This driver supports the Lantiq SSC SPI controller in master
mode. This controller is found on Intel (former Lantiq) SoCs like
the Danube, Falcon, xRX200, xRX300.

The hardware uses two hardware FIFOs one for received and one for
transferred bytes. When the driver writes data into the transmit FIFO
the complete word is taken from the FIFO into a shift register. The
data from this shift register is then written to the wire. This driver
uses the interrupts signaling the status of the FIFOs and not the shift
register. It is also possible to use the interrupts for the shift
register, but they will send a signal after every word. When using the
interrupts for the shift register we get a signal when the last word is
written into the shift register and not when it is written to the wire.
After all FIFOs are empty the driver busy waits till the hardware is
not busy any more and returns the transfer status.
Signed-off-by: NDaniel Schwierzeck <daniel.schwierzeck@gmail.com>
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The calculation of SPR and SPPR doesn't round correctly at several
places which might result in baud rates that are too big. For example
with tclk_hz = 250000001 and target rate 25000000 it determined a
divider of 10 which is wrong.

Instead of fixing all the corner cases replace the calculation by an
algorithm without a loop which should even be quicker to execute apart
from being correct.

Fixes: df59fa7f ("spi: orion: support armada extended baud rates")
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Marvell Armada 3700 SoC comprises an SPI Controller. This Controller
supports up to 4 SPI slave devices, with dedicated chip selects,supports
SPI mode 0/1/2 and 3, CPIO or Fifo mode with DMA transfers and different
SPI transfer mode (Single, Dual or Quad).

This commit adds basic driver support for FIFO mode. In this mode,
dedicated registers are used to store the instruction, the address, the
read mode and the data. Write and Read FIFO are used to store the
outcoming or incoming data. The data FIFOs are accessible via DMA or by
the CPU. Only the CPU is supported for now.
Signed-off-by: NRomain Perier <romain.perier@free-electrons.com>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

In case that error occurs during waiting for txfifo empty, it is
not necessary to read rx fifo. It's better to return directly.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

At the beginning of lpspi driver, it is claimed that the dirver
is under the terms of the GNU General Public License, either
version 2 of the License. While at the end I only declared GPL V2.

This patch make the license consistent.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

fsl_espi_read_reg16 / fsl_espi_write_reg16 are supposed to read / write
big endian values. Therefore ioread16be / iowrite16be have to be used.

Fixes: 	05823432 ("eliminate need for linearization when writing to hardware")
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

After introducing direct transfers between hardware and transfer
buffers remove all code which is unused now.

This includes getting rid of the 64k linearization buffer.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Eliminate need for linearization when reading from the hardware and
write to the transfer buffers directly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Eliminate need for linearization when writing to the hardware and
read from the transfer buffers directly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Determine need for byte swap only once and store it in new member
swab in struct fsl_espi.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The lpspi tx/rx fifo size is a read only parameter resides
lpspi Parameter Register. It's better to read lpspi tx/rx
fifo size in probe().
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

It's a potential problem to use wait_for_completion() because the
completion condition may never come. Thus, it's better to repalce
wait_for_completion() with wait_for_completion_timeout().
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

MVEBU chips (Armada XP, Armada 370 and others) are supported by this
driver. Mention this in the help text to make more obvious what is
already specified in the dependencies of this symbol.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

For DMA transfers, we now use the core DMA framework which provides
channel fields in the spi_master structure. Remove the private channels
from atmel_spi stucture which were located in a sub-structure. This
last one (atmel_spi_dma) which is now empty is also removed.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The atmel_spi_dma structure was cluttered with unused fields relative
to older DMA channel selection API. Remove them.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use the SPI core DMA mapping framework instead of our own
in case of DMA support. PDC support is not converted to this
framework.

The driver is now able to transfer a complete sg list through DMA.
This eventually fix an issue with vmalloc'ed DMA memory that is
provided for example by UBI/UBIFS layers.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
[nicolas.ferre@atmel.com: restrict the use to non-PDC DMA]
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

We need both RX and TX data for each transfer in any case (PIO, PDC, DMA).
So convert the driver to the core dummy buffer handling with the
SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure.

This move changes the maximum PDC/DMA buffer handling to 65535 bytes
instead of a single page and sets master->max_dma_len to this value.

All dummy buffer management is removed from the driver.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The info banner is here to tell that everything went well, so place
it at the very end of the probe function.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

It's more rational that just do the schedule when necessary
other than do it every time. Thus, it's better to replace
schedule() with cond_resched() in fsl_lpspi_txfifo_empty(),
which contributes to saving cpu time.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is a static checker warning in fsl_lpspi_set_cmd().
I intended to write "temp |= (fsl_lpspi->config.mode & 0x3) << 30",
but used "temp |= (fsl_lpspi->config.mode & 0x11) << 30" by mistake.

This patch fixes this potential shift truncation.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The old driver enable clk in fsl_lpspi_prepare_message() and
disable clk in fsl_lpspi_unprepare_message().

