Conditions per spi_transfer are:
* transfer.len >= 96 bytes (to avoid mapping overhead costs)
* transfer.len < 65536 bytes (limitaion by spi-hw block - could get extended)
* an individual scatter/gather transfer length must be a multiple of 4
for anything but the last transfer - spi-hw block limit.
(some shortcut has been taken in can_dma to avoid unnecessary mapping of
pages which, for which there is a chance that there is a split with a
transfer length not a multiple of 4)
If it becomes a necessity these restrictions can get removed by additional
code.
Note that this patch requires a patch to dma-bcm2835.c by Noralf to
enable scatter-gather mode inside the dmaengine, which has not been
merged yet.
That is why no patch to arch/arm/boot/dts/bcm2835.dtsi is included - the
code works as before without dma when tx/rx are not set, but it writes
a message warning about dma not used:
spi-bcm2835 20204000.spi: no tx-dma configuration found - not using dma mode
To enable dma-mode add the following lines to the device-tree:
dmas = <&dma 6>, <&dma 7>;
dma-names = "tx", "rx";
Tested-by: Noralf Trønnes <noralf@tronnes.org> (private communication)
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix a race (with some kernel configurations) where a queued
master->pump_messages runs and frees dummy_tx/rx before
spi_unmap_msg is running (or is finished).
This results in the following messages:
BUG: Bad page state in process
page:db7ba030 count:0 mapcount:0 mapping: (null) index:0x0
flags: 0x200(arch_1)
page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set
...
Reported-by: Noralf Trønnes <noralf@tronnes.org>
Suggested-by: Noralf Trønnes <noralf@tronnes.org>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
spi: Fixes for v4.1
A few driver fixes plus two changes for the core, one to make the
setup_transfer() callback optional which fixes crashes in some drivers
which were updated to use new interfaces without apparent testing and
one to ensure we don't expose the data buffers we use for dummy
transfers to drivers which avoids potential issues with multiple
accesses to them or reuse.
# gpg: Signature made Sat 25 Apr 2015 10:59:47 BST using RSA key ID 5D5487D0
# gpg: key CD7BEEBC: no public key for trusted key - skipped
# gpg: key CD7BEEBC marked as ultimately trusted
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# gpg: key AF88CD16 marked as ultimately trusted
# gpg: key 16005C11: no public key for trusted key - skipped
# gpg: key 16005C11 marked as ultimately trusted
# gpg: key 5621E907: no public key for trusted key - skipped
# gpg: key 5621E907 marked as ultimately trusted
# gpg: key 5C6153AD: no public key for trusted key - skipped
# gpg: key 5C6153AD marked as ultimately trusted
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg: aka "Mark Brown <broonie@debian.org>"
# gpg: aka "Mark Brown <broonie@kernel.org>"
# gpg: aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg: aka "Mark Brown <broonie@linaro.org>"
# gpg: aka "Mark Brown <Mark.Brown@linaro.org>"
Remove unneeded variable used to store return value.
The semantic patch that makes this change is available
in scripts/coccinelle/misc/returnvar.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
If GPIO chip select is specified, request the GPIO in the setup function
and release it in the cleanup function.
Signed-off-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Switches from transfer_one_message to transfer_one to prepare driver for
use of GPIO chip selects.
Signed-off-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
To reduce indentation and complexity of code, insteeds of returning zero
the function rspi_dma_check_then_transfer should return rspi_dma_transfer
directly after checking error.
Signed-off-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
move spi controller's gpio request work out from probe() to spi device
register stage, so after spi device register spi controller can deactive
device's gpio chipselect. old code can't do it because gpio request has
not be done until device register is finised in spi_bitbang_start.
and add cleanup function to free CS gpio.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.
Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
I got following error on CONFIG_GPIOLIB=n.
drivers/spi/spi-bcm2835.c: In function 'chip_match_name':
drivers/spi/spi-bcm2835.c:356:21: error: dereferencing pointer to incomplete type 'struct gpio_chip'
return !strcmp(chip->label, data);
^
drivers/spi/spi-bcm2835.c: In function 'bcm2835_spi_setup':
drivers/spi/spi-bcm2835.c:382:9: error: implicit declaration of function 'gpiochip_find' [-Werror=implicit-function-declaration]
chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
^
drivers/spi/spi-bcm2835.c:382:7: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
^
drivers/spi/spi-bcm2835.c: In function 'chip_match_name':
drivers/spi/spi-bcm2835.c:357:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>
The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
return error for unsupported bits-per-word format, BUG() is not right
for this scenerios as we are not an ASSERT but an error handler.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <baohua.song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The polling mode of the driver is designed for transfers that run
less than 30us - it will only execute under those circumstances.
So it should run comfortably without getting interrupted by the
scheduler.
But there are situations where the raspberry pi is so overloaded
that it can take up to 80 jiffies until the polling thread gets
rescheduled - this has been observed especially under heavy
IO situations.
In such a situation we now fall back to the interrupt handler and
log the situation at debug level.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The way that the timeout code is written in the polling function
the timeout does also trigger when interrupted or rescheduled while
in the polling loop.
This patch changes the timeout from effectively 20ms (=2 jiffies) to
1 second and removes the time that the transfer really takes out of
the computation, as - per design - this is <30us and the jiffie resolution
is 10ms so that does not make any difference what so ever.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The internal chip select CS0 wasn't initialized properly to work with
CS HIGH chips.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
Clocks should be prepared and unprepared, fix this by using
clk_prepare_enable() and clk_disable_unprepare() instead of
clk_enable() and clk_disable().
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
Set the OF node of the spi controller and use the generic GPIO based
chip select instead of the custom controller data. As the controller
data isn't used by any board just drop it.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch makes possible for protocol drivers to do full-duplex SPI
transfers properly. Until now this driver could only be used for
half-duplex transfers, since it always expected an spi_transfer with
non-null tx_buf to be only used for TX, and those with non-null rx_buf
to be only used for RX.
The fix consists in correcting the fsl_espi_transfer length by taking
into consideration duplex spi_transfers, and not just by adding n_tx
and n_rx.
Furthermore, this correction has exposed an inconsistency in the
protocol driver <-> controller driver interaction. The spi-fsl-espi
driver artificially inserts TX bytes when message fragmentation is
necessary (due to SPCOM_TRANLEN_MAX) instead of informing the
protocol driver of the hardware limitation. This was tested with the
m25p80 NOR flash protocol driver. Since fixing this issue may cause
other client drivers to malfunction, it was left as is.
Signed-off-by: Jonatas Rech <jonatas.rech@datacom.ind.br>
Signed-off-by: Mark Brown <broonie@kernel.org>
It is unnecessary for DSPI to enable/disable clk when access DSPI register.
And it will reduce efficiency.
Signed-off-by: Haikun Wang <haikun.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The spi queue waits forever for spi_finalize_current_message() to be
called, blocking the bus. Ensure that all error paths from
omap2_mcspi_transfer_one_message() call spi_finalize_current_message().
Signed-off-by: Fionn Cleary <fionn.cleary@streamunlimited.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This has the benefit that the "optimization" of the framework in regards
to spi_sync will also benefit spidev users directly and allow running
spi transfers without a necessary context-switch to message-pump.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
On CPM2, the SPI parameter RAM is dynamically allocated in the
dualport RAM whereas in CPM1, it is statically allocated to a default
address with capability to relocate it somewhere else via the use of
CPM micropatch. The address of the parameter RAM is given by the boot
loader and expected to be mapped via devm_ioremap_resource()
In the current implementation, in function fsl_spi_cpm_get_pram()
there is a confusion between the SPI_BASE register and the base of the
SPI parameter RAM. Fortunatly, it is working properly with MPC866 and
MPC885 because they do set SPI_BASE, but on MPC860 and other old
MPC8xx that doesn't set SPI_BASE, pram_ofs is not properly set.
