Commit Graph

4819 Commits

Author SHA1 Message Date
Rasmus Villemoes
a798a7086c spi: spi-fsl-spi: allow changing bits_per_word while CS is still active
Commit c9bfcb3151 (spi_mpc83xx: much improved driver) introduced
logic to ensure bits_per_word and speed_hz stay the same for a series
of spi_transfers with CS active, arguing that

    The current driver may cause glitches on SPI CLK line since one
    must disable the SPI controller before changing any HW settings.

This sounds quite reasonable. So this is a quite naive attempt at
relaxing this sanity checking to only ensure that speed_hz is
constant - in the faint hope that if we do not causes changes to the
clock-related fields of the SPMODE register (DIV16 and PM), those
glitches won't appear.

The purpose of this change is to allow automatically optimizing large
transfers to use 32 bits-per-word; taking one interrupt for every byte
is extremely slow.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-02 13:00:54 +07:00
Jarkko Nikula
748fbadf95 spi: pxa2xx: Unify remaing prints in pxa2xx_spi_transfer_one()
Use SPI device pointer in the remaining two error and warning prints in
pxa2xx_spi_transfer_one() instead of platform device of the controller

It make prints in the function uniform and more useful especially the
error print here as it can reveal the driver that has mapped the DMA
itself and attempts to transfer more than the maximum supported DMA
transfer length.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-02 13:00:33 +07:00
Jarkko Nikula
20f4c379c3 spi: pxa2xx: Use struct spi_device directly in pxa2xx_spi_transfer_one()
Pointer to a SPI device is passed to pxa2xx_spi_transfer_one() so there
is no need to access it through the current SPI message pointer.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-02 13:00:12 +07:00
Sowjanya Komatineni
2b17a3c759 spi: tegra114: add SPI_LSB_FIRST support
Tegra SPI controller supports lsb first mode. Default is MSB bit first
and on selection of SPI_LSB_FIRST through SPI mode transmission happens
with LSB bit first.

This patch adds SPI_LSB_FIRST flag to mode_bits and also configures it
on request.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:50:47 +07:00
Sowjanya Komatineni
fc9ba6e3e2 spi: tegra114: use packed mode for 32 bits per word
Fixes: Use packed mode for 32 bits per word transfers to increase
performance as each packet is a full 32-bit word.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:48:59 +07:00
Rasmus Villemoes
17ecffa289 spi: spi-fsl-spi: relax message sanity checking a little
The comment says that we should not allow changes (to
bits_per_word/speed_hz) while CS is active, and indeed the code below
does fsl_spi_setup_transfer() when the ->cs_change of the previous
spi_transfer was set (and for the very first transfer).

So the sanity checking is a bit too strict - we can change it to
follow the same logic as is used by the actual transfer loop.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:48:37 +07:00
Rasmus Villemoes
24c3636233 spi: spi-fsl-spi: remove always-true conditional in fsl_spi_do_one_msg
__spi_validate() in the generic SPI code sets ->speed_hz and
->bits_per_word to non-zero values, so this condition is always true.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:48:13 +07:00
Sowjanya Komatineni
0191949333 spi: tegra114: reset controller on probe
Fixes: SPI driver can be built as module so perform SPI controller reset
on probe to make sure it is in valid state before initiating transfer.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:41:23 +07:00
Sowjanya Komatineni
f4ce428c41 spi: tegra114: configure dma burst size to fifo trig level
Fixes: Configure DMA burst size to be same as SPI TX/RX trigger levels
to avoid mismatch.

