[PATCH v4 0/2] add support for Cadence's XSPI controller

From: Parshuram Thombare
Date: Mon Sep 13 2021 - 08:03:24 EST


This patch series adds support for Cadence's XSPI controller.
It supports 3 work modes.
1. ACMD (auto command) work mode
ACMD name is because it uses auto command engine in the controller.
It further has 2 modes PIO and CDMA (command DMA).
The CDMA work mode is dedicated for high-performance application
where very low software overhead is required. In this mode the
Command Engine is programmed by the series of linked descriptors
stored in system memory. These descriptors provide commands to execute
and store status information for finished commands.
The PIO mode work mode is dedicated for single operation where
constructing a linked list of descriptors would require too
much effort.
2. STIG (Software Triggered Instruction Generator) work mode
In STIG mode, controller sends low-level instructions to memory.
Each instruction is 128-bit width. There is special instruction
DataSequence which carries information about data phase.
Driver uses Slave DMA interface to transfer data as only this
interface can be used in STIG work mode.
3. Direct work mode
This work mode allows sending data without invoking any command through
the slave interface.
Currently only STIG work mode is enabled, remaining work modes will
be added later.

Changes since v3:
1. Removed ACMD PIO mode.
2. Return IRQ_HANDLED only for handled interrupts.
3. DT binding changes.

Changes since v2:
1. Removed extra lock around exec_op.
2. Removed PHY parameters setting from the driver, those will be
handled by bootstrap pins available in the controller.

Changes since v1:
1. Use ACMD PIO work mode for NOR read, program and erase operations,
for everything else use STIG(Software Triggered Instruction
Generator) work mode.
2. Changes suggested by Lukas.

Parshuram Thombare (2):
spi: cadence: add dt-bindings documentation for Cadence XSPI
controller
spi: cadence: add support for Cadence XSPI controller

.../devicetree/bindings/spi/cdns,xspi.yaml | 77 +++
drivers/spi/Kconfig | 12 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-cadence-xspi.c | 627 +++++++++++++++++++++
4 files changed, 717 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/cdns,xspi.yaml
create mode 100644 drivers/spi/spi-cadence-xspi.c

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2.7.4