Add support for Quad and Dual SPI Transfers on the Renesas Quad Serial
Peripheral Interface, as found in R-Car Gen2 SoCs like R-Car H2 (r8a7790)
and R-Car M2 (r8a7791):
  - Add unidirectional transfer methods for Quad/Dual SPI Transfers.
  - Program the sequencer to handle SPI messages with multiple transfer
    modes when Quad or Dual transfers are enabled for an SPI slave.
    Up to 4 transfer modes per SPI message are supported by the hardware.
  - Advertise the availability of Quad and Dual SPI modes on QSPI.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

There's only one RSPI/QSPI clock, so we can use NULL as the clock ID
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Get the driver ready for the migration to the common clock framework by
calling clk_prepare_enable() and clk_disable_unprepare().
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add support for specifying loopback mode.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add support for the RSPI variant in the RZ/A1H (r7s72100) SoC.

Main differences with RSPI on SH are:
  - Lack of TX only mode, hence we always have to use full duplex
    transfers,
  - The Data Register must be accessed used 8-bit operations.

RSPI on RZ is matched using the new "rspi-rz" platform device name.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add support for multiple interrupts, based on the SDK reference code.
This is needed for RZ/A1H, which supports 3 interrupts.

When using multiple interrupts, they must be called "rx" (SPRI) and "tx"
(SPTI). The error interrupt (SPEI) is not used, as it matters for slave
mode only.

When using a single interrupt, it may be called "mux". If it cannot be
found, the first interrupt in the device's resources will be used.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

qspi_send_pio() and qspi_receive_pio() are very similar: they both send
and receive full duplex data to/from the hardware, but ignore the data
stream in the unused direction.
Merge them into qspi_transfer_out_in(), now supporting real full duplex.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

rspi_send_pio() and rspi_receive_pio() are very similar:
  - the former only sends data, using TX Only Mode,
  - the latter sends and receives full duplex data to/from the hardware,
    but uses dummy transmit data.
Merge them into rspi_transfer_out_in(), now supporting full duplex if
needed.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Split off qspi_transfer_one() (which doesn't support DMA yet) from
rspi_transfer_one().
Replace the abstraction of send_pio()/receive_pio() by the abstracrion of
transfer_one().
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add helpers rspi_data_{out,in,out_in}() to write, read, or write and
read data to/from the Data Register, taking care of waiting until data
or space is available in the buffers.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add rspi_{write,read}_data(), to abstract 8-bit (QSPI, and RSPI on RZ/A1H)
versus 16-bit (RSPI) Data Register access.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Let the generic SPI core handle SPI messages, calling into our
rspi_transfer_one() method.

rspi_assert_ssl() and rspi_negate_ssl() are absorbed into
rspi_prepare_message() and rspi_unprepare_message(), as they actually
enable/disable the whole SPI function, instead of just (de)asserting the
chip select line.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branches 'spi/topic/pxa2xx', 'spi/topic/qspi', 'spi/topic/s3c24xx', 'spi/topic/s3c64xx', 'spi/topic/sh', 'spi/topic/tegra114', 'spi/topic/tegra20-sflash', 'spi/topic/tegra20-slink', 'spi/topic/txx9' and 'spi/topic/xcomm' into spi-linus

Merge remote-tracking branches 'spi/topic/fsl-espi', 'spi/topic/gpio', 'spi/topic/hspi', 'spi/topic/mpc512x', 'spi/topic/msiof', 'spi/topic/nuc900', 'spi/topic/oc-tiny', 'spi/topic/omap', 'spi/topic/orion' and 'spi/topic/pci' into spi-linus

Merge remote-tracking branches 'spi/topic/bcm2835', 'spi/topic/bcm63xx', 'spi/topic/bcm63xx-hsspi', 'spi/topic/bitbang', 'spi/topic/bpw', 'spi/topic/clps711x', 'spi/topic/coldfire', 'spi/topic/davinci', 'spi/topic/dw' and 'spi/topic/falcon' into spi-linus

Merge remote-tracking branches 'spi/fix/bcm63xx', 'spi/fix/dspi', 'spi/fix/hspi', 'spi/fix/imx', 'spi/fix/msiof', 'spi/fix/pxa2xx', 'spi/fix/qspi', 'spi/topic/altera', 'spi/topic/ath79' and 'spi/topic/atmel' into spi-linus

master->transfer_one returns positive value is not a error.
So set ret to 0 when master->transfer_one returns positive value.
Otherwise, I hit "spi_master spi0: failed to transfer one message from queue"
error when my transfer_one callback returns 1.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

The documentation for spi_master.set_cs() says:

    assert or deassert chip select, true to assert

i.e. its "enable" parameter uses assertion-level logic.

This does not match the implementation of spi_set_cs(), which calls
spi_master.set_cs() with the wanted logic level of the chip select line,
which depends on the polarity of the chip select signal.

Correct the documentation to match the implementation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Since commit 543bb255 "spi: add ability to validate xfer->bits_per_word in SPI
core", the driver can set bits_per_word_mask for the master then the SPI core
will reject transfers that attempt to use an unsupported bits_per_word value.
So we can remove the bits_per_word checking in sc18is602_check_transfer() and
let SPI core handle the checking.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@linaro.org>

The implementation in spi_setup() already set spi->bits_per_word = 8 when
spi->bits_per_word is 0 before calling spi->master->setup.
So we don't need to do it again in setup() callback.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Barry Song <Baohua.Song@csr.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge branches 'topic/sc18is602' and 'topic/rspi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-bpw

CONFIG_PM will be set if either or both CONFIG_PM_SLEEP and
CONFIG_PM_RUNTIME is set. Compiling the driver with !CONFIG_PM_SLEEP causes
following compilation warning:

drivers/spi/spi-pxa2xx.c:1270:12: warning: ‘pxa2xx_spi_suspend’ defined but not used [-Wunused-function]

Fix this by using CONFIG_PM_SLEEP instead.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge branch 'topic/rcar' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-rspi

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add support for specifying the SPI clock phase and polarity, based on the
SDK reference code.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Commit cddb339b (spi/pxa2xx: convert to dma_request_slave_channel_compat())
converted the driver to use ACPI provided DMA helpers but it forgot to
initialize the platform data for the channels to -1. Failing to do so will
result inadvertent match in the filter function because 0 is a valid
channel number.

Prevent this from happening by initializing both platform data channels
correctly to -1.

Fixes: cddb339b (spi/pxa2xx: convert to dma_request_slave_channel_compat())
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

On ARM-based SHMOBILE, the rspi driver builds and works fine without the
DMA controller driver, hence relax the dependencies.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>