reflect this, do so. Reported-by:
Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by:
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- 25 May, 2020 2 commits
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dillon min authored
spi: flags 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX' can't be coexit with 'SPI_3WIRE' mode since chip spi driver need get the transfer direction by 'tx_buf' and 'rx_buf' of 'struct spi_transfer' in 'SPI_3WIRE' mode. so, we need bypass 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX' feature in 'SPI_3WIRE' mode Signed-off-by:
dillon min <dillon.minfei@gmail.com> Link: https://lore.kernel.org/r/1590378348-8115-9-git-send-email-dillon.minfei@gmail.comSigned-off-by:
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dillon min authored
in l3gd20 driver startup, there is a setup failed error return from stm32 spi driver " [ 2.687630] st-gyro-spi spi0.0: supply vdd not found, using dummy regulator [ 2.696869] st-gyro-spi spi0.0: supply vddio not found, using dummy regulator [ 2.706707] spi_stm32 40015000.spi: SPI transfer setup failed [ 2.713741] st-gyro-spi spi0.0: SPI transfer failed: -22 [ 2.721096] spi_master spi0: failed to transfer one message from queue [ 2.729268] iio iio:device0: failed to read Who-Am-I register. [ 2.737504] st-gyro-spi: probe of spi0.0 failed with error -22 " after debug into spi-stm32 driver, st-gyro-spi split two steps to read l3gd20 id first: send command to l3gd20 with read id command in tx_buf, rx_buf is null. second: read id with tx_buf is null, rx_buf not null. so, for second step, stm32 driver recongise this process as 'SPI_SIMPLE_RX' from stm32_spi_communication_type(), but there is no related process for this type in stm32f4_spi_set_mode(), then we get error from stm32_spi_transfer_one_setup(). we can use two method to fix this bug. 1, use stm32 spi's "In unidirectional receive-only mode (BIDIMODE=0 and RXONLY=1)". but as our code running in sdram, the read latency is too large to get so many receive overrun error in interrupts handler. 2, use stm32 spi's "In full-duplex (BIDIMODE=0 and RXONLY=0)", as tx_buf is null, so add flag 'SPI_MASTER_MUST_TX' to spi master. Change since V4: 1 remove dummy data sent out by stm32 spi driver 2 add flag 'SPI_MASTER_MUST_TX' to spi master Signed-off-by:
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- 22 May, 2020 9 commits
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Mark Brown authored
If the delay used is long enough the spi_delay_exec() will use a sleeping function to implement it. Add a might_sleep() here to help avoid callers using this from an atomic context and running into problems at runtime on other systems. Suggested-by:
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Mark Brown authored
Merge series "spi: dw: Add generic DW DMA controller support" from Serge Semin <Sergey.Semin@baikalelectronics.ru>: Baikal-T1 SoC provides a DW DMA controller to perform low-speed peripherals Mem-to-Dev and Dev-to-Mem transaction. This is also applicable to the DW APB SSI devices embedded into the SoC. Currently the DMA-based transfers are supported by the DW APB SPI driver only as a middle layer code for Intel MID/Elkhart PCI devices. Seeing the same code can be used for normal platform DMAC device we introduced a set of patches to fix it within this series. First of all we need to add the Tx and Rx DMA channels support into the DW APB SSI binding. Then there are several fixes and cleanups provided as a initial preparation for the Generic DMA support integration: add Tx/Rx finish wait methods, clear DMAC register when done or stopped, Fix native CS being unset, enable interrupts in accordance with DMA xfer mode, discard static DW DMA slave structures, discard unused void priv pointer and dma_width member of the dw_spi structure, provide the DMA Tx/Rx burst length parametrisation and make sure it's optionally set in accordance with the DMA max-burst capability. In order to have the DW APB SSI MMIO driver working with DMA we need to initialize the paddr field with the physical base address of the DW APB SSI registers space. Then we unpin the Intel MID specific code from the generic DMA one and placed it into the spi-dw-pci.c driver, which is a better place for it anyway. After that the naming cleanups are performed since the code is going to be used for a generic DMAC device. Finally the Generic DMA initialization can be added to the generic version of the DW APB SSI IP. Last but not least we traditionally convert the legacy plain text-based dt-binding file with yaml-based one and as a cherry on a cake replace the manually written DebugFS registers read method with a ready-to-use for the same purpose regset32 DebugFS interface usage. This patchset is rebased and tested on the spi/for-next (5.7-rc5): base-commit: fe9fce6b2cf3 ("Merge remote-tracking branch 'spi/for-5.8' into spi-next") Link: https://lore.kernel.org/linux-spi/20200508132943.9826-1-Sergey.Semin@baikalelectronics.ru/ Changelog v2: - Rebase on top of the spi repository for-next branch. - Move bindings conversion patch to the tail of the series. - Move fixes to the head of the series. - Apply as many changes as possible to be applied the Generic DMA functionality support is added and the spi-dw-mid is moved to the spi-dw-dma driver. - Discard patch "spi: dw: Fix dma_slave_config used partly uninitialized" since the problem has already been fixed. - Add new patch "spi: dw: Discard unused void priv pointer". - Add new patch "spi: dw: Discard dma_width member of the dw_spi structure". n_bytes member of the DW SPI data can be used