We found that adding load, Rx data sometimes drops.(with DMA transfer mode)
The cause is that before starting Rx-DMA processing, Tx-DMA processing starts.
This causes FIFO overrun occurs.
This patch fixes the issue by modifying FIFO tx-threshold and DMA descriptor
size like below.
Current this patch
Rx-descriptor 4Byte+12Byte*341 --> 12Byte*340-4Byte-12Byte
Rx-threshold (Not modified)
Tx-descriptor 4Byte+12Byte*341 --> 16Byte-12Byte*340
Rx-threshold 12Byte --> 2Byte
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Add recovery processing in case FIFO overrun error occurs with DMA transfer mode.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
We found Rx data sometimes drops.(with non-DMA transfer mode)
The cause is read complete condition is not true.
This patch fixes the issue.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
During processing 1 command/data series,
SSN should keep LOW.
However, currently, SSN becomes HIGH.
This patch fixes the issue.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Currently, in case of reading date from SPI flash,
command is sent twice.
The cause is that tx-memory clear processing is missing .
This patch adds the tx-momory clear processing.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
If CPM mode is not used, the fsl_dummy_rx variable is never allocated. When
the cleanup attempts to free it, the reference count is zero and a WARN is
generated. The same CPM mode check used in the initialize is applied to the
free as well.
Tested on 2.6.33 with the previous spi_mpc8xxx driver. The renamed
spi-fsl-spi driver looks to have the same problem.
Signed-off-by: Jeff Harris <jeff_harris@kentrox.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
commit 22a85e4cd5 (spi/imx: add device tree probe support) broke spi-imx usage
when the SPI chipselect is the one internal to the controller.
On a mx31pdk board the following error is seen:
Registering mxc_nand as whole device
------------[ cut here ]------------
WARNING: at drivers/gpio/gpiolib.c:101 gpio_ensure_requested+0x4c/0xf4()
autorequest GPIO-0
Modules linked in:
[<c0014410>] (unwind_backtrace+0x0/0xf4) from [<c0025754>] (warn_slowpath_common+0x4c/0x64)
[<c0025754>] (warn_slowpath_common+0x4c/0x64) from [<c0025800>] (warn_slowpath_fmt+0x30/0x40)
[<c0025800>] (warn_slowpath_fmt+0x30/0x40) from [<c0198688>] (gpio_ensure_requested+0x4c/0xf4)
[<c0198688>] (gpio_ensure_requested+0x4c/0xf4) from [<c01988c8>] (gpio_direction_output+0xa0/0x138)
[<c01988c8>] (gpio_direction_output+0xa0/0x138) from [<c01ed198>] (spi_imx_setup+0x38/0x4c)
[<c01ed198>] (spi_imx_setup+0x38/0x4c) from [<c01eb5d0>] (spi_setup+0x38/0x50)
[<c01eb5d0>] (spi_setup+0x38/0x50) from [<c01eb85c>] (spi_add_device+0x94/0x124)
[<c01eb85c>] (spi_add_device+0x94/0x124) from [<c01eb960>] (spi_new_device+0x74/0xac)
[<c01eb960>] (spi_new_device+0x74/0xac) from [<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40)
[<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40) from [<c01eba88>] (spi_register_master+0xb0/0x104)
[<c01eba88>] (spi_register_master+0xb0/0x104) from [<c01ec0b4>] (spi_bitbang_start+0x104/0x17c)
[<c01ec0b4>] (spi_bitbang_start+0x104/0x17c) from [<c02c2c4c>] (spi_imx_probe+0x2fc/0x404)
[<c02c2c4c>] (spi_imx_probe+0x2fc/0x404) from [<c01c2498>] (platform_drv_probe+0x18/0x1c)
[<c01c2498>] (platform_drv_probe+0x18/0x1c) from [<c01c1058>] (driver_probe_device+0x78/0x174)
[<c01c1058>] (driver_probe_device+0x78/0x174) from [<c01c11e0>] (__driver_attach+0x8c/0x90)
[<c01c11e0>] (__driver_attach+0x8c/0x90) from [<c01c0860>] (bus_for_each_dev+0x60/0x8c)
[<c01c0860>] (bus_for_each_dev+0x60/0x8c) from [<c01c0088>] (bus_add_driver+0xa0/0x288)
[<c01c0088>] (bus_add_driver+0xa0/0x288) from [<c01c179c>] (driver_register+0x78/0x18c)
[<c01c179c>] (driver_register+0x78/0x18c) from [<c0008490>] (do_one_initcall+0x34/0x178)
[<c0008490>] (do_one_initcall+0x34/0x178) from [<c03a5204>] (kernel_init+0x74/0x118)
[<c03a5204>] (kernel_init+0x74/0x118) from [<c000f65c>] (kernel_thread_exit+0x0/0x8)
---[ end trace 759f924b30fd5a44 ]---
Fix this issue by using the original chip select logic and make spi-imx to work again.
