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.
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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>
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>
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>
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>
Transforms the bcm-2835 native SPI-chip select to their gpio-cs equivalent.
This allows for some support of some optimizations that are not
possible due to HW-gliches on the CS line - especially filling
the FIFO before enabling SPI interrupts (by writing to CS register)
while the transfer is already in progress (See commit: e3a2be3030)
This patch also works arround some issues in bcm2835-pinctrl which does not
set the value when setting the GPIO as output - it just sets up output and
(typically) leaves the GPIO as low. When a fix for this is merged then this
gpio_set_value can get removed from bcm2835_spi_setup.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Mark Brown
Jonatas Rech
Linus Torvalds
Christophe Leroy
Haikun Wang
Fionn Cleary
Pelle Nilsson
Robin Gong
Martin Sperl
Guenter Roeck