This SPI controller is present in Apple SoCs such as the M1 (t8103) and
M1 Pro/Max (t600x). It is a relatively straightforward design with two
16-entry FIFOs, arbitrary transfer sizes (up to 2**32 - 1) and fully
configurable word size up to 32 bits. It supports one hardware CS line
which can also be driven via the pinctrl/GPIO driver instead, if
desired. TX and RX can be independently enabled.

There are a surprising number of knobs for tweaking details of the
transfer, most of which we do not use right now. Hardware CS control
is available, but we haven't found a way to make it stay low across
multiple logical transfers, so we just use software CS control for now.

There is also a shared DMA offload coprocessor that can be used to handle
larger transfers without requiring an IRQ every 8-16 words, but that
feature depends on a bunch of scaffolding that isn't ready to be
upstreamed yet, so leave it for later.

The hardware shares some register bit definitions with spi-s3c24xx which
suggests it has a shared legacy with Samsung SoCs, but it is too
different to warrant sharing a driver.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Link: https://patch.msgid.link/20241106-asahi-spi-v5-2-e81a4f3a8e19@jannau.net
Signed-off-by: Mark Brown <broonie@kernel.org>

Add a driver for the SPI-NAND controller on the RTL9300 family of
devices.

The controller supports
* Serial/Dual/Quad data with
* PIO and DMA data read/write operation
* Configurable flash access timing

There is a separate ECC controller on the RTL9300 which isn't currently
supported (instead we rely on the on-die ECC supported by most SPI-NAND
chips).

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://patch.msgid.link/20241015225434.3970360-4-chris.packham@alliedtelesis.co.nz
Signed-off-by: Mark Brown <broonie@kernel.org>

Add a driver for the QiHeng Electronics ch341a USB-to-SPI adapter.

This driver is loosely based on the ch341a module from the flashrom project.

Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Link: https://patch.msgid.link/20240708-spi-ch341a-v3-1-cf7f9b2c1e31@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

The spi-pxa2xx.c is bloated with a platform driver code while
pretending to provide a core functionality. Make it real core
library by splitting out the platform driver to a separate file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240530151117.1130792-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Introduce support for SPI-NAND driver of the Airoha NAND Flash Interface
found on Airoha ARM SoCs.

Tested-by: Rajeev Kumar <Rajeev.Kumar@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/6c9db20505b01a66807995374f2af475a23ce5b2.1714377864.git.lorenzo@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Implements the SPI function of Intel USB-I2C/GPIO/SPI adapter device
named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA SPI
module with specific protocol through interfaces exported by LJCA USB
driver.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/1696833205-16716-4-git-send-email-wentong.wu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge series from Charles Keepax <ckeepax@opensource.cirrus.com>:

This patch chain adds support for the Cirrus Logic cs42l43 PC focused
SoundWire CODEC.

The CS42L43 is an audio CODEC with integrated MIPI SoundWire interface
(Version 1.2.1 compliant), I2C, SPI, and I2S/TDM interfaces designed
for portable applications. It provides a high dynamic range, stereo
DAC for headphone output, two integrated Class D amplifiers for
loudspeakers, and two ADCs for wired headset microphone input or
stereo line input. PDM inputs are provided for digital microphones.

The SPI component incorporates a SPI controller interface for
communication with other peripheral components.

Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230804104602.395892-6-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

This bus driver supports the Loongson SPI hardware controller in the
Loongson platforms and supports the use DTS and PCI framework to
register SPI device resources.

Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230613075834.5219-3-zhuyinbo@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

The RZ/V2M SoC comes with the Clocked Serial Interface (CSI)
IP, which is a master/slave SPI controller.

This commit adds a driver to support CSI master mode.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Link: https://lore.kernel.org/r/Message-Id: <20230622113341.657842-4-fabrizio.castro.jz@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>