instead. - Build the DMA functionality into the DW APB SSI core if required instead of creating a separate kernel module. - Use conditional statement instead of the ternary operator in the ref clock getter. Link: https://lore.kernel.org/linux-spi/20200515104758.6934-1-Sergey.Semin@baikalelectronics.ru/ Changelog v3: - Use spi_delay_exec() method to wait for the DMA operation completion. - Explicitly initialize the dw_dma_slave members on stack. - Discard the dws->fifo_len utilization in the Tx FIFO DMA threshold setting from the patch where we just add the default burst length constants. - Use min() method to calculate the optimal burst values. - Add new patch which moves the spi-dw.c source file to spi-dw-core.c in order to preserve the DW APB SSI core driver name. - Add commas in the debugfs_reg32 structure initializer and after the last entry of the dw_spi_dbgfs_regs array. Link: https://lore.kernel.org/linux-spi/20200521012206.14472-1-Sergey.Semin@baikalelectronics.ru Changelog v4: - Get back ndelay() method to wait for an SPI transfer completion. spi_delay_exec() isn't suitable for the atomic context. Co-developed-by: -
Christopher Hill authored
This patch adds the correcsponding MikroTik vendor and device tree documentation Signed-off-by:
Christopher Hill <ch6574@gmail.com> Link: https://lore.kernel.org/r/20200521183631.37806-3-ch6574@gmail.comSigned-off-by:
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Christopher Hill authored
This patch updates the spi driver spi-rb4xx.c to be device tree aware Signed-off-by:
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Christopher Hill authored
This patch fixes a null pointer bug in the spi driver spi-rb4xx.c by moving the private data initialization to earlier in probe Signed-off-by:
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Serge Semin authored
This member has exactly the same value as n_bytes of the DW SPI private data object, it's calculated at the same point of the transfer method, n_bytes isn't changed during the whole transfer, and they even serve for the same purpose - keep number of bytes per transfer word, though the dma_width is used only to calculate the DMA source/destination addresses width, which n_bytes could be also utilized for. Taking all of these into account let's replace the dma_width member usage with n_bytes one and remove the former. Signed-off-by:
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Serge Semin authored
Seeing the "void *priv" member of the dw_spi data structure is unused let's remove it. The glue-layers can embed the DW APB SSI controller descriptor into their private data object. MMIO driver for instance already utilizes that design pattern. Signed-off-by:
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Serge Semin authored
Having them declared is redundant since each struct dw_dma_chan has the same structure embedded and the structure from the passed dma_chan private pointer will be copied there as a result of the next calls chain: dma_request_channel() -> find_candidate() -> dma_chan_get() -> device_alloc_chan_resources() = dwc_alloc_chan_resources() -> dw_dma_filter(). So just remove the static dw_dma_chan structures and use a locally declared data instance with dst_id/src_id set to the same values as the static copies used to have. Co-developed-by:
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Serge Semin authored
It's pointless to track the Tx overrun interrupts if Rx-only SPI transfer is issued. Similarly there is no need in handling the Rx overrun/underrun interrupts if Tx-only SPI transfer is executed. So lets unmask the interrupts only if corresponding SPI transactions are implied. Co-developed-by:
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- 20 May, 2020 5 commits
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Lukas Wunner authored
On unbind of the BCM2835 SPI driver, the SPI controller is disabled first and the DMA channels are terminated and torn down afterwards. This seems backwards: In the theoretical case that DMA is active, it might try to fill the SPI FIFOs even after the controller has been disabled. Reverse the order, thereby mirroring what's done on ->probe(). Signed-off-by:
Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/ac79f1e3d6fd9a1f5e0cb4008c43b98ea70be3c2.1589557526.git.lukas@wunner.deSigned-off-by:
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Lukas Wunner authored
The BCM2835aux SPI driver uses devm_spi_register_master() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835aux_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835aux_spi_remove() turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_master() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_master(). Note that the struct spi_master as well as the driver-private data are not freed until after bcm2835aux_spi_remove() has finished, so accessing them is safe. Fixes: 1ea29b39 ("spi: bcm2835aux: add bcm2835 auxiliary spi device driver") Signed-off-by:
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Lukas Wunner authored
The BCM2835 SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835_spi_remove() tears down the DMA channels and turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_controller(). Note that the struct spi_controller as well as the driver-private data are not freed until after bcm2835_spi_remove() has finished, so accessing them is safe. Fixes: 247263db ("spi: bcm2835: use devm_spi_register_master()") Signed-off-by:
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Lukas Wunner authored