Tested on a mx31pdk that uses the hardware SPI chipselect pins and also
on a mx27pdk that uses GPIO as SPI chipselect.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The remove function in the PL022 driver cannot abort the remove
function any way, so restructure the code so as not to make that
assumption. Remove will now proceed no matter whether it can
stop the transfer queue or not.
Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* 'spi/next' of git://git.secretlab.ca/git/linux-2.6: (34 commits)
spi/imx: add device tree probe support
spi/imx: copy gpio number passed by platform data into driver private data
spi/imx: use soc name in spi device type naming scheme
spi/imx: merge type SPI_IMX_VER_0_7 into SPI_IMX_VER_0_4
spi/imx: do not use spi_imx2_3 to name SPI_IMX_VER_2_3 function and macro
spi/imx: use mx21 to name SPI_IMX_VER_0_0 function and macro
spi/imx: do not make copy of spi_imx_devtype_data
spi/dw: Add spi number into spi irq desc
spi/tegra: Use engineering names in DT compatible property
spi/fsl_spi: fix CPM spi driver
mach-s3c2410: remove unused spi-gpio.h file
spi: remove obsolete spi-s3c24xx-gpio driver
mach-gta2: remove unused spi-gpio.h include
mach-qt2410: convert to spi_gpio
mach-jive: convert to spi_gpio
spi/pxa2xx: Remove unavailable ssp_type from documentation
spi/bfin_spi: uninline fat queue funcs
spi/bfin_spi: constify pin array
spi/bfin_spi: use structs for accessing hardware regs
spi/topcliff-pch: Support new device ML7223 IOH
...
Fix up trivial conflict in arch/arm/mach-ep93xx/Makefile
It adds device tree probe support for spi-imx driver.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
It copies gpio number passed via platform data embedded pointer into
driver private data, so that we do not need to refer to this embedded
pointer passed by platform data after probe function exits.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Software defined version number is not stable enough to be used
in device type naming scheme. The patch changes it to use implicit
soc name for spi device type definition. In this way, we can easily
align the naming scheme with device tree binding, which comes later.
It removes fifosize from spi_imx_data and adds devtype there, so that
fifosize can be set in an inline function according to devtype.
Also, cpu_is_mx can be replaced by inline functions checking devtype.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The only difference between SPI_IMX_VER_0_7 and SPI_IMX_VER_0_4 is
.config function. The patch uses cpu_is_mx35 (to be removed) as the
temporary solution to consolidate functions spi_imx0_4_config and
spi_imx0_7_config into mx31_config. As a result, type SPI_IMX_VER_0_7
can be merged into SPI_IMX_VER_0_4.
It also renames function spi_imx0_4_reset to mx31_reset to keep
consistency with other function naming.
A couple of redundant macros, MX3_CSPISTAT and MX3_CSPISTAT_RR,
together with the useless type SPI_IMX_VER_0_5 also get cleaned up.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
It's confusing to use spi_imx2_3 to name SPI_IMX_VER_2_3 function
and macro, as it easily make people think of imx2 and imx3. It's
better to use specific soc name just like what other SPI_IMX_VER
do. For SPI_IMX_VER_2_3 case, it will be mx51. To distinguish it
from CSPI on mx51, mx51_ecspi might be a good choice.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
SPI_IMX_VER_0_0 covers i.mx21 and i.mx27. It makes more sense to
use mx21 rather than mx27 to name SPI_IMX_VER_0_0 function and
macro, since i.mx21 comes out ealier than i.mx27.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
spi_imx_devtype_data has already been driver private data. There is
really no need to make a copy in spi_imx_data. Instead, a reference
pointer works perfectly fine.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The existing macro fails for following scenarios.
