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>

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>

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>

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-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>

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>

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>

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>

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>

Only few members of struct mpc8xxx_spi are relevant for fsl-espi.
Therefore replace it with a ESPI-specific struct fsl_espi.
Replace variable names mpc8xxx_spi and mspi with espi.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The register initialization is the same in fsl_espi_probe and in
of_fsl_espi_resume. Therefore factor it out into fsl_espi_init_regs.

It was actually a bug that CSMODE_BEF and CSMODE_AFT were not set
in of_fsl_espi_resume. Seems like nobody ever used values other
than zero for these parameters.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Very little from struct spi_mpc8xxx_cs is relevant for fsl-espi.
Therefore replace it with struct fsl_espi_cs.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Very little of the library functions mpc8xxx_spi_probe and
of_mpc8xxx_spi_probe is relevant for fsl-espi.

Therefore migrate the relevant parts to fsl-espi (considering
that get_brgfreq() always returns -1 on systems with ESPI)
and remove use of these functions.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There's no need to access mpc8xxx_spi->irq, we can use function
parameter irq directly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Change the check to access property "mode" directly.
This allows us to get rid of mpc8xxx_spi->flags in a subsequent
patch in this patch series as it's used nowhere else.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use master->num_chipselect directly instead of pdata->max_chipselect.
In this context let of_fsl_espi_get_chipselects return max_chipselect.

This change allows us to get rid of struct fsl_spi_platform_data
completely in the fsl-espi driver.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Don't set pdata->cs_control as it's nowhere used in fsl-espi and fsl-lib.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Remove pdata->initial_spmode as it is nowhere set.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds support for dual output read mode.

It was successfully tested on a P1014-based device with S25FL128S
SPINOR flash. With 50MHz SPI clock the read rate is 11MByte/s.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds support for ESPI RXSKIP mode. This mode is optimized
for flash reads:
- sends a number of bytes and then reads a number of bytes
- shifts out zeros automatically when reading

Supporting RXSKIP mode is a prerequisite for supporting dual output
read mode.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add DMA support for Vybrid.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Use the managed gpio CS pin request so that we avoid having trouble
in the cleanup code.
In fact, if module was configured with DT, cleanup code released
invalid pin.  Since resource wasn't freed, module cannot be reinserted.

This require to extract the gpio request call from the "setup" function
and call it in the appropriate probe function.
Reported-by: NAlexander Morozov <linux@meltdown.ru>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There's no need to bother the chip if the mode doesn't change.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Resetting the chip to a default transfer mode after each transfer
doesn't provide any benefit. Therefore remove this call.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>