SPI FIFO trigger levels are calculated based on the transfer length.
So this patch moves DMA slave configuration to happen before start
of DMAs.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:39:42 +07:00
Sowjanya Komatineni
c4fc9e5b28 spi: tegra114: flush fifos
Fixes: Flush TX and RX FIFOs before start of new transfer and on FIFO
overflow or underrun errors.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:39:27 +07:00
Sowjanya Komatineni
32bd1a9551 spi: tegra114: terminate dma and reset on transfer timeout
Fixes: terminate DMA and perform controller reset on transfer timeout
to clear the FIFO's and errors.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:38:58 +07:00
Sowjanya Komatineni
1a89ac5b91 spi: tegra114: fix for unpacked mode transfers
Fixes: computation of actual bytes to fill/receive in/from FIFO in unpacked
mode when transfer length is not a multiple of requested bits per word.

unpacked mode transfers fails when the transfer includes partial bytes in
the last word.

Total words to be written/read to/from FIFO is computed based on transfer
length and bits per word. Unpacked mode includes 0 padding bytes for partial
words to align with bits per word and these extra bytes are also accounted
for calculating bytes left to transfer in the current driver.

This causes extra bytes access of tx/rx buffers along with buffer index
position crossing actual length where remain_len becomes negative and due to
unsigned type, negative value is a 32 bit representation of signed value
and transferred bytes never meets the actual transfer length resulting in
transfer timeout and a hang.

This patch fixes this with proper computation of the actual bytes to fill in
FIFO during transmit and the actual bytes to read from FIFO during receive
ignoring 0 padded bytes.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:25:24 +07:00
Sowjanya Komatineni
7b3d10cdf5 spi: tegra114: clear packed bit for unpacked mode
Fixes: Clear packed bit when not using packed mode.

Packed bit is not cleared when not using packed mode. This results
in transfer timeouts for the unpacked mode transfers followed by the
packed mode transfers.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:25:10 +07:00
Cezary Gapinski
94b18a86eb spi: pic32: fix dma channels termination
When timeout occurs DMA TX and RX channels should be stopped
instead of stopping RX channel twice time.

Signed-off-by: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-01 15:24:47 +07:00
Randolph Maaßen
0e694df356 spi: tegra20-slink: change chip select action order
To transfer via SPI the tegra20-slink driver first sets the command
register, which contains the chip select value, and after that the
command2 register, which contains the chip select line. This leads to a
small spike in the chip selct 0 line between the set of the value and
the selection of the chip select line.

This commit changes the order of the register writes so that first the
chip select line is chosen and then the value is set, removing the
spike.

Signed-off-by: Randolph Maaßen <gaireg@gaireg.de>
Reviewed-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-27 12:33:33 +00:00
Ludovic Barre
245308c621 spi: stm32-qspi: add dma support
This patch adds the dma support for the stm32-qspi hardware.
The memory buffer constraints (lowmem, vmalloc, kmap) are taken into
account by framework. In read mode, the memory map is preferred vs
dma (due to better throughput). If the dma transfer fails the buffer
is sent by polling.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-26 13:26:41 +00:00
Ludovic Barre
a88eceb17a spi: stm32-qspi: add spi_master_put in release function
This patch adds spi_master_put in release function
to drop the controller's refcount.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-26 13:26:27 +00:00
Stefan Roese
cbd66c626e spi: mt7621: Move SPI driver out of staging
This patch moves the MT7621 SPI driver, which is used on some Ralink /
MediaTek MT76xx MIPS SoC's, out of the staging directory. No changes to
the source code are done in this patch.

This driver version was tested successfully on an MT7688 based platform
with an SPI NOR on CS0 and an SPI NAND on CS1 without any issues (so
far).

