Dummy buffer is used for half duplex transfers that don't have TX or RX
buffer set. Instead of own dummy buffer management here let the SPI core to
handle it by setting the SPI_MASTER_MUST_RX and SPI_MASTER_MUST_TX flags.
Then core makes sure both transfer buffers are set.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

spi-pxa2xx-dma.c DMA engine implementation stopped using PIO for
unaligned trailing bytes in the commit 111e0a9d ("spi/pxa2xx: Prevent
DMA from transferring too many bytes"). This means there is no need to
update tx/rx transfer buffer pointers after DMA completion. These buffer
pointers will be set to new buffers when handling the next transfer.

Because this buffer pointer update was only remaining use for rx_map_len
and tx_map_len members in struct driver_data after removing the legacy PXA
DMA implementation they can be removed now.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NMark Brown <broonie@kernel.org>

If by some reason pxa2xx_spi_dma_prepare() fails we have not to ignore its
error. In such case we abort the transfer and return the error to upper
level.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[Jarkko: Avoid leaking TX descriptors in case RX descriptor allocation
fails. Noted by Robert Jarzmik <robert.jarzmik@free.fr>.
Unmap also buffers in case of failure.]
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NMark Brown <broonie@kernel.org>

The spi_split_transfers_maxsize() gfp parameter is missing in the
function kernel-doc so building gives the following warning:

.//drivers/spi/spi.c:2359: warning: No description found for parameter 'gfp'
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

rsd_nsecs is defined as u8 memeber of struct rockchip_spi,
but using of_property_read_u32. That means we take risk of
truncation by type conversion if we pass on big value from
dt.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Remove some of unused header files and reoder
it into alphabetical order.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The device which is actually does DMA may have a limitation of the maximum
segment size. Respect this setting when preparing scatter-gather list.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Let's defer probing the driver if the return value of
dma_request_slave_channel is ERR_PTR(-EPROBE_DEFER) instead
of disabling dma capability directly.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

dmaengine_terminate_all is deprecated, let's use
dmaengine_terminate_async for interrupt handling.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

We should check return value of dmaengine_prep_slave_sg, otherwise
we take risk of null pointer.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The function __spi_pump_messages() is called by spi_pump_messages() and
__spi_sync(). The function __spi_sync() has an argument 'bus_locked'
that indicates if it is called with the SPI bus mutex held or not. If
'bus_locked' is false then __spi_sync() will acquire the mutex itself.

Commit 556351f1 ("spi: introduce accelerated read support for spi
flash devices") made a change to acquire the SPI bus mutex within
__spi_pump_messages(). However, this change did not check to see if the
mutex is already held. If __spi_sync() is called with the mutex held
(ie. 'bus_locked' is true), then a deadlock occurs when
__spi_pump_messages() is called.

Fix this deadlock by passing the 'bus_locked' state from __spi_sync() to
__spi_pump_messages() and only acquire the mutex if not already held. In
the case where __spi_pump_messages() is called from spi_pump_messages()
it is assumed that the mutex is not held and so call
__spi_pump_messages() with 'bus_locked' set to false. Finally, move the
unlocking of the mutex to the end of the __spi_pump_messages() function
to simplify the code and only call cond_resched() if there are no
errors.

Fixes: 556351f1 ("spi: introduce accelerated read support for spi flash devices")
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

16-bit transfers must be in big endian mode on wire.
Signed-off-by: NAlexander Kochetkov <al.kochet@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Rockchip_spi_set_cs could be called by spi_setup, but
spi_setup may be called by device driver after runtime suspend.
Then the spi clock is closed, rockchip_spi_set_cs may access the
spi registers, which causes cpu block in some socs.

Fixes: 64e36824 ("spi/rockchip: add driver for Rockchip RK3xxx")
Signed-off-by: NHuibin Hong <huibin.hong@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Commit b36f09c3 ("dmaengine: Add transfer termination
synchronization support") marked dmaengine_terminate_all() as
deprecated and is being replaced by explicit synchronous and asynchronous
terminate functions.

Here DMA termination are done in two cases: FIFO overrun and module
removal.

FIFO overrun is handled in interrupt context and converting
dmaengine_terminate_all() to dmaengine_terminate_async() does the same than
before.