Rather than doing this per message it's a bit better to do it
in prepare_transfer_hardware(), that way if there's a sequence
of messages queued one after another we don't turn the clock on
and off all the time.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/spi/spi-ath79.ko | grep alias
alias:          platform:ath79-spi

After this patch:

$ modinfo drivers/spi/spi-ath79.ko | grep alias
alias:          platform:ath79-spi
alias:          of:N*T*Cqca,ar7100-spiC*
alias:          of:N*T*Cqca,ar7100-spi
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/spi/spi-xlp.ko | grep alias
alias:          acpi*:BRCM900D:*

After this patch:

$ modinfo drivers/spi/spi-xlp.ko | grep alias
alias:          acpi*:BRCM900D:*
alias:          of:N*T*Cnetlogic,xlp832-spiC*
alias:          of:N*T*Cnetlogic,xlp832-spi
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/spi/spi-jcore.ko | grep alias
alias:          platform:jcore_spi

After this patch:

$ modinfo drivers/spi/spi-jcore.ko | grep alias
alias:          platform:jcore_spi
alias:          of:N*T*Cjcore,spi2C*
alias:          of:N*T*Cjcore,spi2
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/spi/spi-axi-spi-engine.ko | grep alias
$

After this patch:

$ modinfo drivers/spi/spi-axi-spi-engine.ko | grep alias
alias:          of:N*T*Cadi,axi-spi-engine-1.00.aC*
alias:          of:N*T*Cadi,axi-spi-engine-1.00.a
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds lpspi driver to support new i.MX products which use
lpspi instead of ecspi.

The lpspi can continue operating in stop mode when an appropriate
clock is available. It is also designed for low CPU overhead with
DMA offloading of FIFO register accesses.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Reviewed-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current DMA implementation was not handling the continuous selection
format viz. SPI chip select would be deasserted even between sequential
serial transfers.

Use existing dspi_data_to_pushr function to restructure the transmit
code path and set or reset the CONT bit on same lines as code path
in EOQ mode does. This correctly implements continuous selection format
while also correcting and cleaning up the transmit code path.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Currently dmaengine_prep_slave_single was being called with length
set to the complete DMA buffer size. This resulted in unwanted bytes
being transferred to the SPI register leading to clock and MOSI lines
having unwanted data even after chip select got deasserted and the
required bytes having been transferred.

While at it also clean up the use of curr_xfer_len which is central
to the DMA setup, from bytes to DMA transfers for every use.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Reviewed-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NMark Brown <broonie@kernel.org>

Buffers allocated with a call to dma_alloc_coherent should be
freed with dma_free_coherent instead of the currently used
devm_kfree.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

A null dereference or Oops exception might occurs when reading at once the
whole content of an spi-nor of big enough size that requires an scatterlist
table that does not fit into one single page.

The spi_map_buf function is ignoring the chained sg case by dereferenceing
the scatterlist elements in an array fashion. This wrongly assumes that
the allocation of the scatterlist elements are contiguous. This is true as
long as the scatterlist table fits within a PAGE_SIZE. However, for
allocation where the scatter table is bigger than that, the pages allocated
by sg_alloc might not be contigous.

The sg table can be properly walked by sg_next instead of using an array.
Signed-off-by: NJuan Gutierrez <juan.gutierrez@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Since commit 0d357739 ("spi: spi-topcliff-pch: Remove deprecated
create_singlethread_workqueue"), 'retval' is no more used in this function.

So some now dead code can be removed.
Also axe a debug message which looks useless now.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NMark Brown <broonie@kernel.org>

MSIOF in R-Car M3-W (r8a7796) is handled fine by the existing driver.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current DMA implementation had a bug where the DMA transfer would
exit the loop in dspi_transfer_one_message after the completion of
a single transfer. This results in a multi message transfer submitted
with SPI_IOC_MESSAGE to terminate incorrectly without an error.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Reviewed-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NMark Brown <broonie@kernel.org>

ESPI has a max and min supported SPI frequency, determined by the
clock divider range. Set master->min_speed_hz/max_speed_hz to inform
the SPI core about these limits.
Then the SPI core handles cases where a transfer requests a frequency
outside the supported range.

So far the driver simply set the lowest supported frequency if the
requested frequency was below the supported range. This is not
necessarily an appropriate action as the device might not support
frequencies greater than the requested one.
With this patch the SPI core will reject transfers requesting a
too low frequency.

The check in fsl_espi_setup can be removed because the SPI core sets
spi->max_speed_hz to master->max_speed_hz if it's not set already.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Simplify of_fsl_espi_suspend a little.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

A call to clk_get_rate appears to be called in the context of an interrupt,
cache the bus clock for the frequency calculations in transmission.

This fixes a 'BUG: scheduling while atomic' and
'WARNING: CPU: 0 PID: 777 at kernel/sched/core.c:2960 atmel_spi_unlock'
Signed-off-by: NBen Whitten <ben.whitten@lairdtech.com>
Signed-off-by: NSteve deRosier <steve.derosier@lairdtech.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

completion variable should be reinitialized before reusing.
Signed-off-by: NPrahlad V <prahlad.eee@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

These lines were indented one extra tab.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

IS_DMA_ALIGNED() became unused by the 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>

After having removed all code dependencies we can make fsl-espi
completely independent of fsl-lib now.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>