linux-stable/drivers/spi
Linus Walleij 9b00bc7b90
spi: spi-gpio: Rewrite to use GPIO descriptors
This converts the bit-banged GPIO SPI driver to looking up and
using GPIO descriptors to get a handle on GPIO lines for SCK,
MOSI, MISO and all CS lines.

All existing board files are converted in one go to keep it all
consistent. With these conversions I rarely find any interrim
steps that makes any sense.

Device tree probing and GPIO handling should work like before
also after this patch.

For board files, we stop using controller data to pass the GPIO
line for chip select, instead we pass this as a GPIO descriptor
lookup like everything else.

In some s3c24xx machines the names of the SPI devices were set to
"spi-gpio" rather than "spi_gpio" which can never have worked, I
fixed it working (I guess) as part of this patch set. Sometimes
I wonder how this code got upstream in the first place, it
obviously is not tested.

mach-s3c64xx/mach-smartq.c has the same problem and additionally
defines the *same* GPIO line for MOSI and MISO which is not going
to be accepted by gpiolib. As the lines were number 1,2,2 I assumed
it was a typo and use lines 1,2,3. A comment gives awat that line 0
is chip select though no actual SPI device is provided for the LCD
supposed to be on this bit-banged SPI bus. I left it intact instead
of just deleting the bus though.

Kill off board file code that try to initialize the SPI lines
to the same values that they will later be set by the spi_gpio
driver anyways. Given the huge number of weird things in these
board files I do not think this code is very tested or put in
with much afterthought anyways.

In order to assert that we do not get performance regressions on
this crucial bing-banged driver, a ran a script like this dumping the
Ilitek ILI9322 regmap 10000 times (it has no caching obviously) on
an otherwise idle system in two iterations before and after the
patches:

 #!/bin/sh
 for run in `seq 10000`
 do
     cat /debug/regmap/spi0.0/registers > /dev/null
 done

Before the patch:

time test.sh
real    3m 41.03s
user    0m 29.41s
sys     3m 7.22s

time test.sh
real    3m 44.24s
user    0m 32.31s
sys     3m 7.60s

After the patch:

time test.sh
real    3m 41.32s
user    0m 28.92s
sys     3m 8.08s

time test.sh
real    3m 39.92s
user    0m 30.20s
sys     3m 5.56s

So any performance differences seems to be in the error margin.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-02-14 16:02:41 +00:00
..
Kconfig Merge remote-tracking branches 'spi/topic/sh-msiof', 'spi/topic/slave', 'spi/topic/spreadtrum' and 'spi/topic/tegra114' into spi-next 2017-11-10 21:33:51 +00:00
Makefile Merge remote-tracking branches 'spi/topic/sh-msiof', 'spi/topic/slave', 'spi/topic/spreadtrum' and 'spi/topic/tegra114' into spi-next 2017-11-10 21:33:51 +00:00
spi-adi-v3.c
spi-altera.c spi: altera: Consolidate TX/RX data register access 2017-08-16 11:53:31 +01:00
spi-armada-3700.c Merge remote-tracking branches 'spi/topic/a3700', 'spi/topic/atmel', 'spi/topic/bcm53xx', 'spi/topic/davinci' and 'spi/topic/dw' into spi-next 2018-01-26 17:57:24 +00:00
spi-ath79.c spi/ath79: Fix checkpatch warnings 2017-07-17 12:09:38 +01:00
spi-atmel.c spi: atmel: Implements transfers with bounce buffer 2018-01-05 12:42:09 +00:00
spi-au1550.c
spi-axi-spi-engine.c spi: spi-axi: fix potential use-after-free after deregistration 2017-10-31 11:15:10 +00:00
spi-bcm-qspi.c spi: bcm-qspi: Fix use after free in bcm_qspi_probe() in error path 2017-10-12 09:26:23 +01:00
spi-bcm-qspi.h
spi-bcm53xx.c spi: bcm53xx: simplify reading SPI data 2018-01-03 11:39:16 +00:00
spi-bcm53xx.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-bcm63xx-hsspi.c Merge remote-tracking branches 'spi/topic/altera', 'spi/topic/at79', 'spi/topic/bcm-qspi', 'spi/topic/bcm63xx' and 'spi/topic/bcm63xx-hspi' into spi-next 2017-09-04 15:51:14 +01:00
spi-bcm63xx.c spi/bcm63xx: fix error return code in bcm63xx_spi_probe() 2017-08-08 11:36:35 +01:00
spi-bcm2835.c
spi-bcm2835aux.c
spi-bfin-sport.c
spi-bfin5xx.c
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-brcmstb-qspi.c
spi-butterfly.c
spi-cadence.c spi: cadence: Add support for context loss 2017-08-08 10:43:41 +01:00
spi-cavium-octeon.c
spi-cavium-thunderx.c
spi-cavium.c
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-coldfire-qspi.c
spi-davinci.c spi: davinci: Initialize dspi->done before any possible use of it 2017-12-12 10:51:52 +00:00
spi-dln2.c
spi-dw-mid.c
spi-dw-mmio.c spi: dw: Disable clock after unregistering the host 2017-04-18 19:16:49 +01:00
spi-dw-pci.c
spi-dw.c spi: dw: Remove unused members from struct chip_data 2018-01-26 14:50:43 +00:00
spi-dw.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spi-efm32.c
spi-ep93xx.c spi: spi-ep93xx: use the default master transfer queueing mechanism 2017-08-09 17:53:14 +01:00
spi-falcon.c spi: spi-falcon: drop check of boot select 2017-09-01 11:33:22 +01:00
spi-fsl-cpm.c
spi-fsl-cpm.h
spi-fsl-dspi.c spi: spi-fsl-dspi: account for const type of of_device_id.data 2018-01-03 12:19:24 +00:00
spi-fsl-espi.c
spi-fsl-lib.c
spi-fsl-lib.h
spi-fsl-lpspi.c
spi-fsl-spi.c Merge remote-tracking branches 'spi/topic/devprop', 'spi/topic/fsl', 'spi/topic/fsl-dspi', 'spi/topic/imx' and 'spi/topic/lantiq' into spi-next 2017-04-26 15:58:04 +01:00
spi-fsl-spi.h
spi-gpio.c spi: spi-gpio: Rewrite to use GPIO descriptors 2018-02-14 16:02:41 +00:00
spi-img-spfi.c
spi-imx.c Merge remote-tracking branches 'spi/topic/fsl-dspi', 'spi/topic/imx', 'spi/topic/jcore', 'spi/topic/meson' and 'spi/topic/orion' into spi-next 2018-01-26 17:57:27 +00:00
spi-iproc-qspi.c
spi-jcore.c spi: jcore: disable clock when registering spi conroller failed 2017-12-13 19:08:24 +00:00