Using synchronous termination in module removal however adds a bit more
robustness as it waits all completion callbacks have finished. Although it
looks all known DMA engines used with spi-pxa2xx don't implement
device_synchronize() callback so this too appears to be a no-op in
practice.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add support for third Intel Broxton variant and update comment for
A-Step variant.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NSteve Sakoman <steve.sakoman@intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The spi_lp8841_rtc_probe() function misses an initialization of the
return code when it fails to get its memory resource, as gcc notices:

drivers/spi/spi-lp8841-rtc.c: In function 'spi_lp8841_rtc_probe':
drivers/spi/spi-lp8841-rtc.c:239:9: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This changes the code to propagate the error from devm_ioremap_resource().

Fixes: 7ecbfff6 ("spi: master driver to enable RTC on ICPDAS LP-8841")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NSergei Ianovich <ynvich@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The driver tries to be clever by only setting up DMA channels when
the corresponding sg tables are non NULL. The sg tables are embedded
structs in struct spi_transfer, so they are guaranteed to be non NULL
which makes the if(tx)/if(rx) tests completely bogus. The driver even
sets the SPI_MASTER_MUST_RX / SPI_MASTER_MUST_TX flags which makes sure
the sg tables are not only present but also non empty.
Drop the tests and make the DMA path easier to follow.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now that the config function knows whether we are doing DMA or not we
can do the necessary register setup in the config function and no longer
have to do this in the trigger function. With this the trigger function
becomes a no-op for DMA, so instead of testing if we are doing DMA or
not in the trigger function we simply no longer call it in the DMA case.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The watermark levels in the DMA register are write only, the driver
should never have to read them back from the hardware. Replace the
current _MASK and _OFFSET defines with defines taking the watermark
level directly.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

This reverts patch 1476253c (spi: imx: fix ecspi mode setup)
The patch tried to fix something by clearing bits in the cfg variable,
but cfg is initialized to zero on function entry. There are no bits to
clear.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

DMA transfer for SPI was limited to up to 8 bits word size until now.
Sync in SPI burst size and DMA bus width is necessary to correctly
support 16 and 32 BPW.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

There's no need for an extra dma_is_inited variable when we can
equally well check for the existence of a DMA channel.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

When the MX51_ECSPI_DMA is configured we control every single bit
of the register, so there's no need to read/modify/write it. Instead
just write the value we want to have in the register. Also, drop
unnecessary check if we are actually doing DMA. The values written
to the register have no effect in PIO mode and value written there
during the last DMA transfer is still in the register, so we can
equally well always write a value.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The SoC specific config function does not know if DMA will be used or
not. This information will be useful to configure the SPI controller
correctly for DMA in following patches, so initialize the usedma
variable before calling into the SoC specific config function.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

At the moment the driver decides to fallback to PIO mode the buffers
are already mapped for DMA. It's a bug to access them with the CPU
afterwards, so we cannot just fallback to PIO mode.
It should not be necessary anyway, since we only use DMA when we
verified that it's possible in the fist place, so when prep_slave_sg
fails it's a bug, either in the SDMA driver or in the can_dma
implementation.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

ICP DAS LP-8841 contains a DS-1302 RTC. This driver provides an SPI
master which makes the RTC usable. The driver is not supposed to work
with anything else.

The driver uses the standard MicroWire half-duplex transfer timing.
Master output is set on low clock and sensed by the RTC on the rising
edge. Master input is set by the RTC on the trailing edge and is sensed
by the master on low clock.
Signed-off-by: NSergei Ianovich <ynvich@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch fix following warnings while make xmldocs.

.//drivers/spi/spi.c:2354: warning: Excess function parameter
'message' description in 'spi_split_transfers_maxsize'
.//drivers/spi/spi.c:2354: warning: Excess function parameter
 'max_size' description in 'spi_split_transfers_maxsize'
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

WildcatPoint PCH as seen on MacBook 12-inch (Early 2015) has a PCI enabled
SPI controller. Enable it by adding its ID to the corresponding driver.
The ACPI enumerated name for this SPI controller (found in spi-pxa2xx.c) is INT33C1.
Therefore, we associate the SPI controller with the corresponding type of LPSS_LPT_SSP.
Signed-off-by: NLeif Liddy <leif.liddy@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Only legacy PXA DMA implementation was using these rx_dma and tx_dma DMA
addresses so they are not needed after commit 6356437e
("spi: spi-pxa2xx: remove legacy PXA DMA bits").
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fixed timeout value can fire while transaction is ongoing. This may happen
because there are no strict requirements on SPI transaction duration.
Dynamic timeout value is generated based on SCLK and transaction size.

