linux/drivers/spi
Vladimir Oltean 4da9d4e740 spi: fsl-dspi: avoid SCK glitches with continuous transfers
[ Upstream commit c5c31fb71f ]

The DSPI controller has configurable timing for

(a) tCSC: the interval between the assertion of the chip select and the
    first clock edge

(b) tASC: the interval between the last clock edge and the deassertion
    of the chip select

What is a bit surprising, but is documented in the figure "Example of
continuous transfer (CPHA=1, CONT=1)" in the datasheet, is that when the
chip select stays asserted between multiple TX FIFO writes, the tCSC and
tASC times still apply. With CONT=1, chip select remains asserted, but
SCK takes a break and goes to the idle state for tASC + tCSC ns.

In other words, the default values (of 0 and 0 ns) result in SCK
glitches where the SCK transition to the idle state, as well as the SCK
transition from the idle state, will have no delay in between, and it
may appear that a SCK cycle has simply gone missing. The resulting
timing violation might cause data corruption in many peripherals, as
their chip select is asserted.

The driver has device tree bindings for tCSC ("fsl,spi-cs-sck-delay")
and tASC ("fsl,spi-sck-cs-delay"), but these are only specified to apply
when the chip select toggles in the first place, and this timing
characteristic depends on each peripheral. Many peripherals do not have
explicit timing requirements, so many device trees do not have these
properties present at all.

Nonetheless, the lack of SCK glitches is a common sense requirement, and
since the SCK stays in the idle state during transfers for tCSC+tASC ns,
and that in itself should look like half a cycle, then let's ensure that
tCSC and tASC are at least a quarter of a SCK period, such that their
sum is at least half of one.

Fixes: 95bf15f386 ("spi: fsl-dspi: Add ~50ns delay between cs and sck")
Reported-by: Lisa Chen (陈敏捷) <minjie.chen@geekplus.com>
Debugged-by: Lisa Chen (陈敏捷) <minjie.chen@geekplus.com>
Tested-by: Lisa Chen (陈敏捷) <minjie.chen@geekplus.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230529223402.1199503-1-vladimir.oltean@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-06-21 15:59:16 +02:00
..
atmel-quadspi.c spi: atmel-quadspi: Fix the buswidth adjustment between spi-mem and controller 2022-04-27 14:39:02 +02:00
internals.h spi: Add an helper to flush the message queue 2018-04-23 15:48:18 +01:00
Kconfig spi: dw_bt1: fix MUX_MMIO dependencies 2023-03-10 09:39:27 +01:00
Makefile spi: rockchip-sfc: add rockchip serial flash controller 2021-08-17 13:36:04 +01:00
spi-altera-core.c spi: altera: separate core code from platform code 2021-04-20 17:26:40 +01:00
spi-altera-dfl.c spi: spi-altera-dfl: Fix an error handling path 2022-08-17 14:23:06 +02:00
spi-altera-platform.c spi: altera: Change to dynamic allocation of spi id 2021-10-20 01:53:15 +01:00
spi-amd.c spi: amd: Limit max transfer and message size 2022-07-21 21:24:16 +02:00
spi-ar934x.c spi: ar934x: Don't leak SPI master in probe error path 2020-12-07 14:18:59 +00:00
spi-armada-3700.c spi: change clk_disable_unprepare to clk_unprepare 2021-12-29 12:28:39 +01:00
