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

While normal Dual and Quad SPI Transfers are unidirectional, we must do
a bidirectional transfer if loopback mode is enabled, else rx_buf is not
filled.

With spidev it seemed to work, as spidev uses the same buffer for
tranmission and reception.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

If spi_master.cleanup() is not needed, it can be left unimplemented.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

rspi_wait_for_interrupt() unconditionally enables interrupts, even when the
wait condition is already satisfied. This causes a high interrupt load (2
interrupts/byte for full-duplex Single SPI transfers, 1 interrupt/byte for
RSPI with TX Only mode, or QSPI in unidirectional Dual or Quad Transfer
mode).

Change this to return immediately when the wait condition is satisfied.
This dramatically reduces the interrupt load, especially in high-speed
Quad Transfer mode, and increases transfer speed, as no interrupts need to
be handled when there's space available in the output FIFO, or data
available in the input FIFO.

Benchmark results for QSPI on r8a7791 while reading 1 MiB from 30 MHz SPI
FLASH on the Koelsch development board:

Before:
                        Single SPI      Dual SPI        Quad SPI
    Interrupts:         2096856         1048592         1048594
    Mbps:               0.9             1.6             1.6

After:

                        Single SPI      Dual SPI        Quad SPI
    Interrupts:         1048569         21295           8
    Mbps:               0.7             10.8            12.9

I don't know why Single SPI slowed down a bit.

I've also verified functionality for RSPI-RZ on r7s72100, but don't have
benchmark results as there's no SPI FLASH connected to RSPI on the Genmai
development board. Unlike RSPI and QSPI, RSPI-RZ has separate interrupts
for RX and TX, which shows that Single SPI transfers now generate (mostly)
RX interrupts, as expected.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

This patch fixes an issue that the following build error happens when
the CONFIG_OF is not set:

drivers/spi/spi-rspi.c: In function 'rspi_probe':
drivers/spi/spi-rspi.c:1203:26: error: 'rspi_of_match' undeclared (first use in this function)
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

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

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

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

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

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark 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: NAxel Lin <axel.lin@ingics.com>
Acked-by: NMarek Vasut <marex@denx.de>
Acked-by: NBarry Song <Baohua.Song@csr.com>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NMark Brown <broonie@linaro.org>

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

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

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

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

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

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

Make it more obvious that this value is dummy data.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

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

Remove useless casts, and do not cast away const.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NMark Brown <broonie@linaro.org>

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

The overrun flag should be cleared in the SPI Status Register, not in the
SPI Control Register, based on the SDK sample code.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NMark Brown <broonie@linaro.org>

SH7757 doesn't pass platform data, in which case spi-rspi uses default
parameters.

However, commit 5ce0ba88 ("spi: rcar: add
Renesas QSPI support on RSPI") added a new user of the platform data, but
forgot to check for its validity first, causing a NULL pointer dereference
on SH7757.

Add the missing check to fix this.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NMark Brown <broonie@linaro.org>

Use devm_spi_register_master() to make cleanup paths simpler.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

This simplies error and cleanup code paths.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

The platform driver data is set to point to the rspi_data structure at
probe time. Calling spi_master_get() on the pointer is just plain wrong
and only works by chance. Fix it by using the platform driver data
directly.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

The transfer data length variable is set based on the desired access
size, without a default case. This results in a compiler warning, even
though the access size is always set to a supported value. Create a
default case to silence the warning.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

We had set the platform drvdata in rspi_probe() as a type of
struct rspi_data, but use it as struct spi_master in rspi_remove()
Fix by remove the unnecessary spi_master_[get|put]() since rspi->master
is no longer used after spi_unregister_master().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NMark Brown <broonie@linaro.org>

The R8A7790 has QSPI module which added into RSPI together.
The transmit or receive data should be read from or written to
with the longword-, word-, or byte-access width. Modify word-
access to byte-access. In 16-bit data register, QSPI send or
receive datas access from high 8-bit while RSPI send or receive
datas access from low 8-bit on single mode.
Modify to reset transmit-receive buffer data and reading dummy
after data are transmited. RSPI has a TXMD bit on control
register(SPCR) to set transmit-only mode when transmit data or
Full-duplex synchronous mode when receive data. In QSPI the TXMD
bit is not supported, so after transmit data, dummy should be
read and before transmit or receive data the bufer register
should be reset.
This driver is the implementation of send and receive pio only,
DMA is not supported at this time.
Without this patch, it will occur error when transmit and receive
Signed-off-by: NHiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: NMark Brown <broonie@linaro.org>

The R8A7790 has QSPI module which is very similar to RSPI.
This patch adds into RSPI module together to supports QSPI module.
Signed-off-by: NHiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: NMark Brown <broonie@linaro.org>

In rspi_remove(), current code dereferences rspi after spi_unregister_master(),
thus add an extra spi_master_get() call is necessary to prevent use after free.

Current code already has an extra spi_master_put() call in rspi_remove(), so
this patch just adds a spi_master_get() call rather than a spi_master_get() with
spi_master_put() calls.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@linaro.org>