There is also 4 * SCLK delay between TX bursts related to HW internal CS change.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

In spi_imx_dma_transfer(), when desc_rx = dmaengine_prep_slave_sg()
fails, the context goes to label no_dma and then return. However,
the memory allocated for desc_tx has not been freed yet, which leads
to resource leak.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Reviewed-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

When a controller has only PIO support it is very likely that we will
run into use cases where we spend a very large amount of time consuming
CPU.  Code that does this should call cond_resched() every once in a
while to give other tasks more of a chance to run so do that in the main
SPI loop, the overhead is negligable if it's not needed.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add missing docbook documentation for the gfp parameter
in function spi_replace_transfers.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Make use of ARCH_RENESAS in place of ARCH_SHMOBILE.

This is part of an ongoing process to migrate from ARCH_SHMOBILE to
ARCH_RENESAS the motivation for which being that RENESAS seems to be a more
appropriate name than SHMOBILE for the majority of Renesas ARM based SoCs.
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add devicetree bindings for Rockchip rk3399 spi which found on
Rockchip rk3399 SoCs.
Signed-off-by: NJianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use min_t(size_t,..) in order to avoid the following
build warning on ARM64:

include/linux/kernel.h:754:17: warning: comparison of distinct pointer types lacks a cast
  (void) (&_min1 == &_min2);  \
                 ^
drivers/spi/spi.c:2304:17: note: in expansion of macro 'min'
  xfers[0].len = min(maxsize, xfer[0].len);
Suggested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use %zu for printing 'size_t' type in order to fix the following
build warning on ARM64:

drivers/spi/spi.c: In function '__spi_split_transfer_maxsize':
drivers/spi/spi.c:2278:2: warning: format '%i' expects argument of type 'int', but argument 4 has type 'size_t' [-Wformat=]
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add a struct device * member to the private driver data and use
it to print messages using dev_* functions rather than pr_*.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

RX DMA tail data handling doesn't work correctly in many cases with current
implementation. It happens because SPI core was setup to generates both RX
and RX TAIL events. And RX TAIL event does not work correctly.
This can be easily verified by sending SPI transaction with size modulus
WML(32 in our case) not equal 0.

Also removing change introduced in f6ee9b58
since this change only fix usecases with transfer size from 33 to 128 bytes
and doesn't fix 129 bytes and bigger.

This is output from transaction with len 138 bytes in loopback mode at 10Mhz:
TX0000: a3 97 a2 55 53 be f1 fc f9 79 6b 52 14 13 e9 e2
TX0010: 2d 51 8e 1f 56 08 57 27 a7 05 d4 d0 52 82 77 75
TX0020: 1b 99 4a ed 58 3d 6a 52 36 d5 24 4a 68 8e ad 95
TX0030: 5f 3c 35 b5 c4 8c dd 6c 11 32 3d e2 b4 b4 59 cf
TX0040: ce 23 3d 27 df a7 f9 96 fc 1e e0 66 2c 0e 7b 8c
TX0050: ca 30 42 8f bc 9f 7b ce d1 b8 b1 87 ec 8a d6 bb
TX0060: 2e 15 63 0e 3c dc a4 3a 7a 06 20 a7 93 1b 34 dd
TX0070: 4c f5 ec 88 96 68 d6 68 a0 09 6f 8e 93 47 c9 41
TX0080: db ac cf 97 89 f3 51 05 79 71

RX0000: a3 97 a2 55 53 be f1 fc f9 79 6b 52 14 13 e9 e2
RX0010: 2d 51 8e 1f 56 08 57 27 a7 05 d4 d0 52 82 77 75
RX0020: 1b 99 4a ed 58 3d 6a 52 36 d5 24 4a 68 8e ad 95
RX0030: 5f 3c 35 00 00 b5 00 00 00 c4 00 00 8c 00 00 dd
RX0040: 6c 11 32 3d e2 b4 b4 59 cf ce 23 3d 27 df a7 f9
RX0050: 96 fc 1e e0 66 2c 0e 7b 8c ca 30 42 8f 1f 1f bc
RX0060: 9f 7b ce d1 b8 b1 87 ec 8a d6 bb 2e 15 63 0e ed
RX0070: ed 3c 58 58 58 dc 3d 3d a4 6a 6a 3a 52 52 7a 36
RX0080: 06 20 a7 93 1b 34 dd 4c f5 ec

Zeros at offset 33 and 34 caused by reading empty RX FIFO which not possible
if DMA RX read was triggered by RX event. This mean DMA was triggered
by RX TAIL event.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

These structure members were removed in 2012 by the commit ffbbdd21
("spi: create a message queueing infrastructure").
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>