spi-at91-usart.c spi: spi-at91-usart: Remove unused OF table 'struct of_device_id' 2020-07-17 16:38:54 +01:00
spi-ath79.c spi: ath79: set number of chipselect lines 2021-05-24 09:51:38 +01:00
spi-atmel.c spi: atmel: Fix PDC transfer setup bug 2021-10-01 19:34:55 +01:00
spi-au1550.c spi: spi-au1550: Fix various whitespace warnings 2021-01-22 16:26:21 +00:00
spi-axi-spi-engine.c spi: spi-axi-spi-engine: remove usage of delay_usecs 2021-03-12 14:30:42 +00:00
spi-bcm-qspi.c spi: bcm-qspi: fix MSPI only access with bcm_qspi_exec_mem_op() 2022-04-13 20:59:19 +02:00
spi-bcm-qspi.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 459 2019-06-19 17:09:09 +02:00
spi-bcm63xx-hsspi.c spi: bcm63xx-hsspi: Fix multi-bit mode setting 2023-03-10 09:39:30 +01:00
spi-bcm63xx.c spi: bcm63xx-spi: don't check 'delay_usecs' field 2021-03-12 14:30:43 +00:00
spi-bcm2835.c spi: bcm2835: bcm2835_spi_handle_err(): fix NULL pointer deref for non DMA transfers 2022-07-29 17:25:24 +02:00
spi-bcm2835aux.c spi: bcm2835aux: use 'unsigned int' instead of 'unsigned' 2021-08-03 18:27:25 +01:00
spi-bitbang-txrx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-bitbang.c spi: Cleanup on failure of initial setup 2021-06-01 14:03:12 +01:00
spi-brcmstb-qspi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 459 2019-06-19 17:09:09 +02:00
spi-butterfly.c spi: butterfly: Switch to use module_parport_driver() 2021-03-10 12:46:05 +00:00
spi-cadence-quadspi.c spi: cadence-quadspi: fix suspend-resume implementations 2023-05-11 23:00:33 +09:00
spi-cadence.c spi: cadence: Correct initialisation of runtime PM again 2021-07-19 12:58:44 +01:00
spi-cavium-octeon.c spi: octeon: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:17:27 +01:00
spi-cavium-thunderx.c spi: spi-cavium-thunderx: flag controller as half duplex 2020-06-16 00:38:39 +01:00
spi-cavium.c spi: use new spi_transfer_delay_exec helper where straightforward 2019-10-15 11:51:57 +01:00
spi-cavium.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-clps711x.c spi: clps711xx: remove redundant white-space 2021-02-04 18:45:59 +00:00
spi-coldfire-qspi.c spi: coldfire-qspi: Use clk_disable_unprepare in the remove function 2021-08-19 18:20:10 +01:00
spi-davinci.c spi: davinci: invoke chipselect callback 2021-08-24 20:53:24 +01:00
spi-dln2.c spi: dln2: Fix reference leak to master 2021-04-09 13:43:57 +01:00
spi-dw-bt1.c spi: dw: Fix PM disable depth imbalance in dw_spi_bt1_probe 2022-10-26 12:34:45 +02:00
spi-dw-core.c spi: dw: Fix wrong FIFO level setting for long xfers 2023-02-14 19:18:02 +01:00
spi-dw-dma.c spi: dw-dma: decrease reference count in dw_spi_dma_init_mfld() 2022-12-02 17:41:03 +01:00
spi-dw-mmio.c spi: delete repeated words in comments 2021-05-10 13:07:52 +01:00
spi-dw-pci.c spi: dw: Add DWC SSI capability 2020-10-08 23:00:06 +01:00
spi-dw.h spi: dw: Add support for 32-bits max xfer size 2020-12-09 12:14:22 +00:00
spi-ep93xx.c spi: spi-ep93xx: Prepare clock before using it 2021-08-03 18:27:24 +01:00
spi-falcon.c spi: spi-falcon: remove check for 'delay_usecs' 2021-03-12 14:30:48 +00:00