This patch also documents the devicetree bindings for the MT7621 SPI
device driver.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: NeilBrown <neil@brown.name>
Cc: Sankalp Negi <sankalpnegi2310@gmail.com>
Cc: Chuanhong Guo <gch981213@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: Armando Miraglia <arma2ff0@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-25 12:13:34 +00:00
Axel Lin
72dca1f674 spi: at91-usart: Remove duplicated checking for spi->bits_per_word
This checking is already done in __spi_validate_bits_per_word().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-25 12:13:20 +00:00
YueHaibing
55e3dacaf5 spi: atmel-quadspi: Make atmel_qspi_get_name static
Fix sparse warning:

drivers/spi/atmel-quadspi.c:369:12: warning:
 symbol 'atmel_qspi_get_name' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-25 12:13:10 +00:00
Arnd Bergmann
ca1438dcb3 spi: export tracepoint symbols to modules
The newly added tracepoints in the spi-mxs driver cause a link
error when the driver is a loadable module:

ERROR: "__tracepoint_spi_transfer_stop" [drivers/spi/spi-mxs.ko] undefined!
ERROR: "__tracepoint_spi_transfer_start" [drivers/spi/spi-mxs.ko] undefined!

I'm not quite sure where to put the export statements, but
directly after the inclusion of the header seems as good as
any other place.

Fixes: f3fdea3af4 ("spi: mxs: add tracing to custom .transfer_one_message callback")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-21 15:05:07 +00:00
Clark Wang
69c8a9bcb0 spi: lpspi: fix dataloss when SS is inactivated between every words
If we don't use CONT to keep SS activated or use DMA mode without
cs-gpio, SS will be inactivated between every words. The word here
means the data sent once which length can be set as 1/2/4 bytes.

In the isr function, we read the FSR_RXCOUNT just behind the
fsl_lpspi_read_rx_fifo. This causes the value of FSR_RXCOUNT cannot
reflect whether there is still data not sent timely. So do this
judgement by FSR_TXCOUNT.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-21 15:02:28 +00:00
Andy Shevchenko
5ba846b1ee dmaengine: idma64: Use actual device for DMA transfers
Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.

In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.

We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-03-21 19:48:26 +05:30
Andy Shevchenko
000c6af417 spi: pxa2xx: Debug print DMA burst size
It's useful during debug to see what DMA burst size is.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:21:32 +00:00
Andy Shevchenko
37821a82e6 spi: pxa2xx: Introduce DMA burst size support
Some masters may have different DMA burst size than hard coded default.
In such case respect the value given by DMA burst size provided via
platform data.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:21:17 +00:00
Phil Edworthy
560ee7e910 spi: dw: Add support for an optional interface clock
The Synopsys SSI Controller has an interface clock, but most SoCs hide
this away. However, on some SoCs you need to explicitly enable the
interface clock in order to access the registers. Therefore, add support
for an optional interface clock.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Gareth Williams <gareth.williams.jx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:21:02 +00:00
Wolfram Sang
f457cb7078 spi: mxic: simplify getting .driver_data
We should get 'driver_data' 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>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:20:29 +00:00
kbuild test robot
43a8d240ee spi: spi-mem: stm32-qspi: stm32_qspi_pm_ops can be static
Fixes: 2e541b64ee ("spi: spi-mem: stm32-qspi: add suspend/resume support")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:20:14 +00:00
Mark Brown
249acb5f47 Merge tag 'v5.1-rc1' into spi-5.2
Linux 5.1-rc1
2019-03-19 13:12:32 +00:00
Andy Shevchenko
9384d0e6fa spi: pxa2xx-pci: Drop unused header inclusion
There is nothing in the driver which requires OF specific header
to be included.

Remove it for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-19 13:04:57 +00:00
kbuild test robot
809b169abb spi: lpspi: fsl_lpspi_runtime_resume() can be static
Fixes: 944c01a889 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-19 11:55:44 +00:00
Rasmus Villemoes
69b921acae spi: spi-fsl-spi: support use of the SPISEL_BOOT signal on MPC8309
The MPC8309 has a dedicated signal, SPISEL_BOOT, usually used as chip
select for the flash device from which the bootloader is loaded. It is
not an ordinary gpio, but is simply controlled via the SPI_CS register
in the system configuration.

