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58f46e41c1
linux/drivers/spi
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Trent Piepho 58f46e41c1 spi: spi-mxs: Always set LOCK_CS 
There are two bits which control the CS line in the CTRL0 register:
LOCK_CS and IGNORE_CRC.  The latter would be better named DEASSERT_CS
in SPI mode.

LOCK_CS keeps CS asserted though the entire transfer.  This should
always be set.  The DMA code will always set it, explicitly on the
first segment of the first transfer, and then implicitly on all the
rest by never clearing the bit from the value read from the ctrl0
register.

The PIO code will explicitly set it for the first transfer, leave it
set for intermediate transfers, and then clear it for the final
transfer.  It should not clear it.

The only reason to not set LOCK_CS would be to attempt an altered
protocol where CS pulses between each word.  Though don't get your
hopes up if you want to do this, as the hardware doesn't appear to do
this in any sane manner.  It appears to be related to the hardware
FIFO fill level.

The code can be simplified by just setting LOCK_CS once and then not
needing to deal with it at all in the PIO and DMA transfer functions.

Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-10-18 01:00:28 +01:00
..
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Makefile Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-altera.c ARM: SoC DT updates for 3.12 2013-09-06 13:26:27 -07:00
spi-ath79.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-atmel.c spi: atmel: Fix incorrect error path 2013-10-07 12:36:01 +01:00
spi-au1550.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bcm63xx.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-bcm2835.c spi: bcm2835: Add spi_master_get() call to prevent use after free 2013-08-22 19:07:51 +01:00
spi-bfin5xx.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bfin-sport.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-bfin-v3.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-bitbang-txrx.h
spi-bitbang.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
spi-butterfly.c
spi-clps711x.c spi/clps711x: drop clk_put for devm_clk_get in spi_clps711x_probe() 2013-09-27 10:49:09 +01:00
spi-coldfire-qspi.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-davinci.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-dw-mid.c dmaengine/dma_slave: introduce inline wrappers 2012-03-21 19:20:22 +05:30
spi-dw-mmio.c spi: remove unnecessary platform_set_drvdata() 2013-05-13 18:00:30 +04:00
spi-dw-pci.c spi: Remove HOTPLUG section attributes 2012-12-07 17:06:43 +00:00
spi-dw.c spi: convert drivers to use bits_per_word_mask 2013-05-29 20:48:17 +01:00
spi-dw.h
spi-efm32.c spi: efm32: Fix build error 2013-08-31 16:29:14 +01:00
spi-ep93xx.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-falcon.c spi/mips-lantiq: set SPI_MASTER_HALF_DUPLEX flag 2013-02-05 17:16:55 +00:00
spi-fsl-cpm.c spi/spi-fsl-spi: Make driver usable in CPU mode outside of an FSL_SOC environment 2013-04-07 10:07:54 +01:00
spi-fsl-cpm.h spi/spi-fsl-spi: Make driver usable in CPU mode outside of an FSL_SOC environment 2013-04-07 10:07:54 +01:00
spi-fsl-dspi.c spi: fix return value check in dspi_probe() 2013-09-12 10:53:16 +01:00
spi-fsl-espi.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-fsl-lib.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-fsl-lib.h spi/spi-fsl-spi: Add support for gpio chipselects for GRLIB type cores 2013-04-07 10:07:57 +01:00
spi-fsl-spi.c PTR_RET() is a weird name, and led to some confusing usage. We ended 2013-09-04 17:31:11 -07:00
spi-fsl-spi.h spi/spi-fsl-spi: Add support for Aeroflex Gaisler GRLIB cores normally running on SPARC 2013-04-07 10:07:56 +01:00