spi-fsi.c spi: fsi: Reduce max transfer size to 8 bytes 2021-07-19 16:56:14 +01:00
spi-fsl-cpm.c spi: fsl-cpm: Use 16 bit mode for large transfers with even size 2023-05-30 13:55:29 +01:00
spi-fsl-cpm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-fsl-dspi.c spi: fsl-dspi: avoid SCK glitches with continuous transfers 2023-06-21 15:59:16 +02:00
spi-fsl-espi.c spi: fsl-espi: remove usage of 'delay_usecs' field 2021-03-12 14:30:49 +00:00
spi-fsl-lib.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-fsl-lib.h spi: fsl: Convert to use CS GPIO descriptors 2019-08-28 14:10:41 +01:00
spi-fsl-lpspi.c spi: fsl-lpspi: Fix PM reference leak in lpspi_prepare_xfer_hardware() 2021-04-09 13:43:59 +01:00
spi-fsl-qspi.c spi: spi-fsl-qspi: check return value after calling platform_get_resource_byname() 2022-06-09 10:22:55 +02:00
spi-fsl-spi.c spi: fsl-cpm: Use 16 bit mode for large transfers with even size 2023-05-30 13:55:29 +01:00
spi-fsl-spi.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
spi-geni-qcom.c spi: spi-geni-qcom: Remove confusing comment about setting the watermark 2021-07-14 16:37:58 +01:00
spi-gpio.c spi: spi-gpio: Don't set MOSI as an input if not 3WIRE mode 2022-12-31 13:14:18 +01:00
spi-hisi-kunpeng.c spi: hisi-kunpeng: Fix the debugfs directory name incorrect 2022-01-27 11:03:12 +01:00
spi-hisi-sfc-v3xx.c spi: hisi-sfc-v3xx: drop unnecessary ACPI_PTR and related ifendif protection 2021-04-12 17:07:38 +01:00
spi-img-spfi.c spi: img-spfi: Fix pm_runtime_get_sync() error checking 2022-06-09 10:22:48 +02:00
spi-imx.c spi: spi-imx: fix MX51_ECSPI_* macros when cs > 3 2023-05-24 17:36:46 +01:00
spi-iproc-qspi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
spi-jcore.c spi: jcore: Fix trailing statements should be on next line 2021-03-24 19:51:09 +00:00
spi-lantiq-ssc.c spi: lantiq: remove redundant irqsave and irqrestore in hardIRQ 2020-09-17 19:56:02 +01:00
spi-lm70llp.c spi: lm70llp: add parenthesis for sizeof 2021-05-20 18:00:34 +01:00
spi-loopback-test.c spi: spi-loopback-test: Fix 'tx_buf' might be 'rx_buf' 2021-05-10 13:07:53 +01:00
spi-lp8841-rtc.c spi: lp-8841: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:18:35 +01:00
spi-mem.c spi: spi-mem: fix doc warning in spi-mem.c 2021-06-14 15:05:00 +01:00
spi-meson-spicc.c spi: meson-spicc: do not rely on busy flag in pow2 clk ops 2022-10-26 12:34:42 +02:00
spi-meson-spifc.c spi: spi-meson-spifc: Add missing pm_runtime_disable() in meson_spifc_probe 2022-01-27 11:03:59 +01:00
spi-mpc52xx-psc.c spi: mpc52xx-psc: add parenthesis for sizeof 2021-05-20 18:00:37 +01:00
spi-mpc52xx.c spi: mpc52xx: add parenthesis for sizeof 2021-05-20 18:00:36 +01:00
spi-mpc512x-psc.c spi: mpc512x-psc: add parenthesis for sizeof 2021-05-20 18:00:35 +01:00
spi-mt65xx.c spi: mediatek: Fix DEVAPC Violation at KO Remove 2022-12-14 11:37:15 +01:00
spi-mt7621.c spi: mt7621: Fix an error message in mt7621_spi_probe() 2022-10-26 12:34:40 +02:00
spi-mtk-nor.c spi: spi-mtk-nor: initialize spi controller after resume 2022-04-27 14:38:52 +02:00