spi-lantiq-ssc.c Merge remote-tracking branches 'spi/topic/devprop', 'spi/topic/fsl', 'spi/topic/fsl-dspi', 'spi/topic/imx' and 'spi/topic/lantiq' into spi-next 2017-04-26 15:58:04 +01:00
spi-lm70llp.c
spi-loopback-test.c spi: loopback-test: implement testing with no CS 2017-07-26 13:08:56 +01:00
spi-lp8841-rtc.c
spi-meson-spicc.c spi: meson-axg: add SPICC driver support 2017-11-28 20:21:31 +00:00
spi-meson-spifc.c
spi-mpc52xx-psc.c
spi-mpc52xx.c
spi-mpc512x-psc.c
spi-mt65xx.c spi: mediatek: add spi support for mt2712 IC 2017-06-20 13:39:14 +01:00
spi-mxs.c spi: mxs: implement runtime pm 2017-09-27 10:02:57 -07:00
spi-nuc900.c
spi-oc-tiny.c
spi-omap-100k.c
spi-omap-uwire.c
spi-omap2-mcspi.c spi: omap: Allocate bus number from spi framework 2017-08-18 12:15:41 +01:00
spi-orion.c spi: orion: Fix a resource leak if the optional "axi" clk is deferred 2018-01-26 11:43:39 +00:00
spi-pic32-sqi.c
spi-pic32.c spi: pic32: fix spelling mistakes on macro names 2017-07-26 13:04:21 +01:00
spi-pl022.c spi: pl022: constify amba_id 2017-08-23 17:12:05 +01:00
spi-ppc4xx.c
spi-pxa2xx-dma.c
spi-pxa2xx-pci.c
spi-pxa2xx.c spi: pxa2xx: Use gpiod_put() not gpiod_free() 2017-12-22 16:15:36 +00:00
spi-pxa2xx.h spi: pxa2xx: Convert to GPIO descriptor API where possible 2017-08-04 12:41:55 +01:00
spi-qup.c spi: qup: fix 64-bit build warning 2017-08-10 15:50:23 +01:00
spi-rb4xx.c
spi-rockchip.c spi: rockchip: configure CTRLR1 according to size and data frame 2017-08-16 11:58:23 +01:00
spi-rspi.c spi: rspi: Do not set SPCR_SPE in qspi_set_config_register() 2017-12-07 11:55:38 +00:00
spi-s3c24xx-fiq.h
spi-s3c24xx-fiq.S
spi-s3c24xx.c
spi-s3c64xx.c spi: s3c64xx: add SPDX identifier 2018-01-08 15:38:06 +00:00
spi-sc18is602.c
spi-sh-hspi.c
spi-sh-msiof.c Merge remote-tracking branches 'spi/topic/pxa2xx', 'spi/topic/s3c64xx', 'spi/topic/sh-msiof', 'spi/topic/sirf' and 'spi/topic/sun6i' into spi-next 2018-01-26 17:57:31 +00:00
spi-sh-sci.c
spi-sh.c spi: spi-sh: fix error return code in spi_sh_probe() 2017-08-09 17:18:06 +01:00
spi-sirf.c spi: sirf: account for const type of of_device_id.data 2018-01-03 11:38:46 +00:00
spi-slave-system-control.c spi: slave: Add SPI slave handler controlling system state 2017-05-26 13:12:19 +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: Fix the possible negative value of BIT() 2017-10-25 14:00:03 +02:00
spi-st-ssc4.c spi: st-ssc4: whitespace cleanup 2017-05-26 12:41:07 +01:00
spi-stm32.c spi: stm32: Fix logical error in stm32_spi_prepare_mbr() 2017-09-13 09:42:27 -07:00
spi-sun4i.c spi: sun4i: disable clocks in the remove function 2017-12-07 11:59:15 +00:00
spi-sun6i.c spi: sun6i: disable/unprepare clocks on remove 2017-12-07 17:45:17 +00:00
spi-tegra20-sflash.c spi: tegra20-sflash: explicitly request exclusive reset control 2017-07-19 17:06:31 +01:00
spi-tegra20-slink.c spi: tegra20-slink: explicitly request exclusive reset control 2017-07-19 17:06:26 +01:00
spi-tegra114.c spi: tegra114: correct register name in definition 2017-10-09 10:16:38 +01:00
spi-test.h spi: loopback-test: add elapsed time check 2017-03-17 21:54:08 +00:00
spi-ti-qspi.c Merge remote-tracking branches 'spi/topic/ti-qspi' and 'spi/topic/xlp' into spi-next 2017-04-26 15:58:22 +01:00
spi-tle62x0.c
spi-topcliff-pch.c
spi-txx9.c
spi-xcomm.c
spi-xilinx.c spi: xilinx: Add support for xlnx,axi-quad-spi-1.00.a 2017-11-27 16:31:20 +00:00
spi-xlp.c spi: xlp: fix error return code in xlp_spi_probe() 2017-08-08 11:36:07 +01:00
spi-xtensa-xtfpga.c
spi-zynqmp-gqspi.c
spi.c Merge remote-tracking branch 'spi/topic/core' into spi-next 2017-11-10 21:33:43 +00:00
spidev.c Merge branch 'for-spi' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:41:53 -07:00