When an SPI controller unregisters, it unbinds all its slave devices. For this, their drivers may need to access the SPI bus, e.g. to quiesce interrupts. However since commit ffbbdd21 ("spi: create a message queueing infrastructure"), spi_destroy_queue() is executed before unbinding the slaves. It sets ctlr->running = false, thereby preventing SPI bus access and causing unbinding of slave devices to fail. Fix by unbinding slaves before calling spi_destroy_queue(). Fixes: ffbbdd21 ("spi: create a message queueing infrastructure") Signed-off-by:
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- 19 May, 2020 1 commit
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Kangmin Park authored
Fix unit address to match the first address specified in the reg property of the node in example. Signed-off-by:
Kangmin Park <l4stpr0gr4m@gmail.com> Link: https://lore.kernel.org/r/1589873541-5587-1-git-send-email-l4stpr0gr4m@gmail.comSigned-off-by:
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- 15 May, 2020 7 commits
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Serge Semin authored
Since commit 22d48ad7 ("spi: dw: Add Elkhart Lake PSE DMA support") the spi-dw-mid.c module supports a platform DMA engine handling the DW APB SSI controller requests. Lets alter the DW SPI bindings file to accept the Rx and Tx DMA line specifiers. Signed-off-by:
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Mark Brown authored
Merge series "spi: dw: Add generic DW DMA controller support" from Serge Semin <Sergey.Semin@baikalelectronics.ru>: Baikal-T1 SoC provides a DW DMA controller to perform low-speed peripherals Mem-to-Dev and Dev-to-Mem transaction. This is also applicable to the DW APB SSI devices embedded into the SoC. Currently the DMA-based transfers are supported by the DW APB SPI driver only as a middle layer code for Intel MID/Elkhart PCI devices. Seeing the same code can be used for normal platform DMAC device we introduced a set of patches to fix it within this series. First of all we need to add the Tx and Rx DMA channels support into the DW APB SSI binding. Then there are several fixes and cleanups provided as a initial preparation for the Generic DMA support integration: add Tx/Rx finish wait methods, clear DMAC register when done or stopped, Fix native CS being unset, enable interrupts in accordance with DMA xfer mode, discard static DW DMA slave structures, discard unused void priv pointer and dma_width member of the dw_spi structure, provide the DMA Tx/Rx burst length parametrisation and make sure it's optionally set in accordance with the DMA max-burst capability. In order to have the DW APB SSI MMIO driver working with DMA we need to initialize the paddr field with the physical base address of the DW APB SSI registers space. Then we unpin the Intel MID specific code from the generic DMA one and placed it into the spi-dw-pci.c driver, which is a better place for it anyway. After that the naming cleanups are performed since the code is going to be used for a generic DMAC device. Finally the Generic DMA initialization can be added to the generic version of the DW APB SSI IP. Last but not least we traditionally convert the legacy plain text-based dt-binding file with yaml-based one and as a cherry on a cake replace the manually written DebugFS registers read method with a ready-to-use for the same purpose regset32 DebugFS interface usage. This patchset is rebased and tested on the spi/for-next (5.7-rc5): base-commit: fe9fce6b2cf3 ("Merge remote-tracking branch 'spi/for-5.8' into spi-next") Co-developed-by: -
Chris Ruehl authored
The original implementation set num_chipselect to ROCKCHIP_SPI_MAX_CS_NUM (2) which seems wrong here. spi0 has 2 native cs, all others just one. With enable and use of cs_gpiods / GPIO CS, its correct to set the num_chipselect from the num-cs property and set max_native_cs with the define. If num-cs is missing the default set to num_chipselect = 1. Signed-off-by:
Chris Ruehl <chris.ruehl@gtsys.com.hk> Link: https://lore.kernel.org/r/20200511083022.23678-4-chris.ruehl@gtsys.com.hkSigned-off-by:
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Chris Ruehl authored
Add support for spi slave mode in spi-rockchip. The register map has an entry for it. If spi-slave is set in dts, set this corresponding bit and add to mode_bits the SPI_NO_CS, allow slave mode without explicit CS use. Slave abort function had been added. Signed-off-by:
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Chris Ruehl authored
Cleanup, move from the compatibily layer struct spi_master over to struct spi_controller, and rename the related function calls. Signed-off-by:
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Serge Semin authored
If DMAC register is left uncleared any further DMAless transfers may cause the DMAC hardware handshaking interface getting activated. So the next DMA-based Rx/Tx transaction will be started right after the dma_async_issue_pending() method is invoked even if no DMATDLR/DMARDLR conditions are met. This at the same time may cause the Tx/Rx FIFO buffers underrun/overrun. In order to fix this we must clear DMAC register after a current DMA-based transaction is finished. Co-developed-by:
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Serge Semin authored
This field is used only for the DW SPI DMA code initialization, that's why there were no problems with it being uninitialized in Dw SPI MMIO driver. Since in a further patch we are going to introduce the DW SPI DMA support in the MMIO version of the driver, lets set the field with the physical address of the DW SPI controller registers region. Co-developed-by:
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