1) S5P64X0 channel 1
2) S5PV210 channel 1
The FIFO data level supported in the above SoCs either 64 or
256 bytes depending on the channel. Because of this the TX_DONE
is the 25 bit in the status register.
The existing macro works for the following scenarios
1) S3C6410 all channels
2) S5PC100 all channels
The FIFO data level supported in the above SoCs 64 bytes
on all the channels. Because of this the TX_DONE is the 21 bit
in the status register.
So when we use the existing macro for the non-working SoCs
it is not anding with the TX_DONE bit for transmission status check.
Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Engineering names are more stable than marketing names. Hence, use them
for Device Tree compatible properties instead.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch fixes the freescale spi driver for CPM. Without this
patch SPI on CPM failed because cpm_muram_alloc_fixed tries to
allocate muram in an preserved area. The error reported was:
mpc8xxx_spi f0011a80.spi: can't allocate spi parameter ram
mpc8xxx_spi: probe of f0011a80.spi failed with error -12
Now the driver uses of_iomap to get access to this area
similar to i2c driver driver in the i2c-cpm.c which has a
similar device tree node. This is tested on a MPC8247 with CPM2.
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
It was equivalent to spi-gpio, and there's no longer any in-tree users
of it, so get rid of it.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
There's no need for these queue funcs to be inlined, so drop the
markings. This shaves off a few hundred duplicated bytes.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This array isn't written anywhere, so constify it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Rather than hardcoding the register sizes/offsets in this file, use the
existing struct in the spi header for reading/writing the hardware.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The default bits per word setting should be 8 bits, but since most of our
devices have been explicitly setting this up, we didn't notice when the
default stopped working.
At the moment, any default transfers without an explicit bit size setting
error out with:
bfin-spi bfin-spi.0: transfer: unsupported bits_per_word
So in the transfer logic, have a bits_per_word setting of 0 fall into the
8 bit transfer logic.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Support new device OKI SEMICONDUCTOR ML7223 IOH(Input/Output Hub).
The ML7223 IOH is for MP(Media Phone) use.
The ML7223 is companion chip for Intel Atom E6xx series.
The ML7223 is completely compatible for Intel EG20T PCH.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The platform configuration can select custom FIFO watermarks, but
these may conflict the actual FIFO size of the PL022 variant if
set too high. So strengthen the sanity checks to deny any
conflicting settings.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Insert notifiers for the runtime PM API. With this the runtime
PM layer kicks in to action where used.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
[Rebased to Linux 3.0-rc3, edit description]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Configure the DMA burstsize from the FIFO trigger level supplied
with the controller configuration data. This is based on a patch
from Virupax, but I rewrote it differently.
Reported-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Return error on out of range cpsdvsr value.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Done via coccinelle scripts like:
@@
struct resource *ptr;
@@
- ptr->end - ptr->start + 1
+ resource_size(ptr)
and some grep and typing.
Mostly uncompiled, no cross-compilers.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch enables this SPI driver works with DMA mode.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Support ML7213 device of OKI SEMICONDUCTOR.
ML7213 is companion chip of Intel Atom E6xx series for IVI(In-Vehicle Infotainment).
ML7213 is compatible for Intel EG20T PCH.
v4: - Delete unrelated whitespace
- Prevent device driver from accessing platform data
- Add __devinit and __devexit
- Save pdev->dev to pd_dev->dev.parent
- Have own suspend/resume processing in platform_driver.
- Care returned value in pch_spi_init
- Change unregister order
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch adds DMA support for the EP93xx SPI driver. By default the DMA is
not enabled but it can be enabled by setting ep93xx_spi_info.use_dma to true
in board configuration file.
Note that the SPI driver still uses PIO for small transfers (<= 8 bytes) for
performance reasons.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.
This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.
v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
be the predominant pattern for subsystem prefixes.
