This converts the Cadence SPI master driver to use GPIO
descriptors for chip select handling.
The Cadence driver was allocating a state container just
to hold the requested GPIO line and contained lots of
polarity inversion code. As this is all handled by gpiolib
and a simple devm_* request in the core, and as the driver
is fully device tree only, most of this code chunk goes
away in favour of central handling. The setup/cleanup
callbacks goes away.
This driver does NOT drive the CS line by setting the
value of the GPIO so it relies on the SPI core to do
this, which should work just fine with the descriptors.
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Janek Kotas <jank@cadence.com>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix the missing clk_disable_unprepare() before return
from cnds_runtime_resume() in the error handling case.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The path "spi: cadence: Add usleep_range() for
cdns_spi_fill_tx_fifo()" added a usleep_range() function call,
which cannot be used in atomic context.
However the cdns_spi_fill_tx_fifo() function can be called during
an interrupt which may result in a kernel panic:
BUG: scheduling while atomic: grep/561/0x00010002
Modules linked in:
Preemption disabled at:
[<ffffff800858ea28>] wait_for_common+0x48/0x178
CPU: 0 PID: 561 Comm: grep Not tainted 4.17.0 #1
Hardware name: Cadence CSP (DT)
Call trace:
dump_backtrace+0x0/0x198
show_stack+0x14/0x20
dump_stack+0x8c/0xac
__schedule_bug+0x6c/0xb8
__schedule+0x570/0x5d8
schedule+0x34/0x98
schedule_hrtimeout_range_clock+0x98/0x110
schedule_hrtimeout_range+0x10/0x18
usleep_range+0x64/0x98
cdns_spi_fill_tx_fifo+0x70/0xb0
cdns_spi_irq+0xd0/0xe0
__handle_irq_event_percpu+0x9c/0x128
handle_irq_event_percpu+0x34/0x88
handle_irq_event+0x48/0x78
handle_fasteoi_irq+0xbc/0x1b0
generic_handle_irq+0x24/0x38
__handle_domain_irq+0x84/0xf8
gic_handle_irq+0xc4/0x180
This patch replaces the function call with udelay() which can be
used in an atomic context, like an interrupt.
Signed-off-by: Jan Kotas <jank@cadence.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In case of xspi work in busy condition, may send bytes failed.
once something wrong, spi controller did't work any more
My test found this situation appear in both of read/write process.
so when TX FIFO is full, add one byte delay before send data;
Signed-off-by: sxauwsk <sxauwsk@163.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Context could be lost across the suspend and resume.
Reinit the driver to tide over.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
call pm_runtime_enable after set_active other wise it will
enable clock always.
Signed-off-by: Naga Sureshkumar Relli <nagasure@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This adds support for using GPIOs for chipselects as described by the
default dt-bindings.
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
The newly added runtime PM support for the cadence spi driver
causes harmless warnings when PM is disabled:
drivers/spi/spi-cadence.c:681:12: warning: 'cnds_runtime_suspend' defined but not used
drivers/spi/spi-cadence.c:652:12: warning: 'cnds_runtime_resume' defined but not used
This adds __maybe_unused annotations to the respective functions
to shut up the warnings, while leaving the code in place for
compile testing and avoiding ugly #ifdefs.
Fixes: d36ccd9f7e ("spi: cadence: Runtime pm adaptation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
No functional change.
Fixing some style related issues
CHECK: multiple assignments should be avoided
+ new_ctrl_reg = ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
CHECK: Alignment should match open parenthesis
+static void cdns_spi_config_clock_freq(struct spi_device *spi,
+ struct spi_transfer *transfer)
CHECK: Please use a blank line after function/struct/union/enum declarations
+}
+static int cdns_prepare_message(struct spi_master *master,
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Return the error code for cdns_spi_suspend and cdns_spi_resume.
Also fixes a comment where which claims that the error code is
returned.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Now that the clocks are enabled and disabled per transaction
, remove the clock enable and disable from resume and suspend
hooks.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently the clocks are enabled at probe and disabled
at remove. This patch moves the clock enable to the
start of transaction and disables at the end.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
cdns_spi_chipselect has parameter is_high however the comment
describes it as is_on.
Also fixes the below warning.
drivers/spi/spi-cadence.c:182: warning: No description found for
parameter 'is_high'
drivers/spi/spi-cadence.c:182: warning: Excess function parameter 'is_on'
description in 'cdns_spi_chipselect'
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The clock disabling is missed out in some
error cases at probe. Fix the same.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Remove the _MASK and _OFFSET from the macros.
It improves readability, removes some checkpatch
error for exceeding 80 chars and also prevents some
linebreaks.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
CHECK: Comparison to NULL could be written "!master"
+ if (master == NULL)
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use to_platform_device() instead of open-coding it.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In 3-to-8 mux mode for the CS pins we need to set the PERI_SEL bit in the
control register. Currently the driver never sets this bit even when
configured for 3-to-8 mux mode. This patch adds code which sets the bit
during device initialization when necessary.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This will make it possible to use the settings specified in the devicetree
to configure the hardware.
Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
There is no need to init .owner field.
Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"
This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Currently the cadence SPI driver does the SPI clock configuration (setup CPOL
and CPHA) in the prepare_transfer_hardware() callback. The
prepare_transfer_hardware() callback is only called though when the controller
transitions from a idle state to a non-idle state. Such a transitions happens
when the message queue goes from empty to non-empty. If multiple messages from
different SPI slaves with different clock settings are in the message queue the
clock settings will not be properly updated when switching from one slave device
to another. Instead do the updating of the clock configuration in the
prepare_message() callback which will be called for each individual message.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
It seems that the cadence SPI controller does not immediately change the clock
polarity setting when writing the CR register. Instead the change is delayed
until the next transfer starts. This happens after the chip select line has
already been asserted. As a result the first transfer after a clock polarity
change will generate spurious clock transitions which typically results in the
SPI slave not being able to properly understand the message. Toggling the ER
register seems to cause the SPI controller to apply the clock polarity changes,
so implement this as a workaround to fix the issue.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Make of_device_id array const, because all OF functions handle
it as const.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Add driver for Cadence SPI controller. This is used in Xilinx Zynq.
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