spi-mux.c spi-mux: Fix false-positive lockdep splats 2021-10-14 13:32:19 +01:00
spi-mxic.c spi: mxic: Fix the transmit path 2022-04-08 14:22:53 +02:00
spi-mxs.c spi: mxs: fix reference leak in mxs_spi_probe 2020-11-18 18:00:26 +00:00
spi-npcm-fiu.c spi: npcm-fiu: Disable clock in probe error path 2020-12-07 14:19:00 +00:00
spi-npcm-pspi.c spi: npcm-pspi: Use SPI_MODE_X_MASK 2021-05-11 15:42:48 +01:00
spi-nxp-fspi.c spi: spi-nxp-fspi: don't depend on a specific node name erratum workaround 2021-10-02 01:31:49 +01:00
spi-oc-tiny.c spi: oc-tiny: Use SPI_MODE_X_MASK 2021-05-11 15:42:49 +01:00
spi-omap-100k.c spi/omap100k:Fix PM disable depth imbalance in omap1_spi100k_probe 2022-10-26 12:34:46 +02:00
spi-omap-uwire.c Merge branch 'for-5.13' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.14 2021-06-01 18:33:33 +01:00
spi-omap2-mcspi.c Merge branch 'for-5.13' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.14 2021-06-01 18:33:33 +01:00
spi-orion.c spi: orion: Prevent incorrect chip select behaviour 2021-08-16 13:28:14 +01:00
spi-pic32-sqi.c spi: pic32-sqi: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:20:52 +01:00
spi-pic32.c spi: spi-pic32: Fix issue with uninitialized dma_slave_config 2021-08-10 13:22:20 +01:00
spi-pl022.c spi: spl022: fix Microwire full duplex mode 2021-10-26 11:53:57 +01:00
spi-ppc4xx.c spi: ppc4xx: add parenthesis for sizeof 2021-05-20 18:00:40 +01:00
spi-pxa2xx-dma.c spi: pxa2xx: Fix style of and typos in the comments and messages 2021-05-18 14:05:35 +01:00
spi-pxa2xx-pci.c spi: pxa2xx-pci: Balance reference count for PCI DMA device 2022-04-08 14:23:07 +02:00
spi-pxa2xx.c spi: pxa2xx: Adapt reset_sccr1() to the case when no message available 2021-07-22 12:41:19 +01:00
spi-pxa2xx.h spi: pxa2xx: Fix style of and typos in the comments and messages 2021-05-18 14:05:35 +01:00
spi-qcom-qspi.c spi: spi-qcom-qspi: Convert to use resource-managed OPP API 2021-03-16 10:14:11 +05:30
spi-qup.c spi: qup: Request DMA before enabling clocks 2023-06-14 11:13:00 +02:00
spi-rb4xx.c spi: rb4xx: Don't leak SPI master in probe error path 2020-12-07 14:18:55 +00:00
spi-realtek-rtl.c spi: realtek-rtl: Add support for Realtek RTL838x/RTL839x SPI controllers 2021-02-04 18:45:57 +00:00
spi-rockchip-sfc.c spi: spi-rockchip: Fix missing unwind goto in rockchip_sfc_probe() 2023-04-26 13:51:49 +02:00
spi-rockchip.c spi: rockchip: fix missing error on unsupported SPI_CS_HIGH 2022-06-09 10:22:50 +02:00
spi-rpc-if.c spi: spi-rpc-if: Check return value of rpcif_sw_init() 2021-11-18 19:16:42 +01:00
spi-rspi.c spi: spi-rspi: Fix PIO fallback on RZ platforms 2022-08-17 14:23:05 +02:00
spi-s3c24xx-regs.h ARM: s3c24xx: move regs-spi.h into spi driver 2020-08-19 21:40:14 +02:00
spi-s3c24xx.c ARM: SoC platform updates 2020-10-24 10:33:08 -07:00
spi-s3c64xx.c spi: s3c64xx: Fix large transfers with DMA 2022-10-26 12:34:47 +02:00
spi-sc18is602.c spi: sc18is602: implement .max_{transfer,message}_size() for the controller 2021-05-21 13:13:33 +01:00
spi-sh-hspi.c spi: use new spi_transfer_delay_exec helper where straightforward 2019-10-15 11:51:57 +01:00