- Clean up filenames in Kconfig and header comment blocks
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
SPI protocol drivers can submit messages specifying needed bits_per_word
parameter for a message transfer. The bitbang driver currently ignores
bits_per_word given by a singe message and always uses master's
bits_per_word parameter. Only use master's bits_per_word when a
message didn't specify needed bits_per_word for ongoing transfer.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
fixes below compilation warning. The variable doesn't actual ever get
used uninitialized, but that's no reason to be sloppy.
drivers/spi/omap2_mcspi.c: In function 'omap2_mcspi_txrx_dma':
drivers/spi/omap2_mcspi.c:301: warning: 'elements' may be used uninitialized in this function
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
[grant.likely: amended description]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The Blackfin SPORT peripheral is a pretty flexible device. With enough
coaching, we can make it generate SPI compatible waveforms. This is
desirable as the SPORT can run at much higher clock frequencies than the
dedicated on-chip SPI peripheral, and it can do full duplex DMA. It also
opens up the possibility of multiple SPI buses in case someone wants to
dedicate a whole bus to a specific part that does not play well with
others.
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch includes below fixes:
1. Add missing device_remove_file for dev_attr_status_show in tle62x0_remove.
2. Fix tle62x0_probe error handling:
Currently, if the error happens when ptr > 0, gpio_attrs[0] is not
properly remove.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6: (57 commits)
regulator: Fix 88pm8607.c printk format warning
input: Add support for Qualcomm PMIC8XXX power key
input: Add Qualcomm pm8xxx keypad controller driver
mfd: Add omap-usbhs runtime PM support
mfd: Fix ASIC3 SD Host Controller Configuration size
mfd: Fix omap_usbhs_alloc_children error handling
mfd: Fix omap usbhs crash when rmmoding ehci or ohci
mfd: Add ASIC3 LED support
leds: Add ASIC3 LED support
mfd: Update twl4030-code maintainer e-mail address
mfd: Correct the name and bitmask for ab8500-gpadc BTempPullUp
mfd: Add manual ab8500-gpadc batt temp activation for AB8500 3.0
mfd: Provide ab8500-core enumerators for chip cuts
mfd: Check twl4030-power remove script error condition after i2cwrite
mfd: Fix twl6030 irq definitions
mfd: Add phoenix lite (twl6025) support to twl6030
mfd: Avoid to use constraint name in 88pm860x regulator driver
mfd: Remove checking on max8925 regulator[0]
mfd: Remove unused parameter from 88pm860x API
mfd: Avoid to allocate 88pm860x static platform data
...
* 'spi/next' of git://git.secretlab.ca/git/linux-2.6:
spi/amba-pl022: work in polling or interrupt mode if pl022_dma_probe fails
spi/spi_s3c24xx: Use spi_bitbang_stop instead of spi_unregister_master in s3c24xx_spi_remove
spi/spi_nuc900: Use spi_bitbang_stop instead of spi_unregister_master in nuc900_spi_remove
spi/spi_tegra: use spi_unregister_master() instead of spi_master_put()
spi/spi_sh: use spi_unregister_master instead of spi_master_put in remove path
spi: Use void pointers for data in simple SPI I/O operations
spi/pl022: use cpu_relax in the busy loop
spi/pl022: mark driver non-experimental
spi/pl022: timeout on polled transfer v2
spi/dw_spi: improve the interrupt mode with the batch ops
spi/dw_spi: change poll mode transfer from byte ops to batch ops
spi/dw_spi: remove the un-necessary flush()
spi/dw_spi: unify the low level read/write routines
With the addition of a device platform mfd_cell pointer, MFD drivers
can go back to passing platform data back to their sub drivers.
This allows for an mfd_cell->mfd_data removal and thus keep the
sub drivers MFD agnostic. This is mostly needed for non MFD aware
sub drivers.
Acked-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
If pl022_dma_probe fails, we can try to transfer data in polling or interrupt
mode. Also, set platform_info->enable_dma to 0, so that no other code tries to
use dma.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Calling spi_bitbang_stop() will also destroy bitbang->workqueue,
which is created by calling spi_bitbang_start() in s3c24xx_spi_probe().
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Calling spi_bitbang_stop() will also destroy bitbang->workqueue,
which is created by calling spi_bitbang_start() in nuc900_spi_probe().
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
spi_master_put() should only be used in error handling.
Once spi_register_master() returns success, we should call
spi_unregister_master() instead.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
