Commit Graph

27 Commits

Author SHA1 Message Date
Wei Yongjun
2ba87a9bcc
spi: cadence: Fix missing clk_disable_unprepare() on error in cnds_runtime_resume()
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>
2018-07-11 15:34:53 +01:00
Janek Kotas
931c4e9a72
spi: cadence: Change usleep_range() to udelay(), for atomic context
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
2018-06-18 13:05:38 +01:00
Mark Brown
16c10b3bf8
Merge branch 'spi-4.17' into spi-4.18 for the merge window 2018-06-04 11:51:12 +01:00
Wolfram Sang
e1f16b0493
spi: simplify getting .drvdata
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>
2018-04-20 17:53:20 +01:00
sxauwsk
49530e6411
spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo()
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>
2018-04-18 11:28:29 +01:00
Shubhrajyoti Datta
802740890c spi: cadence: Add support for context loss
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>
2017-08-08 10:43:41 +01:00
Naga Sureshkumar Relli
48767fd898 spi: cadence: change sequence of calling runtime_enable
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>
2017-08-08 10:43:16 +01:00
Moritz Fischer
b42a33bd93 spi: cadence: Allow for GPIO pins to be used as chipselects
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>
2017-04-26 15:23:45 +01:00
Arnd Bergmann
148b1eb93c spi: cadence: mark pm functions __maybe_unused
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>
2016-04-18 10:58:49 +01:00
Shubhrajyoti Datta
57bb1369de spi: cadence: Fix some checkpatch warnings
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>
2016-04-06 10:16:46 -07:00
Shubhrajyoti Datta
6fe9b67dbe spi: cadence: Return the error code for cdns_spi_suspend and cdns_spi_resume
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
2198b7483d spi: cadence: Remove the clock enable and disable from suspend and resume
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
d36ccd9f7e spi: cadence: Runtime pm adaptation
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
b4037360e6 spi: cadance: Fix the Documentation
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
50ac697baf spi: cadence: Fix probe error handling
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
24746675fb spi: cadence: Remove _MASK and _OFFSET suffix
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>
2016-04-05 11:51:10 -07:00
Shubhrajyoti Datta
15a1c5030a spi: cadence: Fix a check patch warning
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>
2016-04-05 11:51:10 -07:00
Geliang Tang
9033a5f9ac spi: cadence: use to_platform_device()
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>
2016-01-05 11:34:23 +00:00
Mark Brown
3bcfca617a Merge remote-tracking branches 'spi/topic/atmel', 'spi/topic/cadence', 'spi/topic/dw' and 'spi/topic/fsl-cpm' into spi-next 2014-12-08 12:17:12 +00:00
Lars-Peter Clausen
ee0ebe8100 spi: cadence: Fix 3-to-8 mux mode
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>
2014-11-28 11:42:11 +00:00
Paul Cercueil
3cc291061c spi: cadence: Init HW after reading devicetree attributes
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>
2014-11-28 11:41:13 +00:00
Michal Simek
e67f04c918 spi: cadence: Remove .owner field for driver
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>
2014-08-16 17:11:32 -05:00
Mark Brown
d1345c524e Merge remote-tracking branches 'spi/topic/adi-v3', 'spi/topic/atmel', 'spi/topic/cleanup' and 'spi/topic/davinci' into spi-next 2014-08-04 17:21:04 +01:00
Lars-Peter Clausen
b48b9488e3 spi: cadence: Configure SPI clock in the prepare_message() callback
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>
2014-07-11 14:39:26 +01:00
Lars-Peter Clausen
a39e65e9cc spi: cadence: Make sure that clock polarity changes are applied
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>
2014-07-11 14:39:26 +01:00
Jingoo Han
f7f994a4c5 spi: cadence: Make of_device_id array const
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>
2014-06-06 12:37:41 +01:00
Harini Katakam
c474b38665 spi: Add driver for Cadence SPI controller
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>
2014-04-14 21:00:28 +01:00