To allow accessing such a spi slave, we need to teach
fsl_spi_cs_control() how to control the SPISEL_BOOT signal. To
distinguish the gpio-controlled slaves, continue to have those use
chip_select values of 0..ngpios-1, and use chip_select == ngpios for
the boot flash.

I'm not too happy with all the ifdeffery, but it seems to be necessary
for guarding the sysdev/fsl_soc.h and use of
get_immrbase() (spi-fsl-lib.c already contains similar ifdeffery).

Googling suggests that the MPC8306 is similar, with the SPI_CS
register at the same offset.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 14:47:24 +00:00
Rajan Vaja
3d03137864 drivers: Defer probe if firmware is not ready
Driver needs ZynqMP firmware interface to call EEMI
APIs. In case firmware is not ready, dependent drivers
should wait until the firmware is ready.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2019-03-18 13:45:27 +01:00
Jan Kundrát
84d8df745b spi: orion: Support spi_xfer->word_delay_usecs
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:18:42 +00:00
Jan Kundrát
2ed6692e8c spi: spidev: Enable control of inter-word delays
Commit b7bb367afa added support for inserting delays in between
individual words within a single SPI transaction. This makes it
accessible from userspace.

WARNING: This delay is silently ignored unless the SPI controller
implements extra support for it. This is similar to how the in-kernel
users handle the other existing property, spi_transfer->word_delay.

Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:18:28 +00:00
Clark Wang
4e3891a55f spi: lpspi: Code cleanup
Delete the extra space.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:18:13 +00:00
Clark Wang
578465ea2b spi: lpspi: Add the missing NULL check
The spi_transfer *t will be used in one transfer whatever. If t is NULL,
there has no need to try sending data, so add an error return here.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:59 +00:00
Clark Wang
09c04466ce spi: lpspi: add dma mode support
Add dma mode support for LPSPI. Any frame longer than half txfifosize will
be sent by dma mode.

For now, there are some limits:
1. The maximum transfer speed in master mode depends on the slave device,
   at least 40MHz(tested by spi-nor on 8qm-lpddr4-arm2 base board);
2. The maximum transfer speed in slave mode is 15MHz(imx7ulp),
   22MHz(8qm/qxp). In order to reach the maximum speed which is mentioned
   in datasheet, the load of connect wires between master and slave
   should be less than 15pF.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:44 +00:00
Clark Wang
c7a4025995 spi: lpspi: use the core way to implement cs-gpio function
Use the default implementation of transfer_one_msg/chipselect/setup
functions in spi core to implement cs-gpio control.
Use fsl_lpspi_prepare_message to init the cs_gpio pin.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:30 +00:00
Clark Wang
77736a98b8 spi: lpspi: add the error info of transfer speed setting
Add a error info when set a speed which greater than half of per-clk of
spi module.

The minimum SCK period is 2 cycles(CCR[SCKDIV]). So the maximum transfer
speed is half of spi per-clk.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:15 +00:00
Han Xu
944c01a889 spi: lpspi: enable runtime pm for lpspi
Enable the runtime power management for lpspi module.

Do some adaptation work from kernel 4.9 to 4.14.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:17:00 +00:00
Clark Wang
f5e5afdb0e spi: lpspi: Add i.MX8 boards support for lpspi
Add both ipg and per clock for lpspi to support i.MX8QM/QXP boards.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:16:37 +00:00
Aditya Pakki
f37d8e67f3 spi : spi-topcliff-pch: Fix to handle empty DMA buffers
pch_alloc_dma_buf allocated tx, rx DMA buffers which can fail. Further,
these buffers are used without a check. The patch checks for these
failures and sends the error upstream.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-18 12:14:33 +00:00
Ludovic Barre
2e541b64ee spi: spi-mem: stm32-qspi: add suspend/resume support
This patch adds suspend and resume support for spi-stm32-qspi
drivers.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 17:14:32 +00:00
Mark Brown
3949ba3b37 Merge branch 'spi-5.1' into spi-5.2 for stm32 2019-03-15 17:06:34 +00:00
Ludovic Barre
5356c2c70e spi: spi-mem: stm32-qspi: avoid memory corruption at low frequency
This patch solves a memory corruption seen at 8 MHz.
To avoid such issue, timeout counter is disabled.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:33 +00:00
Geert Uytterhoeven
26843bb128 spi: rspi: Fix sequencer reset during initialization
While the sequencer is reset after each SPI message since commit
880c6d114f ("spi: rspi: Add support for Quad and Dual SPI
Transfers on QSPI"), it was never reset for the first message, thus
relying on reset state or bootloader settings.

