Zephyr AXI QSPI Driver Support

This page gives an overview of the AXI QSPI Zephyr driver which is available as part of the zephyr-amd repo.

HW Features

Configurable AXI4 interface; when configured with an AXI4-Lite interface the core is backward compatible with version 1.00 of the core (legacy mode)
Configurable AXI4 interface for burst mode operation for the Data Receive Register (DRR) and the Data Transmit Register (DTR) FIFO
Configurable eXecute In Place (XIP) mode of operation
Connects as a 32-bit slave on either AXI4-Lite or AXI4 interface
Configurable SPI modes:
- Standard SPI mode
- Dual SPI mode
- Quad SPI mode
Programmable SPI clock phase and polarity
Configurable FIFO depth (16 or 256 element deep in Dual/Quad/Standard SPI mode).

Design Notes

TBA

Implementation

Zephyr AXI QSPI Driver Implementation

Features Supported

Master mode
Sync Mode
Async mode.
All SPI flash Instruction.
Configurable FIFO size.
Startup block support

Missing Features

Dual SPI mode
Quad SPI mode

Known Issues

TBA

Limitations

TBA

Kernel Configuration

/*  SPI  and flash z-test config */
CONFIG_TEST=y
CONFIG_ZTEST=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_MAIN_STACK_SIZE=2048

Device Tree

Example SPI Node

axi_spi0: spi@44a00000 {
                status = "okay";
                #address-cells = <0x01>;
                #size-cells = <0x00>;
                fifo-size = <256>;
                reg = <0x44a00000 0x10000>;
                compatible = "xlnx,xps-spi-2.00.a";
                interrupt-parent = <&axi_intc>;
                xlnx,startup-block;
                interrupts = < 3 0 >;
                xlnx,num-ss-bits = <0x2>;
                xlnx,num-transfer-bits = <8>;
                flash@0 {
                        compatible = "jedec,spi-nor";
                        reg = <0x00>;
                        spi-max-frequency = <8000000>;
                        jedec-id = [20 bb 19]; /* n25q256 */
                        size = <134217728>;
                        has-dpd;
                        t-enter-dpd = <10000>;
                        t-exit-dpd = <35000>;
                };
};

Driver Stack Size

TBA

Example Tests

Test Name

Example Source

Description

Flash Ztest

tests/drivers/flash/common/

These tests focus on the correct functionality of the flash drivers, covering cases such as:

Reading and writing data to the flash device
Erasing the flash device
Handling out-of-bounds addresses and sizes
Correct error handling

Flash Example test

samples/drivers/spi_flash/

This example application performs basic Erase/Write/ Read on spi-nor flash using Axi-Quad SPI driver

Code Coverage

TBA

Expected Output / Test Logs

*** Booting Zephyr OS build xilinx_v2024.2-38-g0b6ff6486056 ***
Running TESTSUITE flash_driver
===================================================================
Test will run on device flash@0
START - test_flash_fill
 PASS - test_flash_fill in 42.034 seconds
===================================================================
START - test_flash_flatten
 PASS - test_flash_flatten in 41.980 seconds
===================================================================
START - test_read_unaligned_address
 PASS - test_read_unaligned_address in 1.081 seconds
===================================================================
TESTSUITE flash_driver succeeded

------ TESTSUITE SUMMARY START ------

SUITE PASS - 100.00% [flash_driver]: pass = 3, fail = 0, skip = 0, total = 3 duration = 85.095 seconds

PASS - [flash_driver.test_flash_fill] duration = 42.034 seconds

PASS - [flash_driver.test_flash_flatten] duration = 41.980 seconds

PASS - [flash_driver.test_read_unaligned_address] duration = 1.081 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
PROJECT EXECUTION SUCCESSFUL

*** Booting Zephyr OS build xilinx_v2024.2-26-ged251cbf3a56 ***

flash@0 SPI flash testing
==========================

Perform test on single sector
Test 1: Flash erase
Flash erase succeeded!

Test 2: Flash write
Attempting to write 4 bytes
Data read matches data written. Good!!

Performance Metric

TBA

Mainline Status

spi_xlnx_axi_quadspi-mainline

Driver Source Path

drivers/spi/spi_xlnx_axi_quadspi.c

Misra C Report

TBA