spi-gpio.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-imx.c spi/imx: expose module alias for loading from device-tree 2013-07-29 12:40:08 +01:00
spi-lm70llp.c spi: By default setup spi_masters with 1 chipselect and dynamics bus number 2012-05-19 23:42:08 -06:00
spi-mpc52xx-psc.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-mpc52xx.c spi: use platform_{get,set}_drvdata() 2013-05-23 09:09:55 -05:00
spi-mpc512x-psc.c spi: mpc512x: fix error return code in mpc512x_psc_spi_do_probe() 2013-09-12 10:48:57 +01:00
spi-mxs.c spi: spi-mxs: Always set LOCK_CS 2013-10-18 01:00:28 +01:00
spi-nuc900.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-oc-tiny.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-octeon.c spi: octeon: Convert to use bits_per_word_mask 2013-08-20 11:34:08 +01:00
spi-omap2-mcspi.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-omap-100k.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi-omap-uwire.c spi: use platform_{get,set}_drvdata() 2013-05-23 09:09:55 -05:00
spi-orion.c Merge remote-tracking branch 'spi/topic/orion' into spi-next 2013-09-01 13:49:02 +01:00
spi-pl022.c Merge remote-tracking branch 'spi/topic/qspi' into spi-next 2013-09-01 13:49:06 +01:00
spi-ppc4xx.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-06-26 16:21:02 +01:00
spi-pxa2xx-dma.c Merge remote-tracking branch 'spi/topic/pxa' into spi-next 2013-06-26 16:21:03 +01:00
spi-pxa2xx-pci.c spi/pxa2xx-pci: correct the return value check of pcim_iomap_regions() 2013-03-12 18:30:56 +00:00
spi-pxa2xx-pxadma.c spi/pxa2xx: break out the private DMA API usage into a separate file 2013-02-08 12:15:21 +00:00
spi-pxa2xx.c spi/pxa2xx: check status register as well to determine if the device is off 2013-09-04 20:14:29 +01:00
spi-pxa2xx.h spi/pxa2xx: add support for Intel Low Power Subsystem SPI 2013-02-08 13:14:40 +00:00
spi-rspi.c Merge remote-tracking branch 'spi/topic/rspi' into spi-next 2013-09-01 13:49:08 +01:00
spi-s3c24xx-fiq.h
spi-s3c24xx-fiq.S
spi-s3c24xx.c spi: Use dev_get_drvdata at appropriate places 2013-08-29 13:57:14 +01:00
spi-s3c64xx.c spi/s3c64xx: Ensure runtime PM is enabled prior to registration 2013-09-27 14:26:04 +01:00
spi-sc18is602.c spi/sc18is602: Return -EINVAL for probe failures due to I2C function mismatch 2012-08-23 12:13:54 +01:00
spi-sh-hspi.c spi/hspi: fixup Runtime PM enable timing 2013-10-03 14:08:06 +01:00
spi-sh-msiof.c Merge remote-tracking branch 'spi/topic/sh-msiof' into spi-next 2013-09-01 13:49:11 +01:00
spi-sh-sci.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-sh.c spi: use platform_{get,set}_drvdata() 2013-05-23 09:09:55 -05:00
spi-sirf.c Merge remote-tracking branch 'spi/topic/sirf' into spi-next 2013-09-01 13:49:12 +01:00
spi-tegra20-sflash.c spi/tegra20-sflash: Use core runtime PM 2013-07-29 18:00:26 +01:00
spi-tegra20-slink.c spi/tegra20-slink: Use core runtime PM 2013-07-29 18:00:30 +01:00
spi-tegra114.c Merge remote-tracking branch 'spi/topic/tegra' into spi-next 2013-09-01 13:49:13 +01:00
spi-ti-qspi.c spi/qspi: fix missing unlock on error in ti_qspi_start_transfer_one() 2013-09-01 13:47:55 +01:00
spi-ti-ssp.c spi: use dev_get_platdata() 2013-08-29 13:56:23 +01:00
spi-tle62x0.c Merge remote-tracking branch 'spi/topic/tel62x0' into spi-next 2013-09-01 13:49:14 +01:00
spi-topcliff-pch.c spi-topcliff-pch: Add MODULE_DEVICE_TABLE 2013-08-13 01:00:51 +01:00
spi-txx9.c spi/txx9: Use linux/gpio.h not asm/gpio.h 2013-07-30 12:16:04 +01:00
spi-xcomm.c spi: convert drivers to use bits_per_word_mask 2013-05-29 20:48:17 +01:00
spi-xilinx.c Merge remote-tracking branch 'spi/topic/pdata' into spi-next 2013-09-01 13:49:03 +01:00
spi.c Merge remote-tracking branch 'spi/topic/quad' into spi-next 2013-09-01 13:49:07 +01:00
spidev.c PTR_RET is now PTR_ERR_OR_ZERO(): Replace most. 2013-07-15 11:25:01 +09:30