Fix this by initializing it explicitly during configuration.

Fixes: 0b2182ddac ("spi: add support for Renesas RSPI")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:19 +00:00
Geert Uytterhoeven
42bdaaece1 spi: rspi: Fix register initialization while runtime-suspended
The Renesas RSPI/QSPI driver performs SPI controller register
initialization in its spi_operations.setup() callback, without calling
pm_runtime_get_sync() first, which may cause spurious failures.

So far this went unnoticed, as this SPI controller is typically used
with a single SPI NOR FLASH containing the boot loader:
  1. If the device's module clock is still enabled (left enabled by the
     bootloader, and not yet disabled by the clk_disable_unused() late
     initcall), register initialization succeeds,
  2. If the device's module clock is disabled, register writes don't
     seem to cause lock-ups or crashes.
     Data received in the first SPI message may be corrupted, though.
     Subsequent SPI messages seem to be OK.
     E.g. on r8a7791/koelsch, one bit is lost while receiving the 6th
     byte of the JEDEC ID for the s25fl512s FLASH, corrupting that byte
     and all later bytes.  But until commit a2126b0a01 ("mtd:
     spi-nor: refine Spansion S25FL512S ID"), the 6th byte was not
     considered for FLASH identification.

Fix this by moving all initialization from the .setup() to the
.prepare_message() callback.  The latter is always called after the
device has been runtime-resumed by the SPI core.

This also makes the driver follow the rule that .setup() must not change
global driver state or register values, as that might break a transfer
in progress.

Fixes: 490c97747d ("spi: rspi: Add runtime PM support, using spi core auto_runtime_pm")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-15 16:32:04 +00:00
Volker Haspel
8fcb830a00 spi: spi-fsl-qspi: use devm_spi_register_controller
The driver does not clearly unregister the spi controller.
Therefore calling an unbind and bind again will end up in a
Kernel crash.

The function devm_spi_register_controller will automatically
be unregister the SPI device.

Signed-off-by: Volker Haspel <volker.haspel@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-13 15:18:39 +00:00
Trent Piepho
c842749ea1 spi: imx: stop buffer overflow in RX FIFO flush
Commit 71abd29057 ("spi: imx: Add support for SPI Slave mode") added
an RX FIFO flush before start of a transfer.  In slave mode, the master
may have sent more data than expected and this data will still be in the
RX FIFO at the start of the next transfer, and so needs to be flushed.

However, the code to do the flush was accidentally saving this data into
the previous transfer's RX buffer, clobbering the contents of whatever
followed that buffer.

Change it to empty the FIFO and throw away the data.  Every one of the
RX functions for the different eCSPI versions and modes reads the RX
FIFO data using the same readl() call, so just use that, rather than
using the spi_imx->rx function pointer and making sure all the different
rx functions have a working "throw away" mode.

There is another issue, which affects master mode when switching from
DMA to PIO.  There can be extra data in the RX FIFO which triggers this
flush code, causing memory corruption in the same manner.  I don't know
why this data is unexpectedly in the FIFO.  It's likely there is a
different bug or erratum responsible for that.  But regardless of that,
I think this is proper fix the for bug at hand here.

Fixes: 71abd29057 ("spi: imx: Add support for SPI Slave mode")
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-13 15:16:24 +00:00