spi-sh-msiof.c spi: spi-sh-msiof: : use proper DMAENGINE API for termination 2021-06-23 16:33:53 +01:00
spi-sh-sci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-sh.c spi: spi-sh: replace 'delay_usecs' with 'delay.value' in pr_debug 2021-03-12 14:30:45 +00:00
spi-sifive.c spi: sifive: disable clk when probe fails and remove 2019-11-04 13:26:11 +00:00
spi-slave-mt27xx.c spi: mediatek: add mt8195 spi slave support 2021-03-23 17:19:45 +00:00
spi-slave-system-control.c spi: slave: Fix missing break in switch 2018-10-03 16:23:10 +01:00
spi-slave-time.c spi: slave: Add SPI slave handler reporting uptime at previous message 2017-05-26 13:12:04 +01:00
spi-sprd-adi.c spi: sprd: Add ADI r3 support 2021-08-26 12:09:38 +01:00
spi-sprd.c spi: sprd: Add missing MODULE_DEVICE_TABLE 2021-05-12 13:01:43 +01:00
spi-st-ssc4.c spi: st-ssc4: Fix unbalanced pm_runtime_disable() in probe error path 2020-11-12 15:16:35 +00:00
spi-stm32-qspi.c spi: stm32-qspi: Fix wait_cmd timeout in APM mode 2022-06-09 10:22:36 +02:00
spi-stm32.c spi: stm32: fix stm32_spi_prepare_mbr() that halves spi clk for every run 2022-12-02 17:41:01 +01:00
spi-sun4i.c spi: sun4i: update max transfer size reported 2020-07-27 14:55:21 +01:00
spi-sun6i.c spi: spi-sun6i: Fix chipselect/clock bug 2021-06-23 11:48:36 +01:00
spi-synquacer.c spi: synquacer: Fix timeout handling in synquacer_spi_transfer_one() 2023-03-10 09:39:31 +01:00
spi-tegra20-sflash.c spi: spi-tegra20-flash: don't check 'delay_usecs' field for spi transfer 2021-03-12 14:30:46 +00:00
spi-tegra20-slink.c spi: tegra20-slink: fix UAF in tegra_slink_remove() 2022-08-17 14:23:12 +02:00
spi-tegra114.c spi: tegra114: Add missing IRQ check in tegra_spi_probe 2022-04-08 14:23:05 +02:00
spi-tegra210-quad.c spi: tegra210-quad: Fix missin IRQ check in tegra_qspi_probe 2022-04-08 14:23:06 +02:00
spi-test.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
spi-ti-qspi.c spi: spi-ti-qspi: Fix return value handling of wait_for_completion_timeout 2022-06-09 10:22:46 +02:00
spi-tle62x0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
spi-topcliff-pch.c spi: spi-topcliff-pch: Fix potential double free in pch_spi_process_messages() 2021-05-10 13:17:16 +01:00
spi-uniphier.c spi: uniphier: fix reference count leak in uniphier_spi_probe() 2022-02-08 18:34:08 +01:00
spi-xcomm.c spi: use new spi_transfer_delay_exec helper where straightforward 2019-10-15 11:51:57 +01:00
spi-xilinx.c spi: xilinx: Fix info message during probe 2020-09-17 19:56:01 +01:00
spi-xlp.c spi: xlp: use devm_platform_ioremap_resource() to simplify code 2019-09-04 17:23:28 +01:00
spi-xtensa-xtfpga.c spi: xtensa-xtfpga: Use devm_platform_ioremap_resource() in xtfpga_spi_probe() 2019-10-01 12:35:18 +01:00
spi-zynq-qspi.c spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op() 2022-03-02 11:48:01 +01:00
spi-zynqmp-gqspi.c spi: spi-zynqmp-gqspi: Handle error for dma_set_mask 2022-04-08 14:23:07 +02:00
spi.c spi: Ensure that sg_table won't be used after being freed 2022-10-26 12:34:48 +02:00
spidev.c spi: spidev: remove debug messages that access spidev->spi without locking 2023-02-01 08:27:18 +01:00