Also, the parameter RAM is not properly mapped with
devm_ioremap_resource() as it should but still gets accessible by
chance through the full RAM which is mapped from somewhere else.
This patch applies to the SPI driver the same principle as for the
CPM UART: when the CPM is of type CPM1, we simply do an
devm_ioremap_resource() of the area provided via the device tree.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
As it turns out, the set_cs() enable parameter refers to the logic level
on the CS pin, not the state of chip selection.
This broke functionality of the LEDs behind the CPLD, or at least delayed
the commands until another one came in to toggle CS.
Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This driver mediates access between the connected CPLD and other devices
on the bus.
The m25p80-compatible boot flash and (some models) MMC use regular SPI,
bitbanged as required by the SoC. However the SPI-connected CPLD has
a two-wire mode, in which two bits are transferred per SPI clock
cycle. The second bit is transmitted with the SoC's CS2 pin.
Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Some controller drivers have no need of this callback (spi-altera even
causes a NULL pointer dereference because it doesn't register the callback,
falsely assuming that it is already optional).
Fixes: 30af9b558a ("spi/bitbang: Drop empty setup() functions")
Signed-off-by: Pelle Nilsson <per.nilsson@xelmo.com>
Reviewed-by: Ezequiel Garcia <ezequiel.garcia@vanguardiasur.com.ar>
Signed-off-by: Mark Brown <broonie@kernel.org>
Some spi device drivers use the same tx_buf and rx_buf repeatly for better
performance such as driver/input/touchsreen/ads7846.c, but spi core grab tx_buf
/rx_buf of transfer and set them as dummy_tx/dummy_rx once they are NULL. Thus,
in the second time the tx_buf/rx_buf will be replaced by dummy_tx/dummy_rx and
the data which produced by the last tx or rx may be wrongly sent to the device
or handled by the upper level protocol. This patch just keep the orignal value
of tx_buf/rx_buf if they are NULL after this transfer processed.
Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The way that the timeout code is written in the polling function
the timeout does also trigger when interrupted or rescheduled while
in the polling loop.
This patch changes the timeout from effectively 20ms (=2 jiffies) to
1 second and removes the time that the transfer really takes out of
the computation, as - per design - this is <30us and the jiffie resolution
is 10ms so that does not make any difference what so ever.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix:
drivers/spi/spi-bcm2835.c: In function 'chip_match_name':
drivers/spi/spi-bcm2835.c:356:21: error:
dereferencing pointer to incomplete type
drivers/spi/spi-bcm2835.c: In function 'bcm2835_spi_setup':
drivers/spi/spi-bcm2835.c:382:2: error:
` implicit declaration of function 'gpiochip_find'
drivers/spi/spi-bcm2835.c:387:21: error:
dereferencing pointer to incomplete type
by adding the now mandatory GPIOLIB dependency.
Fixes: a30a555d74 ("spi: bcm2835: transform native-cs to gpio-cs
on first spi_setup")
Cc: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
In cases of short transfer times the CPU is spending lots of time
in the interrupt handler and scheduler to reschedule the worker thread.
Measurements show that we have times where it takes 29.32us to between
the last clock change and the time that the worker-thread is running again
returning from wait_for_completion_timeout().
During this time the interrupt-handler is running calling complete()
and then also the scheduler is rescheduling the worker thread.
This time can vary depending on how much of the code is still in
CPU-caches, when there is a burst of spi transfers the subsequent delays
are in the order of 25us, so the value of 30us seems reasonable.
With polling the whole transfer of 4 bytes at 10MHz finishes after 6.16us
(CS down to up) with the real transfer (clock running) taking 3.56us.
So the efficiency has much improved and is also freeing CPU cycles,
reducing interrupts and context switches.
Because of the above 30us seems to be a reasonable limit for polling.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
